An analysis of 42 clinical trials of all the approved direct-acting antiviral (DAA) hepatitis C virus (HCV) regimens has concluded that overall, the treatments are highly effective, safe and easy to take. But there is still room for improvement.

The trials, which sometimes gave participants ribavirin along with DAAs, saw less than 10 percent of individuals experience serious adverse health events, a less than 10 percent rate of participants being lost to follow-up and a less than 5 percent rate of treatment discontinuation.

There was particularly robust evidence about six different regimens given to those with genotype 1 of hep C, who typically had cure rates greater than 95 percent, including among those with HIV.

“There are multiple outstanding options for persons with HCV genotype 1 infection—most can be cured without interferon and without ribavirin,” says the study’s lead author, Mark Sulkowski, MD, medical director of the Viral Hepatitis Center at Johns Hopkins Medicine.

Treating genotype 3 remains more complex, and there are fewer available DAA regimens approved for this population. Those with genotype 3 had lower cure rates if they had cirrhosis, were being re-treated for hep C or had resistance to the NS5A inhibitor class of DAAs.

There were fewer available studies of people with genotypes 2, 4, 5 and 6, which are more rare in the United States. Cure rates were generally above 92 percent and were 99 percent for Epclusa (sofosbuvir/velpatasvir).

Hep C cure rates were also promising for those with HIV, a liver transplant, decompensated cirrhosis or severe chronic kidney disease. However, treatment options for the latter two groups remain limited, and their cure rates can dip into the mid-80 percent range. For those with such advanced cirrhosis, rates of adverse health events while on hep C treatment were as high as 52 percent.

Ribavirin still has a place in improving cure rates for some, the study authors found, in particular for those with genotypes 1a or 3, cirrhosis or those who have been treated before.

“The key issue is to identify persons infected with hepatitis C and link them to care and treatment,” says Sulkowski. He notes that the greater difficulty in curing those with cirrhosis “underscores the need to treat HCV infection at all stages of liver disease.”