The worldwide patent battle over Atorvastatin Calcium, the generic name of the best-selling anticholesterol drug Lipitor, has been so heated, which is not surprising, considering that Atorvastatin Calcium is considered the world’s top-selling drug. Generic pharmaceutical companies worldwide have launched their own generic version, prompting suits for patent infringement.

The litigation strategy and outcome of these Atorvastatin Calcium litigations worldwide vary, depending on the circumstances and applicable law in each jurisdiction.

For instance, to demonstrate the variations in the litigation strategy, it may be interesting to note that in the United States, two patents were the subject of the Atorvastatin Calcium litigation—US Patent Nos. 4,681,893 and 5,273,995. US ‘893, also known as the “molecule” patent, was supposed to expire on May 30, 2006, but the patent term was extended, a feature available under US patent laws. Apart from the “molecule” patent, generic companies in the US were also sued for infringement of US ‘995, commonly known as the “enantiomer” patent.

The United Kingdom Atorvastatin Calcium litigation is similar in the sense that both the “molecule” (UK 0 247 633) and “enantiomer” (UK 0 409 281) patents were subsisting at the time of the Atorvastatin Calcium litigation.

In the Philippines patent protection lasts for 20 years without the possibility for an extension. Hence, unlike in the United Kingdom and in the United States, the Philippine equivalent for the “molecule” patent, or Philippine Patent No. 24661, already expired without benefit of extension when Atorvastatin Calcium patent suits were filed.

This made the defense for Atorvastatin infringement in the Philippines simpler as the litigation focused on Philippine Patent No. 29,149, or the “enantiomer” patent. In their defense, generic companies mainly argued that Philippine Patent No. ‘149 is void for lack of novelty and inventiveness in view of the teachings made in the earlier Patent No. ‘661 for the “molecule” patent.

This is a departure from the strategy in other jurisdictions where the generic competitor generally argued that their Atorvastatin Calcium product is non-infringing by claiming that their product is not covered by the broad “molecule” patent and, at the same time, argued that the “enantiomer” patent is void or unenforceable.

Considering that the validity of Philippine Patent No. ‘149 was already in issue after it was argued that such patent was already disclosed in Patent No. ‘661, generic manufacturers and distributors of Atorvastatin Calcium was also able to prevent an injunction from being issued. Under Philippine laws, a patent holder needs to clearly establish the validity of the patent before an injunction may be issued and the mere issuance of letters patent standing alone is generally not sufficient to support an injunctive relief.

The importance for patent holders to establish the validity of their patent is essential, considering that patent linkage is not available in the Philippines. The Philippine Food and Drug Administration (FDA) has authority over matters on safety quality and efficacy of drugs and medicines, and procedures on parallel importation. The Philippine FDA, however, has no authority over patent matters.

Consistent with the aforementioned rules, on July 5, 2010, the Makati Regional Trial Court, Branch 66, has issued an order dated July 5, 2010, denying an application for preliminary injunction in one of the Philippine patent-infringement cases relating to Atorvastatin Calcium. In this particular case, Pfizer Inc. and Warner Lambert Llc. filed a patent-
infringement case against Unilab Laboratories Inc. and Therapharma Inc. wherein it was alleged that the latter companies infringed Warner Lambert’s patent over Atorvastatin Calcium.

The order relates to a motion for reconsideration filed by Pfizer and Warner Lambert. In that motion, Pfizer and Warner Lambert asked the trial court to reconsider its earlier order dated February 8, 2010, denying their application for preliminary injunction against Unilab and Therapharma to restrain the latter from distributing or selling a generic equivalent of Lipitor.

In the order dated July 5, 2010, the trial court affirmed its earlier order and denied Pfizer and Warner Lambert’s motion “after a painstaking and assiduous perusal of the arguments raised by both parties, as well as the records of the case.” The trial court held there was no cogent reason to reconsider its order dated February 2010 since it found that the motion for reconsideration is a mere rehash of issues tackled and discussed in its earlier order.

The trial court reiterated that an applicant for an injunction has the burden to prove its right to an injunction. It found that Pfizer and Warner Lambert had failed to discharge the burden of proof, especially considering that “any presumption of validity of Warner Lambert’s patent had been put into serious question by no less than plaintiffs’ own witnesses.”

The case is now expected to move into trial on the merits.

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Atty. Villanueva heads the Intellectual Property Law Department. A professorial lecturer of Intellectual Property Law and current president of the Intellectual Property Professors and Researchers Organization of the Philippines, she is a principal litigator of intellectual-property litigation and enforcement cases, as well as trade-remedy cases.

Atty. Baclay is an associate of the Intellectual Property Law Department, where he specializes in chemical and pharmaceutical patents. He is also a registered chemist and registered Philippine Patent agent.