Merck Sends Hepatitis C Drug Application to FDA

Pharmaceutical giant Merck has joined the competition to develop the next hepatitis C drug with its submission of a New Drug Application to the Food and Drug Administration for a once-daily pill to treat certain genotypes of the liver-damaging virus

The NDA seeks approval of grazoprevir/elbasvir, a combination regimen investigational drug that would be taken once daily as treatment for adult patients with chronic infection of hepatitis C genotypes 1, 4 and 6, according to a company release. Grazoprevir is an NS3/4A second-generation protease inhibitor and elbasvir is a potent NS5A inhibitor.

The FDA has 60 days to decide whether to accept Merck’s application as it was submitted. A Merck representative said the application is a significant step in the company’s hepatitis C drug development plan.

“Merck's submission is based on evidence from our wide-ranging clinical program assessing the efficacy and tolerability profile of grazoprevir/elbasvir in populations with chronic hepatitis C,” Roy Baynes, MD, PhD, senior vice president of clinical development of Merck Research Laboratories said in the release. “This submission to the US FDA is an important milestone as we seek to provide patients with a new treatment option for this serious infection.”

Hepatitis C is a blood borne virus that if left untreated can turn into a chronic infection and over time damage the liver, leading to cirrhosis, liver cancer, or the need for a liver transplant. An estimated 150 million people are infected with the disease worldwide and as much as 500,000 deaths each year are related to hepatitis C liver disease, according to the World Health Organization.

The virus has a high degree of genetic diversity and treatment may vary depending on the genotype of the patient being treated. Merck’s drug application seeks approval for treatment of three of those genotypes, including genotype 1- the most prevalent worldwide that accounts for almost half of all cases - as well as genotypes 4 and 6.

As part of the NDA submission, Merck included data results presented earlier this year at the International Liver Congress from clinical trials that tested grazoprevir/elbasvir in 100 mg and 50 mg doses. The studies include the pivotal C-EDGE clinical trial program and the C-SURFER and C-SALVAGE trials that evaluated the investigational drug with or without ribavirin in patients with chronic hepatitis C infection, the release states.

Reported response rates ranged from 92-100% among patients with genotypes 4 and 6 and 80% among those with genotype 6, according to results presented during the congress. Merck is also testing its drug for co-infection of hepatitis C and HIV, advanced kidney disease and inherited blood disorders.

The FDA previously granted Breakthrough Therapy designation for grazoprevir/elbasvir for hepatitis C treatment of patients with genotype 1 and end stage renal disease on hemodialysis and for patients with hepatitis C genotype 4. The designation is given for investigational drugs that could significantly improve the safety or effectiveness of treatment of a serious condition when compared to drugs currently available.