FDA Agrees to Review Cobicistat and Elvitegravir for HIV Therapy
Approval decisions expected in October
The FDA has accepted the refiling of two new drug applications (NDAs) for cobicistat, a pharmacoenhancing or “boosting” agent that increases blood levels of the protease inhibitors atazanavir and darunavir to enable once-daily dosing of these medications in human immunodeficicny virus (HIV) therapy, and elvitegravir, an integrase inhibitor for the treatment of HIV-1 infection in treatment-experienced adults.
Both drugs are being developed in the U.S. by Gilead Sciences, Inc.
The FDA has set target review dates under the Prescription Drug User Fee Act (PDUFA) of October 3, 2014 for cobicistat and October 4, 2014 for elvitegravir.
The NDAs for cobicistat and elvitegravir were originally submitted to the FDA in June 2012. In April 2013,Gilead Sciences received complete response letters from the FDA. In its communications, the agency stated that it could not approve the cobicistat and elvitegravir applications in their current forms, citing deficiencies in the documentation and validation of certain quality-testing procedures and methods that were observed during inspections.
Cobicistat and elvitegravir are components of Stribild (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg, Gilead Sciences), a once-daily single-tablet regimen for the treatment of HIV-1 infection. Stribild was approved in the U.S. in August 2012.
Cobicistat is a cytochrome P450-3A (CYP3A) inhibitor. It boosts blood levels of the HIV protease inhibitors atazanavir and darunavir by suppressing CYP3A, an enzyme that metabolizes these drugs in the body. Cobicistat acts only as a pharmacokinetic enhancer and has no antiviral activity.
Cobicistat is approved under the trade name Tybost and elvitegravir is approved under the trade name Vitekta in Europe, Canada, and Australia. Both drugs are considered to be investigational products in the U.S., and their safety and efficacy have not been established.
Source: Gilead Sciences; April 21, 2014.