Amicus Shares Fall On Another Bump in Rough Road To U.S. Fabry Nod

Xconomy New York — 

After more than a decade of ups and downs, Amicus Therapeutics in May won its first drug approval, of Fabry disease pill migalastat (Galafold), in Europe. But the Cranbury, N.J. company won’t see the drug sold in the U.S. for at least a few more years.

Amicus (NASDAQ: FOLD) said this afternoon that the FDA won’t consider approval of migalastat based on the data the company has accrued. The FDA wants Amicus to produce more data on gastrointestinal symptoms, which means running another clinical trial for migalastat. Amicus says the study will be a randomized, 12-month, placebo-controlled trial of roughly 35 Fabry patients who have GI symptoms.

Amicus says it will begin enrolling patients next year and expects data in 2019, at which point it will seek FDA approval. Shares of Amicus plummeted about 30 percent on the news.

Investors were expecting Amicus to ask the FDA for a faster-than-usual approval based on data that measures migalastat’s impact on levels of a fatty substance, called GL-3, that builds up in the kidney cells of Fabry patients. Amicus had been hoping that the data it had already accrued would be sufficient for approval on an “accelerated” basis, on less evidence than the agency typically requires.

“While we believe that the totality of the data from our studies with migalastat support the submission of a new drug application today, we acknowledge the FDA’s position that accelerated approval based on kidney GL-3 reduction is not currently an option,” said CEO John Crowley in a statement.

People who have Fabry disease, a rare disorder, don’t properly clear out a certain type of fat from their cells, which can lead to kidney damage or heart attacks. It is typically treated with infusions of a genetically engineered enzyme that replaces its missing or faulty counterpart. Enzyme replacement therapies like Genzyme’s agalsidase beta (Fabrazyme) and Shire’s agalsidase alfa (Replagal)—the only other Fabry therapies approved in Europe—have to be infused every two weeks. Migalastat is a pill.

After a big trial failure in 2012, Amicus tried to find better results in retrospect by digging through the data. The FDA was lukewarm to the idea, and Amicus had on-again, off-again ambitions for U.S. approval the next few years. In March 2015 Amicus said it aimed to seek accelerated approval of migalastat in the U.S., but changed those plans after what it called “follow-up interactions” with the agency.

Today’s announcement at least makes it clear that the company is not going to try for an accelerated approval.

Migalastat is approved in Europe for patients with Fabry-causing mutations that lead to about 35 to 50 percent of cases. An estimated 5,000 to 10,000 patients worldwide are diagnosed with Fabry. Amicus estimates that about 25 percent of them are in the U.S.

Here’s more on Amicus and migalastat’s previous setbacks in the U.S.