Positive results from BOSON Phase III study with Sovaldi (sofosbuvir) in HCV-Gilead

Gilead Sciences has announced results from the BOSON Phase III study evaluating the safety and efficacy of Sovaldi (sofosbuvir 400 mg) in combination with ribavirin (RBV) or with pegylated interferon (PEG)/RBV which demonstrated high cure rates across all patients with chronic hepatitis C virus (HCV)-infection of genotypes 2 and 3. Among genotype 3 patients, rates of sustained virologic response 12 weeks after treatment (SVR12) were highest among those receiving Sovaldi plus PEG/RBV for 12 weeks (93 percent, n=168/181), compared to those receiving Sovaldi plus RBV for 24 weeks (84 percent, n=153/182) or for 16 weeks (71 percent, n=128/181). Treatment-experienced genotype 3 patients with cirrhosis receiving Sovaldi plus PEG/RBV demonstrated SVR12 rates of 86 percent (30/35).

Genotype 2 patients also demonstrated high SVR12 rates across all treatment arms. SVR12 rates among patients receiving Sovaldi plus PEG/RBV were 94 percent (15/16), and 100 percent (17/17) and 87 percent (13/15) for those receiving Sovaldi plus RBV for 24 and 16 weeks, respectively. Sovaldi plus PEG/RBV and Sovaldi plus RBV were well tolerated. The most common adverse events in the study were fatigue, headache, insomnia and nausea.Data will be presented at the Annual Meeting of the European Association for the Study of the Liver.

Comment: Last year CVS Health Research Institute produced a report that showed that patients who began Sovaldi in combination with other medications, Sovaldi discontinuation rates were approximately four times greater than the rates observed in clinical trials. Across regimens, treatment-naïve patients were 64 percent more likely to discontinue therapy with Sovaldi than treatment-experienced patients. 8.1% of patients discontinued the drug during the recommended 12-week course. These findings emphasise the fact that real world adherence to medication is often worse than that observed in clinical trials. CVS data suggests that all patients who receive Sovaldi should be followed closely by their providers to support adherence to therapy.