Peeling Back the Layers: Recurrent Talquetamab Skin Toxicity after Supportive Stem Cell Boost in Multiple Myeloma

Abstract

<b><i>Introduction:</i></b> Bispecific antibodies have meaningfully expanded the therapeutic armamentarium in multiple myeloma. Talquetamab is a CD3+ T-cell-redirecting antibody targeting GPRC5D, which is expressed on multiple myeloma plasma cells as well as in keratinized tissues. Due to the expression pattern, toxicity of talquetamab involves skin toxicity. <b><i>Case Presentation:</i></b> Here we report the case of a patient who was treated with talquetamab after relapse after CAR-T therapy. The patient developed a severe recurrence of talquetamab-mediated skin toxicity after the administration of a supportive hematopoietic stem cell boost to treat persistent late cytopenias after CAR-T therapy. <b><i>Conclusion:</i></b> This case underscores the complex dynamics between novel immunotherapies like talquetamab and stem cell-based interventions in the context of MM treatment, shedding light on the need for personalized approaches to maximize the benefits of these therapies while minimizing their associated adverse effects.