Can Type of Myeloma Influence Response to Monoclonal Antibodies?
Disease characteristics may affect response to immunoglobulin G (IgG) monoclonal antibodies such as daratumumab in patients with relapsed or refractory multiple myeloma, according to a study published in Clinical Pharmacokinetics. Paul G. Richardson, MD, of Dana-Farber Cancer Institute, and colleagues from other institutions found significantly higher clearance and lower serum concentrations of daratumumb in patients with IgG multiple myeloma than in those with non-IgG multiple myeloma. Thus, consideration of the type of myeloma may prove to be warranted in the selection of antibody-based therapies.
The investigators focused on data from 2 phase II trials: GEN501 (104 patients; ClinicalTrials.gov identifier NCT00574288) and SIRIUS (124 patients; NCT01985126). The clearance of daratumumab was reported to be about 110% higher in patients with IgG myeloma than in those with non-IgG myeloma. The overall response rates, however, appeared to be similar in these patient populations. As for other patient and diseases characteristics, the impact was minimal, with no major effect on efficacy reported. As for toxicity, there did not appear to be any differences in adverse events with daratumumab treatment in these myeloma patient subgroups.