Pharmaceutical marketing and legal experts are closely watching a lawsuit filed in September by Pacira Pharmaceuticals following Amarin’s legal success last summer.

Amarin had sued the FDA for the right to promote some off-label uses of its top-selling drug, Vascepa.

Pacira seeks injunctive relief so that it can promote its painkiller Exparel as a postsurgical treatment for multiple types of surgery sites.

The FDA in 2011 had approved Exparel as a treatment for postsurgical pain. The agency later told Pacira in a warning letter, issued by the FDA’s Office of Drug Promotion, that the company could only market the therapy as a postsurgical treatment for the two surgeries cited in the pivotal clinical trials.  

The company later issued a “Dear Healthcare Provider Letter” and a corrective journal ad.

Pacira and two independent physicians alleged that the warning letter violated the drugmaker’s First Amendment rights. Pacira’s suit was filed in US District Court for the Southern District of New York, where Amarin filed its case.   

Court documents filed last week said the FDA’s response to the lawsuit is due Nov. 12. An FDA spokesperson said the agency does not comment on ongoing or pending litigation.

The Medical Information Working Group, a coalition of pharmaceutical and medical-device manufacturers, and PhRMA, the industry’s lobbying arm, on Oct. 15 filed amicus briefs in support of Pacira.

“When FDA denies protection to the indications unambiguously set forth in a product’s approved labeling, it chills that critically important speech and empowers arbitrary regulatory decision-making that impinges on First Amendment rights,” PhRMA said in the brief.

PhRMA’s brief goes on to reference the Amarin case, as well as the Caronia and IMS Health cases, which make up the industry’s legal argument in support of certain forms of off-label marketing.

The Amarin case is similar in some ways to Pacira’s allegations. The company had sued the FDA for the right to legally market some off-label uses of its fish-oil pill, Vascepa. A federal judge in August ruled in favor of Amarin and the drugmaker has since moved forward with such marketing plans.

Marketers “are watching Pacira even more closely,” said James Beck, a lawyer for law firm Reed Smith. “This could become a trend.”

Although the case may have wider implications for the industry, it may also directly impact the company’s revenue and performance. Exparel generated $59.7 million in sales in the third quarter of 2015, up 19% from the $50.2 million in revenue the drug brought in during the same period  a year ago. Exparel makes up 97% of Pacira’s total product sales.