| |
SUBJECT: Results of Pharmacokinetic Study in Healthy Volunteers Given VICTRELIS™ (boceprevir) and Ritonavir-Boosted HIV Protease Inhibitors May Indicate Clinically Significant Drug Interactions for Patients Coinfected with Chronic Hepatitis C and HIV
|
| |
| |
February 6, 2012
IMPORTANT DRUG WARNING
Dear Health Care Professional,
The purpose of this communication is to inform you of recent pharmacokinetic study results evaluating drug interactions between VICTRELIS, an oral chronic hepatitis C virus (HCV) NS3/4A protease inhibitor, and ritonavir-boosted human immunodeficiency virus (HIV) protease inhibitors in healthy volunteers (n=39). VICTRELIS is indicated for the treatment of chronic hepatitis C virus (HCV) genotype 1 (G1) infection, in combination with peginterferon alfa and ribavirin (PR), in adult patients (18 years and older) with compensated liver disease, including cirrhosis, who are treatment-naïve or who have failed previous interferon and ribavirin therapy. In the pharmacokinetic study, concomitant administration of VICTRELIS with Norvir® (ritonavir) in combination with Reyataz® (atazanavir) or Prezista® (darunavir), or with Kaletra® (lopinavir/ritonavir) resulted in reduced exposures of the HIV medicines and VICTRELIS. Specifically, VICTRELIS reduced mean trough concentrations of ritonavir-boosted atazanavir, lopinavir, and darunavir by 49%, 43%, and 59%, respectively. Mean reductions of 34% to 44% and 25% to 36% were observed in AUC and Cmax of atazanavir, lopinavir, and darunavir. Coadministration of ritonavir-boosted atazanavir with VICTRELIS did not alter the exposure of VICTRELIS, but coadministration of VICTRELIS with lopinavir/ritonavir or ritonavir-boosted darunavir decreased the exposure of VICTRELIS by 45% and 32%, respectively.
These drug interactions may be clinically significant for patients infected with both chronic HCV and HIV by potentially reducing the effectiveness of these medicines when coadministered. VICTRELIS is not indicated for use in patients who are infected with both HIV-1 and chronic HCV. The safety and efficacy of VICTRELIS™ (boceprevir) has not been established in this coinfected population. Merck does not recommend the coadministration of VICTRELIS and ritonavir-boosted HIV protease inhibitors.
Health care providers who might have initiated VICTRELIS in combination with PR in HIV-HCV coinfected patients on fully suppressive antiretroviral therapy containing a ritonavir-boosted protease inhibitor should discuss these findings with those patients, and closely monitor those patients for HCV treatment response and for potential HCV and HIV virologic rebound.
Patients should be advised to contact their health care provider before stopping any of their medications.
Merck is sharing these pharmacokinetic data with regulatory authorities in the countries where VICTRELIS is approved. Merck will be submitting requests to regulators to update the product labeling with these data. These data have been submitted for scientific presentation at an upcoming medical forum.
For more information, please consult the enclosed Prescribing Information for VICTRELIS. The Prescribing Information can also be found at http://www.merck.com/product/usa/pi_circulars/v/victrelis/victrelis_pi.pdf.
Should you have any questions, require further information on product safety, or wish to report an adverse event with VICTRELIS, please contact Merck at 1-877-888-4231. Alternatively, an adverse event can be
reported directly to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch".
Sincerely,
S. Sethu K. Reddy, MD
|
|
| |
| |
|
|
|
