What happened

Shares of Amicus Therapeutics (FOLD 0.97%) were soaring 9.7% higher at 12:07 p.m. EDT on Wednesday. The big gain came after Cantor Fitzgerald analyst Kristen Kluska upgraded Amicus stock to overweight from neutral.

So what

It's best to take analysts' ratings with a grain of salt. However, understanding the reason behind their optimism about a given stock can be helpful.

In this case, Cantor Fitzgerald's Kluska likes the prospects for Amicus because she thinks the company's gene therapy candidates are promising based on recent clinical updates. That's a pretty good reason to upgrade the biotech stock.

Two scientists looking through microscopes

Image source: Getty Images.

At a major clinical meeting earlier this year, Amicus presented positive results from its late-stage study evaluating AT-GAA in treating Pompe disease, a genetic disorder that causes sugar to build up in the body and damage muscles and organs. At the same meeting, it also reported good initial results from a phase 1/2 study of its CLN3 gene therapy in treating Batten disease, a neurological disorder that primarily affects children.

Now what

Amicus Therapeutics plans to submit for U.S. regulatory approval of AT-GAA in the second quarter of this year. The company expects to file for regulatory approval of the experimental drug in the European Union and other countries later in 2021.