Elbasvir/grazoprevir (Zepatier) and sofosbuvir (Sovaldi) are used to treat hepatitis C around the world, but is one better than the other?
A comparison study of two hepatitis C drug regimens found which one has a superior efficacy and safety profile.
Elbasvir/grazoprevir (Zepatier) and sofosbuvir (Sovaldi) are both approved in the United States, Europe, and elsewhere as treatments for chronic infection of the liver-damaging hepatitis C virus. Researchers involved in the comparison study noted that while patients have benefited from these new direct-acting antivirals, pegylated interferon and ribavirin remain a component of treatment regimens in countries where access to treatment has limitations.
The aim of the phase 3 randomized head-to-head study was to compare the safety and efficacy of elbasvir and grazoprevir with that of sofosbuvir plus pegylated interferon and ribavirin. The latter regimen is recommended standard of care in the European Association for the Study of Liver guidelines for patients infected with genotypes 1 through 6 of the hepatitis C virus.
The trial, dubbed the C-Edge Head-2-Head Study, was conducted at several sites in the European Union and involved 257 patients who were infected with genotype 1 or 4 strains. Participants were randomized to receive 12 weeks of a daily fixed-dose combination of elbasvir at 50 mg and grazoprevir at a 100 mg (129 patients) or a daily dose of sofosbuvir at 400 mg daily plus pegylated interferon/ribavirin (128 patients).
The majority (82.0%) of patients had genotype 1b hepatitis C, one of the most common strains of the virus. Most of the patients (83.1%) did not have cirrhosis and had never received treatment for the virus. Some patients had prior treatment failures with pegylated interferon/ribavirin, according to the article.
The primary efficacy outcome tested was sustained virologic response (SVR) at 12 weeks after the treatment. The primary safety objective measured “tier 1 safety events”, which included serious adverse events considered to be drug related, adverse events that led a patient to discontinue taking the study drug, and certain liver-related abnormal lab results.
SVR was achieved by all but one of the 129 patients (99.2%) in the elbasvir and grazoprevir group. For those given sofosbuvir plus pegylated interferon/ribavirin, 114 out of 129 patients (90.5%) achieved SVR.
The authors concluded that the 12-week combination of elbasvir/grazoprevir “was highly effective in treating patients with chronic hepatitis C, genotypes 1 or 4 infection. This regimen was more effective than sofosbuvir/pegylated interferon/ribavirin for 12â€…weeks, and was notably superior in patients regarded as difficult to treat, including those with previous treatment failure, cirrhosis, or a high baseline viral load.”
The frequency of tier 1 safety events was lower among patients who were given elbasvir and grazoprevir than those in the sofosbuvir plus pegylated interferon/ribavirin group (0.8% vs 27.8%)—a difference of 27.0% (95% CI, 35.5%to -19.6; p<0.001) between the two groups, the authors pointed out.
“The combination of elbasvir/grazoprevir also demonstrated a superior safety and tolerability profile based on fewer serious adverse events, no serious drug-related adverse events, and no treatment discontinuations,” the authors wrote.
The article, “Efficacy and safety of elbasvir/grazoprevir and sofosbuvir/pegylated interferon/ribavirin: A phase III randomized controlled trial,” appeared in the December issue of the Journal of Hepatology.
The study was funded by Merck, the drug company that makes Zepatier. Under conflict of interest, the authors reported research grants from Gilead, which makes Sovaldi, and speaker fees from several pharmaceutical interests.