ENGINEERED Fc CONSTRUCTS
20220267388 · 2022-08-25
Inventors
Cpc classification
A61P1/04
HUMAN NECESSITIES
A61P29/00
HUMAN NECESSITIES
A61P31/00
HUMAN NECESSITIES
C07K2319/30
CHEMISTRY; METALLURGY
C07K2317/60
CHEMISTRY; METALLURGY
C07K16/00
CHEMISTRY; METALLURGY
A61P1/16
HUMAN NECESSITIES
A61P7/04
HUMAN NECESSITIES
A61P21/00
HUMAN NECESSITIES
A61P37/06
HUMAN NECESSITIES
C07K2317/71
CHEMISTRY; METALLURGY
A61K39/0008
HUMAN NECESSITIES
International classification
A61K39/00
HUMAN NECESSITIES
Abstract
The present disclosure relates to engineered IgG Fc constructs and uses thereof.
Claims
1. An Fc construct comprising: a) a first polypeptide comprising i). a first Fc domain monomer; ii). a second Fc domain monomer; and iii). a linker joining the first Fc domain monomer to the second Fc domain monomer; b). a second polypeptide comprising i). a third Fc domain monomer; ii). a fourth Fc domain monomer; and iii). a linker joining the third Fc domain monomer to the fourth Fc domain monomer; c). a third polypeptide comprises a fifth Fc domain monomer; and d). a fourth polypeptide comprises a sixth Fc domain monomer; wherein the first Fc domain monomer and fifth Fc domain monomer combine to form a first Fc domain; the second Fc domain monomer and fourth Fc domain monomer combine to form a second Fc domain; and the third Fc domain monomer and sixth Fc domain monomer combine to form a third Fc domain; each of the first and second polypeptides comprises the sequence of SEQ ID NO: 78; and each of the third and fourth polypeptides comprises the sequence of SEQ ID NO: 73
2.-133. (canceled)
134. A pharmaceutical composition comprising the construct of claim 1 a and one or more pharmaceutically acceptable carriers or excipients.
135.-139. (canceled)
140. A method of reducing immune cell activation of the immune response in a subject, the method comprising administering to the subject an Fc construct of claim 1.
141. The method of claim 140, wherein the subject has an autoimmune disease.
142. A method of treating inflammation in a subject, the method comprising administering to the subject the Fc construct of claim 1.
143. A method of promoting clearance of autoantibodies and/or suppressing antigen presentation in a subject, the method comprising administering to the subject the Fc construct of claim 1.
144.-147. (canceled)
148. A composition comprising a polypeptide comprising or consisting of the sequence: TABLE-US-00018 (SEQ ID NO: 78) DKTHTCPPCPAPELLGGPSVFLEPPKPKDTLMASRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDKLTKNQVSLWC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGGGGGGG GGDKTHTCPPCPAPELLGGPSVFLEPPKPKDTLMISRTPEVTCVVVDVS HEDPEVKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNG KEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDK SRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG, and a polypeptide comprising or consisting of the sequence: TABLE-US-00019 (SEQ ID NO: 73) DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSC AVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPG.
149.-163. (canceled)
164. A method for treating an inflammatory or autoimmune disease in a subject in need thereof, comprising administering a therapeutically effective amount of the Fc construct of claim 1.
165. The method of claim 164, wherein the inflammatory or autoimmune or immune disease selected from rheumatoid arthritis (RA); systemic lupus erythematosus (SLE); ANCA-associated vasculitis; antiphospholipid antibody syndrome; autoimmune hemolytic anemia; chronic inflammatory demyelinating neuropathy; organ transplant; GVHD; dermatomyositis; Goodpasture's Syndrome; organ system-targeted type II hypersensitivity syndromes mediated through antibody-dependent cell-mediated cytotoxicity, e.g., Guillain Barre syndrome, CIDP, Felty's syndrome, antibody-mediated rejection, autoimmune thyroid disease, ulcerative colitis, autoimmune liver disease; idiopathic thrombocytopenia purpura; Myasthenia Gravis, neuromyelitis optica; pemphigus and other autoimmune blistering disorders; Sjogren's Syndrome; autoimmune cytopenias and other disorders mediated through antibody-dependent phagocytosis; heparin induced thrombocytopenia (HIT); myositis; polymyositis; antibody dependent enhancement; stiff persons syndrome; Kawasaki Disease; inclusion body myositis; systemic sclerosis; IgA nephropathy; IgG4-related disease; Graves disease; autoimmune inner ear disease (AIED); antiphospholipid syndrome (APS); pemphigus vulgaris; pemphigus follaceus; pemphigus gestationis; paraneoplastic pemphigus; optic neuritis, Parry Romberg syndrome; FcR-dependent inflammatory syndromes; synovitis; glomerulitis; and vasculitis.
Description
DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
[0206] Therapeutic proteins that include Fc domains of IgG can be used to treat inflammation and immunological and inflammatory diseases, cancers, and infections. The present disclosure features compositions and methods for preparing Fc constructs containing Fc domains (e.g., Fc constructs having 2-10 Fc domains, e.g., Fc constructs having 2, 3, 4, 5, 6, 7, 8, 9, or 10 Fc domains). The Fc constructs described herein facilitate the preparation of homogenous pharmaceutical compositions by incorporating structural features (for example, glycine spacers) that significantly improve manufacturing outcome.
[0207] Accordingly, the disclosure features pharmaceutical compositions that include a substantially homogenous population of an Fc construct described herein (e.g., an Fc construct having three Fc domains). Homogeneity is an important aspect of a pharmaceutical composition as it influences the pharmacokinetics and in vivo performance of the composition. Traditionally, in the manufacture of pharmaceutical products, there exists the problem of product heterogeneity that may be caused by several factors depending on how the product is produced. For example, the pharmaceutical product may undergo random product cleavage, proteolysis, degradation, and/or aggregation, off-target association of subunits, and/or inefficient protein folding. Different organisms having different biosynthetic processes or cellular machineries that are used to produce the pharmaceutical product may also cause heterogeneity in the product. Often, the initial culture containing the desired pharmaceutical product needs to undergo a rigorous purification process to produce a less heterogenous composition containing the pharmaceutical product.
[0208] The disclosure features, in one aspect, Fc constructs having structural features that significantly improve the folding efficiency of the Fc constructs and minimize off-target association of the subunits, thus, leading to pharmaceutical compositions containing these Fc constructs with high homogeneity. Having a high degree of homogeneity ensures the safety, efficacy, uniformity, and reliability of the pharmaceutical composition. Having a high degree of homogeneity also minimizes potential aggregation or degradation of the pharmaceutical product caused by unwanted materials (e.g., degradation products and/or aggregated products or multimers, as well as limiting off-target and adverse side effects caused by the unwanted materials.
[0209] As described in detail herein, the disclosure features substantially homogenous containing Fc constructs that all have the same number of Fc domains, as well as methods of preparing such substantially homogenous compositions.
[0210] The Fc constructs described herein include glycine spacers between Fc domains. As is well-known in the art, linkers containing both serines and glycines provide structural flexibility in a protein and are commonly used for joining two polypeptides. We have observed through experimentation (see Example 4) that linkers containing both serines and glycines undergo O-glycosylation (e.g., O-xylosylation) at multiple serines in the linker and proteolysis at the N-terminal side of serine. We aimed to optimize the linker sequence and length to further improve the homogeneity of the Fc constructs. We made Fc constructs in which all the linkers within the constructs are glycine spacers having only glycines (e.g., at least 12 glycines, e.g., 12-30 glycines; SEQ ID NO: 27). Having all glycine spacers in the Fc constructs further improved the homogeneity of the Fc constructs by removing O-glycosylation at serines and also decreasing the rate of proteolysis of the constructs (see Example 4). Consequently, we were able to achieve a more substantially homogenous population of Fc constructs by using all glycine spacers in the Fc constructs.
[0211] Homogeneity is the result of Fc construct components. For example, in a first approach (“approach (a)”), incorporation of linkers containing only glycines to join Fc domain monomers may be utilized. As we observed through experimentation, all-glycine spacers (e.g., at least 12 glycines, e.g., 12-30 glycines; SEQ ID NO: 27) in an Fc construct do not undergo O-glycosylation and are less susceptible to proteolysis as compared to traditional linkers that include serines and glycines (see Example 4).
[0212] In addition, in another approach (“approach (b)”), homogeneity of a composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) is improved by removal of C-terminal lysines. Such C-terminal lysine residue are highly conserved in immunoglobulins across many species and may be fully or partially removed by the cellular machinery during protein production. Removal of the C-terminal lysines in the Fc constructs of the disclosure improves uniformity of the resulting composition and achieves a more homogenous Fc construct preparation (see Example 8). For example, in some embodiments of Fc constructs described herein (e.g., an Fc construct having three Fc domains), the codon of the C-terminal lysine is removed, thus, generating Fc constructs having polypeptides without C-terminal lysine residues and a resultant homogenous population.
[0213] A further approach (“approach (c)”) to improve the homogeneity of a composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains), two sets of heterodimerizing selectivity modules were utilized: (i) heterodimerizing selectivity modules having different reverse charge mutations and (ii) heterodimerizing selectivity modules having engineered cavities and protuberances. We have observed through experimentation, e.g., see Example 6, that when trying to form a heterodimeric Fc domain in an Fc construct, having both (i) and (ii) further improved the homogeneity of the pharmaceutical composition produced by reducing uncontrolled association of Fc domain monomers, and therefore undesirable oligomers and multimers. In particular examples, an Fc domain monomer containing (i) at least one reverse charge mutation and (ii) at least one engineered cavity or at least one engineered protuberance may be produced and will selectively combine with another Fc domain monomer containing (i) at least one reverse charge mutation and (ii) at least one engineered protuberance or at least one engineered cavity to form an Fc domain. In another example, an Fc domain monomer containing reversed charge mutation K370D and engineered cavities Y349C, T366S, L368A, and Y407V and another Fc domain monomer containing reversed charge mutation E357K and engineered protuberances S354C and T366W may be produced and will selectively combine to form an Fc domain.
[0214] As described in detail herein, a substantially homogenous composition containing an Fc construct of the disclosure (e.g., an Fc construct having three Fc domains) may be achieved by using all-glycine spacers between two Fc domain monomers in the Fc construct (approach (a)), by using polypeptides that lack C-terminal lysines in the Fc construct (approach (b)), and/or by using two sets of heterodimerizing selectivity modules ((i) heterodimerizing selectivity modules having different reverse charge mutations and (ii) heterodimerizing selectivity modules having engineered cavities and protuberances) to promote heterodimeric Fc domain formation by some Fc domain monomers in the Fc construct (approach (c)).
[0215] In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through approach (a).
[0216] In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through approach (b).
[0217] In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through approach (c). In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through a combination of approaches (a) and (b).
[0218] In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through a combination of approaches (a) and (c).
[0219] In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through a combination of approaches (b) and (c).
[0220] In some embodiments, a substantially homogenous composition containing an Fc construct described herein (e.g., an Fc construct having three Fc domains) may be achieved through a combination of approaches (a), (b), and (c).
[0221] In some embodiments, to further improve the homogeneity of the pharmaceutical composition containing an Fc construct described herein, the N-terminal Asp in one or more of the polypeptides in the Fc construct in the composition is mutated to Gln. In some embodiments of a composition including a substantially homogenous population of an Fc construct described herein, the N-terminal Asp in each of the polypeptides in the Fc construct in the composition is mutated to Gln.
[0222] Furthermore, in Fc constructs of the disclosure (e.g., an Fc construct having three Fc domains), the length of the linkers that join Fc domain monomers influences the folding efficiency of the Fc constructs. In some embodiments, a linker having at least 4, 8, or 12 glycines (e.g., 4-30, 8-30, 12-30 glycines; SEQ ID NOs: 26 and 27) may be used to join Fc domain monomers in Fc constructs of the disclosure.
I. Fc Domain Monomers
[0223] An Fc domain monomer includes a hinge domain, a C.sub.H2 antibody constant domain, and a C.sub.H3 antibody constant domain. The Fc domain monomer can be of different origins, e.g., human, mouse, or rat. The Fc domain monomer can be of immunoglobulin antibody isotype IgG, IgE, IgM, IgA, or IgD. The Fc domain monomer may also be of any immunoglobulin antibody isotype (e.g., IgG1, IgG2a, IgG2b, IgG3, or IgG4). The Fc domain monomers may also be hybrids, e.g., with the hinge and C.sub.H2 from IgG1 and the C.sub.H3 from IgA, or with the hinge and C.sub.H2 from IgG1 but the C.sub.H3 from IgG3. A dimer of Fc domain monomers is an Fc domain (further defined herein) that can bind to an Fc receptor, e.g., FcγRIIIa, which is a receptor located on the surface of leukocytes. In the present disclosure, the C.sub.H3 antibody constant domain of an Fc domain monomer may contain amino acid substitutions at the interface of the C.sub.H3-C.sub.H3 antibody constant domains to promote their association with each other. In other embodiments, an Fc domain monomer includes an additional moiety, e.g., an albumin-binding peptide or a purification peptide, attached to the N- or C-terminus. In the present disclosure, an Fc domain monomer does not contain any type of antibody variable region, e.g., V.sub.H, V.sub.L, a complementarity determining region (CDR), or a hypervariable region (HVR).
