FDA Approves Tybost
FDA Approves Tybost (cobicistat) for use in the treatment of HIV-1 Infection
September 24, 2014 -- The U.S. Food and Drug Administration (FDA) has approved Tybost (cobicistat), a CYP3A inhibitor used in combination with atazanavir or darunavir for the treatment of human immunodeficiency virus type 1 (HIV-1) infection.
Cobicistat is a pharmacokinetic enhancer that works by inhibiting the enzyme (CYP3A) that metabolizes atazanavir and darunavir. It increases the systemic exposure of these drugs and prolongs their effect. Cobicistat is also one of the ingredients in the combination HIV drug Stribild, which was approved by the FDA in August, 2012.
Tybost comes in 150 mg tablets and is administered once daily in combination with the protease inhibitors atazanavir (Reyataz), or darunavir (Prezista).
Because Tybost inhibits CYP3A, other medications metabolized by CYP3A may result in increased plasma concentrations and potentially severe side effects, which may be life-threatening or even fatal. Extra care should be exercised by healthcare professionals to ensure than other medications are reviewed and their concentrations monitored, especially when initiating new medicines or changing doses.
The approval of Tybost was based on the following clinical trials:
- The data to support the use of atazanavir and Tybost were from a phase 2 and 3 trial in treatment-naïve adults comparing atazanavir/cobicistat 300/150 mg and atazanavir/ritonavir 300/100 mg once daily each in combination with Truvada. The atazanavir/cobicistat based regimen was non-inferior to the atazanavir/ritonavir based regimen.
- The data to support the use of cobicistat with darunavir is from a multiple dose trial in healthy subjects comparing the relative bioavailability of darunavir/cobicistat 800/150 mg to darunavir/ritonavir 800/100 mg.
The most common adverse drug reactions observed with Tybost (in combination with atazanavir) in clinical trials were jaundice, ocular icterus, and nausea.
Tybost is a product of Gilead Sciences, Foster City, CA.
Posted: September 2014
Related articles
- Gilead Sciences’ New Drug Application for Cobicistat for HIV Therapy Accepted by U.S. FDA - April 21, 2014
- Gilead Receives Complete Response Letters from U.S. Food and Drug Administration for Elvitegravir and Cobicistat - April 29, 2013
- Gilead Submits New Drug Application to U.S. FDA for Boosting Agent Cobicistat - June 29, 2012
Tybost (cobicistat) FDA Approval History
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