FDA OKs Talquetamab, a First-in-Class Multiple Myeloma Drug

Sharon Worcester, MA

August 10, 2023

The US Food and Drug Administration (FDA) has granted accelerated approval to talquetamab-tgvs (Talvey, Janssen Biotech, Inc), a first-in-class bispecific antibody targeting the GPRC5D receptor, for heavily pretreated adults with relapsed or refractory multiple myeloma. Patients must have received at least four prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody.

The agent, which also received breakthrough and orphan drug designation, is available only through the Tecvayli-Talvey Risk Evaluation and Mitigation Strategy (REMS) due to a boxed warning for life-threatening or fatal cytokine release syndrome (CRS) and neurological toxicity, including immune effector cell-associated neurotoxicity (ICANS), the FDA announced.

Talquetamab-tgvs was evaluated in the single-arm, open-label MonumenTAL-1 study of 187 patients who had previously been treated with at least four prior systemic therapies.

The overall response rate in 100 patients who received a subcutaneous dose of 0.4 mg/kg weekly was 73% and median duration of response was 9.5 months. The overall response rate in 87 patients who received a subcutaneous dose of 0.8 mg/kg biweekly was 73.6% with about 85% of responders maintaining their response for at least 9 months. In this group, the median duration of response was not estimable.

Patients in the 0.4 mg/kg weekly dose group were treated following two step-up doses in the first week of therapy, and those in the 0.8 mg/kg biweekly group were treated following three step-up doses, until disease progression or unacceptable toxicity.

Adverse reactions occurring in at least 20% of the 339 patients in the safety population included CRS, dysgeusia (foul, metallic taste sensation), nail disorder, musculoskeletal pain, skin disorder, rash, fatigue, decreased weight, dry mouth, pyrexia, xerosis, dysphagia, upper respiratory tract infection, and diarrhea.

Both the weekly 0.4 mg/kg and biweekly 0.8 mg/kg doses are recommended. The full dosing schedule is included in the prescribing information.

The approval follows a series of market withdrawals for other multiple myeloma drugs that initially received accelerated FDA approval. For instance, the FDA recently requested withdrawal of melphalan flufenamide (Pepaxto) after 2021 confirmatory trial results showed an increased risk of death. This agent had received accelerated approval in 2021. Blood cancer drugs panobinostat (Farydak) and belantamab mafodotin-blmf  (Blenrep) were also withdrawn based on confirmatory trial results.

Continued approval of talquetemab-tgvs for this indication is also contingent on verifying efficacy in confirmatory trials.

The new treatment approach represents a "welcome addition to the myeloma community," Michael Andreini, president and chief executive officer of the Multiple Myeloma Research Foundation stated in a Janssen press release. "Although options for the treatment of multiple myeloma have expanded significantly in recent years, the disease remains incurable, and therefore, patients are in need of new treatment options."

Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System or by calling 1-800-FDA-1088.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at  sworcester@mdedge.com  or on Twitter:  @SW_MedReporter .

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