Monte Rosa announces clinical data from Phase 1/2 study of MRT-2359

Monte Rosa Therapeutics (GLUE) announced updated, positive clinical data from an ongoing Phase 1/2 clinical study evaluating MRT-2359 in combination with enzalutamide in heavily pretreated patients with metastatic castration-resistant prostate cancer. The data, being presented at the 2026 ASCO GU Symposium in San Francisco, CA, build on data released by the company in December 2025. MRT-2359 is an investigational, orally bioavailable, GSPT1-directed MGD discovered and developed by Monte Rosa. The ongoing Phase 1/2 study evaluated 0.5 mg and 0.75 mg of MRT-2359 administered orally on a 21-days-on, 7-days-off drug schedule in combination with enzalutamide, an AR inhibitor. The study population as of the data cutoff date of January 30, 2026 included 23 individuals with advanced CRPC who were heavily pretreated, including 18 previously treated with a second-generation AR inhibitor, 19 previously treated with taxane chemotherapy, and 13 previously treated with Pluvicto. For analysis of efficacy, all patients were required to be evaluable for RECIST measurable disease and not known to have a neuroendocrine phenotype.