FPI-2265 Phase 2 Dosing Begins in AlphaBreak Prostate Cancer Trial

Fusion Pharmaceuticals, a company in the midst of clinical-stage oncology research, has initiated a new phase in its AlphaBreak clinical trial. This program is centered around the drug candidate FPI-2265, which is being tested for its efficacy in treating metastatic castration-resistant prostate cancer (mCRPC). The trial has reached a significant milestone with the dosing of the first patient in its Phase 2 segment.

FPI-2265 is an innovative radioconjugate that utilizes actinium-225, an isotope that emits alpha particles. This characteristic positions it as a potential next-generation cancer treatment, as alpha particles can deliver a high radiation dose over a short distance, which may enhance the destruction of cancer cells while sparing the surrounding healthy tissue.

The AlphaBreak trial is structured as a Phase 2/3 study, which is a randomized, open-label, and multicenter evaluation. It aims to assess the safety and effectiveness of FPI-2265 in mCRPC patients who have previously undergone 177Lu-PSMA radiotherapy. The Phase 2 segment will particularly focus on determining if alternative dosing regimens can offer additional benefits in terms of safety and efficacy, compared to the previously studied dosage of 100 kBq/kg administered every eight weeks.

Enrollment for the Phase 2 portion is anticipated to include approximately 60 patients by the close of 2024. Following the analysis of Phase 2 data and consultation with the U.S. Food and Drug Administration (FDA) to establish the recommended Phase 3 dosing strategy, the Phase 3 segment of the AlphaBreak trial is projected to enroll around 550 patients, with a commencement expected in 2025.

Fusion Pharmaceuticals is dedicated to the advancement of next-generation radioconjugates, with FPI-2265 being a leading example. The company's strategy involves linking alpha particle-emitting isotopes with various targeting molecules to selectively target tumors. In addition to FPI-2265, which is aimed at PSMA for mCRPC, Fusion is also developing novel radioconjugates for solid tumors.

Fusion operates a state-of-the-art radiopharmaceutical manufacturing facility that adheres to Good Manufacturing Practice standards, ensuring the supply chain for its growing pipeline of radioconjugates. The company has also secured strategic actinium supply agreements, which are crucial for the development of its leading drug candidate.

The company's approach to developing FPI-2265 is underpinned by promising results from previous trials and the belief that it can offer a significant new treatment option for mCRPC patients in need of further therapeutic choices, especially following progression on lutetium-based radiotherapy. The initiation of the AlphaBreak trial signifies a crucial step towards bridging the existing treatment gap and potentially providing a much-needed alternative for these patients.