Previous treatment failure patients Retreatment of prior treatment failures (relapse and non-responder patients) with peginterferon alfa- 2b in combination with Rebetol In a non-comparative trial, 2,293 patients with moderate to severe fibrosis who failed previous treatment with combination alpha interferon/ribavirin were retreated with peginterferon alfa 2b, 1.5 microgram/kg subcutaneously, once weekly, in combination with weight adjusted Rebetol.