Characterization of dysgeusia and xerostomia in patients with multiple myeloma treated with the T-cell redirecting GPRC5D bispecific antibody talquetamab.

PURPOSE: In recent years, various immunotherapies have improved the survival of patients with multiple myeloma (MM). However, there remains an unmet need for novel agents. Talquetamab is the first-in-class GPRC5D-targeting T-cell redirecting bispecific antibody, which has substantial activity in advanced MM. Rapidly after the start of talquetamab treatment, patients reported taste changes (dysgeusia; 60% of patients), and a feeling of dry mouth (xerostomia; 30-57% of patients), which may be related to expression of the target antigen in healthy tissues, such as taste buds. Here, we aimed at better characterizing these oral toxicities.

METHODS: We measured salivary flow and the ability to taste (objectively and patient-reported), assessed the feeling of dry mouth, and evaluated quality of life before and 8 weeks after the start of talquetamab therapy in eight heavily pretreated MM patients.

RESULTS: Talquetamab treatment led to the rapid and significant decrease in objectively measured taste scores (total score 8.8 ± 2.0 vs 4.9 ± 2.5). All patients reported moderate to severe taste changes. Moreover, patients experienced severe xerostomia after the initiation of talquetamab treatment, in the absence of changes in unstimulated and stimulated salivary flow. Because of these oral toxicities a significant impairment in global health status/(oral health related) quality of life was reported.

CONCLUSION: Studying taste changes in patients treated with talquetamab following up on the described leads provides a new and unique opportunity to further unravel the pathophysiology of taste changes after cancer treatment.