On March 21, 2011, the U.S. Supreme Cour t denied a petition for writ of certiorari seeking review of the U.S. Court of Appeals for the Federal Circuit's (CAFC) decision in Daiichi Sankyo Company, Ltd. et al. v. Matrix Laboratories, LTD., Mylan Inc. et al. (Mylan). Mylan sought review of the CAFC's decision barring it from producing generic versions of Daiichi's two patented anti-hypertension drugs before 2016.
In September, 2010 the CAFC ruled that Mylan could not market generic version of the anti-hypertension drugs, Benicar?, Benicar HCT? and Azor?, before 2016, when the patent covering the drugs is set to expire. The decision ended the five-year lawsuit between Daiichi Sankyo Co. Ltd., a Japanese innovative pharmaceutical company, and Mylan Pharmaceuticals Inc., a U.S. generic drug maker.
On December 8, 2010, Mylan asked the Supreme Court to review the CAFC's injunction. In their petition Mylan and its majority-owned subsidiary Matrix Laboratories claimed that the Federal Circuit Court has applied a rigid lead compound test for determining the obviousness in drug patent cases. The petition also noted that the Federal Circuit Court has rejected every obviousness challenge to a patent claiming a new chemical compound. Under Federal Circuit's lead compound test, Mylan argued that the test requires all generic makers to bear the burden of proving that a person of ordinary skill would have chosen the same compound as Daiichi did to arrive at the patented compound.
A three-judge panel of the Federal Circuit, however, let stand the 2009 decision and deemed the district court's ruling as "comprehensive and well reasoned".
Daiichi first sued Mylan Inc. in August 2006, as the generic drug maker was attempting to receive U.S. Food and Drug Administration (FDA) approval to manufacture and sell the generic versions of Benicar?, a drug used for hypertension treatment which contains the patented ingredient olmesartan medoxomil. It filed a second suit two years later when finding that Matrix Laboratories had submitted another abbreviated new drug application for another anti-hypertension drug Azor?.
In an answer to the lawsuit, Mylan Inc. argued that Daiichi's patent was invalid because Benicar? was the seventh angiotensin II receptor blocker (ARB) to seek patent protection since its initial release in 2002. Moreover, DuPont Co. already had two patents for ARBs sharing the same chemical backbone of olmesartan medoxomil when Daiichi began its R&D in the domain in 1989.
However, Judge William J. Martini of the U.S. District Court for the District of New Jersey found no application of those prior arts for the new products on Daiichi's part. The judge further ruled that the products' commercial success also proved the validity of the patent. In 2008, the combined gross sales for the anti-hypertension drugs reached USD 1.3 billion and the huge success comes from the products' intrinsic properties, rather than from any increased marketing effort. On the other hand, Mylan could not prove by clear and convincing evidence that the patent was invalid due to obviousness.
The patent in dispute was over U.S. Patent Number 5,616,599 (599 patent), claiming olmesartan medoxomil – the active ingredient of Benicar?, Benicar HCT? and Azor?. Sankyo Co. Ltd. applied for the 599 patent in April 1991 as some scientists of the company had "come up with a drug that had 10 times the activity of losartan" and "with a duration long enough to be dosed oncea-day." The patent was granted by the U.S. Patent and Trademark Office in April 1997, and Daiichi Sankyo, the U.S. licensee, marketed the above-mentioned drugs.
Lisa Barons Pensabene with Fitzpatrick, Cella, Harper & Scinto law firm was lead counsel of this litigation, with extensive experience in patent litigation, particularly in the chemical, biological and pharmaceutical areas. She regards the case as "an important one with much at stake for both parties." She explained, "The results in this case reinforced the importance of analyzing obviousness from the perspective of a person of ordinary skill in the art. This approach is the backbone of the obviousness analysis from the historical precedent through the flexible, common sense approach more recently described by the US Supreme Court in the landmark KSR decision."
