# US 7,608,241 B2 · Radiolabeling method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,241 B2 - Document ID: US7608241B2 - Status: Granted - Kind: B2 - Application number: 11/033,439 - Filed: 2005-01-12 - Published: 2005-08-04 - Granted: 2009-10-27 - Earliest claimed: 1999-03-01 - Assignees: Rit Oncology, LLC - Inventors: Paul Chinn; Ronald A. Morena; Michael J. LaBarre; John E. Leonard - Web page: https://patentgrep.com/patent/US7608241B2 ## CPC - G01N 33/534: with radioactive label - A61P 35/00: Antineoplastic agents - G01N 33/60: involving radioactive labelled substances - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS ## Abstract Antibody binding assays and radiolabeling kits are disclosed for radiolabeling and testing therapeutic antibodies in the commercial setting. In particular, the kits are designed for making and evaluating radiolabeled anti-CD20 conjugates to be used for the treatment and imaging of B cell lymphoma tumors. All kit reagents are sterile and are designed to achieve a high level of antibody radiolabeling and product stability with results which are highly reproducible. ## Claims ### Claim 1 A method for radiolabeling a chelator-conjugated antibody with 90Y, comprising: (i) mixing chelator-conjugated antibody with a solution containing 90Y; and (ii) incubating the mixture for a time between 3 and 10 minutes at appropriate temperature to produce a radiolabeled antibody having sufficient radioincorporation and specific activity of about 3.2 mCi/mg to about 16.7 mCi/mg, without further purification of the radiolabeled antibody from unincorporated radiolabel. ### Claim 2 (depends on 1) The method of claim 1, wherein the chelator is selected from the group consisting of MX-DTPA, phenyl-DTPA, benzyl-DTPA, CHX-DTPA and DOTA. ### Claim 3 (depends on 2) The method of claim 2, wherein the chelator is MX-DTPA. ### Claim 4 (depends on 2) The method of claim 2, wherein the antibody is an anti-CD20 antibody. ### Claim 5 (depends on 4) The method of claim 4, wherein the antibody is a chimeric anti-CD20 antibody. ### Claim 6 (depends on 4) The method of claim 4, wherein the anti-CD20 antibody is 2B8. ### Claim 7 (depends on 4) The method of claim 4, wherein the chelator-conjugated anti-CD20 antibody is 2B8-MX-DTPA. ### Claim 8 (depends on 1) The method of claim 1, wherein the solution containing the radiolabel is adjusted to a pH of about 3 to 6 before it is mixed with the chelator-conjugated antibody. ### Claim 9 (depends on 8) The method of claim 8, wherein the pH is adjusted with a sodium acetate solution. ### Claim 10 (depends on 9) The method of claim 9, wherein the sodium acetate is at a concentration of about 10 to 1000 mM. ### Claim 11 (depends on 1) The method of claim 1, wherein the radiolabeled antibodies produced in step (ii) have at least 70% immunoreactivity. ### Claim 12 (depends on 1) The method of claim 1, wherein the radiolabel is 90Y chloride, and the formulation buffer comprises a radioprotectant that inhibits radiolysis of the 90Y-labeled antibody selected from human serum albumin (HSA) and free-radical scavengers. ### Claim 13 (depends on 12) The method of claim 12, wherein the specific activity of the 90Y -labeled antibodies is in the range of 10-15 mci/mg antibody. ### Claim 14 (depends on 12) The method of claim 12, wherein the volume quantity of 90Y chloride used is between about 5 to 100 mCi divided by the radioactivity concentration at the time of labeling. ### Claim 15 (depends on 14) The method of claim 14, wherein the volume quantity of 90Y chloride used is about 45 mCi divided by the radioactivity concentration at the time of labeling. ### Claim 16 (depends on 12) The method of claim 12, wherein about 1 to 2 ml of MX-DTPA-conjugated antibody at a concentration of about 0.5 to 30 mg/ml is mixed with the radiolabel solution. ### Claim 17 (depends on 12) The method of claim 12, wherein the chelator is MX-DTPA. ### Claim 18 (depends on 1) The method of claim 1, wherein the formulation buffer is added in an amount necessary to achieve a total final volume of about 10 ml to about 50 ml. ### Claim 19 (depends on 1) The method of claim 1, further comprising diluting the radiolabeled antibody to an appropriate concentration in formulation buffer for administration to a human patient. ### Claim 20 (depends on 19) The method of claim 19, wherein the mixture is incubated for 3 minutes. ### Claim 21 (depends on 19) The method of claim 19, wherein the mixture is incubated for 5 minutes. ### Claim 22 (depends on 19) The method of claim 19, wherein the formulation buffer contains physiological saline, a radioprotectant, and unconjugated chelator. ### Claim 23 (depends on 22) The method of claim 22, wherein the radioprotectant is selected from the group consisting of human serum albumin (HSA), ascorbate, ascorbic acid, phenol, sulfites, glutathione, cysteine, gentisic acid, nicotinic acid, ascorbyl palmitate, HOP(:O)H2, glycerol, sodium formaldehyde sulfoxylate, Na2S2O5, Na2S2O3 and SO2. ### Claim 24 (depends on 22) The method of claim 22, wherein the unconjugated chelator is DTPA or EDTA. ### Claim 25 A method for radiolabeling a chelator-conjugated antibody with 90Y, comprising: (i) mixing chelator-conjugated antibody with a solution containing 90Y; and (ii) incubating the mixture for 3-10 minutes at an appropriate temperature to produce a radiolabeled antibody having sufficient radioincorporation of at least 95%; and (iii) diluting the radiolabeled antibody to an appropriate concentration in formulation buffer for administration to a human patient without further purification of the radiolabeled antibody from unincorporated radiolabel. ### Claim 26 (depends on 25) The method of claim 25, wherein the mixture is incubated for 3 minutes. ### Claim 27 (depends on 25) The method of claim 25, wherein the mixture is incubated for 5 minutes.