The FDA has approved Zepatier, a new pill for hepatitis C that combines the two drugs elbasvir and grazoprevir.

In April 2015, the FDA designated the combo drug as a breakthrough therapy for patients with hepatitis C genotype 1 disease who have end-stage kidney disease and are on hemodialysis, and for patients with hepatitis C genotype 4. The breakthrough designation is intended to accelerate development and review of drugs that offer substantial improvement over existing therapies. The new pill is made by Merck.

Zepatier doesn’t require additional interferon treatments to cure hepatitis C, which means fewer difficult side effects — good news for patients.

Investigators previously reported encouraging findings on Zepatier at the International Liver Congress in Vienna from phase-3 clinical trials to treat people with chronic hepatitis C infection. Cure rates of 92 to 99 percent were reported, depending on the history of the patient’s hepatitis C infection.

The set of three clinical trials, called C-EDGE, included several types of patients with hepatitis C: those who had never been treated for hepatitis C, patients who'd been treated with drugs but whose infections did not respond to treatment, and patients co-infected with HIV. Three different hepatitis C genotypes were included: genotype 1, which is the most common in the United States, genotype 4, and genotype 6. Patients with the advanced liver disease cirrhosis were included in the trials.

Shorter Treatments and a Safer Profile

“This combination achieves the high SVR [sustained viral response, or cure] in treatment-experienced patients with a 16-week duration, which is shorter than comparable treatment regimens currently available,” says David Bernstein, MD, chief of the division of hepatology at the North Shore University Hospital in Manhasset, New York. Dr. Bernstein attended the Vienna meeting but did not take part in the research studies.

“There were no red flags in regards to safety,” he says. “I feel that this regimen will be widely used by practitioners if it is made readily available.”

Common side effects reported by patients who took Zepatier without ribavirin include fatigue, headache, and nausea. And some of those taking Zepatier along with ribavirin also experienced side effects, including anemia and headache.

The drug is the third all-oral hepatitis C treatment on the market, along with AbbVie’s Viekira Pak and Gilead's Harvoni.

As is the case with all three of these newer treatment approaches, patients don't need to take them along with interferon, an older hepatitis C drug that can cause serious side effects, like anemia and debilitating depression.

High Hepatitis C Cure Rates for the Hardest-to-Treat Cases

Stefan Zeuzem, MD, chief of the department of medicine at the J.W. Goethe University Hospital in Frankfurt, Germany, and colleagues published the results of their trial in a 2015 issue of the Annals of Internal Medicine. Among 316 patients in the 60-center study, investigators found that 95 percent were cured: They showed no evidence of the hepatitis C virus after finishing a 12-week course of the elbasvir-grazoprevir combo. Cure rates were also 95 percent for 218 patients who were co-infected with HIV and hepatitis C.

Importantly, patients with and without cirrhosis — a late stage of liver disease — caused by the hepatitis C virus participated in the trials of the new drug and saw positive results. The drug combination was very effective for patients in whom prior treatments with other hepatitis C medications had failed. Patients were randomly assigned to 12 or 16 weeks of new drug treatments with or without ribavirin. Cure rates were 92 percent for patients who received the elbasvir-grazoprevir combo for 12 or 16 weeks. Adding ribavirin improved cure rates slightly: to 94 percent for 12 weeks, and up to 97 percent for 16 weeks of treatment.

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“We are now seeing response rates of 95 percent or higher, so it's a very exciting time for patients and for physicians who care for these patients,” says Janice Wahl, MD, coauthor of the paper and clinical lead of Merck's hepatitis C portfolio. She notes that mild side effects such as headaches, fatigue, or nausea occurred in 10 to 20 percent of patients in the trials, and “very rarely were patients discontinued for any side effects.”

Hepatitis C Cure for Patients with Advanced Kidney Disease

Researchers in Vienna also presented results of elbasvir plus grazoprevir to treat genotype 1 hepatitis C infection in patients with advanced kidney disease (the C-SURFER study). After 12 weeks of treatment, 99 percent of the 116 patients in the trial were reported cured of hepatitis C.

Hepatitis C accelerates the loss of kidney function in addition to damaging the liver, Dr. Wahl notes. But curing hepatitis C improves kidney-disease patients' survival, and also boosts the likelihood of a successful kidney transplant.