Expert Withstands Daubert Challenge in Prilosec Patent Infringement Case

This patent case relates to the drug Prilosec(R), one of the most widely prescribed medicines in history. Plaintiffs AstraZeneca, LP (“AstraZeneca”) asserted certain claims of two patents which cover the Prilosec(R) formulation, U.S. Patent Numbers 4,786,505 and 4,853,230 (the “‘505 Patent” and the “‘230 Patent“), as being infringed by the multiple defendant pharmaceutical corporations, including Mylan Pharmaceuticals Inc. (“Mylan”), and Apotex Inc., (“Apotex”). The Judicial Panel on Multidistrict Litigation consolidated the patent infringement suits for pre-trial purposes.

The ‘505 Patent claimed a new formulation that permitted the omeprazole drug molecule to pass unharmed through the stomach’s acidic environment and to dissolve rapidly in the small intestine. The ‘230 Patent covered not just omeprazole but acid-labile pharmaceutically active substances. Plaintiffs alleged that the generic omeprazole formulations for which defendants sought approval would infringe or induce infringement of the asserted claims.

Expert Witnesses

A number of expert witnesses were called to the stand so as to provide insight as to the composition, operation, and efficacy of the subject drugs.

One of these experts was Plaintiff’s expert Dr. Davies, who was accepted by the Court as an expert in the testing, analysis, and characterization of drug formulations.

Dr. Davies had over twenty years’ experience in the area of characterization of pharmaceutical dosage forms, and conducts his research in that area. Dr. Davies has a pharmacy degree from University of Brighton and a Ph.D. from the University of London. He then spent six months at Welsh Pharmaceuticals, where he focused on characterizing drugs, preparing dosage forms, and preparing samples for clinical trials. He also spent time in the production plant, operating production facilities, and in the marketing and development departments.

Dr. Davies had been a professor of biomedical surface chemistry in the school of pharmacy at the University of Nottingham since 1985. Ha also founded Molecular Profiles Ltd., a company which assists pharmaceutical companies with developing better formulations and conducts research for the pharmaceutical industry in that same area. Dr. Davies also had been published in over 300 publications for his research on characterization of pharmaceutical dosage forms, including articles on the fluorescence techniques used in this litigation.

On top of all that, Dr. Davies was involved in pharmaceutical scientific societies, and had received multiple international awards for his work in characterizing pharmaceutical systems.

Daubert Challenges:

Dr. Davies performed many experiments on Prilosec and Apotex/Mylan’s allegedly infringing versions of Prilosec to determine whether the formulations used by the Defendants constituted infringement. The Defendants motioned to exclude all or parts of Dr. Davies’ testimony and reports for a variety or reasons.

Apotex moved to exclude Dr. Davies’ testimony based on Daubert on the grounds that: (1) Dr. Davies’ ATR-FTIR spectra of Apotex’s washed pellets are an unreliable indicator of the pellet composition prior to the wash; (2) Dr. Davies’ washing procedure for removing the enteric coating from Apotex’s pellets renders his data unreliable for the purposes of supporting a finding that there is a layer-like distribution of wash-resistant material surrounding the pellet core; (3) Dr. Davies’ fluorescent images are not reliable evidence that there is a layer-like distribution of an MACP-PVP complex and Mg salt; and (4) Dr. Davies failed to consider an alternative hypothesis for the composition of the fluorescing region of Apotex’s pellets. The Court finds these objections go to the weight – not the admissibility — of Dr. Davies’ testimony.

Mylan argued that Dr. Davies’s conclusions regarding the rapidly disintegrating nature of Mylan subcoating are unreliable because he did not personally conduct the disintegration and FTIR tests and because of the lack of protocol or written record. The Court was not persuaded by Mylan’s assertions. Even though other scientists conducted the disintegration and FTIR tests at issue, Dr. Davies testified that he personally attended the initial testing of each experiment to ensure it was done properly.

Outcome of the case:

The Court found that Defendants failed to show by clear and convincing evidence that any claims in the ‘505 or ‘230 Patents should be rejected for: (1) failing to satisfy the best mode, enablement, or written description requirements of 35 U.S.C. § 112; (2) being in the public use or described in a printed publication more than one year prior to the date of the application for patent in the United States under 35 U.S.C. 102(b); or (3) obviousness under 35 U.S.C. § 103(a). For those reasons, Defendant Apotex did infringe on both the ‘505 Patent, and the ‘230 Patent.

However, the Court also found that the court found that plaintiffs failed to show by a preponderance of the evidence that talc, HMPC, and omeprazole performed the same function (stabilizing the omeprazole), in substantially the same way (by reacting to create a micro-pH of not less than 7 around the particles of omeprazole), to produce the same result as an alkaline reacting compound (long-term shelf-life stability of the formulated product). For those reasons, Defendant Mylan did not infringe the asserted claims of the ‘505 and ‘230 patents.