Elevated serum uric acid level was a notable adverse event during combination therapy with sofosbuvir and ribavirin

Aim Combination therapy with sofosbuvir and ribavirin (SOF/RBV) has been recently available for chronic hepatitis C patients with genotype 2 (CHG2) in Japan. The domestic phase-III clinical trial showed a high antiviral effect with a relatively safe adverse event (AE) profile. Our aim was to report an important AE detected during treatment. Methods A prospective multi-institutional study of 12-week combination therapy with SOF/RBV for CHG2 was performed to evaluate efficacy and safety. Results The eligible subjects include 142 patients. Out of 50 assessable patients, 16% of the patients were diagnosed with hyperuricemia. The proportions of subjects with grade 1, grade 3 and grade 4 hyperuricemia were 12, 2, and 2%, respectively. Serum uric acid (UA) levels at week 1 of the therapy (W1) were the numerically highest during the therapy in patients with hyperuricemia and a ratio of W1/baseline serum UA levels was significantly higher than that of post-treatment week 4 or 8/baseline serum UA levels in assessable patients. Serum UA levels at W1 were significantly correlated with body mass index. The difference between serum UA levels at W1 and baseline serum UA levels was significantly correlated with that between serum creatinine levels at W1 and baseline serum creatinine levels. Conclusions Elevated serum UA level was a notable AE associated with the therapy. However, because of the small number of subjects, the exact frequency of AEs should be re-evaluated with larger cohorts. We need to remember that elevated serum UA level might develop during the therapy, especially at W1.