Nurix Therapeutics, Inc. 8-K

What Happened

• On June 11, 2026, Nurix Therapeutics announced updated clinical data from its Phase 1a/1b study of the BTK degrader bexobrutideg (NX‑5948), to be presented at the European Hematology Association Congress (EHA2026). The data cutoff was January 1, 2026.
• Across the Phase 1a/1b safety population (n=142), 86 patients received the recommended Phase 2 dose (RP2D) of 600 mg once daily. In the Phase 1a efficacy update (48 patients treated at 50–600 mg, median follow-up 22.4 months), the objective response rate (ORR) among 47 evaluable patients was 83.0% (including 4.3% CR); median progression‑free survival was 22.1 months (95% CI: 14.0–NR). Safety was consistent with prior disclosures; no dose‑limiting toxicities were observed and three Grade 5 events were deemed not related to treatment.

Key Details

• Phase 1a/1b safety population: 142 CLL/SLL patients; 86 treated at 600 mg (RP2D); common TEAEs included purpura/contusion, neutropenia, petechiae, diarrhea and fatigue.
• Phase 1a efficacy (median follow‑up 22.4 months): ORR 83.0% (47 evaluable), median PFS 22.1 months.
• Earlier‑line Phase 1b cohorts: Cohort 5 (BTKi‑treated, BCL2i‑naïve) — ORR 92.9% (14 evaluable, median follow‑up 5.2 mo); Cohort 15 (BTKi‑naïve, incl. treatment‑naïve) — ORR 84.2% (19 evaluable, median follow‑up 4.9 mo).
• Baseline patient features: median 4 prior lines (range 2–12); prior BTKi 97.9%, prior BCL2i 83.3%; BTK mutations 38.3%, PLCG2 14.9%, TP53 mutations 44.7%; 10.4% had CNS involvement.

Why It Matters

• These updated Phase 1 results show high response rates and a tolerable safety profile for NX‑5948 across heavily pretreated and earlier‑line CLL/SLL patients, including those with BTK resistance mutations — data that support continued clinical development and forthcoming presentation at EHA2026.
• For investors, the announcement highlights clinical progress (efficacy and safety at the 600 mg RP2D) but does not include financial guidance or commercialization decisions; longer follow‑up and later‑stage trial results will be needed to assess clinical durability and market potential.