- Category: HIV/HCV Coinfection
- Published on Tuesday, 16 October 2012 00:00
- Written by Liz Highleyman
Near-perfect adherence to pegylated interferon plus ribavirin offers the best chance of sustained virological response -- or a cure -- for HIV positive people coinfected with hepatitis C virus (HCV), according to a U.S. veterans study described in the August 21, 2012, advance online edition of AIDS and Behavior.
HIV/HCV coinfected individuals tend to experience more rapid liver disease progression and respond less well to interferon-based therapy than people with hepatitis C alone. The advent of direct-acting anti-HCV agents such as the protease inhibitors boceprevir (Victrelis) and telaprevir (Incivek) offer the prospect for shorter and more effective therapy -- eventually without interferon and its difficult side effects -- but coinfected people with progressive liver disease may not have much time to wait.
Vincent Lo Re from the University of Pennsylvania Perelman School of Medicine and colleagues looked at the effects of adherence to the outgoing standard-of-care treatment for chronic hepatitis C in people with HIV. Pegylated interferon stimulates the body's natural immune response to HCV, while ribavirin helps prevent relapse after completing therapy.
This retrospective cohort analysis included 333 HIV/HCV coinfected participants receiving care through the Department of Veterans Affairs medical system. Almost all (98%) were men, about half were white, and 45% were black. Most (80%) had difficult-to-treat HCV genotypes 1 or 4. 90% were on antiretroviral therapy for HIV and 6% were receiving methadone to manage opiate addiction.
Between 2001 and 2006, participants were treated with once-weekly pegylated interferon plus daily ribavirin for 48 weeks. They had available HCV RNA measurements from before and after treatment, and adherence was estimated over 12-week intervals using pharmacy refill information.
- Adherence to treatment declined over time.
- Average interferon adherence fell by 2.5% per 12-week interval (from about 99% to about 88% overall).
- Average ribavirin adherence fell by 4.1% per interval (from about 93% to about 78% overall).
- Among participants with HCV genotypes 1 or 4, the overall early virological response (EVR) rate -- or significant HCV viral load reduction by week 12 -- was 45%.
- In this group the overall sustained virological response (SVR) rate -- or continued undetectable HCV RNA at 12 weeks after completing treatment -- was 27%.
- The likelihood of EVR increased with greater ribavirin adherence.
- EVR also increased somewhat with better interferon adherence, but the effect was less strong.
- The likelihood of SVR increased with better adherence to both interferon and ribavirin over the first, second, and third 12-week intervals, but not the final interval.
- Use of methadone was associated with poorer adherence to both interferon and ribavirin.
"Among HIV/HCV patients, EVR and SVR increased with higher interferon and ribavirin adherence," the study authors concluded. "Adherence to both antivirals declined over time, but more so for ribavirin."
"Future studies should examine additional risk factors for non-adherence and evaluate interventions to maximize adherence to HCV therapy in this population," they recommended. "[I]dentifying suboptimal adherence using pharmacy refill records might allow clinicians to counsel patients to improve their adherence during therapy."
V Lo Re, V Teal, AR Localio, et al. Adherenceto Hepatitis C Virus Therapy in HIV/Hepatitis C-Coinfected Patients. AIDS and Behavior. August 21, 2012 (Epub ahead of print).