Chronic hepatitis C is an insidious disease associated with prior interferon therapy were more likely to have a serum HCV RNA end-of-retreatment and sustained response than significant morbidity and mortality. Currently, the only approved therapies for chronic hepatitis C are the alpha interfer-patients who were nonresponders to prior interferon therapy.
After patients from the 3-mg CIFN cohort were excluded, the ons. Consensus interferon (CIFN) is a nonnatural, synthetic, recombinant type I interferon derived by assigning the most HCV RNA sustained response rates were 28% in relapsers and 5% in nonresponders, respectively, in the 24-week re-commonly observed amino acid in each position of several alpha interferon nonallelic subtypes to generate a consensus treatment cohort and 58% and 13%, respectively, in the 48week retreatment cohort. The administration of 9 or 15 mg sequence. The efficacy and safety of CIFN in the treatment of chronic hepatitis C were assessed in two large phase 3 CIFN was well tolerated, and the adverse effects were similar to those for interferon alfa-2b. These data demonstrate that trials. The first trial was a multicenter, randomized, doubleblind, controlled study of 704 patients who were treated with CIFN at a dose of 9 mg is effective initial therapy for patients with chronic hepatitis C, and that retreatment with a higher one of two doses of CIFN (3 mg and 9 mg) or interferon alfa-2b (3 million units [MU]) weekly for 24 weeks and then CIFN dose of 15 mg for 48 weeks provides meaningful responses in both relapsers and nonresponders. (HEPATOLOGY observed for an additional 24 weeks. Treatment with CIFN at a dose of 9 mg was safe and effective, with serum alanine 1997;26(Suppl 1):101S-107S.) aminotransferase (ALT) and hepatitis C virus (HCV) RNA sustained response rates of 20% and 12%, respectively. Re-
The hepatitis C virus (HCV) is a single-stranded RNA virus sponses to 3 MU interferon alfa-2b were comparable to 9 mg that has been identified as the causative agent of most cases CIFN. The response rates were lower in the 3-mg CIFN cohort. of non-A, non-B hepatitis. 1 Hepatitis C is an important infec-At the end of the treatment and posttreatment observation tious disease; 85% or more of patients with acute disease periods, an undetectable serum HCV RNA was a better preinsidiously progress to chronic liver disease. Chronic hepatidictor of a normal ALT than the converse. Serum samples tis C is characterized by intermittent or persistent elevation from early time points were available for HCV RNA quantitaof serum alanine aminotransferase (ALT) levels and the contion from 27 of the 28 patients who experienced a sustained tinuing presence of serum HCV RNA. 2 The spectrum of response with 9 mg CIFN. Of these, 13 patients (48%) had chronic disease varies, but it is believed that the natural undetectable HCV RNA at 2 weeks, 21 patients (78%) at 4 progression of chronic HCV infection leads to cirrhosis in weeks, and 26 patients (96%) at 12 weeks. CIFN (9 mg) 10% to 20% of patients over 20 years and progression to induced a significantly greater reduction in the mean serum hepatocellular carcinoma in a small but important fraction HCV RNA concentration than interferon alfa-2b during treatof cirrhotic patients. [2][3][4][5] Underscoring the morbidity and morment (P รต .01). In patients with high viral titers (ยข4.75 1 tality associated with chronic HCV infection, 20% to 30% of 10 6 copies/mL), the HCV RNA sustained response rate in liver transplantations in the United States are performed for patients treated with CIFN (9 mg) and interferon alfa-2b was complications associated with chronic hepatitis C. 6 7% and 0%, respectively (P ร
.03). In patients infected with Chronic hepatitis C can be diagnosed conveniently by se-HCV genotype 1, the HCV RNA end-of-treatment (24% vs. rologic testing with measurement of antibody to HCV. In 15%; P ร
.04) and sustained (8% vs. 4%; P ร
not significant) addition, direct measurement of HCV RNA and quantitation response rates were greater in patients treated with CIFN (9 of viremia is now possible by use of two methods: the mg) than with interferon alfa-2b (3 MU). In a subsequent branched-chain DNA assay, and various polymerase chain multicenter trial, a higher dose of CIFN (15 mg) was reinstireaction assays. 7 Several distinct strains of HCV genotypes tuted in patients who either had relapsed or were nonrespondhave been identified, which may have clinical significance ers to prior CIFN or interferon alfa-2b therapy. Patients were with respect to disease progression and treatment outrandomized to receive 24 or 48 weeks of retreatment followed comes. 8,9 The current system of nomenclature includes six by 24 weeks of observation. Patients who had relapsed after major genotypes and numerous subtypes that are more closely related. 10