Drug Utilization Similar for Hepatitis C Dual and Triple Therapy

San Francisco—The use of the protease inhibitors boceprevir or telaprevir in conjunction with peginterferon and ribavirin (known as triple therapy) for the treatment of type 1 hepatitis C did not result in increased drug utilization compared with dual therapy (peginterferon and ribavirin), according to information presented during a poster session at the AMCP meeting. Costs associated with triple therapy were higher than dual therapy, however, because of the expense of protease inhibitors.

The poster was titled Evaluation of Drug Utilization and Treatment Cost for Patients with Chronic Hepatitis C Virus in a Managed Care Population.

Hepatitis C is the most common chronic bloodborne infection, for which standard treatment consists of peginterferon and ribavirin together for either 24 weeks (for genotypes 2 and 3) or 48 weeks (for genotypes 1, 4, 5, and 6). Boceprevir and telaprevir were approved last year, either of which may be used in combination with peginterferon and ribavirin for type 1 hepatitis C in adults. The regimen is complex, involving multiple oral pills and weekly subcutaneous injections. Patient noncompliance can result in treatment failure and developing resistance, so adherence is a key component to treatment success as well as cost-effective management of patients.

Researchers conducted a retrospective cohort study of pharmacy and medical claims data to examine the difference in drug utilization patterns of members receiving dual (n=749) and triple therapy (n=94). They calculated adherence over a 24-week period using the medication possession ratio (MPR). They defined persistence of use as the number of days from the first prescription fill to the run-out date of the last fill (with an allowed maximum refill gap of 60 days). Cost differences were also evaluated.

Results over 24 weeks showed adherence to peginterferon regimens (MPR of ≥80%) was 88.5% for the dual therapy cohort and 75.5% for the triple therapy cohort; mean adherence was 93.6% and 93.7%, respectively. Persistence was found to be 43.2% for those receiving dual therapy compared with 46.2% for those receiving triple therapy.

Results also showed adherence to peginterferon regimens over 24 weeks in the triple therapy cohort (MPR of ≥80%) was 81.3% for those who received boceprevir and 74.4% for those who received telaprevir; mean adherence was 92.3% and 94%, respectively. Persistence was shown to be 21.5% for those given boceprevir and 48.1% for those who received telaprevir (triple therapy comparison, P<.001).

The researchers found medical costs per member per month (PMPM) for the dual therapy cohort were $586.81 compared with $272.15 for the boceprevir group and $314.06 for the telaprevir group. Pharmacy costs PMPM were $2279.34 for the dual therapy group, $5649.09 for the boceprevir group, and $10,180.77 for the telaprevir group.

Limitations to the study included the use of pharmacy claims to assess patient compliance, which may not have necessarily reflected an accurate consumption of medication. Additionally, the collection of data for only 24 weeks of follow-up may have been different from what might have been observed over a 48-week duration. Administrative pharmacy and medical claims were also subject to missing data and coding errors that might have affected study results.