Tislelizumab plus zanubrutinib for Richter transformation: the phase 2 RT1 trial

There is a significant need for improved treatments in patients with CLL who develop Richter Transformation. In this phase 2 trial, researchers presented data that the combination of the PD-1 checkpoint inhibitor tislelizumab with the BTK inhibitor zanubrutinib demonstrate efficacy and tolerability to warrant further study in RT. The overall response rate (ORR) after 6 cycles of combination therapy was 58.3% (N = 48, 95% CI: 43.2-72.4); 9 patients (20%) experienced a complete response and 19 patients (40%) experienced a partial response. With a median follow-up of around 14 months, neither median duration of response nor median overall survival has been reached. The median progression-free survival was 10 months (95% CI: 3.8-16.3), and the 12-month overall survival rate was 74.7% (95% CI: 58.4-91.0). The most common adverse events included infections (18%), gastrointestinal disorders (13%), and hematologic toxicities (11%). The study is ongoing with an estimated study completion date later this year.