A phase II randomized, double-blind, placebo-controlled multicenter study of recombinant human interleukin-12 for the treatment of chronic hepatitis C virus infection in patients non-responsive to previous treatment with interferon-alpha with or without ribavirin: Paul J Pockros, John G McHutchison, Scripps Clinic, La Jolla, CA; Chris O'Brien, University of Miami, Miami, FL; Myron Tong, Huntingon Medical Research Institute, Pasadena, CA; Coleman Smith, Minnesota Clinical Research Center, St. Paul, MN; Vinod Rustgi, Metropolitan Research Group, Fairfax, VA; Robert L Carithers, University of Washington Medical Center, Seattle, WA; Elizabeth Olek, Genetics Institute, Cambridge, MA