Hepatitis C infection, a common liver disease that affects an estimated four million people in the United States, is transmitted through exposure to infected blood (blood was not screened effectively for hepatitis C until 1992) or sexual contact with an infected person. The majority of people with the ailment don’t realize that they have the disease because of a lack of symptoms.
Hepatitis C is typically diagnosed when abnormal liver enzymes are identified through a routine blood test or if the infection becomes severe. Seventy percent of patients with hepatitis C develop chronic disease and 30% may develop scarring of the liver and cirrhosis of the liver within 20 years of exposure to the virus. An additional 20% of these patients eventually develop liver cancer. About 15,000 deaths are linked to the disease in the United States each year.
Until 2011, there were no proven medicines for patients who didn’t respond to traditional hepatitis C therapy. Two advanced drugs called hepatitis C protease inhibitors, Top 10 selections from Cleveland Clinic in 2011, were the first drugs approved by the FDA in a decade. These medications fundamentally changed the treatment for hepatitis C for patients who had not responded to previous therapies—patients infected with genotype 1 disease.
The drugs belong to a class of medications called protease inhibitors, which work by blocking a key enzyme that viruses need in order to proliferate. When the drug telaprevir (Incivek) is added to standard treatments for hepatitis C, more than 70% of patients can expect sustained viral response (or viral cure) after taking the medication for 24 weeks.
Study results with the second drug, boceprevir (Victrelis), showed that when combined with the drugs interferon and ribavirin, boceprevir cured the infections of about 66% of the patients who took the drugs for 48 weeks.
While hepatitis C treatment has improved considerably, especially when compared to the 1990s, the news is even better now. Sofosbuvir, the first all-oral hepatitis C treatment, is moving through the final stages of FDA approval. What this direct-acting antiviral (DAA) drug has is the potential to improve what for many has been a very difficult treatment regimen that can take up to 48 weeks and requires injections of interferon, a drug that is difficult to tolerate. More important, the drug can improve treatment response rates to 90% or higher in certain groups of patients.
In addition to significantly higher cure rates, sofosbuvir—and others now in the pipeline—has better tolerability, safety, and a 12-week treatment duration.
In the FISSION trial, treatment-naïve genotype 2 patients treated with an oral DAA (1 pill daily) and ribavirin (2-3 pills twice daily) had a 67% cure rate, which was just as good as standard therapy, but without the use of interferon.
In the FUSION trial, a study with patients with genotype 2 disease who did not respond to standard 24-week therapy or who had relapsed, those who completed 12 weeks of therapy with the oral DAA and ribavirin had an 86% cure rate. An additional four weeks of the therapy increased the cure rate to 94%. An oral drug with the highest cure rates ever and few side effects: There is finally real hope on the horizon for people with chronic hepatitis C.