Merck has reported interim results from the ongoing C-WORTHy study, a multi-arm Phase II clinical trial assessing the efficacy and safety of an all-oral, once-daily regimen combining MK-5172 and MK-8742 in patients with chronic HCV Genotype 1 infection (GT1).
The randomised, dose-responsive, parallel-group, multiple-site, double-blind C-WORTHy trial is comparing different patient populations exposed to different durations of treatment of MK-5172 (100mg once-daily) in combination with MK-8742 (50mg once-daily) with or without ribavirin (RBV) in subjects with chronic HCV infection.
MK-5172 is an investigational hepatitis C virus (HCV) NS3/4A protease inhibitor, while MK-8742 is an investigational HCV NS5A replication complex inhibitor.
Interim analysis of patients administered MK-5172/MK-8742 with and without RBV for 12 or 18 weeks showed sustained viral response (SVR), 4 to 8 weeks after the completion of therapy.
In HCV GT1 infected, treatment-naïve cirrhotic patients, MK-5172/MK-8742 treated 97% for 12 and 18 weeks, and MK-5172/MK-8742 plus RBV treated 90% and 97% for 12 and 18 weeks respectively.
In HCV GT1 infected prior-null responder patients, MK-5172/MK-8742 treated 91% and 97% for 12 and 18 weeks, respectively, while MK-5172/MK-8742 plus RBV treated 94% and 100% for the 12 and 18 weeks respectively.
The company said that in treatment-naïve, non-cirrhotic patients with HCV/HIV co-infection, MK-5172/MK-8742 treated 90% for 12 weeks and MK-5172/MK-8742 plus RBV 97% for 12 weeks.
The Texas Liver Institute vice-president of scientific and research development and University of Texas Health Science Center clinical professor of medicine Eric Lawitz said there is still a need for further options for the most difficult-to-cure patients, including those with cirrhosis and HCV/HIV co-infection.
"These findings provide additional clinical evidence regarding the potential of MK-5172/MK-8742 in treating a broad spectrum of HCV patients," Lawitz said.
The company has enrolled a total of 471 patients with chronic HCV GT1 and HCV RNA levels of =10,000IU/mL in the trial and randomised across 16 arms.
Most common adverse events seen among treatment-naïve patients with cirrhosis and prior-null responder patients with and without cirrhosis were fatigue, headache, and asthenia.
The most common adverse events seen among HIV co-infected patients were headache, asthenia, fatigue, and sleep disorder.
Image: C-WORTHy study is a multi-arm Phase II study. Photo: courtesy of freedigitalphotos.net.