Nurix Therapeutics' NX-5948 Gets PRIME Status from EMA for Relapsed/Refractory CLL Treatment

Nurix Therapeutics, Inc., a biopharmaceutical company listed on the Nasdaq under the ticker NRIX, has announced a significant milestone in the development of its targeted protein modulation drugs. The European Medicines Agency (EMA) has granted PRIME designation to NX-5948, a selective degrader of Bruton’s tyrosine kinase (BTK), intended for the treatment of adult patients with relapsed or refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). This designation applies to patients who have already been treated with at least one BTK inhibitor and one BCL-2 inhibitor.

The PRIME initiative was launched by the EMA in 2016 to provide early and enhanced support to developers of promising new medicines, with the aim of optimizing development plans and accelerating the evaluation process so that these drugs can reach patients more quickly. Medicines eligible for PRIME must target unmet medical needs and demonstrate potential benefits for patients based on early clinical data.

Arthur T. Sands, M.D., Ph.D., president and CEO of Nurix, emphasized the significance of the PRIME designation for NX-5948. He noted that it underscores the critical need for new treatments in CLL, especially for patients whose cancer has progressed after undergoing therapy with BTK and BCL2 inhibitors. This designation follows positive safety and efficacy data from an ongoing Phase 1 clinical trial, which has shown early evidence of clinical benefit and mechanistic data indicating that NX-5948 can be effective independent of mutations that cause resistance to current BTK inhibitors.

NX-5948 is an experimental, orally available, brain-penetrant small molecule designed to degrade BTK. It works by utilizing the cell’s ubiquitin proteasome system to eliminate BTK, a crucial growth-signaling protein in B cells. Currently, NX-5948 is being tested in a Phase 1 clinical trial involving patients with relapsed or refractory B cell malignancies. Nurix has reported that NX-5948 is highly effective against a variety of tumor cell lines that are resistant to existing BTK inhibitor therapies, which is particularly relevant for heavily pretreated CLL/SLL patient populations. More details about the ongoing clinical trial can be found on clinicaltrials.gov under the identifier NCT05131022.

Nurix Therapeutics is dedicated to discovering, developing, and commercializing innovative small molecules and antibody therapies that modulate cellular protein levels. This approach is seen as a novel treatment strategy for cancer, inflammatory conditions, and other difficult diseases. The company leverages its expertise in E3 ligases and proprietary DNA-encoded libraries to create DELigase, an integrated discovery platform that identifies and advances new drug candidates targeting E3 ligases. These enzymes are crucial for modulating proteins within cells. Nurix’s discovery strategy involves either harnessing or inhibiting the natural functions of E3 ligases within the ubiquitin-proteasome system to selectively alter cellular protein levels.

The company's clinical-stage pipeline includes targeted protein degraders of BTK, a signaling protein in B cells, and inhibitors of Casitas B-lineage lymphoma proto-oncogene B, an E3 ligase that regulates the activation of various immune cells, including T cells and NK cells. Nurix Therapeutics is headquartered in San Francisco, California.