Personalized treatment of Hepatitis C

July 16, 2015

Your Hepatitis C infection could be cured – if you knew that you had it.

Ontario recently approved reimbursement of the drug Harvoni® for treatment of the Hepatitis C (HCV) genotype 1 virus. Harvoni® “offers cure rates between 94 and 99%, reduces the incidence of side effects and shortens the duration of treatment to as little as eight weeks” reports the London Free Press. Over 75% of HCV cases in Canada are the genotype 1 variant, according to a recent study.

Harvoni® is part of a new class of HCV drugs called “direct-acting” antivirals that target specific steps in the HCV life cycle. Like “targeted therapeutics” for cancer treatment, these drugs have come out of a better understanding of the molecular basis of the disease. Harvoni® combines two of these direct acting antiviral drugs for greater efficacy. At the moment, Harvoni® is approved in Ontario for only those with late stage disease – those facing death or a liver transplant.

Hepatitis C is a viral disease that causes inflammation of the liver that can lead to cirrhosis, hepatocellular carcinoma and liver transplantation. An Ontario study found that the disease burden of Hepatitis C exceeds that of all other infectious diseases. The disease can progress silently and many don’t know they have the disease until late stage symptoms appear. Over 32,000 deaths are predicted amongst HCV-infected individuals in Canada over the next twenty years from liver-related causes. With new drugs like Harvoni® perhaps many of these deaths can be prevented.

The problem is that half or more people with Hepatitis C don’t even know they have it, according to the Canadian Liver Foundation. And, like Karen Robson, featured in a recent Toronto Star article, not everyone who has Hepatitis C falls into the high risk categories such as injection drug users who are routinely screened for the disease.

The Centers for Disease Control and Prevention (CDC) recommends routine screening of the “baby boomer” cohort in the USA, those born between 1945 and 1965. This is because this group carries a higher risk of Hepatitis C and accounts for 75% of cases. In contrast, screening in Ontario is restricted to certain high-risk groups such as injection drug users.

There have been recent calls for a similar baby boomer screening program in Canada. However, Canadian experts disagree on what percent of carriers in Canada know their status. Reported estimates range from 79% (reported by the Public Health Agency of Canada) down to 30% (Statistics Canada report). If it is true that most people know their status, then investing in population-level screening will have less impact. Recent recommendations from the Canadian Association for the Study of the Liver include a call for a large-scale population survey “to accurately define the prevalence of Hepatitis C in Canada.” This may lead to more comprehensive screening, and now even the possibility of a cure.

By: Kathryn Deuchars, Director, Ontario Personalized Medicine Network