Pharmaceutical giant Pfizer Inc. has sued United Laboratories Inc. (Unilab) for patent infringement after selling Avamax, a generic drug equivalent to the patented Pfizer’s Lipitor brand, the most prescribed anti-cholesterol drug.

Patricia J. Pascual, Pfizer public affairs director, told reporters they have already filed a case against Unilab before the Makati Regional Trial Court and hopes to get a court injunction against the Filipino drug company.

“We were granted a patent for Lipitor in 2004 and the patent will last until 2012 yet. Why can’t they wait for 2012. We are not against generic drugs, we just want the rules in this country to be followed,” Pascual said.

Aside from selling its generic drug equivalent Avamax to independent drug stores, Pascual said that Unilab has been detailing the drug already to doctors.

While Unilab is marketing Avamax, it has also filed a case before the Intellectual Property Office of the Philippines seeking to “invalidate” Pfizer’s patent on Lipitor on alleged “evergreening” the patent cycle of Lipitor.

Pascual said that the most that Unilab should have done is wait for the decision of the IPO before they start marketing its generic drug equivalent.

“We want Unilab to practice fair competition either they let the 2012 patent expire or wait for the IPO to come out with a decision,” she said.

Lipitor was a target of generic drug companies because Atorvastatin, the generic name where the Lipitor brand falls under, has a huge local market.  Earlier, Pfizer also sued another drug company for selling Ator, another generic drug equivalent of Lipitor.

Unilab accounts for 25 percent of the entire anti-cholasterol drug market locally Simvastatin and Atorvastatin . It is selling the generic drug Vidastat for Simbastatin, which patent already expired.

But, while Pfizer is not the leader in the anti-cholesterol drug its Lipitor brand is the most-prescribed anti-cholesterol drug because of its “lipid reducing compound”, making it the most effective medicine in reducing cholesterol levels and is being used in clinical tests.

Pascual, however, said that Amavax has no impact yet on its Lipitor sales but with the implementation of the Medicine Drug Retail Price (MDRP), the company’s business has been substantially affected with sales being reduced by 40 percent.

Lipitor is the second biggest product of Pfizer after Norvasc, and was placed under MDRP.