Home » Posts tagged 'Tenofovir Alafenamide'
Tag Archives: Tenofovir Alafenamide
November 5, 2015
The U.S. Food and Drug Administration today approved Genvoya (a fixed-dose combination tablet containing elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide) as a complete regimen for the treatment of HIV-1 infection in adults and pediatric patients 12 years of age and older.
The CDC estimates that 1.2 million persons ages 13 years and older are living with HIV infection, and that more than another 150,000 persons in this age range have HIV but are unaware of their infection. Over the past decade, the number of people living with HIV has increased, while the annual number of new HIV infections has remained relatively stable.
“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, M.D., director of the Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research.
Genvoya is approved for use in HIV-infected adults and children ages 12 years and older weighing at least 35 kilograms (77 pounds) who have never taken HIV therapy (treatment-naïve) and HIV-infected adults whose HIV-1 virus is currently suppressed. While Genvoya is not recommended for patients with severe renal impairment, those with moderate renal impairment can take Genvoya.
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.
Genvoya contains a new form of tenofovir that has not been previously approved. This new form of tenofovir provides lower levels of drug in the bloodstream, but higher levels within the cells where HIV-1 replicates. It was developed to help reduce 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. Patients receiving Genvoya experienced greater increases in serum lipids (total cholesterol and low-density lipoprotein) than patients receiving other treatment regimens in the studies.
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). Health care providers are advised to monitor patients for kidney and bone side effects. Genvoya should not be given with other antiretroviral products and may have drug interactions with a number of other commonly used medications.
Genvoya is marketed by Gilead Sciences Inc. based in Foster City, California.
Gilead Initiates Phase 3 Clinical Program for Tenofovir Alafenamide,TAF a Novel Low-Dose Prodrug for the Treatment of HIV
Gilead Sciences, Inc.on January 24, 2013 announced the initiation of the first of two Phase 3 clinical trials (Study 104) evaluating a single tablet regimen containing tenofovir alafenamide (TAF) for the treatment of HIV-1 infection in treatment-naïve adults. TAF is a novel prodrug of tenofovir, the active agent in Viread® (tenofovir disoproxil fumarate). The Phase 3 studies will examine a once-daily single tablet regimen of TAF 10 mg/elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg compared to Gilead’s Stribild® (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) among patients new to HIV therapy. The second Phase 3 study (Study 111) will be initiated later this quarter.
We are pleased to move TAF into Phase 3 clinical research,” said Norbert Bischofberger, PhD, Executive Vice President, Research and Development and Chief Scientific Officer, Gilead Sciences. “We believe that TAF’s smaller milligram size has the potential to offer safety and tolerability advantages over existing therapies, and may enable the creation of new single tablet regimens for HIV.”
In October 2012, Gilead announced topline results from a Phase 2 study comparing the TAF/elvitegravir/cobicistat/emtricitabine single tablet regimen to Stribild. The study found that the TAF-based regimen met its primary objective based on the proportion of patients with HIV RNA (viral load) levels < 50 copies/mL at 24 weeks of therapy. In addition, statistically significant differences in bone and renal safety were observed between the two arms in favor of the TAF-containing regimen. Both the type and frequency of laboratory abnormalities and adverse events were otherwise comparable between study arms. Full results from the Phase 2 study will be presented at an upcoming medical conference.
Stribild was approved by the U.S. Food and Drug Administration (FDA) in August 2012 and is Gilead’s third single tablet regimen for HIV. A marketing application for Stribild is currently pending in Europe.
Tenofovir alafenamide fumarate (TAF), or GS 7340, is a nucleotide reverse transcriptase inhibitor and a novel prodrug of tenofovir. It is under development by Gilead Sciences for use in the treatment of HIV infection. Closely related to the commonly used reverse-transcriptase inhibitor tenofovir disoproxil fumarate (Viread), TAF has greater antiviral activity and better distribution into lymphoid tissues than that agent. Gilead has announced a phase 3 clinical trial evaluating a single-tablet regimen combining GS-7340 with cobicistat, emtricitabine and elvitegravir and plans to coformulate the drug with cobicistat, emtricitabine and the protease inhibitor darunavir. In a 48 week study comparing Elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate toelvitegravir/cobicistat/emtricitabine/GS 7340, the results showed the prodrug to be non inferior to the established agent, but at much lower dosages and with lower incidence of adverse side effects such as impaired kidney function.
- Eisenberg, E. J.; He, G. X.; Lee, W. A. (2001). “Metabolism of Gs-7340, A Novel Phenyl Monophosphoramidate Intracellular Prodrug of Pmpa, in Blood”. Nucleosides, Nucleotides and Nucleic Acids 20 (4–7): 1091–1098. doi:10.1081/NCN-100002496.PMID 11562963. edit
- M Markowitz, A Zolopa, et al. GS-7340 Demonstrates Greater Declines in HIV-1 RNA than Tenofovir Disoproxil Fumarate During 14 Days of Monotherapy in HIV-1 Infected Subjects. 18th Conference on Retroviruses and Opportunistic Infections 2 Mar 2011. Paper # 152LB
- “Gilead Initiates Phase 3 Clinical Program for Tenofovir Alafenamide” (Press release). Gilead. January 2013.
- McQueen, Courtney (16 Nov 2011). “Gilead And Tibotec To Develop Single-Pill Protease Inhibitor-Based Combination Regimen”. The AIDS Beacon.
- GS 7340 Packs Greater HIV Punch, Potentially Better Safety, Versus Viread Horn, Tim. 15 Mar 2012. AIDSmeds.com
- Pharmacokinetics of a Novel EVG/COBI/FTC/GS-7340 Single Tablet Regimen. 13th International Workshop on Clinical Pharmacology of HIV Therapy. Barcelona, Spain. April 16-18, 2012.
- Once-Daily Tenofovir Prodrug Combo Pill as Effective as Stribild. AIDSmeds.com 1 Nov 2012.