Despite the “unfortunate” failure, William Blair analysts do not believe that the utreloxastat readout will heavily affect PTC, instead postulating that the upcoming FDA decision on its phenylketonuria candidate sepiapterin will be a stronger driver of the biotech’s stock.

But utreloxastat had little effect on ALS in the phase 2 trial. PTC powered the study to show whether twice-daily oral dosing of utreloxastat could achieve a two-point difference on ALSFRS, an instrument for evaluating the functional status of ALS patients. The drug candidate fell short of that bar.

The announcement means the company will be pulling the plug on the CardinALS trial after its amyotrophic lateral sclerosis drug failed to halt disease progression.

PTC Therapeutics (NASDAQ:PTCT) said a Phase 2 placebo-controlled study of its ALS drug candidate utreloxastat failed to meet its primary and secondary efficacy endpoints. The biotech company said the drug failed to demonstrate statistical significance in the slowing of disease progression,

PTC Therapeutics' Phase II trial for utreloxastat in ALS failed to meet its primary endpoint, showing no significant improvement in slowing disease progression. This follows a tough year for ALS drug development,