IMS 2024 | Oral symptom assessment using PROs in patients with R/R myeloma treated with talquetamab

Talquetamab is a licensed and approved bispecific antibody targeting GPRC5D and response rates are in the region of 60-70%. One of the main side effects that we see are oral toxicities and in particular taste disturbance and dysgeusia. Now when patients are treated on a clinical trial, one of the restrictions is that oral toxicity isn’t very well characterized and dysgeusia can only be reported as grade 0, 1 or 2 as maximum severity, and that really doesn’t tell you the full picture of what happens to the patient and their experience as they go through. So in this evaluation we decided to take oral patient reported outcome questionnaires which are validated in the field of oral medicine or oral health and we borrowed those and we planted them into a myeloma protocol. And essentially, what we did was that we gave our patients these questionnaires weekly to begin with during a step-up phase, stepping down to four weekly and then three monthly. When you look at it it’s really interesting what you see is there’s a rapid increase in severity of symptoms, namely dry mouth, difficulty swallowing, and taste disturbance that happens very rapidly – maximum at week two and week three, and then there is an improvement as the symptoms settle down. The dysgeusia however does continue for a bit longer, but importantly, when you stop treatment pretty much all of the oral toxicities resolve by three months. And so for the first time we really have characterized the oral toxicity profile of talquetamab and importantly clearly demonstrated resolution of symptoms at three months.