Nurix starts Phase 3 bexobrutideg trial with $1.1bn war chest
Nurix Therapeutics has enrolled its first patient in the Phase 3 DAYBreak CLL-306 study, a randomised trial comparing its BTK degrader bexobrutideg with pirtobrutinib in approximately 620 patients with relapsed or refractory chronic lymphocytic leukaemia and small lymphocytic lymphoma. The milestone caps a quarter in which the Brisbane, California company also closed its global co-development and co-commercialisation agreement with Roche, triggering a $700 million upfront payment and leaving Nurix with $1.1 billion in cash and marketable securities, providing runway into the second half of 2029.
The Phase 3 study carries dual primary endpoints of objective response rate and progression-free survival, each adjudicated by an independent review committee, and is designed to support regulatory submissions globally. Nurix is simultaneously running DAYBreak CLL-201, a pivotal single-arm Phase 2 study intended to underpin a potential Accelerated Approval submission in patients who have progressed through a covalent BTK inhibitor, a BCL2 inhibitor and a non-covalent BTK inhibitor.
Clinical data and pipeline breadth
Phase 1 data presented at EHA 2026 gave investors a clearer read on bexobrutideg's activity profile. Across heavily pretreated relapsed or refractory CLL patients in the Phase 1a cohort, the drug produced a median progression-free survival of 22.1 months and an objective response rate of 83%, including responses in patients carrying BTK inhibitor resistance mutations. In the Phase 1b cohort, patients who were BTK inhibitor-experienced but BCL2 inhibitor-naive achieved an objective response rate of 92.9%, with 18 of 19 patients still on treatment at the data cutoff. Among all evaluable BTK inhibitor-naive patients, including treatment-naive individuals, the rate was 84.2%. Across 142 Phase 1a/1b patients, the company reported no dose-limiting toxicities and no treatment-related Grade 5 adverse events; discontinuations due to adverse events stood at 5.6%.
Beyond CLL, Nurix advanced NX-1607, an oral CBL-B inhibitor, into Phase 1b monotherapy expansion cohorts covering microsatellite stable colorectal cancer, non-small cell lung cancer, castration-resistant prostate cancer and metastatic melanoma, with the first patient dosed in September 2026. The company also initiated recruiting for the Phase 1b/2 NX-5948-203 combination study, which will evaluate bexobrutideg alongside venetoclax.
Financial results and collaboration income
Third-quarter revenue reached $673.1 million, against $7.9 million in the comparable period a year earlier. The surge was driven almost entirely by $653.2 million of licence revenue recognised on the Roche collaboration close. Research and development spending fell to $79.3 million from $86.1 million, partly reflecting Roche's 60% share of development costs under the deal terms. Net income for the quarter was $549.8 million, or $4.73 per diluted share, compared with a net loss of $86.4 million in the prior-year period.
Nurix also earned collaboration income from Sanofi and Pfizer. Sanofi's initiation of a first-in-human Phase 1 trial of its oral STAT6 degrader SAR448272/NX-3911 triggered a $10 million milestone, bringing cumulative payments from that partnership to roughly $139 million, with a further $455 million in potential future milestones remaining. Pfizer triggered a $7 million milestone, and Gilead agreed to extend the research term for one oncology programme by two years in exchange for a $10 million one-time fee.
Market context
The BTK inhibitor and degrader space is intensely competitive. Pirtobrutinib, the non-covalent BTK inhibitor selected as the comparator in CLL-306, is already approved and has carved out a position in later lines of therapy. Bexobrutideg's differentiation rests on its degrader mechanism, brain-penetrant profile and activity in BTK-mutant disease. The Roche partnership significantly de-risks development costs and adds commercial infrastructure, though the 40/60 cost-sharing arrangement means Nurix carries a meaningful share of a programme that will require large, long-duration trials. The broader protein degradation field has attracted several well-capitalised players, including AstraZeneca-partnered Arvinas and Kymera Therapeutics, making execution on Phase 3 timelines a key determinant of competitive positioning.