FibroGen Inc. has announced the initiation of a Phase 2 monotherapy, dose-optimization trial of FG-3246, a first-in-class antibody-drug conjugate $(ADC)$ targeting CD46-expressing cancer lesions in patients with metastatic castration-resistant prostate cancer (mCRPC). The trial, which will enroll 75 patients in the post-androgen receptor signaling inhibitor and pre-chemotherapy setting, will also evaluate FG-3180 as a companion PET imaging agent and potential predictive biomarker for patient selection. An interim analysis of the Phase 2 study is expected in the second half of 2026. Additionally, topline results from an ongoing investigator-sponsored study of FG-3246 in combination with enzalutamide in mCRPC patients are anticipated in the fourth quarter of 2025. No results have been presented at this time.