Nurix Therapeutics, Inc. (Nasdaq: NRIX) announced that the European Medicines Agency (EMA) has granted PRIME (PRIority MEdicines) designation to NX-5948, a highly selective degrader of Bruton’s tyrosine kinase (BTK), for the treatment of adult patients with relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL). This designation is specifically for patients who have previously undergone treatment with at least a BTK inhibitor and a BCL-2 inhibitor. The PRIME initiative is designed to provide enhanced support to developers of promising medicines, optimizing development plans and accelerating the evaluation process. Pivotal trials of NX-5948 are planned to initiate in 2025.
Clinical Significance
The PRIME designation underscores the unmet medical need in CLL/SLL, particularly for patients whose disease has progressed despite treatment with both BTK and BCL-2 inhibitors. According to Nurix, early data from the ongoing Phase 1 clinical trial of NX-5948 have shown encouraging safety and efficacy results. These data suggest potential clinical benefits and mechanistic activity independent of mutations that confer resistance to covalent and non-covalent BTK inhibitors.
About NX-5948
NX-5948 is an investigational, orally bioavailable, brain-penetrant, small molecule degrader of BTK. It is designed to specifically eliminate BTK, a key growth signaling protein in B cells, through degradation via the ubiquitin-proteasome system. The ongoing Phase 1 clinical trial (NCT05131022) is evaluating NX-5948 in patients with relapsed or refractory B-cell malignancies. Preclinical data indicate that NX-5948 is highly potent against tumor cell lines resistant to current BTK inhibitor therapies, making it a potentially valuable treatment for heavily pretreated CLL/SLL patients.
Nurix Therapeutics' Approach
Nurix Therapeutics is focused on discovering, developing, and commercializing innovative small molecules and antibody therapies that modulate cellular protein levels for the treatment of cancer, inflammatory conditions, and other challenging diseases. The company's DELigase platform is used to identify and advance drug candidates targeting E3 ligases, which can modulate proteins within the cell. Nurix’s pipeline includes targeted protein degraders of BTK and inhibitors of Casitas B-lineage lymphoma proto-oncogene B (CBL-B), an E3 ligase that regulates the activation of multiple immune cell types.
Management Commentary
"PRIME designation for NX-5948 is an important recognition of the unmet patient need in CLL, particularly in the growing number of patients whose cancer has progressed following BTK inhibitor and BCL2 inhibitor therapy," said Arthur T. Sands, M.D., Ph.D., president and chief executive officer of Nurix. "This designation follows encouraging safety and efficacy data from our ongoing Phase 1 clinical trial, demonstrating early promise of clinical benefit as well as mechanistic data supporting the activity of NX-5948 independent of mutations that confer resistance to covalent and non-covalent BTK inhibitors."
