By Anand Basu
Feb 29 (Reuters) - The U.S. patent office has rejected a patent application from Amarin Corp Plc for its key experimental heart drug.
Amarin's shares fell 11 percent after United States Patent and Trademark Office (USPTO) posted the "non-final rejection" on its website. They closed at $7.75 on the Nasdaq.
A non-final rejection can be appealed by Amarin.
"Most experts say that they will be able to get it (patent) eventually. But, the question is, how many times will it take to get the patent," MKM Partners analyst Jon LeCroy said.
Amarin, which reported quarterly results after market close on Wednesday, said it learned about the patent rejection from the USPTO's website and has not received any letter yet.
"Every time they get a rejection the stock goes down and a month or two later when they refile people start investing thinking that they will get approval," LeCroy said.
The USPTO rejected Amarin's patent application no 12/702,889 on the drug AMR 101, an ultra-purified form of omega-3 fatty acid from fish oil that helps lower triglycerides.