Merck’s Zepatier (grazoprevir/elbasvir) cured high rates of U.S. veterans of hepatitis C virus (HCV), according to a recent analysis, even though the population had a high rate of other health conditions, also known as comorbidities.

Researchers analyzed the real-world effectiveness of Zepatier among 4,660 veterans with genotype 1 or 4 of hep C according to data in the Veterans Affairs Corporate Data Warehouse. The members of the study cohort were treated with Zepatier with or without ribavirin between February and December 2016. They all received between 11 and 17 weeks of treatment.

Findings were presented at the 52nd International Liver Congress in Paris.

A total of 4,300 members of the study cohort received just Zepatier, 271 received Zepatier plus ribavirin and 89 received Zepatier plus Sovaldi (sofosbuvir) with or without ribavirin.

The study population had high rates of comorbidities, higher than those of participants in clinical trials of Zepatier. Overall, 29.1 percent had anxiety, 57.7 percent had depression, 2.3 percent had hepatocellular carcinoma (HCC, the most common form of liver cancer), 52.9 percent had diabetes, 54.2 percent had a history of drug abuse, 63.2 percent had a history of alcohol abuse, 1.5 percent had received a kidney transplant, 0.7 percent had received a liver transplant, 16.5 percent had Stage 3 chronic kidney disease (CKD) and 15.9 percent had Stage 4 or 5 of CKD.

A total of 4,489 members of the study cohort (96.3 percent) finished treatment and achieved a sustained virologic response 12 weeks after completing therapy (SVR12, considered a cure), while 171 did not. When the study authors included in their analysis those who did not finish treatment, they found that 4,845 of 5,125 (94.5 percent) were cured.

The remainder of the investigators’ analysis focused on those who did finish treatment.

Cure rates among subgroups of the study population were uniformly high, including: those with genotype 1a, 95 percent; those with genotype 1b, 97 percent; those with genotype 4, 98 percent; those with cirrhosis, 95 percent; those who had been treated before, 96 percent; those with a baseline viral load of 800,000 or greater, 96 percent; and those with a baseline viral load below 800,000, 98 percent.

The study authors broke down cure rates among those with genotype 1a and 1b and looked at subgroups who had been treated before, had an eGFR of 30 or greater, had Stage 4 or 5 CKD, had HIV coinfection, had a baseline viral load of 800,000 or greater, had a baseline viral load below 800,000 and who received 12 weeks of treatment. Cure rates in these subgroups ranged between 95 percent and 100 percent.