fizer has been boosted by a decision in the USA which has reaffirmed the company’s patent rights on the blockbuster cholesterol-lowerer Lipitor.

The US Patent & Trademark Office has accepted the company’s application to correct the technical defect in the ‘995 enantiomer patent for atorvastatin calcium, the salt form of the active ingredient in Lipitor. This means that the Patent Office will reissue the patent once Pfizer completes “certain formalities”, such as paying a fee of around $1,500.

An appeals court had originally rejected the patent in 2006, a decision which could have reduced protection on the world’s best-selling drug by over a year. However, last June, Pfizer reached a deal with Ranbaxy Laboratories which meant that the Indian drugmaker would hold off launching its generic version of Lipitor until the end of November 2011.

Importantly the reissued patent will have “the same force and effect as the original ‘995 patent” and the expiration date, including the six-month paediatric exclusivity period, Pfizer noted. Spokesman Raymond Kerins claimed that “this is a very positive development, not just for Pfizer but for all those who believe that defending intellectual property is vital to supporting the enormous investments required to develop life-saving new medicines,”

He added that “we have said all along that we had strong arguments for securing the reissue of the patent, and after a vigorous and thorough examination, the Patent Office agreed with this conclusion”. The reissued patent will help Pfizer in its ongoing battle to stop Canada’s Apotex and Israel’s Teva Pharmaceutical Industries from selling their generic versions of Lipitor before November 2011.