March 6, 2012
Seattle, Wash. -- Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced results from two different investigational studies conducted to better understand the potential use of VICTRELIS (boceprevir), the company's oral HCV NS3/4A protease inhibitor, in treating patients coinfected with chronic hepatitis C virus (HCV) and HIV-1. These data are being presented for the first time today at the 19th Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.
Results were presented from a 12-week post treatment interim analysis of a Phase IIb clinical study evaluating the investigational use of VICTRELIS in combination with peginterferon alfa-2b and ribavirin for the treatment of chronic HCV genotype 1 infection in adult patients coinfected with HIV-1 (n=100). In the study, a higher percentage of patients receiving VICTRELIS in combination with peginterferon alfa-2b and ribavirin had undetectable hepatitis C virus (HCV-RNA) 12 weeks after treatment ended (sustained virologic response-121 or SVR-12) than patients receiving peginterferon alfa-2b and ribavirin alone.
Additionally, Merck announced results as part of a late-breaker poster session [Poster #771] from a pharmacokinetic study evaluating drug interactions between VICTRELIS and ritonavir-boosted HIV protease inhibitors in 39 healthy volunteers. In this study, concomitant administration of VICTRELIS with ritonavir (Norvir®) in combination with atazanavir (Reyataz®) or darunavir (Prezista®), or with lopinavir/ritonavir (Kaletra®) resulted in reduced exposures of the HIV medicines and VICTRELIS. 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 co-administered. Merck does not recommend the co-administration of VICTRELIS and ritonavir-boosted HIV protease inhibitors.
VICTRELIS is indicated for the treatment of chronic hepatitis C virus (HCV) genotype 1 (G1) infection, in combination with peginterferon alfa and ribavirin (P/R), in adult patients (18 years and older) with compensated liver disease, including cirrhosis, who are previously untreated or who have failed previous interferon and ribavirin therapy.
The following points should be considered when initiating VICTRELIS for treatment of chronic HCV infection:
The safety and efficacy of VICTRELIS alone or in combination with peginterferon alfa or ribavirin has not been established in patients coinfected with HIV and HCV.
One hundred (100) adult patients with previously untreated HCV genotype 1 infection, on an optimized antiretroviral regimen and with stable HIV-1 disease (HIV-RNA less than 50 copies/mL; CD4 cell counts equal to or greater than 200 cells/mm3) were randomized into the study. Two patients randomized to the treatment arm receiving VICTRELIS in combination with peginterferon alfa-2b (P) and ribavirin (R) did not receive VICTRELIS. Thus, the interim analysis was based on 98 patients who received at least one dose of study drug: 64 patients in the arm receiving VICTRELIS plus PR, and 34 patients in the control arm receiving PR alone. All patients treated in the study received a 4-week lead-in with PR alone followed by VICTRELIS plus PR or placebo plus PR for 44 weeks, for a total treatment duration of 48 weeks. Preliminary 24-week on-treatment data from this study were presented at the Infectious Diseases Society of America annual meeting in October 2011. Final study completion will be at week 72, or 24 weeks after the end of all treatment.
The interim analysis showed that 60.7 percent (n=37/61) of patients receiving VICTRELIS in combination with PR achieved SVR-12 compared to 26.5 percent (n=9/34) of patients receiving PR alone, a treatment difference of 34.2 percent. Three (3) patients in the VICTRELIS plus PR arm had not reached 12 weeks post treatment and were excluded.
Three (3) patients in treatment arms receiving VICTRELIS plus PR and four (4) patients in the PR control arm experienced HIV breakthrough (HIV viral load greater than 50 copies/mL at two consecutive visits). Preliminary safety data for VICTRELIS in combination therapy in HCV/HIV-1 coinfected patients demonstrated a profile similar to that previously observed in patients with HCV mono-infection.
The most common clinical adverse events with a difference of equal to or greater than 10 percent for the treatment arm receiving VICTRELIS plus PR compared to the PR control arm, respectively, were: anemia (41 vs. 26 percent), pyrexia (fever) (36 vs. 21 percent), asthenia (weakness) (34 v. 24 percent), decreased appetite (34 vs.18 percent), diarrhea (28 v. 18 percent), dysgeusia (bad taste) (28 vs. 15 percent), vomiting (28 vs. 15 percent), flu-like illness (25 v. 38 percent) and neutropenia (19 vs. 6 percent). Serious clinical adverse events occurred in 17 percent and 21 percent of patients in the two treatment arms, respectively. Dose modification for any study drug due to a clinical adverse event occurred in 28 percent and 24 percent of patients, respectively, and study discontinuation due to a clinical adverse event occurred in 20 percent and 9 percent of patients, respectively.
No comments have been made.
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