Research Nurse Practitioner The University of Texas MD Anderson Cancer Center Houston, Texas, United States
Introduction: : Talquetamab (talq) is a GPRC5D bispecific antibody approved for treatment of patients (pts) with multiple myeloma (MM) who have received 4 lines of therapy including an anti-CD38 monoclonal antibody, proteasome inhibitor, and immunomodulatory agent. In addition to plasma cells, GPRC5D is expressed on keratinized tissue and tongue papillae making these areas vulnerable to toxicity including dysgeusia, skin changes, and onychomadesis previously reported in ~ 50-70% of pts (Chari, A., et al 2022, NEJM). These adverse events (AEs) may decrease the quality of life of pts receiving talq. Subsequently a guideline for the prophylaxis and management of talq AEs was developed by a multidisciplinary team for use at MD Anderson Cancer Center in an effort to avoid and/or quickly identify and manage dermal, nail, and oral talq toxicities by initiating early interventions for prophylaxis and treatment including, lotions, nail strengtheners/oils and zinc supplementation among others.
Methods: A retrospective chart review to characterize dermal, nail, and oral toxicities of pts with MM who received talq between 11/2023 - 5/2024 for > 28 days was performed using the aforementioned guidelines. AEs were graded using CTCAE v4.03.
Results: 30 pts who received talq were considered evaluable and included in the analysis. Eighty-two percent experienced skin toxicity, 79% dysgeusia, and 75% dry mouth. Among 22pts with skin AEs, 72% had palmar-plantar erythema, 36% dry skin, and 27% rash. 99% of pts experienced >1 skin toxicity with the majority being Gr 1 except for Gr 2 palmar-plantar erythema (30%) and rash (9%). Onychomadesis occurred in 51.7% of pts of which 85% were Gr 1 and 13.3% Gr2. Dysgeusia was reported by 79.3% of pts among which Gr1 was noted in 77%, Gr 2 in 18%, and Gr 3 in 5%. 22 pts had dry mouth; the majority were Gr 1 (95.5%) or Gr 2 (4.5%) toxicities. 6 pts had dysphagia including 83.3% Gr1 and 16.7% Gr 2 toxicity. Among pts who experienced skin, oral or nail toxicities only 2 required a subsequent treatment delay. Among all pts, 44% had baseline zinc deficiency with a median level of 61.5 mcg/dL (range 60-106 mcg/dL). Further analysis to evaluate median time to onset of toxicities, management strategies, and association with therapeutic response will be presented.
Conclusions: While most patients reported skin, oral, and nail toxicities during therapy w/ talq, the majority of AEs were < Gr 2 in severity. Only 2 patients required treatment delays and no patients discontinued therapy due to oral, skin or nail associated adverse events. Further investigation of the effect of prophylaxis and early intervention for talq-related AEs with optimization of these measures warrant further study in patients receiving treatment with talquetamab.