An anonymous commenter has very helpfully pointed us to a WSJ blurb -- but I've decided to run the entire FDA communication, since it involves issues of patient safety, and it is not uncommon to find Hep C co-infection in HIV-positive patient populations. Without additional introduction, then (more general FDA communication):
. . . .AUDIENCE: Infectious Disease, Pharmacy
ISSUE: FDA notified healthcare professionals and patients that drug interactions between the hepatitis C virus (HCV) protease inhibitor Victrelis® (boceprevir) and certain ritonavir-boosted human immunodeficiency virus (HIV) protease inhibitors (atazanavir, lopinavir, darunavir) can potentially reduce the effectiveness of these medicines when they are used together.
A drug interaction study showed that taking boceprevir (Victrelis) with ritonavir (Norvir) in combination with atazanavir (Reyataz) or darunavir (Prezista), or with Kaletra (lopinavir/ritonavir) reduced the blood levels of the HIV medicines and boceprevir in the body (see Data Summary below). FDA will be updating the Victrelis drug label to include information about these drug interactions.
BACKGROUND: Victrelis is a hepatitis C virus (HCV) protease inhibitor used with the medicines peginterferon alfa and ribavirin to treat chronic (long-lasting) hepatitis C infection in adults. HIV protease inhibitors are a class of anti-viral drugs used to treat HIV infection. Ritonavir is an HIV protease inhibitor used to “boost” other HIV protease inhibitors, increasing their levels in the blood and making them more effective.
RECOMMENDATION: Patients should not stop taking any of their medicines without talking to their healthcare professional. Patients should contact their healthcare professional if they have any questions or concerns.
Healthcare professionals who have started patients infected with both chronic HCV and HIV on Victrelis and antiretroviral therapy containing a ritonavir-boosted protease inhibitor should closely monitor patients for HCV treatment response and for potential HCV and HIV virologic rebound.
Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA's MedWatch Safety Information and Adverse Event Reporting Program. . . .
This will only widen the revenue/market-share gulf between Victrelis® and Incivek®, in my opinion, to Merck's material detriment.