In an ANDA case involving a reissue patent, the U. S. Court of Appeals for the Federal Circuit reversed a district court’s summary judgment that the asserted claims of the reissue patent were not obvious, finding that prior art provided the motivation to combine the teachings of the prior art to derive the claimed subject matter with a reasonable expectation of success.  Bayer Healthcare Pharms., Inc. v. Watson Pharms., Inc., Case Nos. 12-1397, -1398, -1400 (Fed. Cir., Apr. 16, 2013) (Lourie, J.).

The asserted claims of the reissue patent are directed to a combination oral contraceptive (COC) with active pills containing a low dose (20 mcg) of ethinylestradiol and 2.5-3.0 mg of drospirenone that are administered in a 23- or 24-day dosage cycle followed by five or four pill-free or placebo pill days, also referred to as 23/5 and 24/4 regimens, respectively.  Bayer’s YAZ product embodies the claims of the reissue patent.  Defendants Watson, Sandoz and Lupin each filed an Abbreviated New Drug Application seeking approval to market generic versions of Yaz.  Defendants conceded infringement. 

Defendants argued invalidity in view of an Australian patent application that disclosed a COC containing 20-40 mcg and 1-10 mg drospirenone, in combination with 5 other prior art references that each disclosed 23/5 and/or 24/4 dosing regimens, including a European patent application which was expressly referenced in the Australian patent publication..  It was undisputed that the cited prior art references disclosed each of the limitations of the asserted claims.  Nevertheless, the district court entered summary judgment that the claims were not obviousness in view of the cited prior art.  Bayer appealed.

On appeal, Bayer argued three points:  the prior art Australian and European patent publications were primarily directed to hormone replacement therapy in older women, and not contraceptive application of the disclosed COC and regimen;  the prior art taught away from the claimed COC preparations because the “conventional wisdom” in the field favored a 21/7 regimen, and a shorter pill-free interval should be used only with higher hormone doses to avoid “escape ovulation”; and secondary indicia of obviousness including unexpected results, skepticism, industry praise and copying rebutted any prima facie showing obviousness.

The Federal Circuit rejected Bayer’s arguments, holding that the prior art provided the motivation to combine the teachings of the prior art to derive the claimed subject matter with a reasonable expectation of success.  The Court found that the references showed “missed-pill ovulation” in which ovulation occurred during an unintentional extension of the pill-free period was a recognized concern with traditional 21/7 COCs, particularly those with a low ethinylestradiol dose.  The references also expressly proposed a solution to this known problem—to reduce the pill-free interval to four or five days rather than seven.

The Federal Circuit found that the Australian and European patent references “plainly disclose” preparations with both hormone replacement and contraceptive applications and, further, that the asserted claims do not distinguish between target patient populations.  Bayer’s teaching away argument could not overcome the “express teachings of multiple references” that a shorter pill-free interval would improve COC efficacy, stating “[j]ust because one of several references indicated a preference for using 24/4 or 23/5 dosing regimens in tandem with higher dose COCs does not mean the same missed-pill rationale could not also motivate applying the shorter pill-free interval to similarly improve other COC preparations.” 

The Court found Bayer’s evidence of secondary considerations legally insufficient, making particular note that “evidence of copying in the ANDA context is not probative of non-obviousness because a showing of bioequivalence is required for FDA approval.”