An Easier Hepatitis C Cure Test

Clinical trials currently underway at the GI Division of Premier Medical Group have the potential to “completely change the way we look at hepatitis C,”says Dr. Peter M. Varunok, the group’s principal investigator for hepatitis studies.

“There are a number of different protocols and medications that are out there being looked at,” says Dr. Varunok, “but the most exciting are the non interferon-based regimens. The study we are doing is for a non-interferon-based regimen with protease and polymerase inhibitors, with and without ribavirin— avoiding the significant side effects of interferon. These direct acting agents (DAAs) are a new class of drug that acts directly on the viral replication site.”

For two decades, the standard of care (SOC) therapy for patients infected with the hepatitis C virus (HCV) has included some form of an injectable drug called interferon.

When interferon treatment was first approved by the FDA, in 1991, three injections a week for 48 weeks produced a sustained virological response (SVR) in 9 percent of patients with genotype 1 of the disease, the most common type prevalent in the US, and in 30 percent of patients with genotype 2 or 3. An SVR means that no detectable hepatitic C virus remains in a patient’s blood after treatment has ceased.

Adding an oral antiviral drug called ribavirin (in 1998), and using a new form of interferon, called pegylated interferon, led to an SOC that required only one injection a week plus a daily oral medication, and yielded an SVR of 41 percent for genotype 1 and 75 percent for genotypes 2 and 3.

In 2011, the FDA approved two new drugs, the protease in hibitors teleprevir and boceprevir, each of which could be taken along with pegylated interferon and ribavirin. This “triple therapy” has a significantly higher response rate and, for some patients, requires a shorter length of treatment. But the therapy is still difficult to tolerate and would not effect a cure in nearly one million of the four million Americans with hepatitis C.

“We’ve been limited in who we can treat because of the side effects of the standard treatment,” says Dr. Varunok. Some patients with coexisting conditions—psychiatric disorders, low platelet counts, anemia, or autoimmune diseases such as lupus, rheumatoid arthritis and Crohn’s disease, for example—cannot be prescribed interferon-based therapy. A signficant number of patients cannot sustain the rigors of the treatment and withdraw from therapy before completion.

Interim data from mid -stage trials that have been released by the drug maker suggest the possibility of viral cure in the 90 percent range , achieved in about half the time of the current standard therapy, and without interferon-related side effects.

“The first arm of our Phase II study is near completion,” says Dr. Varunok. “The next step would be to progress to a Phase III trial in which a larger number of patients will be treated.”

If the results meet the expectations of many researchers, the new regimen would greatly expand the number of people who could be successfully treated.

Some patients are undoubtedly wondering whether they should delay treatment until a more tolerable, noninterferon- based regimen is available. This may be a reasonable option for some patients, but definitely not for all.

“We’re not completely sure when these medications are going to be available,” says Dr. Varunok. “The decision to wait for newer medication has to be predicated on the patient’s fibrosis (liver scarring) status at this time. Those patients who are at higher risk, with cirrhosis or advanced fibrosis, should not wait but seek treatment now. People with only mild disease on liver biopsy might, after careful discussion with their physicians, make an informed decision to wait.”

Categories

Archives