King Pharmaceuticals markets Altace (ramipril), which is indicated for the treatment of high blood pressure. Until last year, when the Federal Circuit invalidated King's compound patent on ramipril, King earned about $700 million annually from U.S. sales of Altace.
Although Lupin was the ANDA filer who prevailed against King in the patent litigation, Cobalt Labs, as the first ANDA filer, won the 180-day exclusivity rights. In a letter dated January 29, 2008, to attorneys for Lupin, FDA explained that Cobalt's exclusivity was triggered on December 10, 2007, and will expire on June 7, 2008.
Recently, on May 16, 2008, King submitted a citizen petition requesting that FDA require ANDA applicants for generic ramipril to submit a paragraph III or IV certification to U.S. Patent No. 7,368,469, which issued May 6, 2008, prior to final approval. The '469 patent claims methods "for reducing the risk of a cardiovascular event" by administering an ACE inhibitor such as ramipril.
According to the FDA website, at least seven ANDA filers have tentative approval for ramipril and thus appear to have planned on obtaining final approval on June 7, when Cobalt's 180-day exclusivity expires. Those plans may now be in doubt, as it may take FDA some time to decide how to rule on King's petition.