[0224] In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is at least 95% identical (e.g., at least 97%, 99%, or 99.5% identical) to the sequence a wild-type Fc domain monomer (SEQ ID NO: 42). In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is a wild-type Fc domain monomer (SEQ ID NO: 42) with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is at least 95% identical (e.g., at least 97%, 99%, or 99.5% identical) to the sequence any one of SEQ ID NOs: 44, 46, 48, and 50-53 (see Example 1, Tables 4 and 5). In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is any one of SEQ ID NOs: 44, 46, 48, and 50-53 (see Example 1, Tables 4 and 5) with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In some cases, these amino acid modifications are in addition to alteration in the length of the glycine spacer, i.e., the up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications are in addition to changes in the length of the all glycine spacer (SEQ ID NO:23). In certain embodiments, an Fc domain monomer in the Fc construct may comprise, consist of, or consist essentially of a sequence that is at least 95% identical (e.g., at least 97%, 99%, or 99.5% identical) to the sequence any one of SEQ ID NOs: 48, 52, and 53. In certain embodiments, an Fc domain monomer in the Fc construct may comprise, consist of, or consist essentially of a sequence that is any one of SEQ ID NOs: 48, 52, and 53 with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions).
TABLE-US-00001 SEQ ID NO: 42: wild-type human IgG1 Fc domain monomer amino acid sequence DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 44 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSC AVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 46 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSC AVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ ID NO: 48 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSC AVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ ID NO: 50 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 51 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO: 52 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ ID NO: 53 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHE DPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDKLTKNQVSLWC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSR WQQGNVFSCSVMHEALHNHYTQKSLSLSPGK
II. Fc Domains
[0225] As defined herein, an Fc domain includes two Fc domain monomers that are dimerized by the interaction between the C.sub.H3 antibody constant domains. In the present disclosure, an Fc domain does not include a variable region of an antibody, e.g., V.sub.H, V.sub.L, CDR, or HVR. An Fc domain forms the minimum structure that binds to an Fc receptor, e.g., Fc-gamma receptors (i.e., Fcγ receptors (FcγR)), Fc-alpha receptors (i.e., Fcα receptors (FcαR)), Fc-epsilon receptors (i.e., Fcεreceptors (FcεR)), and/or the neonatal Fc receptor (FcRn). In some embodiments, an Fc domain of the present disclosure binds to an Fcγ receptor (e.g., FcγRI (CD64), FcγRIIa (CD32), FcγRIIb (CD32), FcγRIIIa (CD16a), FcγRIIIb (CD16b)), and/or FcγRIV and/or the neonatal Fc receptor (FcRn).
III. Fc Domain Modifications
[0226] An unmodified Fc domain monomer can be a naturally occurring human Fc domain monomer or a WT human Fc domain monomer. An Fc domain monomer can be a naturally occurring human Fc domain monomer comprising a hinge, a C.sub.H2 domain, and a C.sub.H3 domain; or a variant thereof having up to 16 (e.g., up to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16) amino acid modifications (e.g., single amino acid modifications) to accommodate or promote directed dimerization. An Fc domain monomer can be an IgG1 Fc domain, an IgG2 Fc domain, an IgG3 Fc domain, an IgG4 Fc domain, or a combination thereof. An Fc domain monomer can be an IgG1 Fc domain, an IgG2 Fc domain, an IgG3 Fc domain, an IgG4 Fc domain, or a combination thereof with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In some cases, the Fc domain monomer is a human IgG Fc domain monomer having up to ten amino acid modifications (e.g., no more than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 amino acid modifications). In some cases, the Fc domain monomer comprises, consists of, or consists essentially of the sequence of SEQ ID NO: 42 with no more than ten amino acid modifications (e.g., no more than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 amino acid modifications). In some cases, the Fc domain includes at least one amino acid modification, wherein the amino acid modifications alter one or more of (i) binding affinity to one or more Fc receptors, (ii) effector functions, (iii) the level of Fc domain sulfation, (iv) half-life, (v) protease resistance, (vi) Fc domain stability, and/or (vii) susceptibility to degradation (e.g., when compared to the unmodified Fc domain). In some cases, the Fc domain includes no more than 16 amino acid modifications (e.g., no more than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 amino acid modifications in the C.sub.H3 domain).
[0227] At least one Fc domain of an Fc construct of the disclosure includes an amino acid modification at position I253 (e.g., I253A, I253C, I253D, I253E, I253F, I253G, I253H, I253I, I253K, I253L, I253M, I253N, I253P, I253Q, I253R, I253S, I253T, I253V, I253W, or I253Y) and/or at position R292 (e.g., R292P, R292D, R292E, R292L, R292Q, R292R, R292T, and R292Y). In some instances, at least one Fc domain includes an amino acid modification at position I253, e.g., I253A. In some instances, at least one Fc domain includes an amino acid modification at position R292, e.g., R292P. An Fc domain may include both an amino acid modification at position I253 (e.g., I253A) and at position R292 (e.g., R292P). For example, an Fc construct having three Fc domains may include an amino acid modification at position I253 (e.g., I253A) in one, two, or all three Fc domains and may additionally, or alternatively, include an amino acid modification at position R292 (e.g., R292P) in one, two, or all three Fc domains. Exemplary Fc constructs having I253A and/or R292P amino acid modifications are depicted in
[0228] In some embodiments, Fc domain modifications that alter half-life may decrease the binding of a modified Fc domain to FcRn, for example, by modification of the Fc domain at position I253.
[0229] Modifications at position I253 may include an amino acid substitution, wherein the amino acid at position I253 is substituted with a natural or non-natural amino acid; a deletion of the amino acid at position I253; or an insertion of one or more amino acid residues at position I253 of the Fc domain. Modification of amino acid I253 can be as part of a combination including multiple modifications (e.g., at other residue positions, e.g., R292), for example, a combination of one or more amino acid substitutions, deletions, and/or insertions. In particular embodiments, an Fc construct may contain, e.g., three Fc domains wherein at least one Fc domain contains a modification at position I253. For example, the wild-type amino acid residue, e.g., isoleucine (1), at position I253 may be substituted for a natural or non-natural amino acid, e.g., alanine (A). In some instances, each amino acid modification at position I253 is independently selected from, e.g., I253A, I253C, I253D, I253E, I253F, I253G, I253H, I253I, I253K, I253L, I253M, I253N, I253P, I253Q, I253R, I253S, I253T, I253V, I253W, and I253Y.
[0230] In other embodiments, Fc domain modifications that alter half-life may alter the binding of a modified Fc domain to FcγRIIb, for example, by modification of the Fc domain at position R292. Modifications at position R292 may include an amino acid substitution, wherein the amino acid at position R292 is substituted with a natural or non-natural amino acid; a deletion of the amino acid at position R292; or an insertion of one or more amino acid residues at position R292 of the Fc domain. Modification of amino acid 292 can be as part of a combination including multiple modifications (e.g., at other residue positions, e.g., I253), for example, a combination of one or more amino acid substitutions, deletions, and/or insertions. In particular embodiments, an Fc construct may contain, e.g., three Fc domains wherein at least one Fc domain contains a modification at position R292. For example, the wild-type amino acid residue, e.g., arginine (R), at position 292 may be substituted for a natural or non-natural amino acid, e.g., proline (P). In some instances, each amino acid modification at position R292 is independently selected from, e.g., R292P, R292D, R292E, R292L, R292Q, R292R, R292T, and R292Y.
[0231] Exemplary Fc domains with altered binding affinity to Fc receptors include Fc monomers containing the double mutants S267E/L328F. S267E/L328F mutations have been previously shown to significantly and specifically enhance IgG1 binding to the FcγRIIb receptor (Chu et al. Molecular Immunology 45 2008).
[0232] An amino acid modification, e.g., to alter the half-life, at position I253, e.g., I253A, may occur in at least one (e.g., 1, 2, 3, 4, or 5) Fc domain of an Fc construct, e.g., construct 4 (
IV. Dimerization Selectivity Modules
[0233] In the present disclosure, a dimerization selectivity module is the part of the Fc domain monomer that facilitates the preferred pairing of two Fc domain monomers to form an Fc domain. Specifically, a dimerization selectivity module is that part of the C.sub.H3 antibody constant domain of an Fc domain monomer which includes amino acid substitutions positioned at the interface between interacting C.sub.H3 antibody constant domains of two Fc domain monomers. In a dimerization selectivity module, the amino acid substitutions make favorable the dimerization of the two C.sub.H3 antibody constant domains as a result of the compatibility of amino acids chosen for those substitutions. The ultimate formation of the favored Fc domain is selective over other Fc domains which form from Fc domain monomers lacking dimerization selectivity modules or with incompatible amino acid substitutions in the dimerization selectivity modules. This type of amino acid substitution can be made using conventional molecular cloning techniques well-known in the art, such as QuikChange® mutagenesis.
[0234] In some embodiments, a dimerization selectivity module includes an engineered cavity (described further herein) in the C.sub.H3 antibody constant domain. In other embodiments, a dimerization selectivity module includes an engineered protuberance (described further herein) in the C.sub.H3 antibody constant domain. To selectively form an Fc domain, two Fc domain monomers with compatible dimerization selectivity modules, e.g., one C.sub.H3 antibody constant domain containing an engineered cavity and the other C.sub.H3 antibody constant domain containing an engineered protuberance, combine to form a protuberance-into-cavity pair of Fc domain monomers. Engineered protuberances and engineered cavities are examples of heterodimerizing selectivity modules, which can be made in the C.sub.H3 antibody constant domains of Fc domain monomers in order to promote favorable heterodimerization of two Fc domain monomers that have compatible heterodimerizing selectivity modules.
[0235] In other embodiments, an Fc domain monomer with a dimerization selectivity module containing positively-charged amino acid substitutions and an Fc domain monomer with a dimerization selectivity module containing negatively-charged amino acid substitutions may selectively combine to form an Fc domain through the favorable electrostatic steering (described further herein) of the charged amino acids. In some embodiments, an Fc domain monomer may include one of the following positively-charged and negatively-charged amino acid substitutions: K392D, K392E, D399K, K409D, K409E, K439D, and K439E. In one example, an Fc domain monomer containing a positively-charged amino acid substitution, e.g., D356K or E357K, and an Fc domain monomer containing a negatively-charged amino acid substitution, e.g., K370D or K370E, may selectively combine to form an Fc domain through favorable electrostatic steering of the charged amino acids. In another example, an Fc domain monomer containing E357K and an Fc domain monomer containing K370D may selectively combine to form an Fc domain through favorable electrostatic steering of the charged amino acids. In some embodiments, reverse charge amino acid substitutions may be used as heterodimerizing selectivity modules, wherein two Fc domain monomers containing different, but compatible, reverse charge amino acid substitutions combine to form a heterodimeric Fc domain. Specific dimerization selectivity modules are further listed, without limitation, in Tables 1 and 2A described further below.
[0236] In other embodiments, two Fc domain monomers include homodimerizing selectivity modules containing identical reverse charge mutations in at least two positions within the ring of charged residues at the interface between C.sub.H3 domains. Homodimerizing selectivity modules are reverse charge amino acid substitutions that promote the homodimerization of Fc domain monomers to form a homodimeric Fc domain. By reversing the charge of both members of two or more complementary pairs of residues in the two Fc domain monomers, mutated Fc domain monomers remain complementary to Fc domain monomers of the same mutated sequence, but have a lower complementarity to Fc domain monomers without those mutations. In one embodiment, an Fc domain includes Fc domain monomers including the double mutants K409D/D399K, K392D/D399K, E357K/K370E, D356K/K439D, K409E/D399K, K392E/D399K, E357K/K370D, or D356K/K439E. In another embodiment, an Fc domain includes Fc domain monomers including quadruple mutants combining any pair of the double mutants, e.g., K409D/D399K/E357K/K370E. Examples of homodimerizing selectivity modules are further shown in Tables 2B and 2C.
[0237] In further embodiments, an Fc domain monomer containing (i) at least one reverse charge mutation and (ii) at least one engineered cavity or at least one engineered protuberance may selectively combine with another Fc domain monomer containing (i) at least one reverse charge mutation and (ii) at least one engineered protuberance or at least one engineered cavity to form an Fc domain. For example, an Fc domain monomer containing reversed charge mutation K370D and engineered cavities Y349C, T366S, L368A, and Y407V and another Fc domain monomer containing reversed charge mutation E357K and engineered protuberances S354C and T366W may selectively combine to form an Fc domain. The formation of such Fc domains is promoted by the compatible amino acid substitutions in the C.sub.H3 antibody constant domains. Two dimerization selectivity modules containing incompatible amino acid substitutions, e.g., both containing engineered cavities, both containing engineered protuberances, or both containing the same charged amino acids at the C.sub.H3-C.sub.H3 interface, will not promote the formation of a heterodimeric Fc domain.
[0238] Furthermore, other methods used to promote the formation of Fc domains with defined Fc domain monomers include, without limitation, the LUZ-Y approach (U.S. Patent Application Publication No. WO2011034605) which includes C-terminal fusion of a monomer α-helices of a leucine zipper to each of the Fc domain monomers to allow heterodimer formation, as well as strand-exchange engineered domain (SEED) body approach (Davis et al., Protein Eng Des Sel. 23:195-202, 2010) that generates Fc domain with heterodimeric Fc domain monomers each including alternating segments of IgA and IgG C.sub.H3 sequences.
