Three In A Row: FibroGen's Investigational Drug Flunks In Another Study For Rare Disease In Young Boys

Tuesday, FibroGen Inc FGEN announced topline data from the Phase 3 LELANTOS-2 trial of pamrevlumab for ambulatory patients with Duchenne muscular dystrophy (DMD) on background systemic corticosteroids. 

DMD is an inherited progressive muscular weakness disorder primarily affecting young boys.

The study did not meet the primary endpoint of change in the North Star Ambulatory Assessment (NSAA) total score from baseline to week 52.

NSAA measures functional motor abilities in ambulant children with DMD. It is usually used to monitor the progression of the disease and treatment effects.

Secondary endpoints measured by change from baseline at week 52 in 4-stair climb velocity, 10-meter walk/run test, time to stand, time to loss of ambulation, and proportion of patients with greater than 10 seconds in the 10-meter walk/run test were also not met.

Preliminary safety data showed that pamrevlumab was generally safe and well tolerated. The majority of treatment-emergent adverse events were mild or moderate.

FibroGen is evaluating the totality of the data, including other pre-specified endpoints, to determine the next steps for the program. 

In June, FibroGen's Phase 3 LELANTOS-1 trial of pamrevlumab for non-ambulatory DMD patients with on-background corticosteroids failed to meet the primary endpoint of the Performance of the Upper Limb 2.0 score at week 52 compared to baseline. 

The company's recently released topline results from its Phase 3 ZEPHYRUS-1 trial of pamrevlumab for idiopathic pulmonary fibrosis also failed to meet the primary endpoint of change in forced vital capacity at week 48.

William Blair analysts Andy Hsieh and Alexandra Ramsey say limited data support the Phase 3 LAPIS trial in locally advanced pancreatic cancer. Since a previous interim look at event-free survival prompted the trial to continue to the overall survival primary endpoint, investors do not seem bullish on the trial. 

Given the LELANTOS-1 setback, the failure of LELANTOS-2 is somewhat expected, but the analysts seem to be surprised that the pamrevlumab arm performed numerically worse than the placebo arm.

Other pipeline assets are too early to assess their commercial prospects properly.

Price Action: FGEN shares are down 22.3% at $1.00 during the premarket session on the last check Wednesday.