Blood pharmacokinetics of various monoclonal antibodies labeled with a new trifunctional chelating reagent for simultaneous conjugation with 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid and biotin before radiolabeling.
OBJECTIVE
Knowledge of the blood pharmacokinetics of monoclonal antibodies is crucial in deciding the optimal time for starting the administration of a "clearing agent" or using a "clearing device." The primary purpose was to investigate whether the pharmacokinetics of various antibodies labeled with the same chelator and (111)In differed significantly after i.v. injection in immunocompetent rats. A new trifunctional chelator called "1033" containing a biotin and a radiometal chelation moiety is introduced, making it possible to use only one conjugation procedure for the antibody.


METHODS
Sixty-five non-tumor-bearing rats were included and divided into four groups (I-IV). The blood pharmacokinetics was investigated for rituximab, BR96, and trastuzumab labeled with 1033 and (111)In (I-III). The whole-body activity and activity uptake in muscle, liver, and kidney, which might explain differences in the early pharmacokinetics in blood, were also measured. hMN14 labeled with another chelator [1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)], but with the same radionuclide ((111)In-biotin-DOTA-hMN14), was studied (IV). The blood pharmacokinetics from another 15 tumor-bearing rats was compared with those of non-tumor-bearing rats (III) by injection of (111)In-1033-BR96.


RESULTS
No statistical difference was detected between the groups regarding the blood pharmacokinetics of rituximab, BR96, or trastuzumab. The pharmacokinetics and biodistribution of (111)In-biotin-DOTA-hMN14 exhibited a clear difference compared with others. There were no significant differences in the blood pharmacokinetics of (111)In-1033-BR96 between tumor-bearing rats and non-tumor-bearing rats.


CONCLUSIONS
Different antibodies labeled with the trifunctional chelator 1033 and (111)In did not exhibit different blood pharmacokinetics, which means that the pharmacokinetics could be predicted irrespective of the IgG1 antibody chosen. A small tumor burden did not change the pharmacokinetics of the radioimmunoconjugates.
Wang
Zhongmin
Z
Department of Oncology, Lund University Hospital, Sweden.
Mårtensson
Linda
L
Nilsson
Rune
R
Bendahl
Pär-Ola
PO
Lindgren
Lars
L
Ohlsson
Tomas
T
Sjögren
Hans-Olov
HO
Strand
Sven-Erik
SE
Tennvall
Jan
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; D001360:Avidin / Q000737:chemistry; D001710:Biotin / Q000493:pharmacokinetics*; D002614:Chelating Agents / Q000494:pharmacology*; D004317:Doxorubicin / Q000737:chemistry / Q000494:pharmacology; D006573:Heterocyclic Compounds, 1-Ring / Q000493:pharmacokinetics*; D018796:Immunoconjugates / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry; D011786:Quality Control; D016719:Radioimmunodetection; D016499:Radioimmunotherapy / Q000379:methods*; D011868:Radioisotopes / Q000737:chemistry; D051381:Rats; D000069283:Rituximab; D013997:Time Factors; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; C092612:BR96-doxorubicin immunoconjugate; D002614:Chelating Agents; D006573:Heterocyclic Compounds, 1-Ring; D018796:Immunoconjugates; D007074:Immunoglobulin G; D011868:Radioisotopes; D001360:Avidin; C071349:1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid; D000069283:Rituximab; D001710:Biotin; D004317:Doxorubicin; D000068878:Trastuzumab