More than half of HIV-positive patients taking medications like Truvada, Stribild and Atripla will eventually develop a neurocognitive disorder associated with the disease and the drug cocktails used to treat it, according to the findings of a new study.
Chinese researchers published a study in the European Journal of Pharmacology in February, which explored why more than half of all HIV-infected patients who take viral suppressant medications that include the active ingredient tenofovir disoproxil fumarate (TDF) will develop HIV-associated neurocognitive disorder (HAND).
The widely used drugs include Truvada, Viread, Atripla and several others. Most are combinations of several drugs required to suppress the viral load in HIV and AIDs patients.
HAND affects mental and motor function, with increasing severity over time, and is often a sign of the transition from being HIV-positive to having a full AIDS diagnosis. In early stages, symptoms are minimal, including slowed extremity movements that do not impair activities. However, in the later stages it can render victims into a nearly vegetative state.
Previous studies have found that highly active antiretroviral therapy (HAART), such as treatment with drugs like Truvada and Atripla, is linked to the progression of HAND. However, it is unclear in previous studies whether the condition is linked to the known neurotoxicity of those drugs.
In this recent study, researchers conducted a number of tests which showed that TDF drugs significantly inhibit the proliferation of PC-12 cells, which are nerve cells associated with brain function.
“These findings indicated that TDF may induce PC-12 cell apoptosis,” the researchers determined. “TDF has neural toxicity effect that is relevant to the cell apoptosis, which may be related to the increasing prevalence of HAND.”
HIV Drug Lawsuits
The findings come amid concerns that Gilead, which developed all of the current TDF medications on the market, knew the drugs were toxic and had a less toxic alternative, tenofovir alafenamide fumarate (TAF), which it held onto for years to maximize profits, only developing a TAF drug once the patents on TDF medications began to approach their expiration dates.
Gilead now faces a growing number of HIV drug lawsuits brought by patients who say the company has been accumulating data on the toxicity of the drugs ever since, and by the time it released Stribild 10 years later, it had plenty of evidence of the drugs’ effects
The lawsuits claim Gilead knew TAF was less toxic than TDF because it could be administered at a lower dose with the same effectiveness. The company shelved TAF in 2004, and did not begin to sell TAF-designed drugs until 2015, plaintiffs point out, which gives them patent protection until 2032. TDF drug patents began expiring last year.