The experimental drug merimepodib enhances the antiviral effect of pegylated-interferon and ribavirin in treating hepatitis C, according to a study presented December 17 at conference on hepatitis drug development in Kauai, Hawaii.
Vertex Pharmaceuticals is developing Merimepodib as an oral treatment for hepatitis C that inhibits the enzyme inosine monophosphate dehydrogenase. Inhibiting this enzyme is thought to lead to a reduction in intracellular guanosine triphosphate, a cellular molecule required by viruses for replication.
The study involved 31 patients who were treated with either 25 or 50 milligrams of merimepodib or a placebo twice daily in combination with standard doses of pegylated-interferon and ribavirin for 24 weeks. The patients had the most common viral strain of hepatitis C in genotype 1, which is also the most resistant to combination therapy.
The researchers found a statistically significant increase in the proportion of patients with undetectable levels of hepatitis C virus after 24 weeks of treatment.
The three treatment groups had comparable levels of hepatitis C virus RNA at the beginning of the study. However after 24 weeks, 86 percent of patients receiving 50 milligrams of merimepodib had undetectable levels of hepatitis C virus RNA, compared to 33 percent receiving 25 milligrams of the drug and 33 percent receiving the placebo
The researchers also found merimepodib to be well tolerated with the most frequent side effects being diarrhea, abdominal pain and a mild rash. None of these side effects occurred in the placebo group.
The researchers noted that most these adverse events were consistent with the known side effects of pegylated interferon and ribavirin treatment. The addition of merimepodib did not appear to increase the severity of these events, they added.
The study also found that patients treated with merimepodib showed a decline in alanine aminotransferase (ALT), a marker of liver inflammation.
Other sources: Vertex Pharmaceuticals Incorporated