Alopecia Areata: Hair and Nail Findings in a Patient Undergoing Talquetamab Therapy for Multiple Myeloma

Redirecting T cell-mediated killing of GPRC5D-expressing myeloma cells, talquetamab is a novel chemotherapeutic humanized bispecific antibody increasingly used for treatment of relapsed or refractory multiple myeloma. While skin-related adverse events, including nail disorders, were common in the initial clinical trials, hair pathology was not reported. We present a case of a 74-year-old female undergoing talquetamab therapy presenting with a one-year history of alopecic patches in addition to nail changes, glossitis, and keratoderma. Scalp punch biopsy revealed alopecia areata later found to be responsive to betamethasone dipropionate gel. This case highlights a spectrum of adverse cutaneous manifestations of talquetamab therapy likely secondary cross reactivity to GPRC5D-expressing keratinized structures. Deeper investigation is warranted to clarify the pathogenesis underlying these findings and optimal treatment modalities for this patient cohort undergoing talquetamab therapy.