- Category: HCV Treatment
- Published on Wednesday, 10 October 2012 00:00
- Written by Liz Highleyman
HIV negative and HIV positive chronic hepatitis patients in Vancouver with a history of injection drug use -- most of whom were on methadone maintenance -- achieved sustained response rates with interferon-based therapy similar to those of non-users, researchers reported at the 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2012) last month in San Francisco.
Sharing syringes and other drug equipment is an efficient way to transmit hepatitis C virus (HCV) and HIV, and a large proportion of people with a history of injection drug use are infected with one or both viruses.
Although injection drug users (IDUs) are estimated to account for at least half of existing and more than 75% of new cases of hepatitis C in North America, only a minority have received treatment. Many clinicians are hesitant to treat current and past IDUs due to concerns about adherence, dealing with side effects, or simple prejudice. Current guidelines, however, state that this population should not be routinely denied treatment and should instead be evaluated on an individual basis.
Harout Tossonian from the University of British Columbia and colleagues conducted a retrospective and prospective analysis of individuals who began receiving care at 2 inner-city clinics in Vancouver since January 2003 and completed hepatitis C treatment by June 2012.
A total of 302 adult chronic hepatitis C patients received care within a multidisciplinary program that included extensive medical, psychiatric, addiction and counseling support, as well as management of treatment side effects and other clinical and sociological issues.
About two-thirds of study participants were women and the median age was 53 years (range 34-70 years). All had a history of injection drug use and 70% were on methadone maintenance therapy. 83% had not been previously treated for hepatitis C. 63% had difficult-to-treat HCV genotype 1, while 37% had genotypes 2 or 3; 11% had liver cirrhosis. 14% were coinfected with HIV. Researchers deemed the participants to have a "reasonable expectation of adherence to therapy."
Patients were treated with pegylated interferon alfa-2a (Pegasys) or alfa-2b (PegIntron) plus ribavirin. Interferon injections were administered once-weekly on-site by clinic staff. Treatment duration depended on HCV genotype (24 weeks for genotypes 2 or 3, 48 weeks for genotype 1) and HIV status.
- The number of patients treated increased over time, from 14 in 2003 and 2004, to 39 in 2007, to 61 in 2010 and 55 in 2011.
- Overall, 67% of participants completed their assigned therapy, while one-third discontinued prematurely.
o 24% of genotype 1 patients and 7% of genotype 2 or 3 patients stopped due to lack of response;
o 8% and 15%, respectively, did so due to drug side effects;
o 7% and 3%, respectively, did so due to non-adherence or relapse to active drug use.
- Sustained virological response (SVR) rates among HCV monoinfected patients were 45% for genotype 1 and 65% for genotypes 2 and 3.
- Among HIV/HCV coinfected patients, the corresponding SVR rates were 42% and 60%, respectively -- not significantly different from the monoinfected group.
"HCV infection can be treated successfully in IDUs with response rates and patterns of treatment discontinuation similar to those seen in other populations, independent of HIV coinfection status," the investigators continued.
As reflected in 2012 Canadian guidelines for the treatment of HCV infection, they added, "IDUs should be considered for therapy when this is medically indicated, preferentially within the context of multidisciplinary community-based models for the delivery of health care where state-of-the-art expertise for the management of HCV infection is available."
H Tossonian, L Gallagher, S Nouch, et al. Long-term Follow-up of Inner City Populations Treated for HCV Infection. 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2012). San Francisco. September 9-12, 2012. Abstract V-371.