African-Americans less likely to respond to direct-acting antivirals for hep-C

Last Updated: 2018-03-01

By Will Boggs MD

NEW YORK (Reuters Health) - African-Americans are less likely than other patients to achieve sustained virological response 12 weeks (SVR12) after completion of direct-acting antiviral treatment for hepatitis C virus (HCV) infection, according to a retrospective study of U.S. military veterans.

"The results may indicate that the lower response rate in African-Americans may have important underlying pathophysiological rationale and that in the treatment of these patients greater attention will need to be given to being certain that they attain a sustained virological response," Dr. Joseph R. Pisegna from David Geffen School of Medicine at UCLA, in California, told Reuters Health by email.

Previously, African-Americans were shown to be more likely to harbor a genotype that diminished their response to pegylated interferon, which appeared to explain some disparities in outcomes of hepatitis C treatment. Now that direct-acting antivirals (DAAs) have revolutionized hepatitis C therapy, however, racial differences in treatment outcomes persist.

Dr. Pisegna and colleagues used data from 1,068 HCV-infected patients (97% men) treated with DAAs at the VA Greater Los Angeles Healthcare System to address racial/ethnic differences in SVR12, controlling for HCV treatments (older vs. current DAAs), extent of fibrosis, and treatment adherence. Only 3.3% of the cohort was HIV-positive.

African-American race/ethnicity was associated with a 57% lower likelihood of SVR12, whereas advanced liver disease was associated with a 60% lower likelihood of SVR12, according to the February 22 Pharmacological Research and Perspectives online report.

When older therapies were excluded, SVR12 rates were still lower among African-Americans (87.8%) than among whites (92.4%).

Compared with whites, SVR12 rates were also 25% lower among Hispanics, 39% lower among Asians, and 33% lower among patients of other/unknown race/ethnicity.

The odds of achieving SVR12 in African-Americans were consistent with either 8 weeks or 12 weeks of therapy and when adherence was taken into account, and the results persisted when the analyses were limited to patients with HCV genotype 1.

"Given the predominance of males in the VA population, our data may not be generalizable to female patients," the researchers caution. "Similarly, the small number of HIV-coinfected patients in our cohort cannot provide conclusive observations about SVR12 rates in this group."

"Although our data demonstrate the importance of racial/ethnic differences," they add, "the true etiology of these differences remains unclear, which can be further explored in prospective studies where drug levels and patient genetics are taken into account."

Dr. Stuart C. Gordon from Henry Ford Health System, Detroit, Michigan, who has also looked at racial factors influencing HCV infection and its outcomes, told Reuters Health by email, "The retrospective analysis spanned a remarkable period of evolution in HCV antiviral effectiveness, and the roughly 10% of patients who received only sofosbuvir and ribavirin therapy would now be considered to have received suboptimal treatment compared to current regimens. It is thus possible that racial differences in response rates have diminished over the past 4 years with the availability of our current 'third-generation' agents."

"New guidelines for treatment duration should be adhered to for African-Americans, as they may be more likely to fail in shorter regimens versus other races," he said. "Treatment adherence is of particular importance for doctors to discuss with their African-American patients. It is also fortunate that 'rescue' regimens exist for most of the DAA failure patients outlined in (this) paper."

SOURCE: http://bit.ly/2FxD31H

Pharmacol Res Persp 2018.