V. Engineered Cavities and Engineered Protuberances
[0239] The use of engineered cavities and engineered protuberances (or the “knob-into-hole” strategy) is described by Carter and co-workers (Ridgway et al., Protein Eng. 9:617-612, 1996; Atwell et al., J Mol Biol. 270:26-35, 1997; Merchant et al., Nat Biotechnol. 16:677-681, 1998). The knob and hole interaction favors heterodimer formation, whereas the knob-knob and the hole-hole interaction hinder homodimer formation due to steric clash and deletion of favorable interactions. The “knob-into-hole” technique is also disclosed in U.S. Pat. No. 5,731,168.
[0240] In the present disclosure, engineered cavities and engineered protuberances are used in the preparation of the Fc constructs described herein. An engineered cavity is a void that is created when an original amino acid in a protein is replaced with a different amino acid having a smaller side-chain volume.
[0241] An engineered protuberance is a bump that is created when an original amino acid in a protein is replaced with a different amino acid having a larger side-chain volume. Specifically, the amino acid being replaced is in the C.sub.H3 antibody constant domain of an Fc domain monomer and is involved in the dimerization of two Fc domain monomers. In some embodiments, an engineered cavity in one C.sub.H3 antibody constant domain is created to accommodate an engineered protuberance in another C.sub.H3 antibody constant domain, such that both C.sub.H3 antibody constant domains act as dimerization selectivity modules (e.g., heterodimerizing selectivity modules) (described above) that promote or favor the dimerization of the two Fc domain monomers. In other embodiments, an engineered cavity in one C.sub.H3 antibody constant domain is created to better accommodate an original amino acid in another C.sub.H3 antibody constant domain. In yet other embodiments, an engineered protuberance in one C.sub.H3 antibody constant domain is created to form additional interactions with original amino acids in another C.sub.H3 antibody constant domain.
[0242] An engineered cavity can be constructed by replacing amino acids containing larger side chains such as tyrosine or tryptophan with amino acids containing smaller side chains such as alanine, valine, or threonine. Specifically, some dimerization selectivity modules (e.g., heterodimerizing selectivity modules) (described further above) contain engineered cavities such as Y407V mutation in the C.sub.H3 antibody constant domain. Similarly, an engineered protuberance can be constructed by replacing amino acids containing smaller side chains with amino acids containing larger side chains. Specifically, some dimerization selectivity modules (e.g., heterodimerizing selectivity modules) (described further above) contain engineered protuberances such as T366W mutation in the C.sub.H3 antibody constant domain. In the present disclosure, engineered cavities and engineered protuberances are also combined with inter-C.sub.H3 domain disulfide bond engineering to enhance heterodimer formation. In one example, an Fc domain monomer containing engineered cavities Y349C, T366S, L368A, and Y407V may selectively combine with another Fc domain monomer containing engineered protuberances S354C and T366W to form an Fc domain. In another example, an Fc domain monomer containing engineered cavity Y349C and an Fc domain monomer containing engineered protuberance S354C may selectively combine to form an Fc domain. Other engineered cavities and engineered protuberances, in combination with either disulfide bond engineering or structural calculations (mixed HA-TF) are included, without limitation, in Table 1.
TABLE-US-00002 TABLE 1 CH.sub.3 antibody constant CH.sub.3 antibody constant domain of Fc domain domain of Fc domain Strategy monomer 1 monomer 2 Reference Engineered cavities and Y407T T366Y U.S. Pat. No. 8,216,805 protuberances (“knob-into-hole”) Y407A T366W U.S. Pat. No. 8,216,805 F405A T394W U.S. Pat. No. 8,216,805 Y407T T366Y U.S. Pat. No. 8,216,805 T394S F405W U.S. Pat. No. 8,216,805 T394W:Y407T T366Y:F405A U.S. Pat. No. 8,216,805 T394S:Y407A T366W:F405W U.S. Pat. No. 8,216,805 T366W:T394S F405W:Y407A U.S. Pat. No. 8,216,805 Engineered cavities and protuberances T366S:L368A: T366W:S354C Zeidler et al., J Immunol. (“knob-into-hole”), S-S engineering Y407V:Y349C 163: 1246-52, 1999 Mixed HA-TF S364H:F405A Y349T:T394F WO2006106905
[0243] Replacing an original amino acid residue in the C.sub.H3 antibody constant domain with a different amino acid residue can be achieved by altering the nucleic acid encoding the original amino acid residue. The upper limit for the number of original amino acid residues that can be replaced is the total number of residues in the interface of the C.sub.H3 antibody constant domains, given that sufficient interaction at the interface is still maintained. In some cases, the C.sub.H3 antibody constant domain has no more than 16 (e.g., no more than 2, 4, 6, 8, 10, 12, 14, or 16) single amino acid modifications.
VI. Electrostatic Steering
[0244] Electrostatic steering is the utilization of favorable electrostatic interactions between oppositely charged amino acids in peptides, protein domains, and proteins to control the formation of higher ordered protein molecules. A method of using electrostatic steering effects to alter the interaction of antibody domains to reduce for formation of homodimer in favor of heterodimer formation in the generation of bi-specific antibodies is disclosed in U.S. Patent Application Publication No. 2014-0024111.
[0245] In the present disclosure, electrostatic steering is used to control the dimerization of Fc domain monomers and the formation of Fc constructs. In particular, to control the dimerization of Fc domain monomers using electrostatic steering, one or more amino acid residues that make up the C.sub.H3-C.sub.H3 interface are replaced with positively- or negatively-charged amino acid residues such that the interaction becomes electrostatically favorable or unfavorable depending on the specific charged amino acids introduced. In some embodiments, a positively-charged amino acid in the interface, such as lysine, arginine, or histidine, is replaced with a negatively-charged amino acid such as aspartic acid or glutamic acid. In other embodiments, a negatively-charged amino acid in the interface is replaced with a positively-charged amino acid. The charged amino acids may be introduced to one of the interacting C.sub.H3 antibody constant domains, or both. By introducing charged amino acids to the interacting C.sub.H3 antibody constant domains, dimerization selectivity modules (described further above) are created that can selectively form dimers of Fc domain monomers as controlled by the electrostatic steering effects resulting from the interaction between charged amino acids.
[0246] In some embodiments, to create a dimerization selectivity module including reversed charges that can selectively form dimers of Fc domain monomers as controlled by the electrostatic steering effects, the two Fc domain monomers may be selectively formed through heterodimerization or homodimerization.
[0247] Heterodimerization of Fc Domain Monomers
[0248] Heterodimerization of Fc domain monomers can be promoted by introducing different, but compatible, mutations in the two Fc domain monomers, such as the charge residue pairs included, without limitation, in Table 2A. In some embodiments, an Fc domain monomer may include one of the following positively-charged and negatively-charged amino acid substitutions: D356K, D356R, E357K, E357R, K370D, K370E, K392D, K392E, D399K, K409D, K409E, K439D, and K439E. In one example, an Fc domain monomer containing a positively-charged amino acid substitution, e.g., D356K or E357K, and an Fc domain monomer containing a negatively-charged amino acid substitution, e.g., K370D or K370E, may selectively combine to form an Fc domain through favorable electrostatic steering of the charged amino acids. In another example, an Fc domain monomer containing E357K and an Fc domain monomer containing K370D may selectively combine to form an Fc domain through favorable electrostatic steering of the charged amino acids.
[0249] For example, in an Fc construct having three Fc domains, two of the three Fc domains may be formed by the heterodimerization of two Fc domain monomers, as promoted by the electrostatic steering effects. A “heterodimeric Fc domain” refers to an Fc domain that is formed by the heterodimerization of two Fc domain monomers, wherein the two Fc domain monomers contain different reverse charge mutations (heterodimerizing selectivity modules) (see, e.g., mutations in Table 2A) that promote the favorable formation of these two Fc domain monomers. As shown in
TABLE-US-00003 TABLE 2A Reverse charge mutation(s) in Reverse charge mutation(s) in C.sub.H3 antibody constant domain C.sub.H3 antibody constant domain of Fc domain monomer 1 of Fc domain monomer 2 K409D D399K K409D D399R K409E D399K K409E D399R K392D D399K K392D D399R K392E D399K K392E D399R K370D E357K K370D E357R K370E E357K K370E E357R K370D D356K K370D D356R K370E D356K K370E D356R K409D, K392D D399K, E356K K370E, K409D, K439E E356K, E357K, D399K
[0250] Homodimerization of Fc domain monomers Homodimerization of Fc domain monomers can be promoted by introducing the same electrostatic steering mutations (homodimerizing selectivity modules) in both Fc domain monomers in a symmetric fashion. In some embodiments, two Fc domain monomers include homodimerizing selectivity modules containing identical reverse charge mutations in at least two positions within the ring of charged residues at the interface between C.sub.H3 domains. By reversing the charge of both members of two or more complementary pairs of residues in the two Fc domain monomers, mutated Fc domain monomers remain complementary to Fc domain monomers of the same mutated sequence, but have a lower complementarity to Fc domain monomers without those mutations. Electrostatic steering mutations that may be introduced into an Fc domain monomer to promote its homodimerization are shown, without limitation, in Tables 2B and 2C. In one embodiment, an Fc domain includes two Fc domain monomers each including the double reverse charge mutants (Table 2B), e.g., K409D/D399K. In another embodiment, an Fc domain includes two Fc domain monomers each including quadruple reverse mutants (Table 2C), e.g., K409D/D399K/K370D/E357K.
[0251] For example, in an Fc construct having three Fc domains, one of the three Fc domains may be formed by the homodimerization of two Fc domain monomers, as promoted by the electrostatic steering effects. A “homodimeric Fc domain” refers to an Fc domain that is formed by the homodimerization of two Fc domain monomers, wherein the two Fc domain monomers contain the same reverse charge mutations (see, e.g., mutations in Tables 2B and 2C). As shown in
TABLE-US-00004 TABLE 2B Reverse charge mutation(s) in C.sub.H3 antibody constant domain of each of the two Fc domain monomers in a homodimeric Fc domain K409D/D399K K409D/D399R K409E/D399K K409E/D399R K392D/D399K K392D/D399R K392E/D399K K392E/D399R K370D/E357K K370D/E357R K370E/E357K K370E/E357R K370D/D356K K370D/D356R K370E/D356K K370E/D356R
TABLE-US-00005 TABLE 2C Reverse charge mutation(s) Reverse charge mutation(s) in C.sub.H3 antibody constant in CH3 antibody constant domain of each of the two domain of each of the two Fc domain monomers in a Fc domain monomers in a homodimeric Fc domain homodimeric Fc domain K409D/D399K/K370D/E357K K392D/D399K/K370D/E357K K409D/D399K/K370D/E357R K392D/D399K/K370D/E357R K409D/D399K/K370E/E357K K392D/D399K/K370E/E357K K409D/D399K/K370E/E357R K392D/D399K/K370E/E357R K409D/D399K/K370D/D356K K392D/D399K/K370D/D356K K409D/D399K/K370D/D356R K392D/D399K/K370D/D356R K409D/D399K/K370E/D356K K392D/D399K/K370E/D356K K409D/D399K/K370E/D356R K392D/D399K/K370E/D356R K409D/D399R/K370D/E357K K392D/D399R/K370D/E357K K409D/D399R/K370D/E357R K392D/D399R/K370D/E357R K409D/D399R/K370E/E357K K392D/D399R/K370E/E357K K409D/D399R/K370E/E357R K392D/D399R/K370E/E357R K409D/D399R/K370D/D356K K392D/D399R/K370D/D356K K409D/D399R/K370D/D356R K392D/D399R/K370D/D356R K409D/D399R/K370E/D356K K392D/D399R/K370E/D356K K409D/D399R/K370E/D356R K392D/D399R/K370E/D356R K409E/D399K/K370D/E357K K392E/D399K/K370D/E357K K409E/D399K/K370D/E357R K392E/D399K/K370D/E357R K409E/D399K/K370E/E357K K392E/D399K/K370E/E357K K409E/D399K/K370E/E357R K392E/D399K/K370E/E357R K409E/D399K/K370D/D356K K392E/D399K/K370D/D356K K409E/D399K/K370D/D356R K392E/D399K/K370D/D356R K409E/D399K/K370E/D356K K392E/D399K/K370E/D356K K409E/D399K/K370E/D356R K392E/D399K/K370E/D356R K409E/D399R/K370D/E357K K392E/D399R/K370D/E357K K409E/D399R/K370D/E357R K392E/D399R/K370D/E357R K409E/D399R/K370E/E357K K392E/D399R/K370E/E357K K409E/D399R/K370E/E357R K392E/D399R/K370E/E357R K409E/D399R/K370D/D356K K392E/D399R/K370D/D356K K409E/D399R/K370D/D356R K392E/D399R/K370D/D356R K409E/D399R/K370E/D356K K392E/D399R/K370E/D356K K409E/D399R/K370E/D356R K392E/D399R/K370E/D356R
[0252] Replacing an original amino acid residue in the C.sub.H3 antibody constant domain with a different amino acid residue can be achieved by altering the nucleic acid encoding the original amino acid residue. The upper limit for the number of original amino acid residues that can be replaced is the total number of residues in the interface of the C.sub.H3 antibody constant domains, given that sufficient interaction at the interface is still maintained. In some cases, the C.sub.H3 antibody constant domain has no more than 16 (e.g., no more than 2, 4, 6, 8, 10, 12, 14, or 16) single amino acid modifications.
