IP Law Daily Drug patent claims invalidated for lack of adequate written description of efficacy
Thursday, May 16, 2019

Drug patent claims invalidated for lack of adequate written description of efficacy

By John W. Scanlan, J.D.

The patents’ shared specification was “fatally flawed” because it provided nothing more than the mere claim that an uncoated stomach acid drug might work to raise the pH of the stomach acid.

Several claims made in two patents for a tablet combining a pain reliever and a stomach acid reducer were invalid for lack of an adequate written description because their shared specification did not sufficiently describe the effectiveness of an uncoated acid-reducing drug, the U.S. Court of Appeals for the Federal Circuit held in reversing a district court’s determination that the patent claims were valid. The appellate court also dismissed the patent holder’s cross-appeal as moot (Nuvo Pharmaceuticals (Ireland) Designated Activity Company v. Dr. Reddy’s Laboratories Inc., May 15, 2019, Clevenger, R.).

Nuvo Pharmaceuticals is the owner of U.S. Patent Nos. 6,926,907 (the ‘907 patent) and 8,557,285 (the ‘285 patent), both entitled “Pharmaceutical Compositions for the Coordinated Delivery of NSAIDs.” These patents relate to a tablet that combines a non-steroidal anti-inflammatory drug (NSAID) with a proton pump inhibitor (PPI) that is intended to reduce the side effects involved in the release of a NSAID into the acid in the stomach and upper small intestine. The tablet contains an enteric coating around the NSAID to prevent it from being released until the pH of the stomach acid reaches the desired level, with the PPI around the outside of the enteric coating. A second enteric coating around the PPI controls its release. The invention also contemplates the use of some uncoated PPI to allow for its immediate release into the stomach and small intestine.

Nuvo manufactures a drug called Vimovo, which embodies the two patents. Dr. Reddy’s Laboratories, Mylan Pharmaceuticals, Lupin Pharmaceuticals, and related companies (the “Generics”) filed Abbreviated New Drug Applications (ANDAs) with the FDA seeking approval to market generic versions of Vimovo covered by the claims of the two patents. Dr. Reddy’s filed a separate ANDA for a product differing slightly from Vimovo because it contains a small amount of uncoated NSAID in the outer layer that is separate from the enteric-coated NSAID.

Nuvo filed suit against the Generics to prevent their products from going to market before the patents expired, arguing that their products violated several patent claims. The Generics stipulated to infringement (except for Dr. Reddy’s second ANDA) but alleged that the two patents were invalid as obvious and for lack of enablement and an adequate written description. After a trial, the federal district court found that none of the patents’ claims were obvious, the claims had been enabled, and the written descriptions were adequate. It concluded that Dr. Reddy’s second ANDA product infringed the patents’ claims because it satisfied all of the recited limitations. The Generics appealed the district court’s rulings regarding the written description requirement, and Nuvo cross-appealed.

Adequacy of written description. The patents’ shared specification was invalid because it did not adequately describe the claimed effectiveness of uncoated PPI. The district court found that the specification lacked information regarding the efficacy of uncoated PPI, but determined that it was sufficient that the specification described the immediate release of uncoated PPI and potential disadvantages of coated PPI. However, the Federal Circuit observed that this analysis did not provide support for the claimed efficacy of uncoated PPI. It began its analysis by observing that the parties and the trial court had assumed that the claims required a therapeutically effective amount of PPI that could raise the gastric pH to a minimum of 3.5. Finding this a fair reading of the claim language, the court rejected arguments raised by Nuvo for the first time on appeal that the lower court’s written description ruling could be affirmed because the claims do not recite an efficacy requirement for uncoated PPI.

Testimony provided by Nuvo’s expert witness did not identify parts of the specification sufficient to meet the written description requirement because the statements he cited simply called generally for effective amounts of PPI. While the law does not require experimental data to demonstrate effectiveness or for an invention actually to be reduced to practice, the evidence here showed that a person of ordinary skill in the art could not have understood that that uncoated PPI is effective and nothing in the patents’ specifications showed that the inventor actually invented the claimed invention. The specification was “fatally flawed,” the court said, because it provided nothing more than the mere claim that uncoated PPI might work. This finding was consistent with the inventor’s testimony at trial, when he admitted he had only a “general concept of coordinated delivery with acid inhibition” with uncoated PPI when he filed his first patent and was unable to identify any part of the specification supporting his general understanding as to why uncoated PPI would work.

The fact that the specification taught how to make and use the invention was not enough to satisfy the written description requirement because this fact satisfies the enablement requirement, which is a distinct requirement. The purpose of the written description requirement goes beyond explaining how to make and use an invention to notifying the public of the scope and boundaries of the claimed invention and showing that the inventor possessed all of its aspects. However, the specification for these two patents did not provide any data showing that uncoated PPI is effective in increasing the gastric pH to at least 3.5, and there was no disclosure that an person with ordinary skill in the art could rely upon to understand that the inventor possessed effective uncoated PPI.

Finally, while in certain circumstances the written description requirement can be satisfied without an explicit disclosure if the claimed features are necessarily inherent in what is described, whether uncoated PPI was inherently effective in raising gastric pH to 3.5 or higher was in dispute and there was no written disclosure relating to the efficacy of immediately released PPI.

The district court’s determination that the asserted claims of the ’907 and ’285 patents are not invalid for lack of an adequate written description was reversed and Nuvo’s cross-appeal was dismissed as moot.

This case is Nos. 17-2473, 17-2481, 17-2484, 17-2486, 17-2489, 17-2491, 17-2492 and 17-249.

Attorneys: James B. Monroe, (Finnegan, Henderson, Farabow, Garrett & Dunner, LLP) for Nuvo Pharmaceuticals [Ireland] Designated Activity Co. Alan Henry Pollack, (Windels Marx Lane & Mittendorf LLP) for Dr. Reddy’s Laboratories.

Companies: Nuvo Pharmaceuticals [Ireland] Designated Activity Co.; Dr. Reddy’s Laboratories

MainStory: TopStory Patent FedCirNews

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