When is a branded drug maker obligated to turn over product samples to competitors working to develop cheaper generic versions?

A test of that question—an antitrust battle between Actelion Pharmaceuticals Ltd. and three of its generic rivals—settled on Friday without offering a definitive answer. But given the timing of the settlement and the history of the case, the obstacles appear steep for branded drug makers looking to keep their samples under wraps.

As we previously reported, the Actelion case concerned whether brand-name drug companies can rely on their regulatory obligations to fend off antitrust claims. The generics—Apotex Inc., Actavis Elizabeth LLC and Roxane Laboratories Inc.—allegedly threatened to sue Actelion after it took steps to bar them from obtaining samples of two of its drugs, Tracleer and Zavesca. Actelion responded with a declaratory judgment suit in September 2012, claiming that it was required by strict Food and Drug Administration rules to minimize the serious, known side effects of its drugs. Allowing the generic companies to access the samples could invite regulatory backlash, the company asserted.

The generic companies filed antitrust counterclaims in December 2012, claiming that Actelion was using the FDA regulations as an excuse to maintain its monopoly on the drugs. The Generic Pharmaceutical Association and the Federal Trade Commission weighed in as amici for the generic companies, while the branded pharmaceutical trade association PhRMA stayed out of the dispute.

U.S. District Judge Noel Hillman in Camden, N.J., declined to dismiss the generics’ counterclaims last October. After that decision, Actelion’s lawyers at Dechert quickly filed a stipulation of dismissal of the litigation with Apotex, which was represented by Zuckerman Spaeder. Judge Hillman signed off on an order dismissing the remainder of the claims on Friday, giving the parties 60 days to move to reopen the case if a final settlement isn’t reached.

Zuckerman Spaeder’s Aitan Goelman said that details of Apotex’s agreement with Actelion are confidential. Given Actelion’s failure to dodge its opponents’ antitrust claims, however, it seems likely the generic companies got at least some of what they were seeking in the case.

Roxane’s counsel at Kirkland & Ellis and Actavis’s at Latham & Watkins didn’t immediately respond to our calls.

A Dechert team led by George Gordon represents Actelion. Dechert declined to comment, and the company didn’t respond to a request for comment.