VII. Linkers
[0253] In the present disclosure, a linker is used to describe a linkage or connection between polypeptides or protein domains and/or associated non-protein moieties. In some embodiments, a linker is a linkage or connection between at least two Fc domain monomers, for which the linker connects the C-terminus of the C.sub.H3 antibody constant domain of a first Fc domain monomer to the N-terminus of the hinge domain of a second Fc domain monomer, such that the two Fc domain monomers are joined to each other in tandem series. In other embodiments, a linker is a linkage between an Fc domain monomer and any other protein domains that are attached to it. For example, a linker can attach the C-terminus of the C.sub.H3 antibody constant domain of an Fc domain monomer to the N-terminus of an albumin-binding peptide.
[0254] A linker can be a simple covalent bond, e.g., a peptide bond, a synthetic polymer, e.g., a polyethylene glycol (PEG) polymer, or any kind of bond created from a chemical reaction, e.g., chemical conjugation. In the case that a linker is a peptide bond, the carboxylic acid group at the C-terminus of one protein domain can react with the amino group at the N-terminus of another protein domain in a condensation reaction to form a peptide bond. Specifically, the peptide bond can be formed from synthetic means through a conventional organic chemistry reaction well-known in the art, or by natural production from a host cell, wherein a polynucleotide sequence encoding the DNA sequences of both proteins, e.g., two Fc domain monomer, in tandem series can be directly transcribed and translated into a contiguous polypeptide encoding both proteins by the necessary molecular machineries, e.g., DNA polymerase and ribosome, in the host cell.
[0255] In the case that a linker is a synthetic polymer, e.g., a PEG polymer, the polymer can be functionalized with reactive chemical functional groups at each end to react with the terminal amino acids at the connecting ends of two proteins.
[0256] In the case that a linker (except peptide bond mentioned above) is made from a chemical reaction, chemical functional groups, e.g., amine, carboxylic acid, ester, azide, or other functional groups commonly used in the art, can be attached synthetically to the C-terminus of one protein and the N-terminus of another protein, respectively. The two functional groups can then react to through synthetic chemistry means to form a chemical bond, thus connecting the two proteins together. Such chemical conjugation procedures are routine for those skilled in the art.
[0257] Spacer
[0258] In the present disclosure, a linker between two Fc domain monomers can be an amino acid spacer including 3-200 amino acids (e.g., 3-200, 3-180, 3-160, 3-140, 3-120, 3-100, 3-90, 3-80, 3-70, 3-60, 3-50, 3-45, 3-40, 3-35, 3-30, 3-25, 3-20, 3-15, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 3-4, 4-200, 5-200, 6-200, 7-200, 8-200, 9-200, 10-200, 15-200, 20-200, 25-200, 30-200, 35-200, 40-200, 45-200, 50-200, 60-200, 70-200, 80-200, 90-200, 100-200, 120-200, 140-200, 160-200, or 180-200 amino acids)(e.g., 3-150, 3-100, 3-60, 3-50, 3-40, 3-30, 3-20, 3-10, 3-8, 3-5, 4-30, 5-30, 6-30, 8-30, 10-20, 10-30, 12-30, 14-30, 20-30, 15-25, 15-30, 18-22, and 20-30 amino acid). In some embodiments, a linker between two Fc domain monomers is an amino acid spacer containing at least 12 amino acids, such as 12-200 amino acids (e.g., 12-200, 12-180, 12-160, 12-140, 12-120, 12-100, 12-90, 12-80, 12-70, 12-60, 12-50, 12-40, 12-30, 12-20, 12-19, 12-18, 12-17, 12-16, 12-15, 12-14, or 12-13 amino acids) (e.g., 14-200, 16-200, 18-200, 20-200, 30-200, 40-200, 50-200, 60-200, 70-200, 80-200, 90-200, 100-200, 120-200, 140-200, 160-200, 180-200, or 190-200 amino acids). In some embodiments, a linker between two Fc domain monomers is an amino acid spacer containing 12-30 amino acids (e.g., 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids). Suitable peptide spacers are known in the art, and include, for example, peptide linkers containing flexible amino acid residues such as glycine and serine. In certain embodiments, a spacer can contain motifs, e.g., multiple or repeating motifs, of GS, GGS, GGGGS (SEQ ID NO: 1), GGSG (SEQ ID NO: 2), or SGGG (SEQ ID NO: 3). In certain embodiments, a spacer can contain 2 to 12 amino acids including motifs of GS, e.g., GS, GSGS (SEQ ID NO: 4), GSGSGS (SEQ ID NO: 5), GSGSGSGS (SEQ ID NO: 6), GSGSGSGSGS (SEQ ID NO: 7), or GSGSGSGSGSGS (SEQ ID NO: 8). In certain other embodiments, a spacer can contain 3 to 12 amino acids including motifs of GGS, e.g., GGS, GGSGGS (SEQ ID NO: 9), GGSGGSGGS (SEQ ID NO: 10), and GGSGGSGGSGGS (SEQ ID NO: 11). In yet other embodiments, a spacer can contain 4 to 20 amino acids including motifs of GGSG (SEQ ID NO: 2), e.g., GGSGGGSG (SEQ ID NO: 12), GGSGGGSGGGSG (SEQ ID NO: 13), GGSGGGSGGGSGGGSG (SEQ ID NO: 14), or GGSGGGSGGGSGGGSGGGSG (SEQ ID NO: 15). In other embodiments, a spacer can contain motifs of GGGGS (SEQ ID NO: 1), e.g., GGGGSGGGGS (SEQ ID NO: 16) or GGGGSGGGGSGGGGS (SEQ ID NO: 17). In certain embodiments, a spacer is SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18).
[0259] In some embodiments, a spacer between two Fc domain monomers contains only glycine residues, e.g., at least 4 glycine residues (e.g., 4-200, 4-180, 4-160, 4-140, 4-40, 4-100, 4-90, 4-80, 4-70, 4-60, 4-50, 4-40, 4-30, 4-20, 4-19, 4-18, 4-17, 4-16, 4-15, 4-14, 4-13, 4-12, 4-11, 4-10, 4-9, 4-8, 4-7, 4-6 or 4-5 glycine residues) (e.g., 4-200, 6-200, 8-200, 10-200, 12-200, 14-200, 16-200, 18-200, 20-200, 30-200, 40-200, 50-200, 60-200, 70-200, 80-200, 90-200, 100-200, 120-200, 140-200, 160-200, 180-200, or 190-200 glycine residues). In certain embodiments, a spacer has 4-30 glycine residues (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 glycine residues). In some embodiments, a spacer containing only glycine residues may not be glycosylated (e.g., O-linked glycosylation, also referred to as O-glycosylation) or may have a decreased level of glycosylation (e.g., a decreased level of O-glycosylation) (e.g., a decreased level of O-glycosylation with glycans such as xylose, mannose, sialic acids, fucose (Fuc), and/or galactose (Gal) (e.g., xylose)) as compared to, e.g., a spacer containing one or more serine residues (e.g., SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18)) (see Example 4).
[0260] In some embodiments, a spacer containing only glycine residues may not be O-glycosylated (e.g., O-xylosylation) or may have a decreased level of O-glycosylation (e.g., a decreased level of O-xylosylation) as compared to, e.g., a spacer containing one or more serine residues (e.g., SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18)).
[0261] In some embodiments, a spacer containing only glycine residues may not undergo proteolysis or may have a decreased rate of proteolysis as compared to, e.g., a spacer containing one or more serine residues (e.g., SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18)) (see Example 4).
[0262] In certain embodiments, a spacer can contain motifs of GGGG (SEQ ID NO: 19), e.g., GGGGGGGG (SEQ ID NO: 20), GGGGGGGGGGGG (SEQ ID NO: 21), GGGGGGGGGGGGGGGG (SEQ ID NO: 22), or GGGGGGGGGGGGGGGGGGGG (SEQ ID NO: 23). In certain embodiments, a spacer can contain motifs of GGGGG (SEQ ID NO: 24), e.g., GGGGGGGGGG (SEQ ID NO: 25), or GGGGGGGGGGGGGGG (SEQ ID NO: 26). In certain embodiments, a spacer is GGGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27).
[0263] In other embodiments, a spacer can also contain amino acids other than glycine and serine, e.g., GENLYFQSGG (SEQ ID NO: 28), SACYCELS (SEQ ID NO: 29), RSIAT (SEQ ID NO: 30), RPACKIPNDLKQKVMNH (SEQ ID NO: 31), GGSAGGSGSGSSGGSSGASGTGTAGGTGSGSGTGSG (SEQ ID NO: 32), AAANSSIDLISVPVDSR (SEQ ID NO: 33), or GGSGGGSEGGGSEGGGSEGGGSEGGGSEGGGSGGGS (SEQ ID NO: 34).
[0264] In certain embodiments in the present disclosure, a 12- or 20-amino acid peptide spacer is used to connect two Fc domain monomers in tandem series (e.g., polypeptides 102 and 108 in
[0265] In some embodiments, a spacer between two Fc domain monomers may comprise, consist of, or consist essentially of a sequence that is at least 75% identical (e.g., at least 77%, 79%, 81%, 83%, 85%, 87%, 89%, 91%, 93%, 95%, 97%, 99%, or 99.5% identical) to the sequence any one of SEQ ID NOs: 1-36 described above. In some embodiments, a spacer between two Fc domain monomers may comprise, consist of, or consist essentially of a sequence that is any one of SEQ ID NOs: 1-36 described above with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In certain embodiments, a spacer between two Fc domain monomers may comprise, consist of, or consist essentially of a sequence that is at least 80% identical (e.g., at least 82%, 85%, 87%, 90%, 92%, 95%, 97%, 99%, or 99.5% identical) to the sequence any one of SEQ ID NOs: 17, 18, 26, and 27. In certain embodiments, a spacer between two Fc domain monomers may comprise, consist of, or consist essentially of a sequence that is any one of SEQ ID NOs: 17, 18, 26, and 27 with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In certain embodiments, a spacer between two Fc domain monomers may comprise, consist of, or consist essentially of a sequence that is at least 80% identical (e.g., at least 82%, 85%, 87%, 90%, 92%, 95%, 97%, 99%, or 99.5%) to the sequence SEQ ID NO: 18 or 27. In certain embodiments, a spacer between two Fc domain monomers may comprise, consist of, or consist essentially of a sequence that is sequence SEQ ID NO: 18 or 27 with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions).
VIII. Serum Protein-Binding Peptides
[0266] Binding to serum protein peptides can improve the pharmacokinetics of protein pharmaceuticals, and in particular the Fc constructs described here may be fused with serum protein-binding peptides
[0267] As one example, albumin-binding peptides that can be used in the methods and compositions described here are generally known in the art. In one embodiment, the albumin binding peptide includes the sequence DICLPRWGCLW (SEQ ID NO: 37). In some embodiments, the albumin binding peptide comprises, consists of, or consists essentially of a sequence that is at least 80% identical (e.g., 80%, 90%, or 100% identical) to the sequence SEQ ID NO: 37. In some embodiments, the albumin binding peptide comprises, consists of, or consists essentially of a sequence that is the sequence SEQ ID NO: 37 with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions).
[0268] In the present disclosure, albumin-binding peptides may be attached to the N- or C-terminus of certain polypeptides in the Fc construct. In one embodiment, an albumin-binding peptide may be attached to the C-terminus of one or more polypeptides in Fc constructs 1-4 (
IX. Fc Constructs
[0269] In general, the disclosure features Fc constructs having Fc domains (e.g., an Fc construct having three Fc domains). These may have greater binding affinity and/or avidity than a single wild-type Fc domain for an Fc receptor, e.g., FcγRIIIa. The disclosure discloses methods of engineering amino acids at the interface of two interacting C.sub.H3 antibody constant domains such that the two Fc domain monomers of an Fc domain selectively form a dimer with each other, thus preventing the formation of unwanted multimers or aggregates. An Fc construct includes an even number of Fc domain monomers, with each pair of Fc domain monomers forming an Fc domain. An Fc construct includes, at a minimum, one functional Fc domain formed from a dimer of two Fc domain monomers. In some embodiments, the Fc constructs described herein do not include an antigen-recognition region, e.g., a variable domain (e.g., V.sub.H, V.sub.L, a hypervariable region (HVR)) or a complementarity determining region (CDR). In some embodiments, the Fc constructs described herein include an antigen-recognition region, e.g., a variable domain (e.g., V.sub.H, V.sub.L, a HVR) or a CDR.
[0270] An Fc construct containing three Fc domains may form from four polypeptides (
[0271] A first branch heterodimeric Fc domain may be formed by combining Fc domain monomers 106 and 114 (e.g., Fc domain monomer 106 contains engineered protuberances S354C and T366W, and Fc domain monomer 114 contains engineered cavities Y349C, T366S, L368A, and Y409V). A second heterodimeric Fc domain may be formed by combining Fc domain monomers 112 and 116 (e.g., Fc domain monomer 112 contains engineered protuberances S354C and T366W, and Fc domain monomer 116 contains engineered cavities Y349C, T366S, L368A, and Y409V).
