Last week the Patent Trial and Appeal Board found Supernus Pharmaceuticals Inc.’s three patents covering the drug Oracea® (doxycycline, USP 30 mg immediate release & 10 mg delayed release beads) valid in the first ever defense of pharmaceutical patents before the Patent Trial and Appeal Board. Amneal Pharmaceuticals, LLC v. Supernus Pharmaceuticals, Inc., IPR2013-00368, -00371, -00372 (U.S. Patent & Trademark Office Dec. 9, 2014). The Board found the claims were not obvious.

Amneal Pharmaceutical LLC petitioned for inter partes review in June 2013. The three patents (U.S. Patent Nos. 8,394,406; 8,206,740; and 8,394,405) cover once-daily, sub-antimicrobial formulations of doxycycline with specific ratios of immediate-release to delayed-release components. The Board addressed claim construction and prima facie obviousness in its written decision. The crux of the Board’s decision revolved around its interpretation of the term delayed-release for purposes of claim construction and what the prior art disclosed.

The Board broadly construed the claim term “delayed-release” in light of the patents’ specification. Supernus argued for a narrower construction that would not cover formulations providing substantial release of the active ingredient in the stomach, and identified certain preferred embodiments for support. But the Board construed the term more broadly as “release of a drug at a time other than immediately following oral administration.”

In terms of its obviousness analysis, the Board focused on two prior art references. Amneal argued that one of the references disclosed all limitations of the independent claims except for the claimed ratio of immediate-release to delayed-release formulation components. According to Amneal, another reference disclosed the claimed ratios (“ratio reference”), but involved a different tetracycline compound. Amneal argued that combining the ratios disclosed in the ratio reference with the former reference would render the claims obvious.

In contrast, Supernus argued that the ratio reference did not disclose the claimed ratios because it disclosed a modified sustained-release rather than a delayed-release component. In its analysis of whether the ratio reference disclosed a delayed-release component, the Board considered the secondary loading portion of the formulation that contained a water-soluble polymer to facilitate release. The Board credited Supernus’ expert that despite some lag in release while the polymer hydrates, inclusion of the water-soluble polymer results in “release of drug promptly after administration,” which is not delayed-release. According to the Court, without evidence that the claimed ratio was known or could have been reached through routine experimentation, the claims cannot be obvious.

It is unclear from the decision whether Amneal focused solely on establishing that the prior art ratio reference did in fact disclose a delayed-release component to buttress its obviousness defense, but that was certainly the focus of the Board’s analysis and rationale for its conclusion that the prior art did not render the claims obvious. Although the sample size is one, utilizing the inter partes review process to challenge pharmaceutical patents may not be as favorable to patent challengers as it has been for other areas of technology.