PrEP4All Claims Gilead Held Back Safer HIV Drug

The activist group PrEP4All has asked the federal government to reject a patent extension on an HIV drug made by Gilead Sciences, claiming that Gilead postponed the drug's development in order to profit from older medications.

Gilead has asked the U.S. Patent and Trademark Office for a three-year extension of its patent on tenofovir alafenamide, or TAF, which is a component of its brand-name drug Descovy, recently approved by the Food and Drug Administration for use as pre-exposure prophylaxis, or PrEP, by men who have sex with men as well as for transgender women. PrEP involves the daily dosage of a drug to prevent HIV infection if one is exposed to the virus.

Truvada, also a Gilead product, was the first drug approved for PrEP. It contains tenofovir disoproxil fumarate (TDF) and emtricitabine, while Descovy contains emtricitabine and TAF. Studies indicate Descovy may cause fewer side effects than Truvada, which has been shown to negatively affect kidney and bone health. This is because of differences between TAF and TDF.

But PrEP4All contends that Gilead delayed the development of TAF in order to maximize profits from Truvada and other drugs, such as Viread, its brand-name version of TDF, The Washington Post reports. In a petition filed with the Patent and Trademark Office, PrEP4All claims the company knew TAF was safer than TDF. Gilead suspended development of TAF in 2005 and did not resume the process until 2010, and the drug was approved by the FDA in 2015. It is a component of Gilead's combination HIV treatment drug Genvoya in addition to Descovy, which is used in treatment as well as prevention. Truvada is also used in treatment.

"Gilead has not only intentionally delayed clinical development of a drug to artificially manipulate its eligibility for a patent-term extension, but it has done so despite the apparent harm to patients," Christopher Morten, who is supervising attorney at New York University's Technology Policy and Law Clinic and filed the petition on behalf of PrEP4All, told the Post.

Similar claims about the company's delay in the development of TAF have been made in lawsuits filed in California in 2018. Gilead has denied the allegations both in those suits and in PrEP4All's petition. "Patient safety is of foremost importance to us, and any implication that Gilead delayed the development of a drug known to be safer than [the older drug] is false," Gilead spokesman Ryan McKeel told the Post.

Gilead's extension request would keep TAF under patent, and therefore monopolized by the company so that a cheaper generic version could not be marketed, until 2025. PrEP4All's petition may have little chance of stopping the extension, as the patent office considers such third-party petitions only in "extraordinary" circumstances, according to the Post.

Gilead has also been sued by the federal government for patent infringement, as the process that discovered Truvada and Descovy could be effective in prevention was conducted with federal funds. The Department of Health and Human Services holds the patent for this use.

Gilead has agreed to donate PrEP drugs to be distributed by HHS to uninsured Americans. HHS announced this week how the distribution process will work.