Dermatological toxicities induced by T-cell-redirecting GPRC5D bispecific antibody talquetamab

Early trials with talquetamab showed that dermatological adverse events were among the most frequent, along with cytokine release syndrome, hematologic and neurotoxic effects (2). However, dermatological toxicities, which concerned up to 70% of exposed patients, have not been described to date. We conducted a monocentric descriptive retrospective study (from 2020 to 2022) at Comprehensive Cancer Center, IUC, Toulouse, France. All patients with refractory multiple myeloma and exposed to talquetamab, either in monotherapy (subcutaneous infusion, 400µg weekly) or in combination with pomalidomide, carfizomib or cetrelimab (300µg weekly to 800µg every two weeks) were evaluated in the oncodermatology department. The study was approved by the institutional review board (CRE IUCT-O: 2-22-02).