Under the agreement, Nurix will receive US$700m upfront and could earn development, regulatory and sales milestones bringing the total potential value to US$2.3bn. The partners will share development costs, with Roche funding 60% and Nurix 40%. In the US, the companies will split profits and losses equally and co-commercialise the drug, while Roche will take responsibility for commercialisation outside the US, paying Nurix tiered royalties in the low- to high-teens. The transaction is expected to close in Q3/2026, subject to customary conditions.
A new approach
Bexobrutideg, also known as NX-5948, is designed to eliminate the BTK protein rather than merely inhibit its kinase activity. BTK is a validated target in chronic lymphocytic leukaemia (CLL), non-Hodgkin lymphoma and other B-cell malignancies, but resistance to established BTK inhibitors remains a major clinical issue. Roche and Nurix argue that degrading BTK could remove both its enzymatic and scaffolding functions, potentially addressing resistance mechanisms that can emerge with standard-of-care BTK inhibitors.
The deal comes after Nurix had already moved bexobrutideg into a pivotal development programme. In October 2025, the company initiated DAYBreak, a single-arm pivotal Phase II trial in relapsed or refractory CLL. The study is testing bexobrutideg at 600mg once daily in patients whose disease has progressed after treatment with a covalent BTK inhibitor, a B-cell lymphoma 2 (BCL-2) inhibitor and a non-covalent BTK inhibitor. Nurix said the dose had been cleared for pivotal monotherapy studies following alignment with regulators including the FDA, the UK MHRA and the EMA.
DAYBreak is intended to support a potential accelerated approval submission. Nurix has also outlined a confirmatory Phase III trial in relapsed or refractory CLL, designed to compare bexobrutideg monotherapy with investigator’s choice of pirtobrutinib, bendamustine plus rituximab, or idelalisib plus rituximab in patients previously treated with a covalent BTK inhibitor. Roche said the drug is planned for Phase III trial initiation in summer 2026 for second-line CLL.
Earlier clinical data have already drawn attention in the field. At the European Hematology Association Congress in 2024, Nurix reported Phase I data in relapsed or refractory CLL showing an objective response rate of 69.2% among 26 efficacy-evaluable patients, with responses observed as early as eight weeks and deepening over time. The study population was heavily pretreated, and patients had received oral doses ranging from 50mg to 600mg once daily. The most common treatment-emergent adverse events included purpura/contusion, thrombocytopenia and neutropenia.
Roches’ portfolio fit
For Roche, the deal adds a targeted protein degradation programme to an established haematology franchise that already includes antibody-based approaches in B-cell cancers. The company has built a strong position in malignant haematology with drugs such as the CD20xCD3 bispecific antibody glofitamab and the antibody-drug conjugate polatuzumab vedotin, both used in lymphoma settings. Bexobrutideg could therefore become both a standalone CLL asset and a potential combination partner with Roche’s existing B-cell malignancy portfolio.
Beyond oncology, Roche and Nurix plan to explore bexobrutideg in chronic spontaneous urticaria and multiple sclerosis. The rationale is that BTK signalling is also involved in immune-cell activation, including B-cell and myeloid-cell biology. Bexobrutideg’s brain-penetrant profile could be relevant in neurology, particularly in MS, where Roche has already invested heavily in BTK-targeted approaches. Earlier this year, the company reported positive phase 3 results for its BTK inhibitor fenebrutinib in relapsing MS, making it one of the few programmes in the class to deliver late-stage success after several rivals, including Merck KGaA and Sanofi, stumbled. The findings reinforced interest in BTK modulation as a way to target compartmentalised inflammation within the central nervous system, an area where brain-penetrant molecules such as bexobrutideg could potentially offer advantages.
The collaboration gives Nurix the financial and global development muscle to move bexobrutideg through pivotal studies while allowing Roche to access a potentially best-in-class degrader in a commercially important target class. BTK-targeted therapies remain a key segment of the CLL and non-Hodgkin lymphoma markets, where long treatment duration, relapse after prior therapy and resistance to earlier-generation drugs continue to shape clinical and commercial competition.
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