29 January 2016
Zepatier for hepatitis C approved in Canada
On January 19, 2016, Health Canada licensed the use of Zepatier for the treatment of certain strains of hepatitis C virus (HCV) in adults. Canada is the first country to approve Zepatier. This drug is made by the pharmaceutical company Merck and should be available for order by drug stores early in February 2016.
CATIE is developing a fact sheet on Zepatier. In the meantime, here is some preliminary information about this new product.
Zepatier is a fixed-dose formulation (one pill) containing the following two medicines:
- elbasvir – 50 mg
- grazoprevir – 100 mg
In clinical trials, Zepatier, like other modern direct-acting antivirals (DAAs), is highly effective against HCV, with cure rates around 95%.
How Zepatier is used
There are several strains, or genotypes, of HCV (such as genotypes 1 through 6) and there are also subtypes (such as genotype 1a, 1b and so on). Zepatier can be used for between eight and 16 weeks depending on a person’s medical history and HCV genotype. Zepatier can be used in different populations in the following ways:
- people with genotype 1 or 4 who have not been previously treated – Zepatier treatment lasts for 12 weeks
- people with genotype 1 or 4 who have been previously treated with peginterferon and ribavirin and who experienced relapse – Zepatier treatment lasts for 12 weeks
- people with genotype 1 who have been previously treated with peginterferon and ribavirin, with or without an HCV protease inhibitor, and who have relapsed – Zepatier treatment lasts for 12 weeks
- people with genotype 1b who do not have severe liver injury and who have not been previously treated – Zepatier treatment lasts for eight weeks
- people with genotype 1b who have been previously treated with peginterferon and ribavirin, with or without an HCV protease inhibitor, and who developed virological failure while on therapy – Zepatier treatment lasts for 12 weeks.
- people with genotype 1a who have previously taken peginterferon and ribavirin, with or without an HCV protease inhibitor, and who developed virological failure while on treatment – Zepatier and ribavirin treatment lasts for 16 weeks
- people with genotype 4 who have previously taken peginterferon and ribavirin and who developed virological failure while on treatment – Zepatier and ribavirin treatment lasts for 16 weeks
- people with genotype 3 who have not been previously treated – Zepatier and sofosbuvir (Sovaldi) treatment lasts for 12 weeks
Merck advises that “pregnancy should be avoided while taking Zepatier, as there are no data on the use of Zepatier in pregnant women.” Furthermore, the company states: “Zepatier should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus.” This advice is similar to that of other companies who have also released modern DAAs.
Hepatitis B co-infection
Zepatier has not been studied in people co-infected with hepatitis B and C viruses.
Zepatier has been tested in about 2,000 volunteers who had chronic hepatitis C. Like other direct-acting antivirals, Zepatier was generally well tolerated. Common general side effects in clinical trials included the following:
- unexpected tiredness or lack of energy
Most of these side effects were mild.
When Zepatier was tested in combination with ribavirin, common general side effects were as follows:
- unexpected tiredness or lack of energy
The product monograph for Zepatier notes that it has safely and successfully been used in HCV-infected volunteers who have also had serious kidney injury and in other people who have been co-infected with HIV. The dosing for co-infected people is the same as for people who have HCV infection only. However, Zepatier can interact with some medicines used for the treatment of HIV (see below for further information).
Some drug interactions
Merck warns that Zepatier must not be used by people taking the following medicines:
- antibiotics for tuberculosis (TB) – rifampin
- antiseizure drugs – carbamazepine, phenytoin
- herbs – St. John’s wort (or its extracts hypericin and hyperforin)
- anti-HIV drugs – atazanavir (Reyataz), darunavir (Prezista and in Prezcobix), efavirenz (Sustiva, Stocrin and in Atripla), etravirine (Intelence), lopinavir (in Kaletra), saquinavir (Invirase), tipranavir (Aptivus), Stribild or Genvoya
- transplant drugs – cyclosporine (Neoral, Sandimmune)
Once Zepatier becomes available, your pharmacist can tell you more about these and other drug interactions.
After a drug is licensed by Health Canada and later becomes available in pharmacies, doctors can prescribe it but patients will have to pay for it unless they have private insurance coverage.
Canada’s provinces and territories heavily subsidize the cost of many medicines. In the months ahead, Merck will be negotiating with provinces and territories as it seeks to have Zepatier appear on the list of their subsidized drugs.
Zepatier will be supplied as beige tablets. The recommended dose is one tablet daily, with or without food.
The basic cost of Zepatier in Canada is as follows:
- 8 weeks of therapy – $40,200
- 12 weeks of therapy – $60,300
- 16 weeks of therapy – $80,400
Note that prices may vary from one pharmacy to another.
Merck Canada has developed a patient assistance program for Zepatier called Merck Care Hepatitis C Program. Patients who are prescribed Zepatier can be linked to this program by their doctor or nurse. The program helps patients navigate insurance coverage programs and coordinates drug delivery with pharmacies.
Further information on Zepatier will become available on CATIE’s website in the future.
Merck has other drugs in development for HCV treatment.
Understanding Cirrhosis of the Liver: First steps for the newly diagnosed – Canadian Association of Hepatology Nurses (CAHN), CATIE
—Sean R. Hosein
Merck Canada. Zepatier (elbasvir/grazoprevir) tablets. Product Monograph. 19 January 2016.