Case Name: Horizon Medicines LLC v. Alkem Labs. Ltd., No. 2021-1480, 2021 WL 5315424 (Fed. Cir. Nov. 16, 2021) (Circuit Judges Dyk, O’Malley, and Hughes presiding; Opinion by Dyk, J.) (Appeal from D. Del., Andrews, J.)

Drug Product and Patent(s)-in-Suit: Duexis® (ibuprofen/famoditine); U.S. Patents Nos. 8,067,033 (“the ’033 patent”) and 8,067,451 (“the ’451 patent”)

Nature of the Case and Issue(s) Presented: Non-steroidal anti-inflammatory drugs (“NSAIDs”) are drugs for treating rheumatoid arthritis and osteoarthritis. NSAIDs may be selective or non-selective. When taken at high doses, non-selective NSAIDs, like ibuprofen, can cause stomach ulcers after prolonged use. The ’033 and ’451 patents are directed to a pharmaceutical composition wherein ibuprofen and famotidine are combined in a tablet to treat pain while decreasing the risk of ulceration. Ibuprofen as a pain reliever and famotidine as an ulceration reducer were both known in the art. “However, due to the chemical incompatibility between ibuprofen and famotidine, such single dose forms degraded over time, particularly in conditions of elevated temperature and relative humidity.” The claimed invention “exhibits exceptional stability under forced degradation conditions.”

Horizon sells Duexis, a tablet-in-tablet product with a famotidine core, an ibuprofen shell, and an Opadry® White (“Opadry”) barrier layer in between. Alkem submitted an ANDA seeking approval to market ibuprofen and famotidine, and included a Paragraph IV Certification referencing the patents-in-suit. Horizon sued. During claim construction, the district court found that Horizon narrowed the claim scope of the ’451 patent by specifying a barrier layer of Opadry, describing it by listing the ingredients. At trial, the district court found the asserted claims of the ’033 patent invalid as obvious and not infringed. The district court also entered judgment of no infringement with respect to the ’451 patent. Horizon appealed, and the Federal Circuit affirmed.

Why Alkem Prevailed: The district court relied in part on the ’096 publication as invalidating prior art. Horizon argued that the district court committed legal error because the ’096 publication is not prior art to the ’033 patent. The ’033 patent claims the ibuprofen/famotidine combination dosage form disclosed in the ’096 publication. The ’096 publication published on February 22, 2007 and listed Golombik and Tidmarsh as inventors. The ’033 patent has a priority date of November 30, 2007 and listed Tidmarsh but not Golombik as an inventor. Horizon sought to correct the inventorship of the ’033 patent by adding Golombik, but the district court denied the request. The Federal Circuit saw no error in the district court’s denial. Inventing something in an earlier patent or patent application does not automatically make one an inventor of patents that incorporate the earlier invention. The only support for Golombik’s contribution to the ’033 patent is testimony by Tidmarsh and Golombik. The district court discounted these testimonies as “non-specific,” “convenient, uncorroborated, and not very credible,” and concluded that “there was no proof that Mr. Golombik made even the slightest contribution to the '033 patent.”

With regard to the ’033 patent obviousness finding, Horizon argued that the district court committed legal error in finding that a skilled artisan would have had a reasonable expectation of success to achieve the claimed degree of stability. The Federal Circuit affirmed the district court’s finding that that a prior art reference disclosed tablet-in-tablet separation methods, like those recited in the ’033 patent, “to achieve greater stability” in pharmaceutical formulations containing drugs similar to ibuprofen and famotidine, under the same stability conditions claimed in the ’033 patent. This finding was supported by the testimony of Alkem’s expert witness so the Federal Circuit saw no clear error on the part of the district court.

With regard to the ’451 patent, Horizon argued that the district court erred in construing “comprising” in the “barrier layer” term to mean “consisting essentially of,” and that the construction and subsequent finding of non-infringement should be vacated. But Horizon makes no showing in its appeal briefs of prejudice as a result of this claim construction. In any case, the Federal Circuit found that the prosecution history of the ’451 patent supported the district court’s construction. Because the Federal Circuit did not see any error in the district court’s determination that Horizon unambiguously narrowed its claim scope to Opadry, it affirmed the judgment of non-infringement.