In the U.S., which is home to roughly 30,000 ALS patients, Amylyx has seen strong demand for Relyvrio. The company reported $71 million in product revenue in the three month period between January and March, far surpassing the expectations of Wall Street analysts.

Amylyx set the list price for Relyvrio at $158,000 for a year’s supply, which is similar to other marketed ALS treatments but also well above what one prominent watchdog of drug costs believes to be reasonable.

Sales could grow further with an approval in Europe, where more than 30,000 ALS patients live by Amylyx’s estimates.

Graig Suvannavejh, an analyst at the investment firm Mizuho Securities, sees Amylyx’s drug as still having a shot at European approval. In a note to clients late last month, he wrote about his team conducting an “exhaustive review” of cases where the CHMP adopts a negative opinion of a drug, only to have the drug’s developer request a re-examination. Among 36 cases, the committee reversed its conclusion in nine, which then led to approval.

Suvannavejh and his team identified two common threads among the reversals: the drugs targeted diseases that greatly needed more treatment options, and their potential benefits outweighed the possible safety risks. The analyst believes Amylyx’s drug fits this description, and models an 80% likelihood that European regulators eventually give it the green light.

Amylyx’s share value had dipped around 7% by late morning Friday, to trade at roughly $23 apiece.