Nurix Achieves 92.9% ORR in Second-Line CLL and 83% ORR with 22.1-Month PFS
NRIX•Nurix Therapeutics reported a 92.9% objective response rate in second-line CLL/SLL patients post-BTK inhibitor without prior BCL2 therapy, and an 83% ORR with 22.1-month median progression-free survival in pretreated relapsed/refractory CLL/SLL. The CNS-penetrant BTK degrader was well tolerated, with no dose-limiting toxicities and only 5.6% discontinuations due to adverse events.
1. Phase 1a Efficacy in Relapsed/Refractory CLL/SLL
The Phase 1a dose-escalation study enrolled 48 heavily pretreated CLL/SLL patients, achieving an 83% objective response rate and a median progression-free survival of 22.1 months. Responses included two complete responses and were observed in patients with BTK resistance, TP53 mutations and CNS involvement.
2. Phase 1b Early-Line Cohort Results
In Cohort 5 (BTKi-experienced, BCL2i-naïve), 92.9% of evaluable patients achieved objective responses, with 18 of 19 remaining on treatment at a 5.2-month median follow-up. Cohort 15 (BTKi-naïve, including treatment-naïve) saw an 84.2% ORR among evaluable patients, with 19 of 20 still on therapy at 4.9 months.
3. Safety Profile Across Phase 1a/b Patients
Across 142 CLL/SLL patients, bexobrutideg demonstrated a consistent safety profile, with no dose-limiting toxicities, no treatment-related Grade 5 events, and only 5.6% discontinuations due to adverse events. Common treatment-emergent adverse events included purpura, neutropenia, petechiae, diarrhea and fatigue.
4. Plans for Phase 3 Program and Roche Collaboration
The robust efficacy and tolerability data support initiation of a broad Phase 3 monotherapy program and exploration of combination regimens in first- and second-line CLL. Nurix plans to advance these trials in collaboration with Roche, targeting best-in-class BTK degradation therapy.
