Patients with hepatitis C virus (HCV) infection who received a newly approved direct-acting antiviral regimen had a nearly perfect sustained virologic response rate at 12 weeks in an industry-funded study.
Glecaprevir and pibrentasvir (Mavyret) was approved by the FDA on Aug. 3 to treat adults with chronic HCV infection (genotypes 1 through 6) and mild or no cirrhosis, including those with moderate or severe kidney disease and those on dialysis. It was also approved for adult patients with HCV genotype 1 infection who have been previously treated with a regimen containing an NS5A inhibitor or an NS3/4A protease inhibitor but not both.
The drug combination appeared effective in adults with HCV genotypes 1, 2, 4, 5, or 6 infection and compensated cirrhosis in an industry-funded study. Researchers enrolled 146 patients who were either HCV treatment-naïve or had not responded to treatment with interferon or pegylated interferon with or without ribavirin, or sofosbuvir plus ribavirin (with or without pegylated interferon). One-third of patients had genotype 1a, 27% had genotype 1b, 23% had genotype 2, 11% had genotype 4, 1% had genotype 5, and 5% had genotype 6 infection.
Participants received daily oral glecaprevir (300 mg) coformulated with pibrentasvir (120 mg) for 12 weeks. The primary outcome was sustained virologic response (HCV RNA <15 IU/mL). Results of the single-arm, open-label phase III trial were published online on Aug. 14 by The Lancet Infectious Diseases.
After 12 weeks of treatment, 145 of 146 patients (99%; 95% CI, 98% to 100%) achieved sustained virologic response, with one relapse in the eighth week. Despite the standard treatment length of 12 weeks or more, the FDA approved the drug combination as an eight-week treatment.
About 69% of patients reported adverse events, most of which were mild (e.g., headache, fatigue). The authors noted limitations of the study, such as its single-arm design and the exclusion of patients with genotype 3 infection (who were enrolled in a different study) and those with decompensated cirrhosis.
“The biggest question is how these new drugs will be used,” said an accompanying editorial. “Overall, their efficacy is minimally better than that of the already available drug combinations.”
There is also the question of cost. In Europe, the most commonly reimbursed treatment is ombitasvir, paritaprevir, and dasabuvir, which seems to be the cheapest drug combination on the market, the editorial noted. “The hope is that [the manufacturer] will not take ombitasvir, paritaprevir, and dasabuvir from the market to increase the sales of glecaprevir and pibrentasvir,” the editorialist wrote.