The drug is a fixed-dose combination tablet containing elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide (TAF). “Today’s approval of a fixed dose combination containing a new form of tenofovir provides another effective, once daily complete regimen for patients with HIV-1 infection,” said Edward Cox, MD, director of the Office of Antimicrobial Products in FDA’s Center for Drug Evaluation and Research.
Genvoya is being pitched as a safer alternative to other HIV treatments. It contains a new form of tenofovir that has not been previously approved. The new form provides lower levels of drug in the bloodstream, but higher levels within the cells where HIV-1 replicates, reducing some drug side effects. “Genvoya appears to be associated with less kidney toxicity and decreases in bone density than previously-approved tenofovir containing regimens based on laboratory measures,” according to an FDA statement. “Data show that because TAF enters cells, including HIV-infected cells, more efficiently than TDF (Gilead’s Viread), it can be given at a lower dose and there is 91% less tenofovir in the bloodstream,” according to a statement from Gilead
Gilead is promoting Genvoya as an alternative to the company’s Viread (tenofovir disoproxil fumarate, TDF). “TAF is a novel targeted prodrug of tenofovir that has demonstrated high antiviral efficacy similar to and at a dose less than one-tenth that of [Viread] as well as improvement in surrogate laboratory markers of renal and bone safety as compared to TDF in clinical trials in combination with other antiretroviral agent,” according to a Gilead statement. “Given its demonstrated efficacy and safety profile, Genvoya represents an important new treatment option for a range of patients who are either new to therapy or who choose to switch treatments,” said David Wohl, MD, associate professor of medicine, Division of Infectious Diseases, University of North Carolina at Chapel Hill and lead author of the Genvoya efficacy analysis.
Genvoya’s safety and efficacy in adults were evaluated in 3,171 participants enrolled in four clinical trials. Depending on the trial, participants were randomly assigned to receive Genvoya or another FDA-approved HIV treatment. Results showed Genvoya was effective in reducing viral loads and comparable to the other treatment regimens. The approval is supported by 48-week data from two phase 3 double-blind studies among 1,733 treatment-naïve patients in which the regimen met its primary objective of non-inferiority compared to Stribild (elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg and tenofovir disoproxil fumarate 300 mg or E/C/F/TDF). In the combined analysis of the studies, 92.4% of Genvoya patients and 90.4% of Stribild patients had HIV-1 RNA levels less than 50 copies/mL at Week 48. Tests of certain renal and bone laboratory parameters also favored Genvoya over Stribild, according to Gilead. An additional Phase 3 found that patients receiving Genvoya also demonstrated improvements in certain bone and renal laboratory parameters compared to those treated with the TDF-based regimens.
Genvoya carries a Boxed Warning, alerting patients and health care providers that the drug can cause a buildup of lactic acid in the blood and severe liver problems, both of which can be fatal. The Boxed Warning also states that Genvoya is not approved to treat chronic hepatitis B virus infection. The most common side effect associated with Genvoya is nausea. Serious side effects include new or worsening kidney problems, decreased bone mineral density, fat redistribution and changes in the immune system (immune reconstitution syndrome). Healthcare providers are advised to monitor patients for kidney and bone side effects.