[0272] In
[0273] In further embodiments, an Fc domain monomer containing (i) at least one reverse charge mutation and (ii) at least one engineered cavity or at least one engineered protuberance may selectively combine with another Fc domain monomer containing (i) at least one reverse charge mutation and (ii) at least one engineered protuberance or at least one engineered cavity to form an Fc domain. For example, an Fc domain monomer containing reversed charge mutation K370D and engineered cavities Y349C, T366S, L368A, and Y407V and another Fc domain monomer containing reversed charge mutation E357K and engineered protuberances S354C and T366W may selectively combine to form an Fc domain.
[0274] In some embodiments, in an Fc construct including: a) a first polypeptide having the formula A-L-B; wherein i) A includes a first Fc domain monomer; ii) L is a linker; and iii) B includes a second Fc domain monomer; b) a second polypeptide having the formula A′-L′-B′; wherein i) A′ includes a third Fc domain monomer; ii) L′ is a linker; and iii) B′ includes a fourth Fc domain monomer; c) a third polypeptide that includes a fifth Fc domain monomer; and d) a fourth polypeptide that includes a sixth Fc domain monomer; wherein B and B′ combine to form a first Fc domain, A and the fifth Fc domain monomer combine to form a second Fc domain, and A′ and the sixth Fc domain monomer combine to form a third Fc domain, examples of some amino acid mutations that can be incorporated into the Fc domain monomers in the Fc construct are shown in Tables 3A-3D. In some embodiments, each of the first, second, third, and fourth polypeptides in the Fc construct lacks a C-terminal lysine. In some embodiments, the N-terminal Asp in each of the first, second, third, and fourth polypeptides in the Fc construct is mutated to Gln. In some embodiments, each of L and L′ comprises, consists of, or consists essentially of the sequence GGGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27).
TABLE-US-00006 TABLE 3A Fc domain Amino acid mutations monomer (each column represents a set of mutations in an Fc construct having three Fc domains) A and A′ Engineered S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C protuberance T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W reversed E357K E357R E357K E357K E357R E357R E357K E357R E357K E357R E357K E357K E357R E357R E357K E357R charge mutation(s) L and L′ GGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27) B and B′ reversed D399K D399K D399R D399K D399R D399K D399R D399R D399K D399K D399R D399K D399R D399K D399R D399R charge K409D K409D K409D K409E K409D K409E K409D K409D K409D K409E K409D K409E K409D K409E K409E K409E mutation(s) 5.sup.th and 6.sup.th Engineered Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Fc domain cavity T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S monomers L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V reversed K370D K370D K370D K370D K370D K370D K370D K370D K370E K370E K370E K370E K370E K370E K370E K370E charge mutation(s)
TABLE-US-00007 TABLE 3B Fc domain Amino acid mutations monomer (each column represents a set of mutations in an Fc construct having three Fc domains) A and A′ Engineered S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C protuberance T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W reversed E357K E357R E357K E357K E357R E357R E357K E357R E357K E357R E357K E357K E357R E357R E357K E357R charge mutation(s) L and L′ GGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27) B and B′ reversed D399K D399K D399R D399K D399R D399K D399R D399R D399K D399K D399R D399K D399R D399K D399R D399R charge K409D K409D K409D K409E K409D K409E K409D K409D K409D K409E K409D K409E K409D K409E K409E K409E mutation(s) 5.sup.th and 6.sup.th Engineered Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Fc domain cavity T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S monomers L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V reversed K370D K370D K370D K370D K370D K370D K370D K370D K370E K370E K370E K370E K370E K370E K370E K370E charge mutation(s)
TABLE-US-00008 TABLE 3C Fc domain Amino acid mutations monomer (each column represents a set of mutations in an Fc construct having three Fc domains) A and A′ Engineered Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C cavity T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V reversed E357K E357R E357K E357K E357R E357R E357K E357R E357K E357R E357K E357K E357R E357R E357K E357R charge mutation(s) L and L′ GGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27) B and B′ reversed D399K D399K D399R D399K D399R D399K D399R D399R D399K D399K D399R D399K D399R D399K D399R D399R charge K409D K409D K409D K409E K409D K409E K409D K409D K409D K409E K409D K409E K409D K409E K409E K409E mutation(s) 5.sup.th and 6.sup.th Engineered S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C Fc domain protuberance T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W monomers reversed K370D K370D K370D K370D K370D K370D K370D K370D K370E K370E K370E K370E K370E K370E K370E K370E charge mutation(s)
TABLE-US-00009 TABLE 3D Fc domain Amino acid mutations monomer (each column represents a set of mutations in an Fc construct having three Fc domains) A and A′ Engineered Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C Y349C cavity T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S T366S L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A L368A Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V Y407V reversed K370D K370D K370D K370D K370D K370D K370D K370D K370E K370E K370E K370E K370E K370E K370E K370E charge mutation(s) L and L′ GGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27) B and B′ reversed D399K D399K D399R D399K D399R D399K D399R D399R D399K D399K D399R D399K D399R D399K D399R D399R charge K409D K409D K409D K409E K409D K409E K409D K409D K409D K409E K409D K409E K409D K409E K409E K409E mutation(s) 5.sup.th and 6.sup.th Engineered S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C S354C Fc domain protuberance T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W T366W monomers reversed E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K E357K charge mutation(s)
[0275] In some embodiments, an Fc construct contains two Fc domains formed from three polypeptides. The first polypeptide contains two Fc domain monomers joined in tandem series joined by way of a linker (e.g., a glycine spacer; SEQ ID NOs: 26 and 27), and the second and third polypeptides contain one Fc domain monomer. The second and third polypeptides may be the same polypeptide or may be different polypeptides.
[0276] In yet other embodiments, Fc constructs can contain five Fc domains formed from six polypeptides. Two examples are depicted in
[0277]
[0278]
[0279]
[0280] In another embodiment, an Fc construct containing two or more Fc domains can be formed from two polypeptides having the same primary sequence. Such a construct can be formed from expression of a single polypeptide sequence in a host cell. An example is depicted in
[0281] In some embodiments, one or more Fc polypeptides in an Fc construct (e.g., Fc construct 1-3 in
[0282] In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is at least 95% identical (e.g., at least 97%, 99%, or 99.5% identical) to the sequence a wild-type Fc domain monomer (e.g., SEQ ID NO: 42). In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is the sequence a wild-type Fc domain monomer (e.g., SEQ ID NO: 42) with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is at least 95% identical (e.g., at least 97%, 99%, or 99.5% identical) to the sequence any one of SEQ ID NOs: 44, 46, 48, and 50-53. In some embodiments, an Fc domain monomer in an Fc construct described herein (e.g., an Fc construct having three Fc domains) may comprise, consist of, or consist essentially of a sequence that is the sequence any one of SEQ ID NOs: 44, 46, 48, and 50-53 with up to 10 (9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions). In certain embodiments, an Fc domain monomer in the Fc construct may comprise, consist of, or consist essentially of a sequence that is at least 95% identical (e.g., at least 97%, 99%, or 99.5% identical) to the sequence SEQ ID NO: 48, 52, and 53. In certain embodiments, an Fc domain monomer in the Fc construct may comprise, consist of, or consist essentially of a sequence that is the sequence SEQ ID NO: 48, 52, and 53 with up to 10 (e.g., up to 9, 8, 7, 6, 5, 4, 3, 2, or 1) single amino acid modifications (e.g., substitutions, e.g., conservative substitutions).
[0283] In some embodiments, a polypeptide having two Fc domain monomers in an Fc construct described herein (e.g., polypeptides 102 and 108 in
[0284] In some embodiments, the N-terminal Asp in one or more of the first, second, third and fourth polypeptides in an Fc construct described herein (e.g., polypeptides 102, 108, 114, and 116 in
TABLE-US-00010 TABLE 4 Fc construct with N-terminal Asp mutated to Gln in all four polypeptides First and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW second YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG KSGGGSGGGSGGGSGGGSGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMIS RTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLH QDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVF SCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 54) Third and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW fourth YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNY KTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 55) Fc construct with N-terminal Asp mutated to Gln in all four polypeptides First and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW second YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG KSGGGSGGGSGGGSGGGSGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMIS RTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLH QDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTC LVKGFYPSDIAVEwESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVF SCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 56) Third and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW fourth YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNY KTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 57) Fc construct with N-terminal Asp mutated to Gln in all four polypeptides First and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW second YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG KGGGGGGGGGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEV TCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLN GKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFY PSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMH EALHNHYTQKSLSLSPG (SEQ ID NO: 58) Third and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW fourth YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNY KTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 59) Fc construct with N-terminal Asp mutated to Gln in all four polypeptides First and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW second YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG KGGGGGGGGGGGGGGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMI SRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVL HQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNV FSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 60) Third and QKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW fourth YVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK polypeptides TISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNY KTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 59)
X. Host Cells and Protein Production
[0285] In the present disclosure, a host cell refers to a vehicle that includes the necessary cellular components, e.g., organelles, needed to express the polypeptides and constructs described herein from their corresponding nucleic acids. The nucleic acids may be included in nucleic acid vectors that can be introduced into the host cell by conventional techniques known in the art (transformation, transfection, electroporation, calcium phosphate precipitation, direct microinjection, etc.). Host cells can be of mammalian, bacterial, fungal, or insect origin. Mammalian host cells include, but are not limited to, CHO (or CHO-derived cell strains, e.g., CHO-K1, CHO-DXB11 CHO-DG44), murine host cells (e.g., NS0, Sp2/0), VERY, HEK (e.g., HEK293), BHK, HeLa, COS, MDCK, 293, 3T3, W138, BT483, Hs578T, HTB2, BT20 and T47D, CRL7O3O and HsS78Bst cells. Host cells can also be chosen that modulate the expression of the protein constructs, or modify and process the protein product in the specific fashion desired. Different host cells have characteristic and specific mechanisms for the post-translational processing and modification of protein products. Appropriate cell lines or host systems can be chosen to ensure the correct modification and processing of the protein expressed.
[0286] For expression and secretion of protein products from their corresponding DNA plasmid constructs, host cells may be transfected or transformed with DNA controlled by appropriate expression control elements known in the art, including promoter, enhancer, sequences, transcription terminators, polyadenylation sites, and selectable markers. Methods for expression of therapeutic proteins are known in the art. See, for example, Paulina Balbas, Argelia Lorence (eds.) Recombinant Gene Expression: Reviews and Protocols (Methods in Molecular Biology), Humana Press; 2nd ed. 2004 edition (Jul. 20, 2004); Vladimir Voynov and Justin A. Caravella (eds.) Therapeutic Proteins: Methods and Protocols (Methods in Molecular Biology) Humana Press; 2nd ed. 2012 edition (Jun. 28, 2012).
XI. Purification
[0287] An Fc construct can be purified by any method known in the art of protein purification, for example, by chromatography (e.g., ion exchange, affinity (e.g., Protein A affinity), and size-exclusion column chromatography), centrifugation, differential solubility, or by any other standard technique for the purification of proteins. For example, an Fc construct can be isolated and purified by appropriately selecting and combining affinity columns such as Protein A column with chromatography columns, filtration, ultra filtration, salting-out and dialysis procedures (see, e.g., Process Scale Purification of Antibodies, Uwe Gottschalk (ed.) John Wiley & Sons, Inc., 2009; and Subramanian (ed.) Antibodies—Volume I—Production and Purification, Kluwer Academic/Plenum Publishers, New York (2004)).
[0288] In some instances, an Fc construct can be conjugated to one or more purification peptides to facilitate purification and isolation of the Fc construct from, e.g., a whole cell lysate mixture. In some embodiments, the purification peptide binds to another moiety that has a specific affinity for the purification peptide. In some embodiments, such moieties which specifically bind to the purification peptide are attached to a solid support, such as a matrix, a resin, or agarose beads. Examples of purification peptides that may be joined to an Fc construct include, but are not limited to, a hexa-histidine peptide, a FLAG peptide, a myc peptide, and a hemagglutinin (HA) peptide. A hexa-histidine peptide (HHHHHH (SEQ ID NO: 38)) binds to nickel-functionalized agarose affinity column with micromolar affinity. In some embodiments, a FLAG peptide includes the sequence DYKDDDDK (SEQ ID NO: 39). In some embodiments, a FLAG peptide includes integer multiples of the sequence DYKDDDDK in tandem series, e.g., 3×DYKDDDDK. In some embodiments, a myc peptide includes the sequence EQKLISEEDL (SEQ ID NO: 40). In some embodiments, a myc peptide includes integer multiples of the sequence EQKLISEEDL in tandem series, e.g., 3×EQKLISEEDL. In some embodiments, an HA peptide includes the sequence YPYDVPDYA (SEQ ID NO: 41). In some embodiments, an HA peptide includes integer multiples of the sequence YPYDVPDYA in tandem series, e.g., 3×YPYDVPDYA. Antibodies that specifically recognize and bind to the FLAG, myc, or HA purification peptide are well-known in the art and often commercially available. A solid support (e.g., a matrix, a resin, or agarose beads) functionalized with these antibodies may be used to purify an Fc construct that includes a FLAG, myc, or HA peptide.
[0289] For the Fc constructs, Protein A column chromatography may be employed as a purification process. Protein A ligands interact with Fc constructs through the Fc region, making Protein A chromatography a highly selective capture process that is able to remove most of the host cell proteins. In the present disclosure, Fc constructs may be purified using Protein A column chromatography as described in Example 2.
