Results from the EGALITE study showed that 12 weeks of elbasvir/grazoprevir was a highly effective regimen for treatment-naive Asian patients with hepatitis C virus genotype 1b infection and mild liver fibrosis. Those who were given 8 weeks of therapy had “substantially lower” SVR12 rates, researchers said, suggesting that only certain patients — like those with low viral loads and patients without significant resistance to NS5A inhibitor-containing regimens — can benefit from an abbreviated regimen.
“The EGALITE study, to our knowledge, is the first and only randomized, active controlled trial that compared the efficacy of an abbreviated 8-week regimen with the standard 12-week [elbasvir/grazoprevir] regimen for HCV-1b patients with mild liver fibrosis,” Chung-Feng Huang, MD, from the Kaohsiung Medical University Hospital in Taiwan, and colleagues wrote.
The researchers randomly assigned 82 patients aged 20 years or older in Taiwan to 100 mg elbasvir/grazoprevir daily for 8 weeks (short treatment arm) or 12 weeks (standard treatment arm). The patients all had mild liver fibrosis and HCV genotype 1b infection — “the most common subtype in East Asia,” the researchers noted.
Huang and colleagues evaluated the regimen’s efficacy in a full-analysis set population, which included all patients who had received one or more doses of medication, and in a per-protocol population, which included patients who received one or more doses of medication and had SVR12 data available.
For patients in the short treatment arm, 87.8% achieved SVR12 in the full-analysis population and 90% achieved SVR12 in the per-protocol population, whereas patients in the standard treatment arm achieved 100% SVR12 in both analyses (P = .055).
The researchers observed significantly lower SVR12 rate among patients in the short treatment arm who had high viral loads, defined as 1,500,000 IU/mL or greater, and who had more than 15% NS5A Y93H resistance-associated substitution (RAS) frequency at baseline.
All patients had undetectable HCV RNA when treatment ended. Although five patients in the short treatment group experienced virologic relapse during the 12-week post-treatment follow-up, relapse did not occur for any patients in the standard treatment group, according to the study.
The researchers noted that larger studies are needed to assess the regimen for patients with high viral loads and/or RASs.
“In conclusion, we confirmed that the standard 12 weeks of [elbasvir/grazoprevir] provided excellent efficacy for naive HCV-1b patients with mild fibrosis. Nevertheless, a substantially lower SVR12 rate of 8-week [elbasvir/grazoprevir] was observed in the current study, indicating 8 weeks of [elbasvir/grazoprevir] was not noninferior to 12 weeks of [elbasvir/grazoprevir],” Huang and colleagues wrote. “A truncated 8-week grazoprevir/elbasvir regimen might be applied for the subpopulation with low viral loads or without significant NS5A RAS.”
By Marley Ghizzone