FibroGen says Phase 3 ZEPHYRUS-1 study did not meet primary endpoint

FibroGen announced topline results from its Phase 3 ZEPHYRUS-1 trial evaluating the safety and efficacy of pamrevlumab in patients with idiopathic pulmonary fibrosis. The study compared treatment with pamrevlumab to placebo and did not meet the primary endpoint of change from baseline in forced vital capacity at week 48. The mean decline in FVC from baseline to week 48 was 260 ml in the pamrevlumab arm compared to 330 ml in the placebo arm. The secondary endpoint of time to disease progression was also not met. In the safety analysis, pamrevlumab was generally safe and well tolerated and the majority of treatment emergent adverse events were mild or moderate. Treatment-emergent serious adverse events were observed in 28.2% of patients in the pamrevlumab group and 34.3% of patients in the placebo group. Based on the results of ZEPHYRUS-1, ZEPHYRUS-2, the second Phase 3 clinical trial, will be discontinued. FibroGen plans to communicate the results of the ZEPHYRUS-1 study at an upcoming medical forum. “We are deeply disappointed that these results do not support pamrevlumab as a new treatment for IPF,” said Mark D. Eisner, MD, MPH, Chief Medical Officer, FibroGen. “FibroGen would like to thank the patients and clinical trial investigators for their dedication to participating in this study.” FibroGen anticipates reporting topline data from Phase 3 studies with pamrevlumab for the treatment of ambulatory DMD patients in 3Q 2023, locally advanced pancreatic cancer in 1H 2024, and metastatic pancreatic cancer.