In a small open‑label trial, adding the peptide thymosin‑alpha‑1 (thymalfasin) to the standard hepatitis C drugs peginterferon‑alpha‑2a and ribavirin helped about half of the participants clear the virus during treatment, and roughly one‑fifth kept the virus cleared after 24 weeks off therapy. The peptide was well tolerated and didn’t need dose cuts.

Thymalfasin has shown efficacy in the treatment of chronic HCV infection. The aim of this study was to evaluate the efficacy and tolerability of triple therapy with thymalfasin, peginterferon alpha-2a (PEG-IFN alpha-2a), and ribavirin in Hispanic patients with chronic viral hepatitis C who were nonresponders to prior treatment with interferon alfa (IFN-alpha)/ribavirin. In this open-label study, 40 subjects received thymalfasin (1.6 mg twice a week), PEG-IFN alpha-2a (180 microg once a week), and ribavirin (800-1,000 mg/day) for 48 weeks. All patients had positive HCV RNA by PCR analysis, abnormal levels of ALT, compensated hepatic disease, and liver biopsy with chronic damage. Viral response was observed in 52.5% patients at week 12 and 50% at week 24. Of the per protocol group, 52.6% showed an end-of-treatment response at week 48 and 21.1% achieved an SVR at week 72. Among genotype 1 patients, 23.5% achieved an SVR at week 72. A reduction of the dose of PEG IFN alpha-2a and ribavirin was required. Thymalfasin was well tolerated without dose reduction. Triple therapy with thymalfasin, PEG IFN alpha-2a, and ribavirin is an effective treatment option for difficult-to-treat HCV patients who are refractory to prior conventional treatment, with adequate tolerability.