Nurix reports durable bexobrutideg responses in CLL trial
Nurix Therapeutics announced updated Phase 1a/b data for bexobrutideg showing durable responses in relapsed/refractory CLL and high ORR in earlier lines. The data supports a Phase 3 program with Roche.
*this image is generated using AI for illustrative purposes only.
Nurix Therapeutics, Inc. has announced updated clinical data from its ongoing NX-5948-301 Phase 1a/b clinical trial evaluating bexobrutideg (NX-5948), an investigational oral CNS-penetrant BTK degrader, in patients with chronic lymphocytic leukemia (CLL). The data, presented at the 2026 EHA Congress in Stockholm, demonstrates durable responses in heavily pretreated patients and encouraging activity in earlier treatment lines. These findings support the launch of a broad Phase 3 monotherapy program through Nurix's recently announced collaboration with Roche Holdings AG.
The collaboration with Roche targets the B-cell malignancies market, projected to reach $41 billion by 2031. Nurix received an upfront cash payment of $700 million under the agreement, with total potential deal value reaching $2.3 billion. Profits and losses from U.S. commercialization will be shared equally, while Roche will handle commercialization outside the U.S.
Phase 1a Efficacy and Safety
In the Phase 1a dose escalation study of 48 relapsed/refractory CLL/SLL patients, bexobrutideg showed robust efficacy. Patients had received a median of four prior lines of therapy, with high rates of prior BTK and BCL2 inhibitor exposure. As of the January 1, 2026 data cutoff, the objective response rate (ORR) was 83.0%, with a median progression-free survival (PFS) of 22.1 months.
| Metric | Value |
|---|---|
| Median Follow-up | 22.4 months |
| Median PFS | 22.1 months (95% CI: 14.0–NR) |
| ORR | 83.0% (95% CI: 69.2–92.4) |
| Prior BTK Inhibitor Use | 97.9% |
| Prior BCL2 Inhibitor Use | 83.3% |
Across all Phase 1a/b CLL patients (n=142), the drug was well tolerated. There were no dose-limiting toxicities or treatment-related Grade 5 adverse events. Treatment discontinuations due to adverse events occurred in only 5.6% of patients. The most common adverse events included purpura/contusion, neutropenia, petechiae, diarrhea, and fatigue.
Phase 1b Earlier-Line Results
New data from Phase 1b cohorts indicated high response rates in earlier lines of treatment. In Cohort 5 (n=19), comprising patients with prior BTK inhibitor therapy but no prior BCL2 inhibitor, the ORR was 92.9% among evaluable patients. In Cohort 15 (n=20), which included BTKi-naïve and treatment-naïve patients, the ORR was 84.2% among evaluable patients. Most patients in these cohorts remained on treatment at the data cutoff.
What specific milestones must be met to trigger the remaining $1.6 billion in potential value from the Roche collaboration?
How will bexobrutideg differentiate itself from existing BTK inhibitors in the highly competitive $41 billion B-cell malignancies market?
What is the projected timeline for patient enrollment and the release of initial topline data from the Phase 3 monotherapy program?
19
Access Market Heat-map & Insights 
Create, Save & Share your Screener 
Use 200+ Screening Filters 
