The FDA’s Antivirals Drug Advisory Committee voted unanimously in favor of agency approval for the investigational drug, boceprevir, in hopes of offering a new treatment option for the 3 to 4 million people in the United States with hepatitis C infection.
In an 18-0 vote on Wednesday the panel deemed that boceprevir (Victrelis, Merck), appears to be safe and effective in combination with standard treatment peginterferon and ribavirin for treating patients with hepatitis C genotype 1 infections.
The panel reviewed data from clinical trials that indicated that boceprevir produced sustained virological response rates as high as 67% among never-before-treated patients with genotype 1 infections, compared to a response rate of about 40% among patients prescribed to a standard regimen of pegylated interferon injections and ribavirin pills.
“To go to a 60% or 70% [sustained response] really seems like a dream come true,” committee member Lawrence Friedman, MD, chair of the department of medicine at Newton-Wellesley Hospital in Newton, Mass., said during the meeting.
The studies were first published last month in New England Journal of Medicine.
If approved as expected, boceprevir will be one of two new HCV protease inhibitors, the other being telaprevir, to reach the market — representing a major advance in treatment.
Additional data from previous partial and nonresponders also showed higher sustained virological response rates when boceprevir was added to treatment compared to a second round of the same therapy (approximately 60% vs. 21%).
The main boceprevir treatment regimen tested in the trials included a four-week lead-in period with peginterferon and ribavirirn followed by a 44-week period in which boceprevir was added to therapy. Some trial s included a regimen in which boceprevir treatment was extended based on the patients’ response to the drug at eight and 24 weeks.
Merck has asked for a labeling indication that would permit longer treatment for patients who have detectable HCV RNA at eight weeks, but achieve a full virologic response at 24 weeks, as some data suggests that this regimen could improve sustained response. However, the committee expressed concern that this approach would complicate treatment regimens, resulting in poor clinician and patient adherence to the medication.
Common adverse events among patients prescribed boceprevir included higher rates of anemia, neutropenia, thrombocytopenia. Although some panel members expressed concern that these adverse events may be an issue as the drug becomes more commonly used, the majority was convinced that these side effects are manageable and that the benefits of boceprevir outweigh the risks.
Committee members have asked that Merck conduct additional trials to provide data on potential adverse drug reactions between boceprevir and other medications that patients with hepatitis C may be taking concomitantly, including HIV medications, methadone, antidepressants and certain herbal supplements.
They also requested more data regarding boceprevir’s efficacy in special populations such as racial and ethnic minorities, patients with hepatitis B and C coinfection, nonresponders with other hepatitis genotypes, those with cirrhosis, transplant recipients and patients aged 65 and older.
The FDA will decide whether to approve both boceprevir and telaprevir in May.