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What happened

Shares of the rare-disease drugmaker Amicus Therapeutics (NASDAQ:FOLD) fell by more than 11% in pre-market trading today after the company announced a $225 million convertible senior note offering. 

So what

Amicus' move to shore up its cash position isn't unexpected in the least. After all, the Food and Drug Administration is requiring the drugmaker to perform an additional clinical study for its oral drug Galafold (migalastat) as a potential treatment for the rare genetic disorder known as Fabry disease. In short, the drugmaker clearly needed a large cash infusion to fund another pivotal-stage trial for Galafold (as well as its other clinical activities). 

Now what

Amicus believes that it should have a full regulatory filing for Galafold ready by late 2019, implying that the drug may be commercially available in the U.S. by 2020.

The good news is that company is starting to generate revenue from Galafold's approval in the EU earlier this year, which should help to shrink its net loss per share moving forward. As an added bonus, Amicus does have other early to mid-stage clinical assets that could act as a backstop in case the FDA continues to stonewall Galafold from reaching the market. 

In all, Amicus is far from a sure thing based on Galafold's uncertain regulatory fate in the U.S., but then again, early stage orphan drugmakers have proven to be great long-term investments for the most part. That's why this speculative biotech stock might be worth buying on this latest dip.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.