XII. Pharmaceutical Compositions/Preparations
[0290] The disclosure features pharmaceutical compositions that include one or more Fc constructs described herein. In one embodiment, a pharmaceutical composition includes a substantially homogenous population of Fc constructs. In various examples, the pharmaceutical composition includes a substantially homogenous population of any one of Fc constructs 1-4.
[0291] A therapeutic protein construct, e.g., an Fc construct described herein (e.g., an Fc construct having three Fc domains), of the present disclosure can be incorporated into a pharmaceutical composition. Pharmaceutical compositions including therapeutic proteins can be formulated by methods know to those skilled in the art. The pharmaceutical composition can be administered parenterally in the form of an injectable formulation including a sterile solution or suspension in water or another pharmaceutically acceptable liquid. For example, the pharmaceutical composition can be formulated by suitably combining the Fc construct with pharmaceutically acceptable vehicles or media, such as sterile water for injection (WFI), physiological saline, emulsifier, suspension agent, surfactant, stabilizer, diluent, binder, excipient, followed by mixing in a unit dose form required for generally accepted pharmaceutical practices. The amount of active ingredient included in the pharmaceutical preparations is such that a suitable dose within the designated range is provided.
[0292] The sterile composition for injection can be formulated in accordance with conventional pharmaceutical practices using distilled water for injection as a vehicle. For example, physiological saline or an isotonic solution containing glucose and other supplements such as D-sorbitol, D-mannose, D-mannitol, and sodium chloride may be used as an aqueous solution for injection, optionally in combination with a suitable solubilizing agent, for example, alcohol such as ethanol and polyalcohol such as propylene glycol or polyethylene glycol, and a nonionic surfactant such as polysorbate 80™, HCO-50, and the like commonly known in the art. Formulation methods for therapeutic protein products are known in the art, see e.g., Banga (ed.) Therapeutic Peptides and Proteins: Formulation, Processing and Delivery Systems (2d ed.) Taylor & Francis Group, CRC Press (2006).
XIII. Dosage
[0293] The pharmaceutical compositions are administered in a manner compatible with the dosage formulation and in such amount as is therapeutically effective to result in an improvement or remediation of the symptoms. The pharmaceutical compositions are administered in a variety of dosage forms, e.g., intravenous dosage forms, subcutaneous dosage forms, oral dosage forms such as ingestible solutions, drug release capsules, and the like. The appropriate dosage for the individual subject depends on the therapeutic objectives, the route of administration, and the condition of the patient. Generally, recombinant proteins are dosed at 1-200 mg/kg, e.g., 1-100 mg/kg, e.g., 20-100 mg/kg. Accordingly, it will be necessary for a healthcare provider to tailor and titer the dosage and modify the route of administration as required to obtain the optimal therapeutic effect.
XIV. Indications
[0294] The pharmaceutical compositions of the disclosure (e.g., those containing Fc constructs having 2, 3, or 4 Fc domains) are useful to reduce inflammation in a subject, to promote clearance of autoantibodies in a subject, to suppress antigen presentation in a subject, to reduce the immune response, e.g., to block immune complex-based activation of the immune response in a subject, and to treat immunological and inflammatory conditions or diseases in a subject. Exemplary conditions and diseases include rheumatoid arthritis (RA); systemic lupus erythematosus (SLE); ANCA-associated vasculitis; antiphospholipid antibody syndrome; autoimmune hemolytic anemia; chronic inflammatory demyelinating neuropathy; clearance of anti-allo in transplant, anti-self in GVHD, anti-replacement, IgG therapeutics, IgG paraproteins; dermatomyositis; Goodpasture's Syndrome; organ system-targeted type II hypersensitivity syndromes mediated through antibody-dependent cell-mediated cytotoxicity, e.g., Guillain Barre syndrome, CIDP, dermatomyositis, Felty's syndrome, antibody-mediated rejection, autoimmune thyroid disease, ulcerative colitis, autoimmune liver disease; idiopathic thrombocytopenia purpura; Myasthenia Gravis, neuromyelitis optica; pemphigus and other autoimmune blistering disorders; Sjogren's Syndrome; autoimmune cytopenias and other disorders mediated through antibody-dependent phagocytosis; other FcR-dependent inflammatory syndromes e.g., synovitis, dermatomyositis, systemic vasculitis, glomerulitis, and vasculitis.
[0295] In some embodiments, the pharmaceutical compositions of the disclosure containing Fc constructs having 5-10 Fc domains are also useful, e.g., to induce immune cell activation of the immune response in a subject, to increase phagocytosis of a target cell (i.e., a cancer cell or an infected cell) in a subject, and to treat diseases such as cancers and infections in a subject. Fc constructs and homogenous pharmaceutical compositions of the disclosure may bind to activating Fcγ receptors (e.g., FcγRI, FcγRIIa, FcγRIIc, FcγRIIIa, and FcγRIIIb) to induce an immune response. Fc constructs and homogenous pharmaceutical compositions of the disclosure may activate Syk phosphorylation and calcium flux from primary THP-1 monocytes. Activated monocytes and their differentiated macrophages have the ability to phagocytose or kill target cells. The disclosure therefore provides methods of treatment that may be used to treat subjects who are suffering from diseases and disorders such as cancers and infections. In some embodiments, Fc constructs and homogenous pharmaceutical compositions described herein may be administered to a subject in a therapeutically effective amount to phagocytose or kill cancer cells or infected cells in the subject.
[0296] Cancers that are amenable to treatment according to the methods of the disclosure include, but are not limited to, bladder cancer, pancreatic cancer, lung cancer, liver cancer, ovarian cancer, colon cancer, stomach cancer, breast cancer, prostate cancer, renal cancer, testicular cancer, thyroid cancer, uterine cancer, rectal cancer, a cancer of the respiratory system, a cancer of the urinary system, oral cavity cancer, skin cancer, leukemia, sarcoma, carcinoma, basal cell carcinoma, non-Hodgkin's lymphoma, acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), B-cells chronic lymphocytic leukemia (B-CLL), multiple myeloma (MM), erythroleukemia, renal cell carcinoma, astrocytoma, oligoastrocytoma, biliary tract cancer, choriocarcinoma, CNS cancer, larynx cancer, small cell lung cancer, adenocarcinoma, giant (or oat) cell carcinoma, squamous cell carcinoma, anaplastic large cell lymphoma, non-small-cell lung cancer, neuroblastoma, rhabdomyosarcoma, neuroectodermal cancer, glioblastoma, breast carcinoma, melanoma, inflammatory myofibroblastic tumor cancer, and soft tissue tumor cancer.
[0297] Infections that are amenable to treatment according to the methods of the disclosure include, but are not limited to, a bacterial infection, a viral infection, a fungal infection, a helmintic infection, and a protozoal infection.
[0298] Examples of infection-causing bacteria are well-known in the art and include, but are not limited to, bacteria in the genus Streptococcus (e.g., Streptococcus pyogenes), bacteria in the genus Escherichia (e.g., Escherichia coli), bacteria in the genus Vibrio (e.g., Vibrio cholerae), bacteria in the genus Enteritis (e.g., Enteritis salmonella), and bacteria in the genus Salmonella (e.g., Salmonella typhi). Examples of infection-causing viruses are well-known in the art and include, but are not limited to, viruses in the family Retroviridae (e.g., human immunodeficiency virus (HIV)), viruses in the family Adenoviridae (e.g., adenovirus), viruses in the family Herpesviridae (e.g., herpes simplex virus types 1 and 2), viruses in the family Papillomaviridae (e.g., human papillomavirus (HPV)), viruses in the family Poxviridae (e.g., smallpox), viruses in the family Picornaviridae (e.g., hepatitis A virus, poliovirus, rhinovirus), viruses in the family Hepadnaviridae (e.g., hepatitis B virus), viruses in the family Flaviviridae virus (e.g., hepatitis C virus, yellow fever virus, West Nile virus), viruses in the family Togaviridae (e.g., rubella virus), viruses in the family Orthomyxoviridae (e.g., influenza virus), viruses in the family Filoviridae (e.g., ebola virus, marburg virus), and viruses in the family Paramyxoviridae (e.g., measles virus, mumps virus). Examples of infection-causing fungi are well-known in the art and include, but are not limited to, fungi in the genus Aspergillus (e.g., Aspergillus fumigatus, A. flavus, A. terreus. A. niger, A. candidus, A. clavatus, A. ochraceus), fungi in the genus Candida (e.g., Candida albicans, C. parapsilosis, C. glabrata, C. guilliermondii, C. krusei, C. lusitaniae, C. tropicalis), fungi in the genus Cryptococcus (e.g., Cryptococcus neoformans), and fungi in the genus Fusarium (e.g., Fusarium solani, F. verticiffioides, F. oxysporum). Examples of helminths include, but are not limited to, tapeworms (cestodes), roundworms (nematodes), flukes (trematodes), and monogeneans.
[0299] Examples of protozoans include, but are not limited to, protozoans in the genus Entamoeba (e.g., Entamoeba histolytica), protozoans in the genus Plasmodium (e.g., Plasmodium falciparum, P. malariae), protozoans in the genus Giardia (e.g., Giardia lamblia), and protozoans in the genus Trypanosoma (e.g., Trypanosoma brucei).
EXAMPLES
Example 1. Fc Constructs Design
[0300] Desirably, Fc constructs are designed to increase folding efficiencies, to minimize uncontrolled association of subunits, which may create unwanted high molecular weight oligomers and multimers, and to generate compositions that are substantially homogenous. With these goals in mind, we designed four Fc constructs (
[0301] For each Fc construct, the long and short polypeptides, when co-expressed, produce a branched molecule containing three Fc domains, with the C-terminal Fc monomers of the long polypeptides specifically associating with each other to form one C-terminal Fc domain and with the N-terminal Fc monomers of the long polypeptides specifically associating with the short polypeptides to form two N-terminal Fc domains. Fc constructs 1-4 and their design are described in Table 5 and
TABLE-US-00011 TABLE 5 Long Polypeptide #s Short Polypeptide #s Fc construct (SEQ ID NO) (SEQ ID NO) FIG. Fc construct 1 102 and 108 114 and 116 FIG. 1 (SEQ ID NO: 43) (SEQ ID NO: 44) Fc construct 2 102 and 108 114 and 116 FIG. 1 (SEQ ID NO: 45) (SEQ ID NO: 46) Fc construct 3 102 and 108 114 and 116 FIG. 1 (SEQ ID NO: 47) (SEQ ID NO: 48) Fc construct 4 202 and 208 214 and 216 FIG. 2 (SEQ ID NO: 49) (SEQ ID NO: 48)
TABLE-US-00012 TABLE 6 SEQ ID NO Amino Acid Sequence SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 43 PREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKSGGGSGGGSGGGSG GGSGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKF NWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPV LKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 44 PREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 45 PREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKSGGGSGGGSGGGSG GGSGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKF NWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPV LKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 46 PREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 47 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYV DGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAK GQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSD GSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 48 PREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 49 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG
TABLE-US-00013 TABLE 7 Fc construct 1 Fc construct 2 Fc construct 3 Fc construct 4 Spacer in Long SGGGSGGGS SGGGSGGGS GGGGGGGGG GGGGGGGGG Polypeptide (102/202 GGGSGGGSG GGGSGGGSG GGGGGG GGGGGGGGG and 108/208) GG (SEQ ID GG (SEQ ID (SEQ ID NO: GG (SEQ ID NO: 18) NO: 18) 26) NO: 27) C-terminal Lysine in Y N N N Long Polypeptide (102/202 and 108/208) C-terminal Lysine in Y N N N Short Polypeptide (114/214 and 116/216) Amino acid mutations in S354C* S354C S354C S354C 106/206 and 108/208 T366W T366W E357K E357K T366W T366W Amino acid mutations in D399K D399K D399K D399K 104/204 and 110/210 K409D K409D K409D K409D Amino acid mutations in Y349C Y349C Y349C Y349C 114/214 and 116/216 T366S T366S T366S T366S L368A L368A L368A L368A Y407V Y407V K370D K370D Y407V Y407V Figure FIG. 1 FIG. 1 FIG. 1 FIG. 2 *Sequence positions are numbered according to the Kabat numbering system (Kabat et al., Sequences of Proteins of Immunological Interest, National Institutes of Health, Bethesda, Md., ed 5, 1991).
[0302] Each of the long polypeptides 102 and 108 in Fc constructs 1-3 (
TABLE-US-00014 TABLE 8 Fc construct 1 polypeptides 102/108 N-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNG QPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGK (SEQ ID NO: 50) spacer SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18) C-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKS LSLSPGK (SEQ ID NO: 51) Fc construct 2 polypeptides 102/108 N-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNG QPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGK (SEQ ID NO: 50) spacer SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18) C-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKS LSLSPG (SEQ ID NO: 52) Fc construct 3 polypeptides 102/108 N-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNG QPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGK (SEQ ID NO: 53) spacer GGGGGGGGGGGGGGG (SEQ ID NO: 26) C-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKS LSLSPG (SEQ ID NO: 52) Fc construct 4 polypeptides 202/208 N-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNG QPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGK (SEQ ID NO: 53) spacer GGGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27) C-terminal Fc DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN domain WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA monomer PIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKS LSLSPG (SEQ ID NO: 52)
Example 2. Expression of Fc Constructs
[0303] The expressed proteins were purified from the cell culture supernatant by Protein A-based affinity column chromatography, using a Poros MabCapture A (LifeTechnologies) column. Captured Fc constructs were washed with phosphate buffered saline (low-salt wash) and eluted with 100 mM glycine, pH 3. The eluate was quickly neutralized by the addition of 1 M TRIS pH 7.4 and sterile filtered through a 0.2 μm filter.
