An eight-week regimen containing grazoprevir-ruzasvir-uprifosbuvir appears to be effective for treating hepatitis C virus (HCV) infection in patients with or without cirrhosis, according to findings from a pair of randomized phase 2 open-label trials.
Dr. Edward J. Gane from Auckland Clinical Studies, in Auckland, New Zealand, and colleagues – in part A of the C-CREST-1 and C-CREST-2 trials – randomly assigned 240 patients with HCV genotype 1, 2 or 3 and without cirrhosis to receive an eight-week course of a daily three-drug combination:
– grazoprevir 100 mg, plus
– either elbasvir 50 mg or ruzasvir 60 mg, plus
– either 300 mg or 450 mg of uprifosbuvir.
The studies were funded by Merck and Co.
Sustained virologic response rates 12 weeks after the end of therapy (SVR12) were 92% with both doses of the grazoprevir-ruzasvir-uprifosbuvir regimen and ranged from 85% to 88% (depending on uprifosbuvir dose) with grazoprevir-elbasvir-uprifosbuvir, according to one of the reports, both online August 9 in The Lancet Gastroenterology and Hepatology.
All four regimens were well-tolerated.
“These results support the selection of grazoprevir plus ruzasvir plus uprifosbuvir 450 mg as the regimen for further clinical investigation in broader populations,” the researchers conclude.
Dr. Eric Lawitz from Texas Liver Institute at the University of Texas Health San Antonio and colleagues extended these findings in part B of C-CREST-1 and C-CREST-2. In this trial, 675 patients with HCV-1, -2, -3, -4 or -6, with or without cirrhosis, received eight, 12, or 16 weeks of grazoprevir-ruzasvir-uprifosbuvir 450 mg, with or without ribavirin.
SVR12 rates with eight weeks of therapy were 93% in individuals with genotype 1a, 98% with genotype 1b, 86% with genotype 2 (without cirrhosis; patients with HCV-2 and cirrhosis received a longer course), 95% with genotype 3 (treatment naive, without cirrhosis) and 100% with genotypes 4 and 6.
“We were surprised by the relatively lower efficacy of an 8-week duration of this regimen among those with genotype 2 infection,” Dr. Lawitz told Reuters Health by email. “However, extending therapy to 12 weeks overcame this effect.”
SVR12 rates were generally higher among participants with or without cirrhosis who received 12 or 16 weeks of therapy.
There were no documented virologic failures after week 12 of follow-up, although 10 participants who achieved SVR12 were lost to follow-up.
As in part A of the study, treatment with this fixed-dose combination with or without ribavirin was generally well tolerated.
“Results from the current studies support further investigation of grazoprevir, ruzasvir, and uprifosbuvir as a pan-genotypic regimen in individuals infected with HCV with and without cirrhosis, and suggest that this combination has the potential to provide a safe, single-duration regimen in most populations, including individuals with cirrhosis infected with genotype 3 who had previously received treatment with pegylated interferon and ribavirin,” the researchers conclude.
“We await data from phase 3 to know how this regimen might impact the current treatment landscape,” Dr. Lawitz said. “We hope that this regimen will be able to give providers more options with regard to pan-genotypic regimens for the treatment of HCV.”
Dr. Eleanor M. Wilson from the University of Maryland School of Medicine, Baltimore, who coauthored an accompanying comment in the journal, told Reuters Health by email, “The safety and efficacy data seem promising, but it’s still investigational, so not sure about its impact on the field of hepatitis C treatment yet.”
“With the recent approvals of Vosevi and Mavyret, in addition to the previously available options, I think the overall take-away is that it’s fantastic that there are more hepatitis C treatment options for patients and providers,” she said. “It’s tremendous that previously so-called ‘difficult-to-treat patients’ including those with previous treatment experience, comorbid conditions like HIV or renal disease, and those with advanced fibrosis and cirrhosis now have a variety of safe and highly effective options to treat their hepatitis C.”
“My area of expertise is in novel treatment approaches, including strategies to reduce the treatment duration in order to increase access and decrease treatment cost, as well as options for patients who haven’t successfully cleared HCV with first-line therapy (due to problems of adherence or viral resistance), and from that standpoint, it’s an exciting time to be a hepatitis C provider,” Dr. Wilson said.
Dr. Mark Sulkowski, who directs the viral hepatitis center at Johns Hopkins University in Baltimore, told Reuters Health by email, “We currently have multiple outstanding HCV regimens for the treatment of all genotypes of hepatitis C, which typically include combinations of direct-acting antiviral inhibitors of HCV protein targets NS3 (protease), NS5A and NS5B (polymerase). While we have seen the regulatory approval of multiple inhibitors of the NS3 and NS5A proteins, to date, only one (nucleotide) inhibitor of the NS5B polymerase active site has been approved, sofosbuvir.”
“The C-CREST-1 and -2 studies provide a phase 2 evaluation of another (nucleotide) analogue inhibitor of NS5B, uprifosbuvir,” said Dr. Sulkowski, who was not involved in the research. “Based on the results of these studies, uprifosbuvir appears to be poised to move to phase 3 studies, and if successful in phase 3 trials, this agent could become a valuable addition to the available drugs to treat hepatitis C.”
Dr. Gane did not respond to a request for comment.
Merck funded the trials and employed most of the authors.
By Will Boggs
SOURCE: http://bit.ly/2fRhHna, http://bit.ly/2fSnWXK and http://bit.ly/2fSIIXa
Lancet Gastroenterol Hepatol 2017.