ABSTRACT
An integrated pharmacokinetics (PK) model that simultaneously describes concentrations of total antibody (Tab) and antibody-conjugated monomethyl auristatin E (acMMAE) following administration of monomethyl auristatin E (MMAE)-containing antibody-drug conjugates (ADCs) was developed based on phase I PK data with extensive sampling for two ADCs. Two linear two-compartment models that shared all parameters were used to describe the PK of Tab and acMMAE, except that the deconjugation rate was an additional clearance pathway included in the acMMAE PK model compared to Tab. Further, the model demonstrated its ability to predict Tab concentrations and PK parameters based on observed acMMAE PK and various reduced or eliminated Tab PK sampling schemes of phase II data. Thus, this integrated model allows for the reduction of Tab PK sampling in late-phase clinical development without compromising Tab PK characterization.
Subject(s)
Immunoconjugates/pharmacokinetics , Lymphoma, Non-Hodgkin/drug therapy , Oligopeptides/pharmacokinetics , Computer Simulation , Drug Dosage Calculations , Humans , Immunoconjugates/administration & dosage , Models, Biological , Models, Theoretical , Oligopeptides/administration & dosage , Pharmaceutical PreparationsABSTRACT
Antibody-drug conjugates (ADCs) are potent cytotoxic drugs linked to antibodies through chemical linkers, and allow specific targeting of drugs to neoplastic cells. The expression of CD22 is limited to B-cells, and we show that CD22 is expressed on the vast majority of non-Hodgkin's lymphomas (NHLs). An ideal target for an ADC for the treatment of NHL would have limited expression outside the B-cell compartment and be highly effective against NHL. We generated an ADC consisting of a humanized anti-CD22 antibody conjugated to the anti-mitotic agent maytansine with a stable linker (anti-CD22-MCC-DM1). Anti-CD22-MCC-DM1 was broadly effective in in vitro killing assays on NHL B-cell lines. We did not find a strong correlation between in vitro potency and CD22 surface expression, internalization of ADC or sensitivity to free drug. We show that anti-CD22-MCC-DM1 was capable of inducing complete tumor regression in NHL xenograft mouse models. Further, anti-CD22-MCC-DM1 was well tolerated in cynomolgus monkeys and substantially decreased circulating B-cells as well as follicle size and germinal center formation in lymphoid organs. These results suggest that anti-CD22-MCC-DM1 has an efficacy, safety and pharmacodynamic profile that support its use as a treatment for NHL.
