FibroGen slumps on second failed DMD study

FibroGen has revealed that a second late-stage clinical trial of Duchenne muscular dystrophy (DMD) therapy pamrevlumab has failed to show efficacy, extending a run of bad news with the anti-connective tissue growth factor (CTGF) antibody.

Shares in the San Francisco biotech were down more than 22% in after-hours trading after it said top-line results from the LELANTOS-2 study of pamrevlumab given on top of corticosteroids to ambulatory DMD patients failed to show a significant improvement on the North Star Ambulatory Assessment (NSAA) scale.

The drug was also unable to improve secondary outcome measures in the study, such as the four-stair climb velocity, 10-metre walk/run test, time to stand, time to loss of ambulation, and the proportion of patients with greater than 10 seconds in the 10-metre walk/run test.

The failure across the board matches the outcome of the LELANTOS-1 study in non-ambulatory DMD patients, which was reported in June, and also comes after the drug was unable to show efficacy in the phase 3 ZEPHYRUS-1 study in patients with idiopathic pulmonary fibrosis.

The official line is that FibroGen is now evaluating the DMD data before deciding on the next steps for the programme, although there was an air of finality in its official statement.

"We are committed to sharing all learnings from this trial with the Duchenne community and hope that there are insights that may help future efforts to develop treatments for this devastating disease," said interim chief executive Thane Wettig, who took control of FibroGen after Enrique Conterno stepped down last month.

The failure leaves FibroGen waiting on the outcome of LAPIS and PanCAN Precision Promise studies in pancreatic cancer, due to report in the first half of next year, to see if there is any prospect of charting a course to market with the drug anytime soon.

Since coming on board, Wettig has already implemented a cost-reduction programme aimed at shaving $100-$120 million off the biotech's annual costs and extending its operating cash until 2026.

The company is drawing a revenue stream from anaemia therapy roxadustat, adding $24 million in the second quarter from overseas markets, although the drug remains stalled in the US.

With prospects for pamrevlumab looking shaky, greater attention will now be paid to earlier-stage projects. That includes FG-3246, a phase 3-ready CD46-targeting antibody-drug conjugate (ADC) for the treatment of metastatic castration-resistant prostate cancer that it licensed in May from Fortis Therapeutics.