FibroGen lays off 75% of US staff as cancer drug flunks 2 more trials

FibroGen is radically restructuring its business, laying off 75% of its U.S. staff and stopping investment in its lead candidate in response to the failure of two late-phase pancreatic cancer clinical trials.

One year ago, FibroGen laid off 104 employees, around one-third of its U.S. workforce, after the failure of pamrevlumab in two phase 3 trials. Work on two pancreatic cancer studies continued. At a Goldman Sachs event in June, FibroGen CEO Thane Wettig framed the cancer readouts as a pivot point for the biotech—either hit the endpoints and file for approval or miss and be forced to restructure.

The company revealed yesterday that both trials missed their primary endpoints, and Wettig swiftly followed through on his vow to reshape the business for a post-pamrevlumab future. It means that FibroGen is implementing an immediate and significant cost-reduction plan in the U.S.

The plan entails the termination of investment in pamrevlumab R&D and a 75% reduction in FibroGen’s U.S. workforce. Including ex-U.S. employees, FibroGen had 486 staffers at the end of last year. 

FibroGen also plans to “expeditiously wind down any remaining pamrevlumab obligations.”

That rapid retreat from pamrevlumab reflects the results of two studies that dealt the killer blow to the anti-CTGF antibody. Called a hot prospect in 2017 on the back of midphase idiopathic pulmonary fibrosis (IPF) data, the candidate floundered once it reached pivotal trials. Failures in IPF and Duchenne muscular dystrophy precipitated last year’s layoffs and left pamrevlumab with two shots at redemption.

The Pancreatic Cancer Action Network (PanCAN) was studying pamrevlumab in metastatic pancreatic cancer. In parallel, FibroGen was running a trial in locally advanced, unresectable pancreatic cancer. The phase 2/3 PanCAN trial cleared an interim assessment, which showed the study had at least a 35% chance of success, but ultimately found pamrevlumab had no significant effect on overall survival (OS).

FibroGen’s phase 3 trial in another pancreatic cancer population reported a median OS of 17.3 months in people who received pamrevlumab on top of a chemotherapy regimen. Median OS in patients who got placebo plus chemotherapy was 17.9 months.

William Blair analysts said yesterday that they believed “investors had exceedingly low expectations for pamrevlumab in pancreatic cancer” going into the readout because of the candidate’s failures in other indications and the industrywide history of struggles to improve outcomes in the solid tumor. Even so, investors sent the stock down 45% to $0.57 in premarket trading.

The failure of pamrevlumab leaves FibroGen focused on a clutch of earlier-stage candidates that it has in-licensed. FG-3246, a CD46-directed antibody-drug conjugate, is the most advanced pipeline prospect, with a phase 1/2 trial set to start this year.

William Blair analysts said “investor inbounds on FibroGen have increased markedly following the recent M&A activities in the ADC field and competitive top-line data releases.” However, the analysts cautioned that FG-3246 is the only pipeline candidate currently in the clinic, and a potentially registrational-enabling study is still “several years from initiation.”