NX-1607 demonstrated on-target peripheral immune activation characteristic of an active immune-oncology agent with a novel immune checkpoint mechanism distinct from PD-1/PD-L1 therapiesNX-1607 demonstrated evidence of monotherapy anti-tumor activity with reductions in tumor biomarkers, tumor shrinkage, long-term stable disease, and a confirmed partial response in heavily pretreated patientsData support initiation of expansion cohorts at the two highest doses tested as monotherapy or combination for the treatment of advanced solid tumors SAN FRANCISCO, Oct. 18, 2025 (GLOBE NEWSWIRE) -- Nurix Therapeutics, Inc. (NASDAQ:NRIX), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted protein degradation medicines, today announced the presentation of new clinical data from its first-in-human Phase 1a study of NX-1607, a first-in-class oral inhibitor of the E3 ligase Casitas B-lineage lymphoma proto-oncogene B (CBL-B) in patients with relapsed/refractory solid tumors. The data are being presented at the European Society for Medical Oncology Congress (ESMO 2025), taking place October 17–21, 2025, in Berlin, Germany."As a first-in-class oral inhibitor of CBL-B, NX-1607 may offer a novel therapeutic approach to treat solid tumors by targeting a previously unaddressed pathway in immune regulation affecting not only T cells, but also multiple immune cell types, including dendritic cells and natural killer cells, which all play critical roles in the tumor microenvironment," said Paula O'Connor, M.D., chief medical officer of Nurix. "These data highlight NX-1607's activity as an immuno-oncology agent, showing promising signs of biologic activity and clinical benefit, and supporting its continued development as an innovative next generation checkpoint inhibitor therapy designed to improve outcomes for cancer patients."In a poster titled: First-in-Class CBL-B Inhibitor NX-1607: Phase 1a Data in Patients with Advanced Solid Tumors, data were presented from a total of 82 patients with eleven different tumor types treated across six once-daily (QD) and five twice-daily (BID) dosing regimens ranging from 5 mg to 80 mg total daily dose. Patients were heavily pre-treated with a median of 3 prior regimens including a median of 1 prior chemo/immunotherapy regimen. NX-1607 demonstrated dose-dependent exposure, increases in proximal and distal biomarkers, evidence of peripheral immune activation, and reductions in tumor volume and cancer biomarkers. Despite the advanced stages of disease and the broad range of tumor types included in the trial, NX-1607 demonstrated evidence of clinical activity including reductions in tumor-specific biomarkers (prostate-specific antigen (PSA) in prostate cancer and carcinoembryonic antigen (CEA) in colorectal cancer), long-term stable disease, and a confirmed partial response in a patient with micro-satellite stable colorectal cancer (MSS CRC), a tumor type typically unresponsive to immune checkpoint therapy. As of the 26 July 2025 ...Full story available on Benzinga.com