[0304] The proteins were further fractionated by ion exchange chromatography using Poros XS resin (Applied Biosciences). The column was pre-equilibrated with 50 mM MES, pH 6 (buffer A), and the sample was eluted with a step gradient using 50 mM MES, 400 mM sodium chloride, pH 6 (buffer B) as the elution buffer.
[0305] After ion-exchange, the target fraction was buffer exchanged into PBS buffer using a 10 kDa cutoff polyether sulfone (PES) membrane cartridge on a tangential flow filtration system. The samples were concentrated to approximately 30 mg/mL and sterile filtered through a 0.2 μm filter.
Example 3. Experimental Assays Used to Characterize Fc Constructs
[0306] Peptide and Glycopeptide Liquid Chromatography-MS/MS
[0307] The proteins were diluted to 1 μg/μL in 6M guanidine (Sigma). Dithiothreitol (DTT) was added to a concentration of 10 mM, to reduce the disulfide bonds under denaturing conditions at 65° C. for 30 min. After cooling on ice, the samples were incubated with 30 mM iodoacetamide (IAM) for 1 h in the dark to alkylate (carbamidomethylate) the free thiols. The protein was then dialyzed across a 10-kDa membrane into 25 mM ammonium bicarbonate buffer (pH 7.8) to remove IAM, DTT and guanidine. The protein was digested with trypsin in a Barocycler (NEP 2320; Pressure Biosciences, Inc.). The pressure was cycled between 20,000 psi and ambient pressure at 37° C. for a total of 30 cycles in 1 h. LC-MS/MS analysis of the peptides was performed on an Ultimate 3000 (Dionex) Chromatography System and an Q-Exactive (Thermo Fisher Scientific) Mass Spectrometer. Peptides were separated on a BEH PepMap (Waters) Column using 0.1% FA in water and 0.1% FA in acetonitrile as the mobile phases. The singly xylosylated linker peptide was targeted based on the doubly charged ion (z=2) m/z 842.5 with a quadrupole isolation width of ±1.5 Da.
[0308] Intact Mass Spectrometry
[0309] The protein was diluted to a concentration of 2 μg/μL in the running buffer consisting of 78.98% water, 20% acetonitrile, 1% formic acid (FA), and 0.02% trifluoroacetic acid. Size exclusion chromatography separation was performed on two Zenix-C SEC-300 (Sepax Technologies, Newark, Del.) 2.1×350 mm in tandem for a total length column length of 700 mm. The proteins were eluted from the SEC column using the running buffer described above at a flow rate of 80 μL/min. Mass spectra were acquired on an QSTAR Elite (Applied Biosystems) Q-ToF mass spectrometer operated in positive mode. The neutral masses under the individual size fractions were deconvoluted using Bayesian peak deconvolution by summing the spectra across the entire width of the chromatographic peak.
[0310] Capillary Electrophoresis-Sodium Dodecyl Sulfate (CE-SDS) Assay
[0311] Samples were diluted to 1 mg/mL and mixed with the HT Protein Express denaturing buffer (PerkinElmer). The mixture was incubated at 40° C. for 20 min. Samples were diluted with 70 μL of water and transferred to a 96-well plate. Samples were analyzed by a Caliper GXII instrument (PerkinElmer) equipped with the HT Protein Express LabChip (PerkinElmer). Fluorescence intensity was used to calculate the relative abundance of each size variant.
[0312] Non-Reducing SDS-PAGE
[0313] Samples were denatured in Laemmli sample buffer (4% SDS, Bio-Rad) at 95° C. for 10 min. Samples were run on a Criterion TGX stain-free gel (4-15% polyacrylamide, Bio-Rad). Protein bands were visualized by UV illumination or Coommassie blue staining. Gels were imaged by ChemiDoc MP Imaging System (Bio-Rad). Quantification of bands was performed using Imagelab 4.0.1 software (Bio-Rad).
[0314] Complement Dependent Cytotoxicity (CDC)
[0315] CDC was evaluated by a colorimetric assay in which Raji cells (ATCC) were coated with serially diluted Rituximab, Fc construct 4, or IVIg. Human serum complement (Quidel) was added to all wells at 25% v/v and incubated for 2 h at 37° C. Cells were incubated for 12 h at 37° C. after addition of WST-1 cell proliferation reagent (Roche Applied Science). Plates were placed on a shaker for 2 min and absorbance at 450 nm was measured.
Example 4. O-Glycosylation and Proteolysis of Linker Serine Residues
[0316] O-Glycosylation at Linker Serine Residues
[0317] As described in Example 1, we designed the Fc constructs to increase folding efficiencies, to minimize uncontrolled association of subunits, and to generate compositions for pharmaceutical use that are substantially homogenous. In an effort to achieve these goals, we investigated different linkers between the two Fc domain monomers in the long polypeptide (102 and 108 in
[0318] When Fc construct 2, which contains the linker SGGGSGGGSGGGSGGGSGGG (SEQ ID NO: 18) between the two Fc domain monomers in the long polypeptide, was analyzed by peptide LC-MS/MS, O-xylosylation was observed (
[0319] Likewise, O-xylosylation was observed in an Fc construct having two Fc domains (the Fc construct shown in
[0320] After observing O-xylosylation at serine residues in the serine-glycine linker, we investigated alternative linkers that contained only glycine residues in order to further optimize linker sequence and improve the homogeneity of the Fc construct. As a result, an all-glycine spacer was selected for use in Fc construct 3 and Fc construct 4. Fc construct 3 has a 15-mer all-glycine spacer (GGGGGGGGGGGGGGG (SEQ ID NO: 26)) between the two Fc domain monomers in the long polypeptide. Fc construct 4 has a 20-mer all-glycine spacer (GGGGGGGGGGGGGGGGGGGG (SEQ ID NO: 27)) between the two Fc domain monomers in the long polypeptide.
[0321] Proteolysis at Linker Serine Residues
[0322] In some embodiments, Fc constructs were found to undergo proteolysis in the linkers upon incubation at 45° C. in phosphate buffered saline, generating monomeric Fc products. The rate of monomer formation in Fc construct 2 (which contains the linker SGGGSGGGSGGGSGGGSGGG in each of the polypeptides 102 and 108) was faster than in Fc construct 4 (which contains the all-glycine spacer GGGGGGGGGGGGGGGGGGGG in each of the polypeptides 202 and 208) (
TABLE-US-00015 TABLE 9 Rate of monomer formation Linker Sequence (% monomer/day) G.sub.8 0.17 G.sub.15 0.21 G.sub.20 0.24 (SG.sub.4).sub.4 0.33 (S3.sub.2).sub.5 0.34
[0323] Furthermore, analyses by mass spectrometry of the monomeric Fc products in Fc construct 2, with an (SG.sub.3).sub.5 linker in each of polypeptides 102 and 108, demonstrated that the dominant products were cleaved to the N-terminal side of serine, with all but the first serines susceptible to proteolysis (
Example 5. Optimization of the Linker Length
[0324] To further optimized homogeneity, linker length was explored by preparing variations on the Fc construct 2 sequence in which the (SG.sub.3).sub.5 linker was replaced with a G.sub.8, G.sub.15, or G.sub.20 spacer. Analyses by in vitro assays indicated that the linker length impacted biological activity, presumably by altering the ability of the Fc construct to interact with Fcγ receptors.
[0325] Inhibition of IL-8 release by THP-1 cells stimulated by plate-bound IgG was found to depend on linker length (
[0326] Further, the inhibition of calcium flux in neutrophils was found to be dependent upon linker length (
Example 6. Optimization of Heterodimerization by Knob-into-Hole Technology
[0327] Plasmids expressing the Fc construct 2 long and short polypeptides (polypeptides 102, 108, 114, and 116 in
[0328] These results indicate that having both electrostatic steering mutations that promote heterodimerization and knob-into-hole mutations that promote heterodimerization in the “branch” subunits (e.g., Fc domain monomers 106, 114, 112, and 116 in
Example 7. Electrostatic Steering for Control of Homodimerization
[0329] To minimize off-register association of subunits, which generates unwanted high molecular weight oligomers and multimers, mutations that favor heterodimerization (e.g., knobs and holes) were introduced into the “branch” subunits (e.g., Fc domain monomers 106, 112, 114, and 116 in
[0330] HEK293 cells were co-transfected with plasmids expressing Fc construct 2 (which has homodimerizing electrostatic steering mutations in the Fc domain monomer in the carboxyl terminal “stem” subunit in each of the long polypeptides; see Tables 5 and 6 in Example 1), or an Fc construct based on Fc construct 2 in which the Fc domain monomer in the carboxyl terminal “stem” subunit in each of the long polypeptides was replaced with a wild-type Fc domain monomer sequence (SEQ ID NO: 42) (as described above). Following seven days in culture, cells were cleared by centrifugation and raw media supernatants were separated by non-reducing SDS-PAGE. Imaging of stained proteins revealed that the Fc construct without electrostatic steering mutations in the “stem” subunits (labeled “No electrostatic steering” (lanes 1-3) in
[0331] These results confirm that having electrostatic steering mutations that promote homodimerization in the “stem” subunits (e.g., Fc domain monomers 104 and 110 in
Example 8. Optimization of Composition Homogeneity by Elimination of C-Terminal Lysine Residues
[0332] The C-terminal lysine residue of immunoglobulins is highly conserved across many species. In some instances, C-terminal lysines in polypeptides are removed by the cellular machinery during protein production. We aimed to further improve the uniformity of the Fc constructs in the composition and to achieve a more homogenous composition containing an Fc construct described herein by removing the C-terminal lysine from the each of the polypeptides in the Fc construct. Fc construct 2 does not contain any C-terminal lysine residues in either its long polypeptides (102 and 108; see Example 1, Tables 5-7;
Example 9. Design of Fc Constructs Having I253 and/or R292 Amino Acid Modifications
[0333] Fc constructs having an altered (e.g., increased) half-life were designed based on construct 4 (M230) and included amino acid modifications (e.g., single mutations or combinations of mutations) that alter binding affinity to FcRn (e.g., reduce binding to FcRn, e.g., by including an amino acid modification at position I253, e.g., I253A) and/or that alter binding affinity to FcγRIIb (e.g., reduced binding to FcγRIIb, e.g., by including an amino acid modification at position R292, e.g., R292P) (
[0334] Six Fc constructs (
[0335] For each Fc construct, the long and short polypeptides, when co-expressed, produce a branched molecule containing three Fc domains, with the C-terminal Fc monomers of the long polypeptides specifically associating with each other to form one C-terminal Fc domain and with the N-terminal Fc monomers of the long polypeptides specifically associating with the short polypeptides to form two N-terminal Fc domains. Fc constructs 12-15, 24, 26, and 27 and their design are described in Table 10 and
[0336] In construct 4, each of the long polypeptides contains one Fc domain monomer having charged amino acids (D399K and K409D) at the C.sub.H3-C.sub.H3 interface joined by way of a linker to a protuberance-containing (formed by the modifications S354C and T366W) Fc domain monomer. The protuberance-containing Fc domain monomer has an amino acid modification (E357K) that enhances assembly of the Fc domain. The short polypeptides each have a cavity-containing (formed by the modifications Y349C/T366S/L368A/Y407V) Fc domain monomer. The short polypeptides also have an amino acid modification (K370D) that enhance assembly of the Fc domains. Construct 4 is formed by expressing a first and second polypeptide having the amino acid sequence of SEQ ID NO: 49 and a third and fourth polypeptide having the amino acid sequence of SEQ ID NO: 61.
