Roche has entered into an agreement to acquire two experimental breast cancer drugs from Regor Therapeutics, a China-based biotechnology startup, for an upfront payment of $850 million. The acquisition focuses on next-generation CDK inhibitors, with the lead candidate, RGT-419B, already in Phase 1 clinical trials. This move strengthens Roche's pipeline in hormone receptor-positive, HER2-negative breast cancer therapies.
RGT-419B: A Next-Generation CDK Inhibitor
RGT-419B is designed to overcome resistance mechanisms associated with current CDK4/6 inhibitors like Pfizer's Ibrance, Eli Lilly's Verzenio, and Novartis' Kisqali. These existing drugs are widely used in various breast cancer settings but can lead to immune, gastrointestinal, and cardiovascular side effects. Roche's presentation highlighted that RGT-419B targets CDK2, a pathway tumors utilize to develop resistance to other therapies, potentially offering a "best-in-class" alternative.
Early data from the Phase 1 trial of RGT-419B showed promising results. In a cohort of patients who had progressed on prior CDK4/6 inhibitor therapy, RGT-419B demonstrated tumor shrinkage in four out of twelve patients. Notably, two patients experienced durable responses lasting through 35 months. Regor has evaluated four dose levels of RGT-419B in the Phase 1 trial. According to Roche, 67% of patients in Phase I dose escalation studies had metastases and had undergone chemotherapy plus other CDK 4/6 treatments, RGT-419B showed no dose-limiting toxicity.
Roche's Expanding Breast Cancer Portfolio
This acquisition aligns with Roche's strategy to broaden its breast cancer portfolio beyond HER2-targeting medicines like Herceptin. The company is also developing inavolisib, a drug potentially approved in the U.S. by November 27 for use in combination with Ibrance. Furthermore, Roche has late-stage trials underway for a treatment aimed at surpassing the efficacy of traditional hormone therapies.
Under the agreement terms, Regor is eligible for additional payments upon achieving specific clinical, regulatory, and commercial milestones. While Regor will continue managing the ongoing Phase 1 trials, Roche will assume responsibility for clinical development, manufacturing, and commercialization activities. The transaction is expected to close in the fourth quarter of 2024, pending customary closing conditions.
