The Novato, CA-based biopharmaceutical company is focused on developing and commercializing treatments for rare and debilitating diseases.
The downgrade comes after the company reported its 2015 fourth quarter results yesterday.
Raptor posted a net loss of 17 cents per share, narrower than the loss of 18 cents per share analysts had expected. Revenue for the quarter was $24.7 million, missing Wall Street's estimates of $26.08 million.
For the full-year, the company forecasts revenue between $115 and $125 million.
"Procysbi revenue a little light in 4Q15 as Raptor Pharmaceuticals provided in-line 2016 guidance and moved Huntington's to the back seat," JMP Securities said in an analyst note.
Procysbi is for the treatment of nephropathic cystinosis, which begins in infancy and causes poor growth and a certain type of kidney damage.
"While we are pleased that the company is taking prudent steps to deprioritize investment in Huntington's disease, it impacts our model as it was a significant driver of long-term growth," the firm added.
Shares of Raptor are down 5.51% to $3.60 at the start of trading on Friday.
Separately, TheStreet Ratings Team has a "Sell" rating with a score of D on the stock.
This is driven by several weaknesses, which should have a greater impact than any strengths, and could make it more difficult for investors to achieve positive results compared to most of the stocks covered.
The company's weaknesses can be seen in multiple areas, such as its deteriorating net income, generally high debt management risk and generally disappointing historical performance in the stock itself.
Recently, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.
You can view the full analysis from the report here: RPTP