The agency’s decision follows review of the double-blind PRAISE Phase 2b study (NCT01890265) results, which showed that, over 48 weeks, intravenous delivery of 30 mg/kg pamrevlumab halted lung fibrosis (scarring) progression in patients with mild-to-moderate IPF, in comparison to placebo. This correlated with improved lung function, as measured by forced vital capacity.
The trial included a total of 103 patients and also showed that treatment with pamrevlumab was well-tolerated, with no safety risks.
“This Fast Track designation reflects recognition of the great need for a new therapeutic to help patients diagnosed with IPF to reduce the burden and progression of this debilitating disease and another positive step in developing pamrevlumab,” Elias Kouchakji, MD, FibroGen’s senior vice president, clinical development and drug safety, said in a press release.
The FDA grants fast track designation to speed the development and review of potential medications for serious conditions with the aim of filling an unmet medical need. The designation enables more frequent communication with the FDA regarding clinical trials’ designs and collection of all needed data for regulatory approval. Treatment candidates on fast track status also may benefit from accelerated approval and priority review.
“We look forward to advancing pamrevlumab into Phase 3 studies early next year,” Kouchakji added.
Pamrevlumab is an antibody targeting a specific factor — called connective tissue growth factor (CTGF) — known for its key role in promoting fibrosis and related diseases, including IPF, pancreatic cancer, and Duchenne muscular dystrophy.
Prior preclinical data in a mouse model of IPF show that treatment with pamrevlumab led to lower lung density — suggesting reduced lung fibrosis and remodeling — than with either Esbriet (pirfenidone, by Genentech) or Ofev (nintedanib, by Boehringer Ingelheim), two approved medications for IPF.
Besides IPF, the San Francisco-based company also will test pamrevlumab in Phase 3 stage in pancreatic cancer. The therapy is currently being tested in a Phase 2 study of Duchenne muscular dystrophy (NCT02606136). Pamrevlumab was granted orphan drug designation in both IPF and pancreatic cancer.
In March, the antibody therapy received the FDA’s fast track designation for the treatment of locally advanced unresectable pancreatic cancer.