Efficacy and Durability of Catadegbrutinib in Relapsed or Refractory Waldenström Macroglobulinemia

Dr Shadman contextualizes the efficacy of the BTK degrader catadegbrutinib in relapsed or refractory Waldenström macroglobulinemia, where it produced an overall response rate of 83.7%, a major response rate of 76.7%, and a very good partial response rate of 30.2% at a median follow-up of 16.6 months. He notes that while disease control is achievable in the relapse setting with available off-label agents, high-quality responses are uncommon, making a 30% very good partial response rate meaningful. Because deeper responses may translate into longer remission and time to next treatment, he regards these results as important. Drawing on experience with BTK inhibitors, where response quality improves over time, Dr Shadman expresses hope that the relatively short follow-up of under two years will deepen, potentially converting major responses to very good partial responses and some to complete responses. He characterizes the estimated 18-month progression-free survival of 68.6% as promising for a phase 1 assessment.