As with a similar battle in India over the Gleevec cancer med sold by Novartis, the groups charge that the patents amount to evergreening, which would unfairly postpone lower-cost generic versions for many years.

Evergreening refers to patent extensions based on minor changes, a move that patient advocates argue would inhibit access since generic drugmakers would be prevented from competing. The groups recently discovered Gilead applied for three patents for claims on dosage, formulation and combinations – in 2004 and 2006. If approved, patent protection for a fixed-dose combination would run 20 years. Gilead combined Viread and Emtriva to create the Truvada AIDS med.

“The country’s HIV and AIDS treatment will be severely affected and the national goal of the HIV treatment scale-up is impossible if the Department of Intellectual Property agrees to approve patent applications” on Truvada, they wrote in a letter this week to the Department of Intellectual Property, noting that the medicine has been included in the National Essential Drug List since 2010.

They then cite the Thai Patent Act and international patent standards to argue there are three “essential criteria to consider” before granting Gilead its patent requests, which are novelty, inventiveness and capability of industrial application. They insist Gilead is not entitled because Viread is “not a newly invented drug and… its combination requires no high technology to prove significant inventive steps.”

The patient groups express particular concern because they noted that recent research indicated more than 90 percent of patents issued by the Thai government between 2000 and 2010 were what they considered to be evergreening patents. “This is a loophole that the multi-national pharmaceutical industry can take advantage, and block and/or delay the local generic-drug industry’s competition, including the state-enterprise Government Pharmaceutical Organization,” they write.

This argument is at the heart of a court case set to begin next month in India, where the Supreme Court will hear arguments over whether the government had the right to deny a patent to Novartis for its Gleevec cancer med. The drugmaker wants a patent based on what it calls a new form of its drug, which would offer a 20-year extension. A previous government ruling denied the request after deciding the new form did not meet a standard for enhanced efficacy (see this and this).

A Gilead spokesman writes us that Gilead HIV treatments are currently available in Thailand through a regional distribution network, which operates a tiered pricing system based on ability to pay. Currently, he adds, this amounts to $1 a day in Thailand. Gilead has also formed partnerships with Indian generic drugmakers and, he continues, the Thai government purchases meds from another of its partners, Mylan Laboratories.

“These licensing agreements and partnerships are a key component of our ‘access’ program to increase access to HIV therapy,” the Gilead spokesman writes. “As an innovative, research-driven company we do, however, also believe in using intellectual property responsibly and will always strongly defend intellectual property rights.” Viread, by the way, was registered in Thailand in August 2006, and Truvada was registered in September 2008, he noted.

By Ed Silverman