The first class of antiretroviral drugs ever developed may no longer be needed to treat patients with drug-resistant HIV, a new study suggests.
US researchers say these patients can safely achieve viral suppression without taking nucleoside reverse transcriptase inhibitors (NRTIs), which include GlaxoSmithKline’s Retrovir (Zidovudine), the first antiretoviral drug approved by the FDA for the treatment of HIV.
Other drugs include Bristol-Myers Squibb’s Videx and Videx EC (Didanosine), the second FDA-approved antiretroviral drug, and Lamivudine, also marketed by GlaxoSmithKline with the brand names Zeffix, Heptovir, Epivir, and Epivir-HBV.
The multi-site study, carried out by the AIDS Clinical Trials Group in the US over 48 weeks, proves that patients who don’t respond to certain HIV drugs can leave out these medications in their treatment regimen.
The Miriam Hospital HIV clinical trials programme director and study chair Dr Karen Tashima said; "We are so comfortable clinically with the NRTI class that we think we must always use at least one drug from this class in treatment.
"However, some patients have developed within-class resistance, making the NRTIs less effective overall. Therefore, drugs from this class may not be needed if the new treatment plan contains more effective medications."
Designing a treatment plan using new drugs from new classes and omitting NRTIs leads to fewer pills, and hopefully, better adherence, said Dr Richard Haubrich, study co-chair and professor of Medicine at the University of California, San Diego.
"There are several options for treatment-naïve patients, but not as many for treatment-experienced. The HIV research field accepted that nucleosides would be an important component for multiple class-experienced patients," said Haubrich.
"However, our results were very clear. We can safely exclude NRTIs, giving physicians a new paradigm for ART prescription in clinic and potentially changing treatment guidelines."
To ensure eliminating NRTIs from their treatment regimen would not be detrimental for viral suppression, investigators used a web utility to review each of the 413 study participants’ study records to determine optimal treatment plans.
Image: HIV assembling on the surface of an infected macrophage. Photo: Courtesy of Liza Gross.