8-K: Nurix Therapeutics Announces Positive Clinical Data for BTK Degrader NX-5948 at ASH Annual Meeting

Nurix Therapeutics presented promising clinical data for its BTK degrader NX-5948, showing high response rates and tolerability in patients with relapsed or refractory chronic lymphocytic leukemia.

Summary

• Nurix Therapeutics announced updated clinical data from the Phase 1 trial of NX-5948, a Bruton's tyrosine kinase (BTK) degrader, at the American Society of Hematology Annual Meeting.
• The data includes 125 patients, with 60 having relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL).
• The CLL/SLL patients were heavily pretreated, having received a median of four prior lines of therapy, including covalent and non-covalent BTK inhibitors.
• NX-5948 demonstrated a 75.5% objective response rate (ORR) in efficacy evaluable CLL/SLL patients, increasing to 84.2% with longer treatment duration.
• Responses were observed across all patient subgroups, including those with mutations associated with BTK inhibitor resistance and central nervous system involvement.
• The treatment was well-tolerated, with the most common adverse events being purpura/contusion, fatigue, petechiae, neutropenia, and rash, mostly grade 1 or 2.
• Preclinical data also showed NX-5948's effectiveness in a model of primary CNS lymphoma and the immunomodulatory activity of NX-2127, another BTK degrader.
• The company plans to initiate pivotal trials of NX-5948 in 2025.

Sentiment

Score: 9

Explanation: The document presents very positive clinical data with high response rates, good tolerability, and promising preclinical results. The company is also on track to initiate pivotal trials, indicating strong progress and potential for future success.

Positives

• The objective response rate of 75.5% is very encouraging, and the increase to 84.2% with longer treatment is a significant positive.
• The drug's effectiveness in patients with resistance mutations is a major advantage.
• The durability of responses, with some patients remaining on treatment for over a year, is promising.
• The favorable safety profile is a key benefit, especially in a heavily pretreated patient population.
• The preclinical data showing CNS penetration and immunomodulatory effects further support the potential of NX-5948 and NX-2127.
• The company is on track to initiate pivotal trials in 2025.

Negatives

• Some patients experienced treatment-emergent adverse events such as purpura/contusion, fatigue, petechiae, neutropenia, and rash, although mostly grade 1 or 2.
• There were 6 treatment emergent adverse events that resulted in drug discontinuation.
• There were 2 Grade 5 adverse events, although these were deemed not related to NX-5948.

Risks

• The drug development process carries inherent risks, including the emergence of unexpected adverse events.
• Clinical trial results are subject to differing interpretations by regulatory authorities.
• There is no guarantee that Nurix will be able to successfully complete clinical development, obtain regulatory approval, or commercialize NX-5948 and NX-2127.
• The company's ability to fund research and development activities is subject to market conditions and other factors.
• There are risks associated with protecting intellectual property.

Future Outlook

Nurix plans to initiate pivotal trials of NX-5948 in 2025 and is exploring additional indications in other organ systems based on evolving data.

Management Comments

• Paula G. OConnor, M.D., chief medical officer of Nurix, stated that they are highly encouraged to see a deepening of therapeutic responses over time while maintaining a favorable safety profile.
• Paula G. OConnor, M.D., chief medical officer of Nurix, stated that they are on track to initiate pivotal trials of NX-5948 in 2025.

Industry Context

The development of BTK degraders like NX-5948 addresses the unmet need in CLL treatment, particularly for patients who have developed resistance to existing BTK inhibitors. This is a significant area of focus in the hematology space, with companies seeking to overcome the limitations of current therapies.

Comparison to Industry Standards

• The 75.5% ORR, increasing to 84.2% with longer treatment, is very competitive compared to other treatments for relapsed/refractory CLL, including both covalent and non-covalent BTK inhibitors.
• The fact that NX-5948 is effective in patients with mutations associated with resistance to both covalent and non-covalent BTK inhibitors is a significant advantage over existing therapies such as Ibrutinib, Acalabrutinib, and Pirtobrutinib.
• The safety profile of NX-5948 appears favorable compared to some other BTK inhibitors, which can have more significant side effects.
• The preclinical data showing CNS penetration is also a notable advantage, as many existing therapies struggle to reach the central nervous system.
• The immunomodulatory activity of NX-2127 is a unique feature that could differentiate it from other BTK inhibitors.

Stakeholder Impact

• Shareholders will likely react positively to the strong clinical data and the company's progress towards pivotal trials.
• Patients with relapsed or refractory CLL/SLL may benefit from this new treatment option.
• Employees of Nurix will be encouraged by the positive results and the company's advancement.
• The positive results may attract potential partners and investors.

Next Steps

• The company plans to initiate pivotal trials of NX-5948 in 2025.
• Nurix plans to open a new Phase 1b cohort for patients with CLL and associated autoimmune hemolytic anemia in H1 2025.
• Nurix plans a non-malignant hematology IND in 2025 for autoimmune cytopenias.
• Nurix will conduct a healthy volunteer study of a new formulation to address potential need for broader range of doses and dose regimens for I&I indications.
• Nurix will explore potential for additional indications in other organ systems based on evolving data (e.g., dermatology and neurology).
• Nurix will provide additional information in 2025 on their broader I&I pipeline including the STAT6 (Nurix/Sanofi) and IRAK4 (Nurix/Gilead) programs.

Key Dates

Keywords

BTK degrader, NX-5948, NX-2127, chronic lymphocytic leukemia, CLL, small lymphocytic lymphoma, SLL, hematology, cancer, clinical trial, objective response rate, ORR, ASH Annual Meeting, protein degradation, B-cell malignancies