Manila Bulletin – May 9, 2007

By BERNIE CAHILES-MAGKILAT

State-owned Philippine International Trading Corp. (PITC) yesterday filed for the cancellation of Philippine patent of multinational drug firm Pfizer Limited for Norvasc, an anti-hypertensive maintenance medicine commonly used by Filipinos but is sold at exorbitantly high price, a move that is expected to substantially make a dent on the company's projected Php1.5 billion local sales this year for this particular drug alone.

Even as this developed, Teddie Elson Rivera, PITC officer-in-charge and vice president, told reporters after the filing the petition before the Intellectual Property Office that it has created a technical working group that would work closely with IPO to review other essential drugs commonly used by Filipinos with expiring patents.

In particular, PITC is preparing for the registration with the Bureau of Food and Drugs the drug Lipitor, another Pfizer prescription drug that fights against bad cholesterol and reduces the risk of heart attack. Its Philippine registration is due to expire in December this year.

This essential drug has also a price difference as that of Norvasc and Pfizer is also expected to earn Php 1 billion in sales this year from this particular drug.

Rivera said that a favorable decision on its petition on Norvasc would pave the way for the importation of cheaper Norvasc from Pfizer in India and open its manufacturing by local pharmaceutical firms.

Philippine patent No. 24348: Improvements in Pharmaceutically Acceptable Salts of Amlodipine or Norvasc will expire on June 13 this year.

Rivera said that ten local drug companies belonging to the Pharmaceutical Companies of the Philippines Inc. are ready to produce Norvasc once the case on Norvasc is resolved.

These firms, however, had been issued a communication by Pfizer on the legal consequences once they produce Norvasc ahead of the expiration of the patent. These firms include Elite, Seidenham, One Pharma, US Generics, Drugmakers, AM Pharma, Com­pact, Allied, Schelda and Unilab.

Rivera said that should IPO decides in its favor, this would boost its case against Pfizer. PITC was sued by Pfizer on grounds of infringing intellectual property rights for importing 80 samples of Norvasc (40 tablets of 5 mg and 40 tablets of 10 mg) Pfizer in Pakistan in December 2005 to facilitate for the product registration with the Bureau of Food and Drugs preparatory for importation once Pfizer patent expires on June 13,2007.

Pfizer is selling Norvasc locally at Php44.75 per 5 mg and Php74.57 for 10 mg while in Paki­stan, where it is also manufactured by Pfizer, the prices are only Php 8.74 and Php 17.09, respectively. Amvasc, a similar anti-hypertensive drug by Unilab, is being sold at P17.50 per 5 mg.

PITC's petition for the cancellation of the Pfizer patent was based on a decision by the US Court of Appeals decision nullifying Pfizer's patent in favor of Apotext Inc., a Canadian generics drug maker challenging the patent of Pfizer on amlodopine besylate, the active ingredient used in Norvasc.

In nullifying the Pfizer patent, the US Court of Appeals noted that the patent of amlodipine besylate, referred to as the '303 patent issued in 1989.

This, as Pfizer already had a previous patent-referred to '909 patent issued in 1982-already disclosing amlodipine, but combined with a different salt with is maleate.

The Federal Circuit found that the superior property of amlodipine mixed with the salt besylate, compared to the previous amlodipine maleate, was not unexpected, thus, rendering the invention as "obvious."

This means that if the so-called invention just results from the mere discovery of a new use, form or property of a known substance - but its efficacy is still the same - there is no "inventive step."

Given this US court decision PITC lawyers are expecting a favorable IPO decision in a month's time and promised to be able to import Norvasc 22 days after. Local drug makers are also expected to produce the generic drug in 9 months.