By Barbara Grzincic

(Reuters) – Novartis scored a win in litigation over one of the patents underlying its cancer treatment Afinitor, as a federal appeals court on Monday rejected arguments by the would-be maker of a generic version that the patent is invalid.

The U.S. Court of Appeals for the Federal Circuit upheld claims 1-3 of a Novartis patent on the use of everolimus, the active ingredient in Afinitor, to treat advanced renal cell carcinoma (RCC). The decision affirms a December 2017 ruling against New Jersey-based West-Ward Pharmaceuticals, which has been known as Hikma Pharmaceuticals USA since last June.

A skilled practitioner “would not have reasonably expected success in using everolimus to treat advanced RCC as of February 2001,” the priority date of Basel, Switzerland-based Novartis’ patent, Circuit Judge Kara Farnandez Stoll wrote for the unanimous three-judge panel. “We thus agree with the district court’s ultimate determination that the challenged claims would not have been obvious.” She was joined by Circuit Judges S. Jay Plager and Raymond Clevenger III.

Afinitor is a pill shown to slow the spread of cancer cells in the body. The Food and Drug Administration approved it in 2009 for treating advanced RCC and has since approved it for kidney cancer and breast cancer.

Novartis spokeswoman Sofina Mirza-Reid said in an email Monday that the company is pleased with the decision. Hikma and its attorneys did not immediately respond to requests for comment.

Novartis filed the lawsuit in U.S. District Court in Delaware in 2015 against West-Ward’s predecessor, Roxane Laboratories, after Roxane sought approval to create a generic version of everolimus and market it for advanced RCC.

West-Ward acknowledged that the generic would infringe Novartis’ patent, if the patent were valid. However, it argued that the invention was obvious in light of Novartis’ original patents on everolimus and later research involving other compounds with similar chemical makeup.

To show the invention was obvious, West-Ward had to establish that as of February 2001, other practitioners would reasonably expect that combining the available research would lead to a successful treatment for advanced RCC.

U.S. District Judge Richard Andrews found that the “prior art” offered by West-Ward – including a small, “Phase I” trial that tested the safety but not the effectiveness of a related compound – did not meet that burden.

On appeal, West-Ward argued that Andrews had held it to too high a standard, requiring near certainty. The Federal Circuit disagreed.

Andrews reviewed the evidence “determined that the molecular biology of advanced RCC was not fully understood, recognized the limitations in the temsirolimus phase I data, and found that such data did not provide a person of ordinary skill with a reasonable expectation of success,” Stoll wrote for the court.

Novartis sells Afinitor as Votubia in Europe. Sales of Afinitor and Votubia accounted for $1.56 billion of Novartis’ revenue in 2018, an increase of 2 percent over the prior year.

The case is Novartis Pharmaceuticals Corp, Novartis AG, v. West-Ward Pharmaceuticals International Limited (n/k/a Hikma Pharmaceuticals International Ltd).

For Novartis: Christina Schwarz and Nicholas Kallas of Venable

For West-Ward n/k/a Hikma: Keith Zullow and David Zimmer of Goodwin Procter