Nurix Therapeutics Achieves 92.9% ORR with BTK Degrader Bexobrutideg in Phase 1a/b CLL Trial

Nurix Therapeutics' bexobrutideg is generating Phase 1a/b efficacy data that will directly shape the CMC strategy and GMP compliance requirements for a broad Phase 3 monotherapy program, and, through a recently announced Roche collaboration, eventual commercial-scale manufacturing of a targeted protein degrader.

Updated data from the ongoing NX-5948-301 trial, presented at the 2026 European Hematology Association Congress in Stockholm on June 11, reported a 92.9% objective response rate in second-line CLL/SLL patients who had progressed on a BTK inhibitor but had not received BCL2 inhibitor treatment. In the heavily pretreated relapsed/refractory population (n=48, doses 50–600 mg), median progression-free survival reached 22.1 months with an 83% ORR. Responses were observed across high-risk subgroups, including BTK resistance mutations and CNS involvement, the latter relevant given bexobrutideg's oral CNS-penetrant mechanism.

Across all 142 Phase 1a/b CLL patients evaluated at the January 1, 2026 data cutoff, the safety profile remained consistent with prior disclosures. No dose-limiting toxicities were observed, no treatment-related Grade 5 adverse events were reported, and treatment discontinuations due to adverse events occurred in only 5.6% of patients. The 600 mg recommended Phase 2 dose showed safety findings comparable to the broader study population, a consistency that supports process validation assumptions as the program scales.

For manufacturing and analytical teams, the transition of a BTK degrader from Phase 1 to Phase 3 introduces well-documented CMC complexity. Targeted protein degraders present distinct characterisation and stability challenges relative to small molecules, and the bifunctional molecular architecture requires tightly controlled synthetic routes to maintain degrader integrity at commercial scale. The Roche collaboration, announced prior to EHA, adds a partnership layer that will require aligned quality agreements and technology transfer protocols consistent with ICH Q10 pharmaceutical quality system expectations.

Nurix has indicated the EHA data support launching a broad Phase 3 monotherapy program alongside combination regimen exploration in first- and second-line settings, a pipeline scope that will place concurrent demands on process development, analytical method validation, and regulatory submission readiness across multiple geographies.

The Phase 3 program's CMC package, including process validation data and the analytical control strategy for bexobrutideg at the 600 mg RP2D, will serve as the measurable checkpoint against which manufacturing readiness can be assessed as the Roche collaboration advances.

Source: Nurix Therapeutics, Inc. via GlobeNewswire, June 11, 2026.