[0337] Constructs 13-27 (
TABLE-US-00016 TABLE 10 Fc constructs having I253 and/or R292 amino acid modifications FcγRIIb Long Short Binding FcRn Binding Polypeptide #s Polypeptide #s Fc construct Mutations.sup.1 Mutations.sup.2 (SEQ ID NO) (SEQ ID NO) FIG Fc construct 4 None None 1202 and 1208 1214 and 1216 FIG. 2 (SEQ ID NO: 49) (SEQ ID NO: 61) Fc construct 5 None C-terminal Fc 502 and 508 514 and 516 FIG. 18A domain only (SEQ ID NO: 62) (SEQ ID NO: 61) Fc construct 6 None Two N-terminal 602 and 608 614 and 616 FIG. 18B Fc domains (SEQ ID NO: 64) (SEQ ID NO: 57) Fc construct 7 None All three Fc 702 and 708 714 and 716 FIG. 18C domains (SEQ ID NO: 65) (SEQ ID NO: 57) Fc construct 8 C-terminal Fc None 802 and 808 814 and 816 FIG. 18D domain only (SEQ ID NO: 66) (SEQ ID NO: 61) Fc construct 9 C-terminal Fc C-terminal Fc 902 and 908 914 and 916 FIG. 18E domain only domain only (SEQ ID NO: 67) (SEQ ID NO: 61) Fc construct 10 C-terminal Fc Two N-terminal 1002 and 1008 1014 and 1016 FIG. 18F domain only Fc domains (SEQ ID NO: 68) (SEQ ID NO: 57) Fc construct 11 C-terminal Fc All three Fc 1102 and 1108 1114 and 1116 FIG. 18G domain only domains (SEQ ID NO: 69) (SEQ ID NO: 57) Fc construct 12 Two N- None 1202 and 1208 1214 and 1216 FIG. 18H terminal Fc (SEQ ID NO: 71) (SEQ ID NO: 70) domains Fc construct 13 Two N- C-terminal Fc 1302 and 1308 1314 and 1316 FIG. 18I terminal Fc domain only (SEQ ID NO: 72) (SEQ ID NO: 70) domains Fc construct 14 Two N- Two N-terminal 1402 and 1408 1414 and 1416 FIG. 18J terminal Fc Fc domains (SEQ ID NO: 74) (SEQ ID NO: 73) domains Fc construct 15 Two N- All three Fc 1502 and 1508 1514 and 1516 FIG. 18K terminal Fc domains (SEQ ID NO: 75) (SEQ ID NO: 73) domains Fc construct 16 All three Fc None 1602 and 1608 1614 and 1616 FIG. 18L domains (SEQ ID NO: 76) (SEQ ID NO: 70) Fc construct 17 All three Fc C-terminal Fc 1702 and 1708 1714 and 1716 FIG. 18M domains domain only (SEQ ID NO: 77) (SEQ ID NO: 70) Fc construct 18 All three Fc Two N-terminal 1804 and 1808 1814 and 1816 FIG. 18N domains Fc domains (SEQ ID NO: 78) (SEQ ID NO: 73) Fc construct 19 All three Fc All three Fc 1904 and 1908 1914 and 1916 FIG. 18O domains domains (SEQ ID NO: 79) (SEQ ID NO: 73) .sup.1R292P mutation .sup.2I253A mutation
TABLE-US-00017 TABLE 11 Amino acid sequences Amino Acid Sequence SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 61 PREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 49 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 62 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 57 QPREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 64 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 65 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 66 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 67 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 68 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 69 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 70 PREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 71 PREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 72 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 73 QPREPQVCTLPPSRDELTKNQVSLSCAVDGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 74 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 75 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 76 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG ID NO: VEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQ 77 PREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDG SFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGGG GGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEV KFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 78 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPEVKFNWYVD ID NO: GVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG 79 QPREPQVYTLPPCRDKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKGGGGGGGGGGGG GGGGGGGGDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMASRTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPPEEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPI EKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLKSDGSFFLYSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG The I253A and R292P mutations (modifications) are indicated in bold and underlined (when present)
Example 10. Evaluation of I253A and R292P Amino Acid Modifications on Fc Receptor Binding Specificity
[0338] A cell-based binding assay was utilized to confirm that the amino acid modifications at positions I253, e.g., I253A, and R292, e.g., R292P, were specific to the intended receptors, e.g., reduced binding affinity to the FcRn receptor and FcγRIIb receptor, respectively. Relative binding of Fc constructs and controls to Fc gamma receptors (FcγRs) was measured using cell-based homogeneous time-resolved fluorescence resonance energy transfer (TR-FRET) competition assays (CISBIO®) kits for FcγRI, FcγRIIa H131, FcγRIIb, and FcγRIIIa V158. Assay reagents were prepared according to the manufacturer's instructions. A 10-point, 3-fold serial dilution series, plus one blank per sample, was generated using an automated liquid handler (Freedom EVOware 150, TECAN®). Assay plates were read on a PHERAstar fluorescent reader (BMG Labtech GmbH) at 665 and 620 nm. An IgG1 sample was used as a control.
[0339] To assess the impact of the amino acid modifications at position I253, e.g., I253A, and R292, e.g., R292P, on FcRn binding a surface plasmon resonance (SPR) binding experiment was designed to measure the affinity and normalized binding level of solution-phase human FcRn to sensor-bound Fc constructs at pH 6.0. A goat anti-human IgG was immobilized on reference and test sensor surfaces using amine coupling chemistry. Fc constructs were captured on the test sensor surface. Recombinant human FcRn was flowed over the sensor surface in a dilution series with a top concentration of 1.0 μM. The sensor surface was regenerated at the end of each cycle with 10 mM glycine pH 1.7. Double-reference subtracted sensorgrams were subjected to equilibrium binding analysis; the maximum binding level (RMax) and the equilibrium dissociation constant (K.sub.D) were estimated. The normalized maximum binding level was calculated by dividing the RMax by the FC-construct capture level. Construct 16 was captured at the same level as construct 4, indicating no loss of binding to FcRn as expected (
[0340] Together, this data demonstrates that the mutation to reduce binding to FcγRIIb (e.g., an amino acid modification at position R292, e.g., R292P) had the intended effect with little impact on binding to other Fc gamma receptors and minimal impact on binding FcRn. Likewise, the mutation to reduce binding to FcRn (e.g., an amino acid modification at position I253, e.g., I253A) had the desired effect with minimal impact on Fc gamma receptor binding. Moreover, the two mutations (e.g., I253 and R292 mutations, such as I253A and R292P) could be combined to achieve diminished Fc construct binding to both FcγRIIb and FcRn.
Example 11. Evaluation of I253A and R292P Amino Acid Modifications on Fc Receptor Pharmacokinetics in Mice
[0341] The impact of binding-related mutations on pharmacokinetics was initially assessed by comparing construct 4, construct 16, which has reduced FcγRIIb binding in all three Fc domains, and construct 6, which has reduced FcRn binding in two Fc domains. IVIg was included as a comparator showing typical IgG behavior. Female C57BL/6 mice (n=12, 8-10 weeks old), were dosed intravenously (i.v.) with 0.1 g/kg each of construct 4, construct 6, construct 16, or IVIg. Blood samples (50 μL) were collected from saphenous veins of four mice per time point at alternating times 15 min, 30 min, 1 hour, 2 hour, 4 hour, 6 hour, 8 hour, 1 day, 2 days, 3 days, 4 days, and 5 days. All mice were bled at 7, 9, 11, 14, 16, 21, and 23 days. Fc construct and IVIg serum concentrations were determined by human IgG1 Fc-specific ELISA. As demonstrated in
[0342] To further explore the impact of I253A amino acid modification valency towards FcRn on the pharmacokinetics, three compounds with one, two, or three domains with reduced affinity to FcRn were compared as described above. As seen in
[0343] The effect of combining the mutations was also explored (
Example 12. Evaluation of I253A and R292P Amino Acid Modifications on In Vitro Efficacy
[0344] The impact of the binding mutations on efficacy in vitro was assessed using assays previously shown to be sensitive to valency towards Fc gamma receptors. Inhibition of phagocytosis in THP-1 cells was comparable between all Fc constructs (
[0345] IL-8 release by plate-bound IgG-stimulated monocytes was comparably inhibited by all Fc constructs (
[0346] Likewise, the inhibition of ADCC was comparable across all Fc constructs (
[0347] In all assays, the mutations caused negligible reductions on efficacy.
Example 13. Evaluation of I253A and R292P Amino Acid Modifications on In Vivo Efficacy
[0348] To further assess the impact of the receptor binding mutations on activity, the Fc constructs were tested in vivo using the collagen antibody-induced arthritis (CAIA) model. Male C57BL/6 mice were injected i.p. with an arthritogenic monoclonal antibody cocktail of four antibodies to collagen II (ArthritoMab, MDBiosciences; 8 mg). On Day 4, animals were injected i.p. with lipopolysaccharide (100 μg). For therapeutic dosing, animals were randomized based on disease severity into study groups on Day 6, excluding animals with poor disease induction (score of 0 on day of randomization), and dosed i.v. with vehicle or test compound. For prophylactic dosing, animals were dosed i.v. with vehicle or test compound on a single day ranging from Day 1 to Day −14 (days were numbered omitting zero). Clinical scoring parameters were as follows: 0=normal, no swelling, redness, or distortion; complete joint flexibility. 1=mild arthritis: mild swelling and/or distortion; complete joint flexibility. 2=moderate arthritis: moderate swelling and/or distortion; reduced joint flexibility or grip strength. 3=severe arthritis: severe swelling and/or distortion; severely reduced joint flexibility or grip strength. 4=ankylosed joints; no joint flexibility and severely impaired movement; moribund. Animals were sacrificed after 12 days.
[0349] As shown in
Example 14. Evaluation of I253A and R292P Amino Acid Modifications on In Vivo Durability of Response
[0350] Mice in the CAIA model were treated prophylactically up to 14 days prior to injection with the arthritogenic antibodies. As seen in
[0351] Prophylactic dosing in the CAIA model was performed with 100 mg/kg of construct 4 (parent molecule), construct 18 (I253A in two domains and R292P in three domains)(Q1), or construct 19 (I253A and R292P in all three domains)(Q2) on Day 1 (
[0352]
Example 15. Evaluation of I253A and R292P Amino Acid Modifications on Fc Multimers
[0353] Fc multimers were generated as described in (Strome et al, US 2010/0239633 A1; Jain et al, Arthritis Res. Ther. 14, R192 (2012)). Specifically, IgG1 Fc was fused at the C-terminus to an IgG2 hinge sequence. DNA constructs were generated using wildtype IgG1 Fc sequence (construct X1) and using the I253A/R292P double mutant (construct X2). DNA plasmid constructs were transfected via liposomes into HEK293 cells. Following seven days in culture, cells were cleared by centrifugation.
[0354] The expressed proteins were purified from the cell culture supernatant by Protein A-based affinity column chromatography, using a Poros MabCapture A column. Captured constructs were washed with phosphate buffered saline (low-salt wash) and eluted with 100 mM glycine, pH 3. The eluate was quickly neutralized by the addition of 1 M TRIS pH 7.4 and sterile filtered through a 0.2 μm filter.
[0355] The proteins were further fractionated by ion exchange chromatography using Poros XS resin. The column was pre-equilibrated with 50 mM MES, pH 6 (buffer A), and the sample was diluted in the equilibration buffer before loading. The sample was eluted using a multi-step gradient with 50 mM MES, 400 mM sodium chloride, pH 6 (buffer B) as the elution buffer. The gradient steps included 0-40% B for 2 column volumes (CV) to remove low molecular weight species, a step hold at 40% B (4 CV), followed by 40-80% B (4 CV) to isolate the target species and then increased linearly to 100% B. All protein-containing fractions were screened by analytical size exclusion chromatography and components quantified by absorbance at 280 nm. Fractions with more than 8% total content of Fc (approximately 50 kDa) plus Fc dimer (approximately 100 kDa) were excluded. For Construct X1, all remaining fractions were combined. Due to a shift in the molecular weight distribution between Constructs X1 and X2, fractions of Construct X2 were selected to mimic the molecular weight distribution of Construct X1.
[0356] After ion-exchange, the target fraction was buffer exchanged into PBS buffer using a 30 kDa cutoff polyether sulfone (PES) membrane cartridge on a tangential flow filtration system. The samples were concentrated to approximately 30 mg/mL and sterile filtered through a 0.2 μm filter.
[0357] The molecular weight distributions of Construct 4 and Construct X1 were compared by analytical size exclusion chromatography (
[0358] Female C57BL/6 mice (n=15, 8 weeks old), were dosed intravenously (i.v.) with 0.1 g/kg each of construct X1 or construct 4. Blood (25 μL) was collected from the submandibular vein and was processed for serum. Five mice per group were bled at alternating time points through day 5, while for all remaining time points all fifteen mice were bled in each group. Time points collected included 15 and 30 min; 1, 2, 4, 6, 8, 24 h; 2 days. Fc multimer serum concentrations were determined by an anti-human IgG ELISA with an Fc specific detection antibody.
[0359] As demonstrated in
Example 16. Evaluation of I253A and R292P Amino Acid Modifications on Fc Receptor Pharmacokinetics in Cynomolgus Monkeys
[0360] The impact of binding-related mutations on pharmacokinetics in cynomolgus monkeys was assessed by comparing constructs 6, 16, and 18. Historical data for construct 4 came from a study in cynomolgus monkeys performed at different dose levels than the study comparing constructs 6, 16, and 18. Male cynomolgus monkeys (N=3) were dosed i.v. with 10 or 30 mg/kg each of constructs 6, 16, and 18. Blood samples were collected over the course of 44 days. Fc construct concentrations were determined by an ELISA using antibodies specific for human IgG1 Fc constructs, including constructs 4, 6, 16, and 18.
[0361] As demonstrated in
[0362] As demonstrated in
[0363] It is noteworthy that the pharmacokinetic behavior in cynomolgus monkeys differs from that in mice. In mice, both the reduction of FcRn and Fc gamma RIIb binding each resulted in increased persistence, and the combination of both resulted in further increases in persistence. In cynomolgus monkeys, the reduction of FcRn decreased persistence, the reduction of Fc gamma RIIb binding increased persistence, and the combination had little net change in persistence compared to the parent molecule (construct 4).
OTHER EMBODIMENTS
[0364] All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference to the same extent as if each independent publication or patent application was specifically and individually indicated to be incorporated by reference.
[0365] While the disclosure has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the disclosure that come within known or customary practice within the art to which the disclosure pertains and may be applied to the essential features hereinbefore set forth, and follows in the scope of the claims.
[0366] Other embodiments are within the claims.