Merck wins back Breakthrough status for hepatitis combo

The FDA has awarded Breakthrough Therapy Designation to Merck’s grazoprevir/elbasvir combination for hepatitis C in two specialist sub-populations.

The US regulator’s decision is a coup for Merck, which saw an earlier Breakthrough designation for the treatment in hepatitis C genotype 1 (GT1) rescinded in January.

This was because rival hepatitis C drugs such as Gilead’s Sovaldi, Janssen’s Olysio and AbbVie’s Viekira Pak are already on the market, and meeting this patient need in GT1 patients, who represent around 74 per cent of hepatitis patients in the US.

Merck has succeeded in regaining Breakthrough status by targeting its use at two sub-groups. The first sub-group is patients with chronic HCV genotype 4 (GT4) infection – these represent a very small percentage of hepatitis C patients worldwide, mostly found in the Middle East, Egypt and Central Africa.

The second sub-group are patients with chronic HCV genotype 1 (GT1) infection who have end stage renal disease and are on haemodialysis.

Grazoprevir/elbasvir is being developed as a once-daily single tablet regimen, and Merck says it remains on track to file with the FDA in the next few months.

Other companies have had to re-think their involvement in the field – Bristol-Myers Squibb has scaled back its ambitions, and Vertex has exited the therapy area altogether – as competition intensifies.

Merck is persisting, even though it is trailing behind Gilead, Janssen and AbbVie in the HCV market, and is switching it target market to the more difficult-to-treat sub-groups of patients.

This includes patients across all the different genotypes, and those with difficult-to-treat conditions such as HIV/HCV co-infection, advanced chronic kidney disease, inherited blood disorders, cirrhosis and those on opiate substitution therapy.

The next major congress is the International Liver Congress, hosted by EASL from 22 April to 26 April in Vienna, and all the companies in the field will be releasing new data from ongoing studies.

Related article

Gilead profits from hep C drugs

Don't miss your daily pharmaphorum news.
SUBSCRIBE free here.