Treatment of Chronic Hepatitis C Infection with Sofosbuvir-Based Regimens in a Commercially Insured Patient Population.

BACKGROUND: The response to treatment with direct-acting antiviral agents in patients with chronic hepatitis C virus (HCV) is not well-characterized in the real-world setting.
OBJECTIVE: To describe patients' response to 3 sofosbuvir-based treatment regimens among commercially insured patients with chronic HCV.
METHODS: In this observational study, we identified patients with HCV who started sofosbuvir treatment with 1 of 3 sofosbuvir-based regimens between December 1, 2013, and April 30, 2014, in the HealthCore Integrated Research Database, a large managed care repository. All patients were aged ≥18 years and had ≥1 RNA viral load tests after starting treatment. Pharmacy and medical claims, laboratory results, and patient medical records were integrated for information on HCV genotype, treatment regimen, RNA viral load, and other clinical and demographic characteristics. The primary outcome was the response to HCV treatment during and after treatment completion, which was defined as an HCV RNA viral load of <25 IU/mL. The 3 HCV treatment regimens included sofosbuvir plus peginterferon alfa and ribavirin; sofosbuvir plus ribavirin; and sofosbuvir plus simeprevir, with or without ribavirin in patients with HCV genotypes 1 to 3. The secondary outcome was the number of patients who had a treatment response in the first 4, 6, and 8 weeks of therapy to determine whether a lack of early response to treatment is suggestive of a posttreatment lack of response. Relapse was defined as regression from response during treatment, with a detectable viral load of ≥25 IU/mL in the most recent test after treatment completion.
RESULTS: Among 249 patients with ≥1 documented viral load tests after treatment initiation, 200 (80%) patients had ≥1 tests after the end of treatment. The posttreatment response rate for all 3 regimens was 88% (95% confidence interval, 84%-93%), ranging from 81% to 93%. In the largest category-patients with genotype 1 HCV (N = 130)-the response rate was between 83% and 92% across the 3 regimens. During treatment, 34% of the patients with any viral load test results by week 4 did not respond; however, 81% of those patients had a response after week 12. Of the patients who responded during treatment, 8% had relapsed disease after the end of treatment.
CONCLUSION: The response rate to the sofosbuvir-based regimens included in this study was similar to those seen in published randomized clinical trials. Although 34% of the patients with any viral load test result by week 4 of treatment had viral loads of ≥25 IU/mL, persistent treatment was associated with response in the majority of those patients. This supports the effectiveness of sofosbuvir treatment and the need for treatment persistence. The rapid emergence of new treatments in this field presents exciting opportunities for additional research, and holds important clinical and economic implications for patients and their families, healthcare providers, and critically, for payers, who have to accommodate the new pricing models associated with these treatments.