Loss of HBeAg was numerically higher in the combination group because of the interferon effect. That could be viewed as a “subjective benefit” of PEG-IFN, even though the difference wasn’t statistically significant, said Dr. Gish.
The low rates of HBsAg loss could relate to two features of the patient profile, he explained. At study entry, the participants had moderately high levels of quantitative HBsAg and were predominately of Asian ancestry, which are predisposing factors for limited HBsAg loss.
Previous studies have suggested that peak HBsAg loss could take 2-3 years to develop after treatment withdrawal in a trial population. In the HBRN trial, rates almost 1 year after withdrawal are similar to 1-year rates from other studies, Dr. Terrault said. How these results for HBsAg loss in the two treatment groups will look at the 3-year mark is not known.
The trial design standardized withdrawal protocol and the length of time patients were on treatment before withdrawal was attempted, which are strengths of this study, said Dr. Terrault. And “a triumph of this study is execution of a standard for nucleic acid treatment in a protocolized way, followed by withdrawal. That is something we are happy about.”
Dr. Terrault reported receiving institutional grant support from Roche/Genentech and Gilead Sciences. Dr. Gish reported receiving research support from Gilead Sciences and serving as a consultant and on advisory boards for several pharmaceutical companies.
This article first appeared on Medscape.com.