Schering-Plough Corporation, a leader in hepatitis research, posted top- line results of the first large, randomised, IDEAL study comparing its Pegintron and Roche's Pegasys, the leading therapies for chronic hepatitis C.
The results showed that sustained virologic response (SVR), the primary endpoint of the study, was similar for the two leading combination therapies for hepatitis C; and that using a lower dose of Pegintron with Rebetol also resulted in a similar SVR. The study also showed that fewer patients treated with both Pegintron regimens relapsed after the end of treatment compared to those receiving Pegasys and Copegus.
The IDEAL (Individualized Dosing Efficacy vs. Flat Dosing to Assess optimaL pegylated interferon therapy) study, was conducted by comparing Pegintron (peginterferon alfa-2b) and Rebetol (ribavirin, USP) combination therapy vs. Pegasys (peginterferon alfa-2a) and Copegus (ribavirin, USP) combination therapy, as well as a lower dose of Pegintron in an investigational combination regimen.
In the study, both Pegintron regimens utilized investigational weight-based ribavirin dosing. The three treatment regimens studied were:
In the study, 3,070 previously untreated US patients with HCV genotype 1, the most common form of the virus worldwide and most difficult to treat, were randomised to one of the three treatment regimens and received up to 48 weeks of combination therapy with 24 weeks of follow-up. SVR, the primary endpoint of the study, was similar for the three treatment regimens (40 vs. 38 vs. 41 per cent, respectively).
Importantly, while end of treatment response was higher in the Pegasys combination therapy arm, IDEAL showed that fewer patients receiving Pegintron combination therapy relapsed after the end of treatment (24 vs. 20 vs. 32 per cent, respectively).
Overall adverse events reported for the three treatment regimens were similar and, as seen in other studies with these treatments, a range of "flu- like symptoms" were the most commonly reported adverse events for all three treatment regimens. Discontinuation rates due to adverse events also were similar (13 vs. 10 vs. 13 per cent, respectively).
Psychiatric adverse events, which include insomnia, were common (57 per cent) with Pegintron but similar to Intron A (58 per cent). Depression was most common at 29 per cent. Suicidal behaviour including ideation, suicidal attempts, and completed suicides occurred in 1 per cent of patients during or shortly after completing treatment with Pegintron.
"While the sustained response rates were similar in the IDEAL study, we were pleased to see that fewer patients relapsed following Pegintron combination therapy," said Robert J Spiegel, M D, chief medical officer and senior vice president, Schering-Plough Research Institute. "With these results, we now have, for the first time, a large body of well-controlled clinical data demonstrating how the similarities and differences of the two leading combination therapies for hepatitis C affect outcomes for patients. These findings provide important clinical-based evidence that will help physicians in making treatment decisions and in guiding their patients through what is a long and challenging course of therapy. We look forward to further analyses of this large data set to gain additional clinical insights into the management of this serious disease".
The IDEAL study was conducted by Schering-Plough as an important step in meeting the needs of the hepatitis C medical and patient communities to identify improved treatment strategies to optimise outcomes for patients. IDEAL, a phase IIIb, randomised, parallel-group study, was conducted at 118 academic and community centres across the United States. The study treated 3,070 adult patients with chronic HCV genotype 1. Of these, 82 percent of patients had high viral load (greater than or equal to 600,000 IU/mL),(3) 11 percent had grade F3/4 fibrosis/cirrhosis, and 19 percent were African Americans. There were no significant differences in patient demographics or disease characteristics across the three treatment arms.
In the United States, Pegintron is indicated for use alone or with ribavirin for the treatment of chronic hepatitis C in patients with compensated liver disease who have not been previously treated with interferon alpha and who are at least 18 years of age.