Posted: Monday, June 13, 2022
According to updated results from the MonumenTAL-1 study, the G protein–coupled receptor family C group 5 member D x CD3 bispecific antibody talquetamab appears to be well tolerated and effective in the treatment of patients with relapsed or refractory multiple myeloma. The results of this phase I trial were presented at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 8015).
“These data show that both recommended phase II doses of talquetamab have comparable safety, efficacy, and pharmacokinetic profiles and confirm talquetamab as a novel, first-in-class therapy with highly promising efficacy in a heavily pretreated relapsed/refractory patient population,” stated Monique C. Minnema, MD, PhD, of the University Medical Center Utrecht, the Netherlands, and colleagues.
In this phase I study of talquetamab, a bispecific IgG4 antibody that binds to both GPRC5D and CD3 receptors, patients with relapsed or refractory multiple myeloma were given one of two recommended phase II doses: 405 μg/kg subcutaneously weekly (n = 30) or 800 μg/kg subcutaneously every 2 weeks (n = 44). Step-up dosing was used to reduce the risk of severe cytokine-release syndrome.
Patients in the 405-μg/kg and 800-μg/kg groups, respectively, received a median of six and five prior lines of therapy. The overall response rates in response-evaluable patients were 70% and 64%, respectively; a very good partial response or better rate was reported in 57% and 52%, respectively.
The most common adverse events were cytopenias and cytokine-release syndrome. Investigators reported that cytopenias were reversible, mostly confined to step-up and cycle 1 and 2 doses, and generally resolved within 1 week. Neutropenia was reported in 67% and 36%, respectively, in the 405-μg/kg and 800-μg/kg groups; 53 and 23%, respectively, had grade 3 or 4 neutropenia. Infections, dysgeusia, and skin-related and nail disorder adverse events were also reported.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.