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In the latest legal challenge to Gilead Sciences and its register-ringing strategy, the AIDS Healthcare Foundation has filed a lawsuit accusing the drug maker of manipulating the patent system in order to thwart competition to its HIV medicines. And the nonprofit alleged that countless HIV patients have been prevented from accessing treatment — and may have been harmed — as a result.

At issue is tenofovir, or TDF, which is a cornerstone of the combination HIV treatments that Gilead sells. The patent on the TDF compound expires in December 2017 and Gilead hopes to replace it with a modified version known as TAF. The patent on TAF doesn’t expire until May 2022, and the prospect of nearly five more years of sales without generic competition is extremely valuable.

There is another important difference between the two compounds — TAF is more potent and causes fewer side effects, notably bone damage and kidney toxicity. The foundation argued that Gilead knew of these differences thanks to animal testing dating back to 2001, but that the company delayed testing TAF in humans until 2011. In doing so, Gilead extended patent protection by a few years, the foundation charged in the lawsuit.


“The delay in conducting clinical trials deprived those suffering from HIV of TAF for more than a decade,” the nonprofit claimed in its lawsuit, which was filed last week in federal court in San Francisco. “It is possible that HIV patients suffered from 10 years of additional accumulated kidney and bone toxicity using TDF while TAF stayed on the shelf.”

Moreover, the foundation argued that TAF is an obvious modification of TDF and, therefore, does not deserve patent protection. In patent law, obviousness refers to whether an invention is sufficiently inventive – or not obvious – to be patented. The nonprofit, which operates 46 health centers in the United States for which it purchases many medicines, seeks to have the TAF patents invalidated, according to the lawsuit.


The nonprofit also charged that Gilead refuses to make TAF available as a stand-alone drug, which means that doctors are unable to combine the compound with others. TDF, by comparison, is available as a stand-alone medicine under the brand name Viread. We should note that the Food and Drug Administration three months ago approved a Gilead HIV drug containing TAF, called Genvoya.

“Gilead’s refusal to make TAF available as a stand-alone drug appears to be a calculated, anticompetitive maneuver aimed at keeping competing TAF drugs off the market for years despite the weakness of Gilead’s patents covering TAF,” the lawsuit claimed. “The failure to make TAF available as a stand-alone drug highlights Gilead’s motive of avoiding competition at all costs.”

For its part, Gilead rejected the accusations.

A Gilead spokeswoman wrote us that, nearly a decade ago, the company was focused on developing compounds other than nucleoside reverse transcriptase inhibitors, such as TDF and TAF. More recently, Gilead “reevaluated TAF as part of its ongoing R&D review process” and “decided to prioritize” TAF development. She added the company believes its patents are valid.

One AIDS activist maintained the tactics echo findings in a recent US Senate Finance Committee report about Gilead’s strategy for dominating the market for hepatitis C treatments. Citing hundreds of internal Gilead documents, the report concluded the company refused to lower prices or offer meaningful discounts in order to maximize and outmaneuver competition, but did so at the expense of patients.

“Gilead has owned the patent on the TAF compound, so no one else could do their own development work, and, as a result, TAF was not available to patients. So while this less toxic version was sitting on a shelf, TDF was being used and patients were exposed to bone and kidney toxicity,” said James Krellenstein, a member of ACT UP New York.

“The company purposely dragged its feet on a less toxic drug with the same antiviral characteristics” as the older treatment, he continued. “Anyone who asks whether Gilead is again putting profits before the well-being of patients, the answer is clearly ‘Yes.’”

  • There are definitely games that are played with patents. That said, delaying development of a less toxic therapy should be laid at the feet of the 1962 Amendments.

    I saw this problem frequently. While we were developing the first generation compound, we would often come across a better, second generation one years into the development process. The question always was do we 1) switch to the other compound and lose years of work, possibly letting a competitor get to be first to the market with their first generation version of the drug; or 2) wait until we got the earlier drug approved and were sure it worked before spending millions on the second generation compound; or 3) try to develop both at once, doubling down and possibly doubling our losses if the first generation compound went bust in late development? Of course, if the series of drugs were successful, doubling down meant a lot more profit.

    In the 1970s, we usually doubled down because the 1962 Amendments hadn’t “metastasized” as much and development costs and times were more reasonable. By the 1990s, with development costs rising exponentially, doubling down sometimes became financially impossible.

    It’s tough for those who haven’t been faced with such decisions over a couple decades to appreciate the impact of increasing regulatory costs because they are all but invisible to those not in the industry.

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