Open-label trial of therapeutic immunization with oral V-5 Immunitor (V5) vaccine in patients with chronic hepatitis C

We evaluated whether V-5 Immunitor (V5) - tableted therapeutic bivalent vaccine comprising heat - inactivated HCV antigens from pooled blood of HBV- and HCV-infected donors - may produce clinical benefit through induction of oral tolerance and reduction of immunemediated liver injury. Once daily dose of V5 was administered per as to 10 patients with chronic hepatitis C in an open-label study that tasted 1 month. Every patient who entered the study had elevated liver enzyme levels, which at the end of study have decreased in 100% of analyzed patients. The reduction was highly significant, from 157.7 +/- 73.4 to 49.9 +/- 43.8 U/L (P = 0.0013) and 147.0 +/- 79.2 to 58.7 +/- 56.6U/L (P = 0.0132), for ALT and AST, respectively. The AST/ALT ratio has improved from 0.93 to 1.18 (P = 0.00058) indicating the reversion of progression to cirrhosis. None of intent-to-treat patients who were anti-HCV antibody positive at study entry, became negative after 1 month on V5 (P = 0.998). All patients, except one, reported complete recuperation from hepatitis C-associated clinical symptoms present at baseline (P = 0.0016) with Mantel Haenszel's odds ratio 9.4 (P = 0.0021) at 95% confidence interval: 2.7 < OR < 476.3. No adverse events were observed at any time. The favorable biochemical and clinical responses have been observed in a small number of individuals for a limited time period. Larger scale and longer studies are needed to confirm our preliminary observations suggesting that V5 is safe and effective means for immunotherapy of chronic hepatitis C. (C) 2008 Elsevier Ltd. All rights reserved.