Nurix Therapeutics shares drop despite positive leukemia drug data
Nurix Therapeutics (NASDAQ:NRIX) released updated Phase 1a/b clinical data for its experimental leukemia drug, bexobrutideg, demonstrating sustained efficacy and high response rates across multiple lines of therapy for patients with chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL).
The Brisbane, California-based biopharmaceutical firm disclosed the findings in conjunction with an oral presentation scheduled for the European Hematology Association (EHA) 2026 Congress in Stockholm, Sweden.
Despite the positive clinical metrics, Nurix shares fell 4.2% in early trading as Wall Street adjusted models to account for the company's long-term capital expenditure commitments required to advance the candidate into late-stage registrational studies.
The clinical update evaluated bexobrutideg, an oral, targeted Bruton’s tyrosine kinase (BTK) protein degrader previously designated as NX-5948.
In a cohort of heavily pretreated, relapsed or refractory CLL and SLL patients who had failed a median of four prior therapies, the drug achieved an 83% objective response rate (ORR) alongside a median progression-free survival (PFS) of 22.1 months.
Crucially, the therapeutic activity remained consistent in high-risk patient subgroups, including individuals harboring complex genetic mutations that typically confer resistance to conventional, standard-of-care BTK inhibitors.
When moved into earlier lines of treatment, bexobrutideg showed enhanced potency.
In a trial cohort consisting of second-line patients who had progressed on an initial BTK inhibitor but had not yet received a BCL2 inhibitor, the objective response rate climbed to 92.9%.
On safety parameters, the molecule maintained a favorable tolerability profile with extended follow-up, recording a low 5.6% discontinuation rate due to drug-related adverse events, and no new-onset cases of atrial fibrillation.
The updated data drop follows a major corporate milestone reached earlier in the week, when Nurix signed a definitive global collaboration and licensing agreement with Swiss healthcare giant Roche.
Under the terms of that transaction, which is slated for final closure in the third quarter of 2026, Nurix will receive a $700 million upfront cash payment and remains eligible for up to $2.3 billion in subsequent milestone extensions.
However, the joint development structure dictates that Nurix must fund 40% of all global clinical trial costs, while Roche covers the remaining 60%.
With the companies actively preparing to launch a pivotal Phase 3 study in the summer of 2026 to evaluate bexobrutideg as a second-line therapy for CLL, analysts noted that near-term cash burn rates will accelerate significantly, offsetting some of the immediate enthusiasm surrounding the drug's competitive clinical profile.
