The present invention relates to compounds (reactive conjugates) for the chemical modification of therapeutic antibodies or proteins. The compounds enable the regioselective attachment of a payload to an antibody or antibody fragment in one single step, thereby producing a modified antibody or modified antibody fragment, which can be used for diagnosing, monitoring, imaging or treating disease.

Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload inhibits expression or activity of a DMPK allele comprising a disease-associated-repeat. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.

In an embodiment of the invention, a composition for treating a cell population comprises an Affinity Medicant Conjugate (AMC). The medicant moiety can be a toxin including an acylfulvene or a drug moiety. The affinity moiety can be an antibody, a binding protein, a steroid, a lipid, a growth factor, a protein, a peptide or non peptidic. The affinity moiety can be covalently bound to the medicant via a linker. Novel linkers that can be directed to cysteine, arginine or lysine residues based on solution pH allow greater flexibility in preserving and/or generating specific epitopes in the AMC.

The invention relates generally to pyrrolobenzodiazepine monomer and dimer prodrugs having a glutathione-activated disulfide prodrug moiety, a DT-diaphorase-activated quinone prodrug moiety or a reactive oxygen species-activated aryl boronic acid or aryl boronic ester prodrug moiety. The invention further relates to pyrrolobenzodiazepine prodrug dimer-antibody conjugates.

Disclosed herein are polynucleic acid molecules, pharmaceutical compositions, and methods for treating Facioscapulohumeral muscular dystrophy.

Phosphonate linkers and their use for delivering compounds with passive cell permeability into a cell wherein the phosphonate group facilitates cellular retention of the compound are described.

The present invention relates to a conjugate of a cytotoxic drug/molecule to a cell-binding molecule with a bis-linker (a dual-linker) containing a 2,3-diaminosuccinyl group. It also relates to preparation of the conjugate of a cytotoxic drug/molecule to a cell-binding molecule with the bis-linker, particularly when the drug having functional groups of amino, hydroxyl, diamino, amino-hydroxyl, dihydroxyl, carboxyl, hydrazine, aldehyde and thiol for conjugation with the bis-linker in a specific manner, as well as the therapeutic use of the conjugates.

Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload inhibits expression or activity of DUX4. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.

Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload promotes the expression or activity of a functional dystrophin protein. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide, e.g., an oligonucleotide that causes exon skipping in a mRNA expressed from a mutant DMD allele.

Antibodies are engineered by replacing one or more amino acids of a parent antibody with non cross-linked, highly reactive cysteine amino acids. Antibody fragments may also be engineered with one or more cysteine amino acids to form cysteine engineered antibody fragments (ThioFab). Methods of design, preparation, screening, and selection of the cysteine engineered antibodies are provided. Cysteine engineered antibodies (Ab), optionally with an albumin-binding peptide (ABP) sequence, are conjugated with one or more drug moieties (D) through a linker (L) to form cysteine engineered antibody-drug conjugates having Formula I:

Ab-(L-D).sub.p  I

where p is 1 to 4. Diagnostic and therapeutic uses for cysteine engineered antibody drug compounds and compositions are disclosed.