The Indian Patent Office (IPO) has rejected applications from two U.S. pharmaceutical companies on grounds of "evergreening", raising hopes of a further lowering of prices of two life-saving drugs used by HIV/AIDS patients in the country.

U.S. drug companies, Gilead Sciences and Tibotec Pharmaceuticals, manufacturers of Tenofovir and Darunavir, respectively, lost their cases for patents in India last week. Mumbai-based generic drug manufacturer, Cipla, had filed cases against both the companies.

Although Tenofovir is a second generation drug, it is currently being used as a frontline drug against HIV/AIDS. This drug is a less toxic nucleoside reverse transcriptase inhibitor. Darunavir is an expensive protease inhibitor and is used as a second-generation HIV/AIDS drug.

India's rejection of the patent applications is a big step in ensuring that patients in India and in other poor/developing countries will continue to have access to cheap life-saving HIV/AIDS drugs. There are also possibilities that these drugs could become cheaper as more manufacturers can enter this segment.

"Evergreening" not a ground for new patent

The U.S. patent for Tenofovir was revoked last January by the U.S. Patent Office as the evidence provided by contesting parties clearly demonstrated that it was a known substance even at the time the company filed applications for a patent.

The IPO rejected the patent for the same reason. Gilead's application was rejected on the grounds that the clinical trial results do not prove that the new compound is more efficacious than the existing one in terms of therapeutic effects.

"The so-called improvements in the properties [of the drugs in question], do not amount to an enhancement of therapeutic effect,” the judgement states.

Making minor modifications to existing drugs to make a drug appear as a new one, without actually producing significant improvements in its therapeutic effect, is nothing new. Many pharmaceutical companies claim such drugs as new ones and seek a new patent. Extending the patent period by making minor modifications to existing drugs is called “evergreening,” and is prohibited by India’s patent law under Section 3(d).

Foreseeing the possible outcome, Gilead had offered 13 Indian drug companies licenses to manufacture Tenofovir. "They thought they would lose the case, hence offered the licenses,” Michelle Childs, director of the Geneva-based Medecins sans Frontieres' Access to Essential Medicines campaign, told The HIndu.

However, the 13 generic manufacturers would have to buy the active ingredients only from Gilead and sell it to 95 listed countries, including India.

This July, Brazil had also rejected the patent claims for Tenofovir. “Cipla can now sell its generic drug there and it is good for those living with HIV/AIDS as the price of this drug may go down,” Ms. Childs said. A similar further lowering of prices can be expected in India, as well.