On August 7, 2015, in Amarin Pharma Inc. v. Food and Drug Administration, the US District Court for the Southern District of New York granted Amarin Pharma Inc. (Amarin), maker of Vascepa, a preliminary injunction against the Food and Drug Administration (FDA) (119 F. Supp. 3d 196 (S.D.N.Y. 2015)). Under the authority of the First Amendment, the preliminary injunction allows drug makers to promote unapproved off-label uses for drugs that have only been FDA-approved for another use, if done by truthful and non-misleading statements.

The suit arises out of the FDA's rejection of Amarin's application seeking approval of a second use for Vascepa, its triglyceride-lowering cardiovascular drug. Amarin sought and received approval to market Vascepa for treatment in adult patients with triglyceride levels above 500mg/dL of blood. Afterwards, Amarin sought FDA approval to market Vascepa for patients with triglyceride levels between 200 and 499mg/dL of blood, who are also on statin therapy.

In relation to the second application, a FDA-approved study determined that Vascepa was indisputably effective at reducing triglyceride levels in patients with triglyceride levels between 200 and 499mg/dL. However, the FDA Advisory committee ultimately denied Amarin's application. The FDA determined that although Vascepa reduced applicable triglyceride levels it could not be approved because of newly discovered information.

The FDA refused to allow Amarin to use the study results in the Vascepa label and, at issue in this suit, stated that any marketing that included reference to the study's findings could result in liability for misbranding. Amarin restrained from promoting the off-label use and brought a First Amendment challenge to the FDA regulations. In its complaint Amarin sought declaratory relief, confirming:

Amarin argued that under United States v. Caronia, 703 F.3d 149 (2d. Cir. 2012), a misbranding action could not be brought against a manufacturer for conduct that consisted solely of truthful and non-misleading speech. Amarin argued that the FDA could not threaten to bring such an action against a manufacturer whose promotional statements were truthful and that an injunction or declaratory relief was necessary to eliminate the chilling effect of the threat. The FDA argued Caronia was fact specific and not applicable to Amarin.

Caronia is a previous case that dealt with the promotion of an off-label use for an already-approved FDA drug. In Caronia, a sales representative was convicted for conspiracy to misbrand a drug based on his truthful statements regarding off-label uses of a FDA approved drug. The US Court of Appeals for the Second Circuit overturned the conviction and held that the manufacturer's truthful speech promoting an off-label use was constitutionally protected commercial speech. The Second Circuit held that the First Amendment places limits on the FDA's ability to prosecute for misbranding when only truthful speech is used to promote an off-label use.

The district court held that Caronia applies to all potential off-label misbranding actions that deal with truthful, non-misleading statements. The district court granted Amarin's preliminary injunction holding:

Manufacturers who market or promote a drug's off-label use risk criminal liability for misbranding under the Food, Drug, and Cosmetic Act, which prohibits the introduction or delivery for introduction into interstate commerce of any food, drug, device, tobacco product, or cosmetic that is adulterated or misbranded (21 U.S.C. § 331(a)). It is a well-known, widespread, and legal practice for doctors to prescribe drugs to patients for off-label uses. But the FDA's stance has limited drug manufacturers from marketing these well-documented but non-FDA-approved off-label uses until now. According to the Amarin decision, drug manufacturers can promote off-label uses while marketing the drug to doctors and patients, so long as the statements used to market these secondary uses are truthful and non-misleading.

For more information on the US drug regulatory system see Country Q&A, Medicinal product regulation and product liability in the United States: overview.

On March 8, 2016, the US District Court for the Southern District of New York approved settlement terms concerning Amarin's truthful and non-misleading promotion of Vascepa's off-label uses. Under the settlement agreement: