Partial Antiviral Courses for HCV Get Response

Sofosbuvir-based treatment regimens for hepatitis C virus (HCV) infections allow patients to achieve sustained virological response for 12 weeks (SVR12), even when they receive less than a full prescribed course of treatment, according to a new study.

Using prescription refills as a surrogate for treatment adherence, researchers led by Adeel A. Butt, MD, MS, VA Pittsburgh Healthcare System, found that SVR12 rates for all-oral regimens of sofosbuvir plus simeprevir or ledipasvir remain high even when only half of a course is prescribed. For boceprevir-based treatment regimens, SVR12 rates steadily fell if less than 80% of a full course was prescribed.

“Newer direct-acting antivirals (DAAs) have lower pill burdens and shorter treatment durations, and the recently approved all-oral regimens have eliminated the need for injections, which were less acceptable to many patients,” the researchers stated. However, rates of adherence to therapy, completion of a full course of prescribed therapy, and their impact on virological response in patients treated with the newer DAAs are unknown. They set out to determine the impact of treatment adherence to sofosbuvir-based regimens by measuring cumulative doses prescribed.

The researchers analyzed HCV-infected persons in Electronically Retrieved Cohort of HCV Infected Veterans who started sofosbuvir-based regimens. The study included 1050 patients who received sofosbuvir plus simeprevir, 974 receiving sofosbuvir plus ledipasvir, 663 patients with genotype 2 or 3 receiving sofosbuvir plus ribavirin, and 519 patients with genotype 1 or 4 receiving sofosbuvir plus pegylated interferon; 1652 controls received a boceprevir-based regimen.

Patients treated with a sofosbuvir-based regimen were older and more likely to have cirrhosis, diabetes, chronic kidney disease, higher HCV RNA levels, and higher body mass index compared with controls.

SVR12 rates for the sofosbuvir plus simeprevir and sofosbuvir plus ledipasvir groups did not decline significantly even when as low as 50% of the full course was prescribed. Two-thirds of those on the sofosbuvir plus ribavirin regimen who received 50% to 80% of the prescriptions achieved SVR12. For those treated with sofosbuvir plus pegylated interferon and ribavirin, there were no declines in SVR12 with lower rates of prescriptions.

The researchers noted that “completion of a full prescribed course of treatment has been a major challenge in HCV-infected persons with the older treatment regimens” and that more patients on sofosbuvir-based regimens completed a full prescribed course of treatment compared with controls on boceprevir-based regimens in their study.

“As a result of the cost of newer DAA-based HCV treatment regimens, non-adherence with the subsequent consequence of virological failure has been a major concern among providers and payers. Our study helps to allay some of these fears by demonstrating much higher treatment completion rates compared with older regimens, as well as high SVR12 rates even when less than a full course is prescribed,” they stated.

Newer DAA regimens, including sofosbuvir-based regimens, particularly the fixed dose combinations and those without pegylated interferon and ribavirin, are “more convenient and less toxic, as well as much shorter in duration,” they stated.

The researchers published their results in the September 2016 Liver International.