Amarin's Eicosapentaenoic Acid Patents All Found Invalid - Lessons on Obviousness

March 31, 2020
Post by Sarah M. Luth

Earlier this week the U.S. District Court for the District of Nevada issued a decision in the case of Amarin Pharmaceuticals, Inc. v. Hikma Pharmaceuticals USA Inc., regarding the validity of six patents owned by Amarin Pharmaceuticals for the drug Vascepa. Amarin filed suit to prevent Hikma and Dr. Reddy’s Laboratories (DRL) from launching generic competitor drugs to Vascepa, and the Defendants counter-claimed that Amarin’s six patents were invalid as obvious, among other things.

Vascepa is used to treat patients with severe hypertriglyceridemia, a condition where an individual has extremely elevated blood serum levels of triglycerides, requiring the rapid lowering of plasma triglycerides (TG). Amarin’s patents at issue are directed to compositions comprising at least 96% ethyl eicosapentaenoate (EPA) with little or no docosahexaenoic acid [DHA] or its esters, and also methods of lowering the levels of fats in the bloodstream using purified omega-3 fatty acids from fish oil.

The Defendants have patents directed to a method of reducing triglycerides in a person having elevated triglyceride levels by administering a fatty acid composition comprising at least 96% of all fatty acids present, EPA or ethyl EPA, and substantially no docosahexaenoic acid or its esters for a period of 12 weeks.

As evidence of the obviousness of Amarin’s patents at issue, the Defendants submitted a number of clinical studies demonstrating the ability of EPA to lower triglyceride levels. The District Court found that a primary difference between the prior art studies and Amarin’s patents was that the prior art primarily relied on a mixture of DHA and EPA, while Amarin’s claims exclude the presence of DHA.

Amarin’s patents exclude the presence of DHA because it was linked to an undesirable increase in LDL-C. In the prior art, patients would need to take a statin alongside a dose of EPA/DHA to mitigate the increase in LDL-C. The District Court found that a skilled artisan would have been motivated to know which active ingredient in the prior art—DHA or EPA—caused the LDL-C increase, and would have further been motivated to develop a single pill that treats severe hypertriglyceridemia without the LDL-C increases. According to the Court, these “key premises” “lead directly to the motivation to combine [and/or modify] and [a] reasonable expectation of success.”

Amarin’s evidence to the contrary, in particular evidence of secondary considerations such as commercial success and praise, was not persuasive to the Court. The Court conceded that the satisfaction of long-felt need and commercial success weighed in Amarin’s favor. However, there was a strong prima facie case of obviousness based on a motivation to combine, and were no unexpected benefits of Vascepa because the prior art established that EPA did not raise LDL-C levels,

The Court concluded that all of Amarin’s claims were invalid as obvious. Amarin has already indicated they plan on appealing the District Court ruling. Although this ruling will most likely be reviewed and clarified by the Federal Circuit, patentees filing patent applications based on known compositions should take note of Amarin’s struggle to establish non-obviousness, by having extensive experimental data showing efficacy outside of ranges known in the art and/or unexpected results, functions, or uses.

Post Categories

Comments (0)
Post a Comment

Captcha Image
Return to the Filewrapper Blog

Search Posts


The attorneys of McKee, Voorhees & Sease, P.L.C. designed this blog as an informational and educational resource about intellectual property law for our clients, other attorneys, and the public as a whole. Our goal is to provide cutting-edge information about recent developments in intellectual property law, including relevant case law updates, proposed legislation, and intellectual property law in the news.


McKee, Voorhees & Sease, P.L.C. provides this blog for general informational purposes only. By using this blog, you agree that the information on this blog does not constitute legal or other professional advice and no attorney-client or other relationship is created between you and McKee, Voorhees & Sease, P.L.C. Do not consider this blog to be a substitute for obtaining legal advice from a qualified, licensed attorney. While we try to revise this blog on a regular basis, it may not reflect the most current legal developments. We consciously refrain from expressing opinions on this blog and instead, offer it as a form of information and education, however if there appears an expression of opinion, realize that those views are indicative of the individual and not of the firm as a whole.

Connect with MVS

Enter your name and email address to recieve the latest news and updates from us and our attorneys.

Subscribe to: MVS Newsletter

Subscribe to: Filewrapper® Blog Updates

  I have read and agree to the terms and conditions of McKee, Voorhees & Sease, P.L.C.