It hasn’t a great month for the Big Pharmas when it comes to battling the on-slaught of generics. Despite being the time for Valentines and amore, Pfizer is feeling blue since the Technical Board of Appeal revoked Pfizer’s “Viagra-Patent” EP-0 702 555 by dismissing the appeal against an earlier lost.
The viagra patent related to the use of PDE5(phosphodiesterase 5)-inhibitors for the treatment of impotence. Such PDE5-inhibitors include, e.g., the substance sildenafil which in the form of its citrate salt is the active ingredient of the well-known impotence agent Viagra(TM). The EP-0 702 555 patent was not limited to the use of Sildenafil and structurally related compounds, but tried to cover the use of all PDE5-inhibitors. In an opposition proceeding, the EP revoked the patent and Pfizer appealed the decision of the Opposition Division. Now, Pfizer’s appeal has been dismissed dismissed with the revocation of the patent was confirmed by the Technical Board of Appeal of the EPO and the decision is final. But, the lovelorne are not free to start popping generic Viagra just yet since the active ingredient, Sildenafil, is still covered by a patent of Pfizer.
Also, Barr Pharmaceuticals Inc. got a federal court ruling in its favor in a lawsuit involving antidiuretic patents held by Ferring BV and Aventis Pharmaceuticals Inc. The District Court of Southern New York found that the patents for DDAVP tablets in doses of 0.1 milligrams and 0.2 milligrams are unenforceable and not infringed by a product made by the company’s Barr Laboratories Inc. unit. DDAVP tablets had annual sales of $177 million last year.
Finally, as reported at Law.com, a federal judge has allowed a second antitrust suit against GlaxoSmithKline (GSK) relating to it’s alleged use of “sham” patent litigation to block generic versions of its anti-inflammatory drug, Relafen, from reaching the market. GSK filed patent infringement suits against two generic manufacturers in 1997 triggering an automatic 30-month stay of the FDA’s authority to grant approval of the generics. But a U.S. District Court ruled that GSK had procured the patent through fraudulent misrepresentations to the USPTO.
Teva Pharmaceuticals USA and Eon Labs Manufacturing Inc. filed antitrust suits alleging that GSK’s patent suits were “sham” litigation filed for the improper purpose of preserving its monopoly. In February 2004, GSK agreed to pay $175 million to settle the Massachusetts suits. Now, an Italian company, Chemi SpA, has filed suit.