OxyContin® (oxycodone hydrochloride extended-release tablets)
Case Name: Knoa Pharma LLC v. Accord Healthcare, Inc., No. 2025-1060, 2026 WL 1643329 (Fed. Cir. June 8, 2026) (Circuit Judges Hughes and Stoll and Chief District Judge Seeborg presiding; Opinion by Seeborg, J.) (Appeal from D. Del., Bryson, J.)
Drug Product and Patent(s)-in-Suit: OxyContin® (oxycodone hydrochloride extended-release tablets); U.S. Patent No. 11,304,908 (“the ’908 patent”)
Nature of the Case and Issue(s) Presented: Knoa Pharma, formerly Purdue Pharmaceuticals L.P., owns the ’908 patent, which is directed to tamper-resistant extended-release opioid dosage forms. Purdue developed the claimed technology in response to abuse of the original OxyContin product, which could be crushed and snorted or mixed with liquid and injected to deliver oxycodone more rapidly than intended. Purdue’s later abuse-deterrent formulation used polyethylene oxide (“PEO”) and heat treatment to make tablets more resistant to crushing and injection abuse.
The asserted claim on appeal, claim 18, depends from claims 1 and 17. Claim 1 recites a solid oral extended-release dosage form comprising a shaped, convection-heated, and cooled matrix containing PEO and an opioid analgesic, with the PEO particles adhering to or fusing within the matrix. Claim 17 further requires that the matrix be shaped into a tablet and heated “in a coating pan” for at least about 5 minutes at a temperature of at least about 60°C. Claim 18 narrows the opioid analgesic to oxycodone or a pharmaceutically acceptable salt thereof.
Accord filed an ANDA seeking approval to market a generic version of OxyContin. Purdue sued and Accord stipulated to infringement but challenged the asserted claims as invalid for obviousness. After a bench trial, the district court held the asserted claims invalid in view of the Bartholomäus prior art reference. Purdue appealed and the Federal Circuit affirmed.
Why Accord Prevailed: The Federal Circuit held that the district court did not clearly err in finding that a POSA would have been motivated to modify Bartholomäus by using a coating pan to heat the tablets. Bartholomäus taught an abuse-deterrent opioid tablet formulation containing PEO and taught hardening the tablets by heating them. The key difference was that Bartholomäus used a heated tablet press, which was not readily scalable for commercial production, whereas claim 18 required heating in a coating pan.
Accord’s expert testified that coating pans, ovens, and fluid bed dryers were common pieces of equipment in pharmaceutical manufacturing and could process large quantities of tablets. She also explained that a coating pan would have been especially attractive because it could be used to cure tablets at scale and then apply a coating, improving manufacturing efficiency. The district court found Accord’s expert’s testimony credible and convincing, and the Federal Circuit held that those credibility determinations were entitled to substantial deference.
Purdue argued that the district court improperly “collapsed” claim 18’s coating-pan limitation into claim 1’s broader convection-heating limitation. The Federal Circuit rejected that argument. The district court addressed multiple asserted claims, some of which required only convection heating, but it expressly recognized that claim 18 separately required heating in a coating pan. Thus, the district court did not commit legal error in its claim-by-claim obviousness analysis.
The Federal Circuit also rejected Purdue’s challenge to the district court’s finding of a reasonable expectation of success. Purdue’s arguments largely asked the appellate court to reweigh the evidence and credit Purdue’s contrary evidence over Accord’s expert’s testimony. But under the clear-error standard, it was not enough for Purdue to show that the evidence could have supported a different conclusion.
Lastly, the Federal Circuit affirmed the district court’s treatment of objective indicia. Purdue argued that there was a long-felt but unmet need for abuse-deterrent oxycodone tablets. The district court found that Bartholomäus had already met that need by disclosing an extended-release opioid formulation with abuse-deterrent properties. On appeal, Purdue reframed the need as one for scalable, commercially practical abuse-deterrent tablets, but the Federal Circuit held that this theory was forfeited and, in any event, was not commensurate in scope with claim 18 because the claim was directed to a dosage form rather than a scalable manufacturing process.
