Authors: Suzette Girgis, Shun Xin Wang Lin, Kodandaram Pillarisetti, Arnob Banerjee, Tara Stephenson, Xuewen Ma, Shoba Shetty, Tong-Yuan Yang, Brandi W. Hilder, Qun Jiao, Brett Hanna, Homer C Adams III, Yu-Nien Sun, Amarnath Sharma, Jennifer Smit, Jeffrey R. Infante, Jenna D. Goldberg & Yusri Elsayed
Abstract
Background
Teclistamab (JNJ-64007957), a B-cell maturation antigen × CD3 bispecific antibody, displayed potent T-cell–mediated cytotoxicity of multiple myeloma cells in preclinical studies.
Objective
A first-in-human, Phase I, dose escalation study (MajesTEC-1) is evaluating teclistamab in patients with relapsed/refractory multiple myeloma.
Patients and Methods
To estimate the efficacious therapeutic dosing range of teclistamab, pharmacokinetic (PK) data following the first cycle doses in the low-dose cohorts in the Phase I study were modeled using a 2-compartment model and simulated to predict the doses that would have average and trough serum teclistamab concentrations in the expected therapeutic range (between EC50 and EC90 values from an ex vivo cytotoxicity assay).
Results
The doses predicted to have average serum concentrations between the EC50 and EC90 range were validated. In addition, simulations showed that weekly intravenous and subcutaneous doses of 0.70 mg/kg and 0.72 mg/kg, respectively, resulted in mean trough levels comparable to the maximum EC90. The most active doses in the Phase I study were weekly intravenous doses of 0.27 and 0.72 mg/kg and weekly subcutaneous doses of 0.72 and 1.5 mg/kg, with the weekly 1.5 mg/kg subcutaneous doses selected as the recommended Phase II dose (RP2D). With active doses, exposure was maintained above the mean EC90. All patients who responded to the RP2D of teclistamab had exposure above the maximum EC90 in both serum and bone marrow on cycle 3, Day 1 of treatment.
Conclusions
Our findings show that PK simulations of early clinical data together with ex vivo cytotoxicity estimates can inform the identification of a bispecific antibody’s therapeutic range.
Clinical Trial Registration
NCT03145181, date of registration: May 9, 2017.
Key Points |
Early pharmacokinetic simulations using first-in-human Phase I study data and ex vivo cytotoxicity assay estimates provided guidance on the selection of a recommended Phase II dose (RP2D) of teclistamab. |
Active doses of teclistamab yielded drug exposure in the predicted therapeutic dosing range. |
All evaluable patients who responded to the RP2D of teclistamab had exposure above the predicted target concentration in both serum and bone marrow in cycle 3. |