Monte Rosa Therapeutics Announces Clinical Supply Agreement to Support Phase 2 Trial Evaluating MRT-2359 in Combination with Apalutamide for the Treatment of Metastatic Castration-Resistant Prostate Cancer

On March 16, 2026 Monte Rosa Therapeutics, Inc. (Nasdaq: GLUE), a clinical-stage biotechnology company developing novel molecular glue degrader (MGD)-based medicines, reported the company has entered into a supply agreement with Johnson & Johnson to evaluate MRT-2359 in combination with ERLEADA (apalutamide) for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) with androgen receptor (AR) mutations in a planned Phase 2 study expected to initiate in the third quarter of 2026. MRT-2359 is an investigational, orally bioavailable, GSPT1-directed MGD discovered and developed by Monte Rosa. ERLEADA is an AR inhibitor developed by Janssen Research and Development, LLC, indicated for the treatment of patients with metastatic castration-sensitive prostate cancer (mCSPC) and patients with non-metastatic castration-resistant prostate cancer (nmCRPC).

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Under the terms of the agreement, Monte Rosa will conduct and sponsor the trial and Johnson & Johnson will provide ERLEADA as part of a supply agreement.

"We are pleased to enter into this supply agreement with Johnson & Johnson to further explore the potential of MRT-2359 in combination with next-generation AR inhibitors such as apalutamide in patients with advanced prostate cancer," said Markus Warmuth, M.D., Chief Executive Officer of Monte Rosa Therapeutics. "Based on the compelling clinical activity observed to date in heavily pretreated patients with AR mutations, we believe this combination approach holds significant promise. Data generated from these studies have the potential to further confirm MRT-2359’s clinical activity and may position the program for advancement into registrational studies, representing an important step forward for prostate cancer patients with limited therapeutic options for this respective patient population."

The planned Phase 2 study of up to 25 mCRPC patients is designed to efficiently assess the efficacy and safety of MRT-2359 plus ERLEADA in mCRPC patients with AR mutations, with potential to expand the study into additional patient subsets, including patients naïve to next-generation AR inhibitors, should the activity in the AR mutant patient population confirm. The study will evaluate PSA response, RECIST response, duration of response, progression-free survival (PFS), radiographic progression-free survival (rPFS), and safety.

Monte Rosa recently announced additional, positive data from the company’s ongoing Phase 1/2 clinical study evaluating MRT-2359 in combination with enzalutamide in heavily pretreated patients with mCRPC. The data were presented at the 2026 ASCO (Free ASCO Whitepaper) Genitourinary (GU) Cancers Symposium on February 26, 2026.

About MRT-2359
MRT-2359 is a potent, highly selective, and orally bioavailable investigational molecular glue degrader (MGD) of GSPT1. MYC-driven cancers, including prostate cancer, depend on enhanced translation of oncoproteins to support rapid growth. MRT-2359 exploits this therapeutic vulnerability by disrupting translation through selective degradation of the translation termination factor GSPT1. MRT-2359 treatment reduced cellular abundance of many prostate cancer-relevant oncoproteins, including AR, MYC, and Cyclin D1-E2F, and demonstrated robust anti-tumor activity across multiple preclinical models of metastatic castration-resistant prostate cancer (mCRPC). MRT-2359 in combination with the AR inhibitor enzalutamide is being investigated in an ongoing Phase 1/2 study (clinicaltrials.gov identifier NCT05546268) in patients with mCRPC. In heavily pretreated mCRPC patients, MRT-2359 plus enzalutamide demonstrated encouraging early signals of clinical response.

(Press release, Monte Rosa Therapeutics, MAR 16, 2026, View Source [SID1234663586])