BRISBANE, Calif. — October 7, 2026
Nurix Therapeutics, Inc. announced that the first patient has been enrolled in the Phase 1b/2 NX-5948-203 clinical study evaluating bexobrutideg (NX-5948) in combination with venetoclax in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The investigational therapy is an oral Bruton’s tyrosine kinase (BTK) degrader, while venetoclax is a BCL2 inhibitor and established treatment for CLL. The initial study cohort will focus on patients with relapsed or refractory CLL, with the potential to expand evaluation into previously untreated, or first-line, disease. The trial represents another development milestone for the Nurix and Roche collaboration and is designed to generate safety, tolerability and clinical activity data that could guide future registrational development strategies for bexobrutideg across different lines of CLL therapy.
NX-5948 Combination Strategy Targets CLL Treatment
The NX-5948-203 Phase 1b/2 study is designed to evaluate bexobrutideg together with venetoclax and assess whether the combination can provide a differentiated treatment approach for patients with CLL/SLL. Nurix is also planning a broader combination strategy involving selected anti-CD20 antibodies from Roche’s B-cell malignancy portfolio, including rituximab and obinutuzumab. The company intends to evaluate these combinations across multiple patient populations, including individuals with relapsed or refractory CLL and those who have not previously received treatment. The development strategy reflects the growing importance of combination regimens in CLL and is intended to investigate the potential of targeted protein degradation alongside established therapeutic mechanisms. Data generated from the study are expected to help determine future development pathways for bexobrutideg in CLL and potentially other B-cell malignancies.
Bexobrutideg Advances as a Selective BTK Degrader
Bexobrutideg is an investigational, orally bioavailable and brain-penetrant small-molecule degrader of BTK being developed by Nurix and Roche. The molecule is designed to selectively degrade BTK, a protein that plays an important role in B-cell receptor signaling and the biology of several B-cell malignancies. Nurix is evaluating bexobrutideg through a broad clinical program that includes studies in CLL and other B-cell malignancies. The development program includes the DAYBreak CLL-201 pivotal Phase 2 study in heavily pretreated relapsed/refractory CLL, the randomized Phase 3 DAYBreak CLL-306 study comparing bexobrutideg with pirtobrutinib, and the NX-5948-203 Phase 1b/2 combination study with venetoclax. The company is also evaluating bexobrutideg in the NX-5948-301 Phase 1a/1b study in patients with relapsed/refractory B-cell malignancies, supporting the broader investigation of BTK degradation as a therapeutic strategy.
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Nurix Expands Bexobrutideg Clinical Development
The initiation of the NX-5948-203 combination study strengthens Nurix’s broader effort to establish bexobrutideg as a potential therapy across B-cell malignancies. The company said the investigational drug’s differentiated mechanism of action, single-agent activity and tolerability profile support its evaluation in combination regimens designed to potentially achieve deep and durable responses with fixed-duration treatment. Beyond the current CLL program, Nurix and Roche are evaluating opportunities for bexobrutideg across oncology, immunology and neurology. The company’s wider pipeline is focused on targeted protein degradation, including additional investigational degraders designed to address cancer and autoimmune diseases. With the first patient now enrolled in NX-5948-203, Nurix is moving forward with clinical evaluation of bexobrutideg plus venetoclax while building a broader combination strategy intended to support future development across multiple treatment settings.
Source::Nurix Therapeutics, press release
