METHOD FOR RADIOIODINATION OR RADIOASTATINATION OF A BIOMOLECULE

Abstract

The present invention relates to a method for radioiodination or radioastatination of a biomolecule such as proteins and antibodies by reacting a biomolecule carrying a hetero(aryl) boronic acid group with a radioiodide or astatide salt, in the presence of a catalyst and a ligand, in a buffer solution, in order to obtain a radioiodo- or astatolabeled biomolecule. The method of the invention is thus a single step method easy to be implemented and efficient for both radioiodination and radioastatination of antibodies.

Claims

1. A method for radioiodination or radioastatination of a biomolecule comprising a step of reacting a biomolecule carrying a hetero(aryl) boronic acid group with a radioiodide or astatide salt, in the presence of a catalyst and a ligand, in a buffer solution, in order to obtain a radioiodo- or astatolabeled biomolecule.

2. The method of claim 1, wherein the iodide or astatide salt has the formula A.sup.+X.sup.−, wherein A.sup.+ is a monovalent cation selected among sodium, potassium, cesium, tetraalkylammonium, and tetraalkylphosphonium, and X.sup.−is iodide or astatide.

3. The method of claim 2, wherein X.sup.− is 123|, .sup.124|, .sup.125|, .sup.131|, or .sup.211At.sup.−.

4. The method of claim 1, wherein the catalyst is selected from the group consisting of: Cu.sub.2O, Cu(CO.sub.2CH.sub.3).sub.2, Cu(OCOCF.sub.3).sub.2. H.sub.2O, Cu(CH.sub.3CN).sub.4OTf, and Cu(OTf).sub.2pyr.sub.4.

5. The method of claim 1, wherein the ligand is selected from the group consisting of: 1,10-phenanthroline, 4,7-dihydroxyphenanthroline, bathophenanthorlinedisulfonic acid disodium salt hydrate, dichloro (1,10-phenanthroline) copper II, and 3,5,7,8-tetramethyl-1,10-phenanthroline.

6. The method of claim 1, wherein the buffer solution is selected from the group consisting of: carbonate buffer, borate buffer, HEPES buffer, TRIS buffer, acetate buffer, MES buffer, and MOPS buffer.

7. The method of claim 1, wherein the pH of the buffer solution is comprised between 3 and 8.5.

8. The method of claim 1, wherein the biomolecule is selected from the group consisting of: proteins, antibodies, fragments of antibodies, antibody constructs, as recombinant proteins, and synthetic peptides selected to bind target cells.

9. The method of claim 1, wherein the biomolecule carrying a hetero(aryl) boronic acid group is a biomolecule comprising a group having the following formula (I): ##STR00015## wherein: A.sub.1 is a linker, and A.sub.2 is a (hetero)aryl group, optionally substituted with at least one substituent, said hetero(aryl) boronic acid group being a biomolecule comprising a group having the following formula (I-1): ##STR00016##

10. The method of claim 9, wherein the radioiodo- or astatolabeled biomolecule comprises a group having the following formula (II): ##STR00017## wherein X is .sup.123|, .sup.124‥, .sup.125|, .sup.131| or .sup.211At, said radioiodo- or astatolabeled biomolecule comprising a group having the following formula (II-1): ##STR00018##

11. The method of claim 1, for the preparation of a radioiodo- or astatolabeled biomolecule having the following formula (III):
A-A.sub.1-A.sub.2-X   (III) wherein A is a biomolecule, A.sub.1 is a linker, A.sub.2 is a (hetero)aryl group, optionally substituted with at least one substituent, said hetero(aryl) boronic acid group being a biomolecule comprising a group having the following formula (I-1): ##STR00019## and X is .sup.123|, .sup.124|, .sup.125|, .sup.131| or .sup.211At, said radioiodo- or astatolabeled biomolecule having the following formula (III-1): ##STR00020##

12. A biomolecule carrying a (hetero)aryl boronic acid group, wherein the (hetero)aryl boronic acid group is linked to said biomolecule through an (hetero)aromatic group.

13. The biomolecule carrying a (hetero)aryl boronic acid group of claim 12, which comprises a group having the following formula (I): ##STR00021## A.sub.1 is a linker, A.sub.2 is a (hetero)aryl group, optionally substituted with at least one substituent, said hetero(aryl) boronic acid group being a biomolecule comprising a group having the following formula (I-1): ##STR00022## said hetero(aryl) boronic acid group being a biomolecule comprising a group having the following formula (I-1): ##STR00023##

14. The biomolecule carrying a (hetero)aryl boronic acid group of claim 12, which comprises a group having the following formula (IV): ##STR00024## wherein A is a biomolecule, A.sub.1 is a linker and A.sub.2 is a (hetero)aryl group, optionally substituted with at least one substituent, said hetero(aryl) boronic acid group being a biomolecule comprising a group having the following formula (I-1): ##STR00025##

15. The biomolecule carrying a (hetero)aryl boronic acid group of claim 12, wherein the biomolecule is an antibody.

Description

[0098] Results are shown in FIGS. 1-4:

[0099] FIG. 1. Biodistribution of [.sup.125|]9E7.4 produced by the two-step method in mice grafted with MOPC 315 cells (n 3).

[0100] FIG. 2. Biodistribution of [.sup.125|]9E7.4 produced in one step from aBA-9E7.4 in mice grafted with MOPC 315 cells (n≥3).

[0101] FIG. 3. Biodistribution of [.sup.211At]9E7.4 produced by the two-step method in mice grafted with MOPC 315 cells (n≥3).

[0102] FIG. 4. Biodistribution of [.sup.211At]9E7.4 produced in one step from aBA-9E7.4 in mice grafted with MOPC 315 cells (n≥3).

[0103] Comparison of results obtained by both radiolabelling methods indicate that there is no significant difference in the pharmacokinetic behavior of the antibody.

[0104] The only major difference is observed for the tumor uptake of [.sup.125|]9E7.4 obtained by the two-step approach (FIG. 1) that is higher than with the one-step approach (FIG. 2) but that is due to heterogeneity of tumor weigh in both groups, tumors exhibiting lower weights in the first case, resulting in higher %ID/mass ratio.

[0105] Another difference that may be noticed is the lower uptake in intestine with the one-step approach (FIGS. 2 and 4) compared to the two-step approach (FIGS. 1 and 3) indicating a better metabolic elimination resulting in more favorable dosimetry to the intestine of the radiolabelled antibody when labelled by the approach detailed in the present application in comparison with the two-step approach.