FibroGen faces more trouble in clinic as DMD drug fails phase 3 trial

FibroGen has now extended its clinical woes into a second month. After a phase 3 fail last month for Evrenzo dashed any remaining hopes of getting the oral anemia drug to market in the U.S., the biotech’s Duchenne muscular dystrophy (DMD) candidate has now flunked a late-stage study.

The LELANTOS-1 trial saw 99 participants aged 12 years and older with non-ambulatory DMD given either the drug, called pamrevlumab, or placebo in combination with systemic corticosteroids. The study didn’t meet the primary endpoint as measured by a score to test the functioning of patients’ arms when measured at Week 52.

“While disappointed with these results, we look forward to sharing the data at a future medical conference to contribute towards the understanding of this devastating disease,” FibroGen CEO Enrique Conterno said in the relatively sparse press release this morning.

No mention was made of the failure's impact, if any, on the wider pamrevlumab program. In DMD alone, there is another phase 3 trial, the 70-person LELANTOS-2 study, due to read out in the third quarter of the year.

Then there’s idiopathic pulmonary fibrosis (IPF). Pamrevlumab was hailed as a potential blockbuster back in 2017 when the company posted phase 2 data suggesting the anti-connective tissue growth factor antibody might be able to muscle in on the lucrative IPF market. Two ongoing phase 3 studies are due to read out in the third quarter of this year and mid-2024, respectively.

FibroGen is even studying pamrevlumab in locally advanced unresectable pancreatic cancer, with a readout from a phase 3 study expected in the first half of next year.

Despite the numerous clinical avenues being explored, today’s news means that both of FibroGen’s lead assets have struggled to prove their worth recently. While Evrenzo has failed to convince U.S. regulators, the anemia drug at least has the green light in China.

The company did add another clinical contender to its portfolio last month in the form of a phase 1 antibody-drug conjugate for prostate cancer and multiple myeloma, which was acquired from Fortis. Before the year is up, FibroGen also plans to seek FDA permission to launch trials of two preclinical candidates: an anti-Gal9 antibody and an anti-CCR8 antibody.