A federal judge ruled that Amarin can now share unapproved off-label information about an FDA-approved drug as long as it is truthful and not misleading, a decision that bolsters the pharmaceutical industry’s case against current off-label marketing restrictions.

Amarin, which sells the Vascepa prescription fish-oil pill, in May filed a suit against the FDA claiming the regulator violated the company’s First Amendment rights by limiting its ability to legally communicate benefits of the drug because they are not included on the FDA-approved label.

The case is the “first decision that clearly and unequivocally rebuffs the government’s view that off-label promotion can be prosecuted even if it is truthful and non-misleading,” Floyd Abrams, a partner at Cahill Gordon & Reindel and Amarin’s counsel, said during a call with reporters on Friday.

The opinion follows oral arguments on July 7 during which the government sought to defend its off-label marketing policies in the case, known as Amarin v. FDA, and came amidst a busy summer for healthcare policy in which legislation that could also bring change to the FDA’s off-label enforcement advanced, as well.

Vascepa is approved to treat patients with very high triglycerides, but the FDA declined to approve the drug for a secondary indication—treating patients with lower but still persistently high triglycerides, a much broader indication. Amarin sued, seeking to promote Vascepa among that larger and less severely affected patient population.

The decision by Paul Engelmayer, a district judge in the US District Court for the Southern District of New York, on Friday grants preliminary relief to Amarin, based on the precedent set in an earlier case involving the pharma sales rep Alfred Caronia. 

In 2012 the US Court of Appeals Second Circuit vacated the conviction of Caronia, a former sales rep for Jazz Pharmaceuticals. His conviction was tied to his giving off-label information about narcolepsy drug Xyrem to physicians. Although the information he provided was accurate and truthful, it was not included on the drug’s FDA-approved label.

Amarin made a similar argument, contending that the information it wants to provide to physicians is mostly derived from an FDA-approved study and from FDA materials.

“At this stage, the court’s judgment is to err on the side of caution, meaning in favor of giving doctors more, not less, information,” Engelmayer wrote in the Aug. 7 ruling.  

The company said in a statement it plans to begin promotional activities based on the opinion “as soon as possible.”

The case has wider implications for the industry and will likely add force to ongoing efforts to change what are widely considered outdated regulations.

Current laws dictate that drug companies, including sales reps employed by pharma firms, cannot share off-label information with patients, payers or healthcare providers.

However, off-label use of prescription drugs is widespread, in part because physicians can legally prescribe drugs for unapproved uses. Off-label prescriptions make up an estimated 21% of the 160 drugs most commonly prescribed in the US, according to a report in Health Affairs.

Dozens of drug companies, including several of the world’s largest drugmakers, have paid billions of dollars to settle government lawsuits claiming they deliberately marketed drugs off-label to boost profits and in some cases knowingly caused patient harm.

“Healthcare professionals routinely lawfully prescribe FDA-approved drugs for unapproved uses, and informed patient care relies upon doctors having access to accurate, comprehensive, and current information about such uses,” Mit Spears, PhRMA’s general counsel, said in a statement. “Biopharmaceutical manufacturers are an important source of this knowledge.

The FDA declined to comment.