Improved Access to Direct-acting Antivirals Lowers Hepatitis C Incidence Rates

Improving access to direct-acting antivirals (DAAs) was found to reduce incidence rates of hepatitis C virus (HCV) in people living with HIV (PLHIV), according to a study published in eClinicalMedicine, part of The Lancet Discovery Science. The study noted that better access to DAA could lower the incidence rate of HCV through a treatment as prevention (TasP) effect.

“A TasP effect is more likely if broad access to DAAs facilitates high coverage, particularly among people with ongoing high-risk behaviors associated with HCV infection,” the study authors wrote. “This is supported by modelling studies reporting substantial decreases in HCV prevalence and incidence by 2030 among men who have sex with men (MSM) and [people who inject drugs (PWID)] with high DAA coverage.”

For the study, the researchers assessed changes in primary HCV incidence following DAA access in PLHIV. The study authors used pooled individual-level data from the International Collaboration on Hepatitis C Elimination in HIV Cohorts (InCHEHC).

“Given the regular engagement of PLHIV in routine HIV care, monitoring and validating HCV elimination in PLHIV in high-income countries with surveillance systems and affordable, accessible and high-quality health care is highly feasible,” the study authors wrote.

Among 101,045 individuals, 74% had at least 1 negative HCV antibody test result, with 69% of those individuals having a subsequent test to calculate follow-up. After restricting data to 2010–2019, the study’s 6 treatment cohorts included 45,942 participants, who were followed up with following the first recorded negative HCV antibody test date. The follow up ended after the last negative antibody test or estimated infection data, with follow-up restricted to 2010-2019.

The study showed 2042 incident HCV infections over 248,189 person-years. The pooled incidence rate declined from 0.91 per 100 person-years in 2015 to 0.41 per 100 person-years in 2019.

“We observed a strong decline in HCV incidence in the years immediately following broad-DAA access, slowing over time. It is unclear whether HCV incidence will continue to fall in coming years, or stabilize at a lower rate, making HCV elimination by 2030 less likely in PLHIV,” the study authors wrote. “It is unknown whether these trends continued after the study period, but evidence from InCHEHC countries shows decreases in HCV testing and diagnosis since the COVID-19 pandemic began in 2020.”

Average incidence was similar during the limited DAA access period (IRR, 0.98; 95% CI, 0.87-1.11) versus the average pre-DAA period incidence (0.90 per 100 person-years). The study showed that average incidence was 52% lower during the broad DAA access period (RR, 0.48; 95% CI, 0.42-0.52) with an annual drop of approximately 2% in the pre-DAA period. There was a 9% annual decline in incidence during the limited-DAA access period (IRR, 0.91; 95% CI, 0.82-1.00), as well as a 20% further decline in the broad-DAA access period (IRR, 0.80; 95% CI, 0.73-0.89).

“Our findings suggest that broad DAA access has a TasP effect on primary HCV incidence among PLHIV,” the authors wrote. “Based on the initial years of DAA availability, the countries in the InCHEHC collaboration are on track to meet the World Health Organization's 80% HCV incidence reduction target for PLHIV by 2030.”

Reference

Santen, D.K. van et al. (2022) Treatment as prevention effect of direct-acting antivirals on primary hepatitis C virus incidence: Findings from a multinational cohort between 2010 and 2019, eClinicalMedicine. Elsevier. https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(22)00539-9/fulltext. Accessed January 3, 2023.