HIV Coinfection Doesn't Affect Hep C Treatment Adherence

One-third of HIV-infected Americans are co-infected with hepatitis C virus (HCV), and 75% to 90% of HIV-positive intravenous drug users are co-infected.

The FDA approved the direct-acting antivirals ledipasvir/sofosbuvir (Harvoni) in 2014 as a fixed-dose combination product for patients infected with HCV genotype 1. This product cures more than 90% of infected patients who take it.

Patients who do not have HIV and adhere to their prescribed regimens usually have undetectable HCV RNA after 12 weeks of therapy. However, evidence on adherence to prescribed HCV regimens in the HIV/HCV co-infected population had not been collected until now.

The journal AIDS recently published a study showing that HIV coinfection has no impact on adherence to HCV treatment. The authors compared 2 National Institutes of Health trials (SYNERGY and ERADICATE) that enrolled treatment-naïve patients receiving a fixed-dose combination of ledipasvir 90 mg/sofobuvir 400 mg once daily for 12 weeks.

The researchers identified 70 patients, 50 of whom were HIV/HCV co-infected. They monitored treatment adherence using an electronic medication event monitoring system (MEMSCap), pill counts, and written questionnaires. Adherence follow-up visits were scheduled at day 7, week 4, week 8, and the end of treatment (week 12).

Previous studies have shown that most patients’ self-reported adherence is unreliable. The MEMSCap’s data suggested similar findings, as patients’ actual adherence was considerably lower than what they reported themselves. The bottom line: patients overestimate their adherence.

Nevertheless, the researchers found that HIV/HCV coinfection had no effect on patients’ adherence. Despite a higher pill burden, coinfected patients experienced no additional adverse effects.

Patients’ prior experience with the need for near-perfect adherence to HIV medications was also found to be unrelated to HCV medication adherence. They did neither better nor worse than other patients in terms of treatment compliance.

Most patients took more than 90% of their scheduled doses. There was a significant drop in adherence during the last 4 weeks of therapy, which could be attributed to pill fatigue.

The study authors suggested that future study should try to establish an adherence threshold, meaning an adherence level below which response is unlikely.