This story was published on GE Healthy Outlook last spring after the FDA approved INCIVEK. I spoke with Jordan Feld, MD MPH, hepatologist at the Toronto Western Hospital Liver Clinic and clinician scientist at the McLaughlin-Rotman Centre for Global Health at the University of Toronto, to find out what this new drug could mean for patients with hepatitis C.
New direct acting drug offers better cure rate and possible shorter treatment time.
The FDA has approved a new drug called INCIVEK (telaprevir) for adults with difficult-to-treat genotype-1 chronic hepatitis C. Clinical trials showed a significantly better outcome for both people who had never received standard therapy before, as well as those who had previously received standard therapy but did not respond adequately. INCIVEK is a major breakthrough given that less than 50% of patients respond to the standard therapy.
Jordan Feld, MD, MPH is a hepatologist at the Toronto Western Hospital Liver Clinic and a clinician scientist at the McLaughlin-Rotman Centre for Global Health at the University of Toronto. He says, “The introduction of telaprevir as a direct acting antiviral drug is a huge advance for patients who have hepatitis C. This drug increases the rate of response and can shorten treatment for about two-thirds of patients.”
In the clinical studies, 79% of patients who had never been treated before achieved a viral cure after treatment with INCIVEK together with standard therapy, compared to 46% in the control group, who received a placebo plus standard therapy. INCIVEK is a direct-acting antiviral drug that works by inhibiting protease, an enzyme necessary for the hepatitis C virus to replicate. INCIVEK must be administered together with peginterferon and ribavirin (the current standard interferon therapy), to help prevent the virus from becoming resistant.
Hepatitis means inflammation of the liver. Hepatitis C virus is the most common blood infection in the United States: about 3.2 million people are chronically infected and infection rates are highest among those born between 1945-1965. Globally there are six different genotypes of hepatitis C virus, but genotype 1 accounts for about 70% of the cases in the United States.
The majority of infected people may not even know they are infected, but they can still transmit the disease to others and can develop chronic liver disease 20-30 years or more after infection. If symptoms occur from a newly acquired infection, they can include fever, fatigue, dark urine, abdominal pain, loss of appetite and jaundice. Chronic liver disease can lead to cirrhosis, liver cancer, the need for a liver transplant, or even death.
Hepatitis C virus is most often transmitted through exposure to infected blood, which can be contracted from contaminated needles used for tattoos, injection drugs or even vaccines for childhood infections in countries with poor medical care. Hepatitis C was commonly spread through blood transfusions and organ transplants before blood screening started in 1992.
Dr. Feld points out “while there’s no question INCIVEK is a huge advance, it is not a panacea. Those cure rates of 70% and higher are not for everybody.” Dr. Feld was not involved in the telaprevir studies, however his liver disease research focuses on trying to understand response to interferon based therapy, with or without protease inhibitors. Success rates for achieving a viral cure in the clinical studies depended on whether or not the patient had been treated before with standard therapy, how they responded, and if they had more advanced disease characterized by cirrhosis or scarring of the liver. For example, for those who did not respond at all to a previous standard therapy and had cirrhosis, only 14% achieved a viral cure.
Shorter treatment for 24 weeks, rather than the current standard of 48 weeks is a welcome relief for those patients who qualify, because the side effects of peginterferon and ribavirin are challenging because they are similar to having influenza – body ache, fever and headache. Whether a patient qualifies for the shorter treatment depends on their past history of treatment, and whether they are showing early response to the INCIVEK combination therapy as monitored in their blood work at weeks 4 and 12.
The most frequent adverse reactions in the test groups were rash and anemia. While rash developed in 56% of patients who received the INCIVEK combination treatment, only 4% reported a severe rash and only 1% discontinued treatment due to rash. Only 1% of those taking INCIVEK discontinued therapy due to anemia.
The FDA approval of INCIVEK is a significant breakthrough for curing hepatitis C infection. As a direct acting agent specifically targeted to attack the hepatitis C virus, INCIVEK offers a better chance for a viral cure and the possibility for a shorter treatment.
CONNECT THE DOTS
Visit the CDC website to learn more about hepatitis C. For more detailed drug information about INCIVEK from the manufacturer, visit the Vertex site. Read about the FDA approval of INCIVEK to see details of the clinical trial results. To learn more about medical innovation news, check out this post: First New Lupus Drug in 50 Years: Benlysta Gains FDA Approval .