The Janssen Pharmaceutical Companies of Johnson & Johnson have announced that the European Commission (EC) has granted conditional marketing authorisation (CMA) of TALVEY (talquetamab) as monotherapy for the treatment of adult patients with relapsed and refractory multiple myeloma (RRMM) who have received at least three prior therapies, including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 antibody and have demonstrated disease progression on the last therapy.
Talquetamab is a bispecific T-cell engaging antibody that binds to CD3, on the surface of T-cells, and G protein-coupled receptor class C group 5 member D (GPRC5D), a novel target expressed on the surface of multiple myeloma cells and hard keratinised tissues, with minimal to no expression detected on B-cells and B-cell precursors. Talquetamab is approved as a weekly (QW) or biweekly (Q2W) subcutaneous (SC) injection, after an initial step-up phase.
“As multiple myeloma progresses and patients cycle through treatments, the disease becomes more difficult to treat and remission periods shorten,” said Maria-Victoria Mateos, M.D., Ph.D., Consultant Physician in Haematology, University Hospital of Salamanca. “Targeting GPRC5D has been shown to deliver deep responses, and unlike many other targets for multiple myeloma, its expression is limited on immune cells providing an important new approach to targeting this heterogenous disease.”
The CMA was supported by positive results from the Phase 1/2 MonumenTAL-1 study (Phase 1: NCT03399799; Phase 2: NCT04634552), evaluating the safety and efficacy of talquetamab in patients with RRMM. The latest data from the study were recently presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting (2-6 June, Chicago) and the 2023 European Hematology Association (EHA) Congress (8-11 June, Frankfurt).
Patients in the study (0.8 mg/kg Q2W: n=145; 0.4 mg/kg QW: n=143) had received a median of five (range, 2-17) prior lines of therapy and showed meaningful overall response rates (ORR) across both doses. With a median follow-up of 12.7 months, 71.7 percent (95 percent Confidence Interval [CI], 63.7-78.9) of response-evaluable patients treated at the 0.8 mg/kg Q2W dose achieved a response, 60.8 percent achieved a very good partial response (VGPR) or better and 38.7 percent achieved a complete response (CR) or better.1 With a median follow-up of 18.8 months, 74.1 percent (95 percent CI, 66.1-81.1) of response-evaluable patients treated with the 0.4 mg/kg QW dose achieved a response, 59.5 percent achieved a VGPR or better and 33.6 percent achieved a CR or better. Responses were durable with a median duration of response not reached (95 percent CI, 13-Not Estimable [NE]) in the 0.8 mg/kg Q2W dose group and 9.5 months (95 percent CI, 6.7-13.3) in the 0.4 mg/kg QW dose group. An estimated 76.3 percent and 51.5 percent of patients maintained a response for at least nine months at the 0.8 mg/kg Q2W and 0.4 mg/kg QW doses, respectively.
The MonumenTAL-1 study also included 51 patients with prior T-cell redirection therapy. Patients had received a median of five (3-15) prior lines of therapy, including prior exposure to a bispecific antibody (35.3 percent), CAR-T cell therapy (70.6 percent) or both (six percent). With a median duration of follow-up of 14.8 months, 64.7 percent of patients achieved a response, 54.9 percent achieved a VGPR or better and 35.3 percent achieved a CR or better. Median duration of response was 11.9 months (95 percent CI, 4.8-NE) and the 12-month overall survival rate was 62.9 percent.
The most common adverse events (AEs) observed in the study were cytokine release syndrome (CRS; 77 percent, 1.5 percent Grade 3 or 4), dysgeusia (72 percent, all Grade 1 or 2), hypogammaglobulinaemia (67 percent, all Grade 1 or 2) and nail disorders (56 percent, all Grade 1 or 2). In addition, 40 percent of patients experienced weight loss, including 3.2 percent with Grade 3 or 4 weight loss. The most common infections were upper respiratory tract infection (29 percent, 2.1 percent Grade 3 or 4) and COVID-19 (19 percent, 2.9 percent Grade 3 or 4). Neurologic toxicities were reported in 29 percent of patients, including immune effector cell-associated neurotoxicity syndrome (ICANS; 10 percent, 2.3 percent Grade 3 or 4). Adverse reactions leading to treatment discontinuation were mainly due to ICANS (1.1 percent) and weight loss (0.9 percent).
The EC approval follows the U.S. Food and Drug Administration (FDA) approval of talquetamab for the treatment of adult patients with relapsed or refractory multiple myeloma who received at least four prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 antibody, in August 2023.