Nurix Therapeutics' NX-5948 Gains FDA Fast Track for Waldenstrom’s Macroglobulinemia Treatment

Nurix Therapeutics, Inc., a clinical-stage biopharmaceutical company, has announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation for its experimental drug NX-5948. This drug is a highly selective degrader of Bruton’s tyrosine kinase (BTK) and is specifically intended for adult patients suffering from relapsed or refractory Waldenstrom’s macroglobulinemia (WM) after they have undergone at least two lines of therapy, including a BTK inhibitor.

Waldenstrom’s macroglobulinemia is a rare and slowly progressing type of non-Hodgkin’s lymphoma. It is characterized by the replacement of normal bone marrow cells with malignant lymphocytic cells that produce monoclonal IgM, leading to various health issues such as anemia, bleeding, and weakened immune function. In the United States, the incidence of WM ranges from 0.36 to 0.57 cases per 100,000 people, translating to approximately 1,200 to 1,900 new cases annually. The disease typically has a median duration of up to 10 years, with an estimated 12,000 to 19,000 individuals currently living with WM in the U.S. Existing treatments include chemoimmunotherapy and BTK inhibitor therapy; however, there are no approved therapies available for patients whose cancer progresses after BTKi treatment.

NX-5948's designation as a Fast Track drug is a significant acknowledgment of the unmet needs of WM patients, especially those whose cancer continues to advance despite prior treatments. Arthur T. Sands, M.D., Ph.D., the president and CEO of Nurix, expressed optimism about the drug’s potential, highlighting the promising safety and efficacy data from the ongoing Phase 1 clinical trial. The trial has displayed initial signs of clinical benefit with prospects for long-lasting outcomes. Nurix is currently enrolling more Waldenstrom’s macroglobulinemia patients in the Phase 1b expansion cohort and plans to reveal further clinical data in 2025.

Previously, in January 2024, NX-5948 also received Fast Track designation for treating relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) in patients who have been treated with at least two lines of therapy, including a BTK inhibitor and a BCL2 inhibitor. Later, in November 2024, the European Medicines Agency (EMA) granted the drug PRIME designation for the same CLL/SLL conditions, recognizing its potential benefit based on early clinical data.

The FDA’s Fast Track designation is part of an effort to expedite the development and review of drugs that address serious conditions and fulfill unmet medical needs. This designation allows for more frequent communication between the FDA and the drug developers, potentially making the drug eligible for Accelerated Approval and Priority Review if it meets specific criteria. Similarly, the EMA's PRIME initiative, launched in 2016, aims to provide early and proactive support to enhance the development process for promising medicinal products, ensuring that such medicines reach patients more quickly.

NX-5948 is currently undergoing evaluation in a Phase 1 clinical trial for patients with relapsed or refractory B cell malignancies. It has shown high potency against a range of tumor cell lines resistant to existing BTK inhibitor therapies, making it a crucial option for heavily pre-treated patients with CLL/SLL. Nurix's focus on modulating cellular protein levels through innovative small molecules and antibody therapies offers a novel approach to treating cancer and other difficult diseases. Their strategy includes utilizing the natural functions of E3 ligases to either degrade or enhance cellular protein levels, thereby providing targeted treatment options.

Nurix Therapeutics is headquartered in San Francisco, California, and is committed to advancing its pipeline of drug candidates through comprehensive research and clinical trials.