Merck’s Hepatitis C Drug Increases Cure Rates in Clinical Trial, FDA Says

Merck & Co.’s experimental hepatitis C drug cures more patients than current therapies, according to U.S. regulators considering whether to clear the first treatment for the liver disease in more than a decade.

Boceprevir, combined with standard treatments, worked better than those drugs alone in clinical trials, Food and Drug Administration staff said today in a preliminary review on the agency’s website. Outside advisers to the FDA will meet April 27 to evaluate the findings.

Merck, based in Whitehouse Station, New Jersey, is among about a dozen companies seeking to offer hepatitis C drugs with better results and fewer side effects than current treatments. FDA advisers will meet April 28 to review a similar drug from Vertex Pharmaceuticals Inc. (VRTX)

“In general, we agreed with the applicant’s analysis of the primary efficacy endpoint” of boceprevir in patients for whom prior treatments had failed, FDA staff said in today’s report. The drug also worked in patients who hadn’t previously been treated for the disease.

The drug’s side effects in clinical studies included increased frequency and severity of anemia, according to the FDA staff report. The agency asked its advisory panel to weigh the drug’s benefits against those risks.

Sales of boceprevir may surpass $604 million in 2013, according to the average estimate of six analysts surveyed by Bloomberg.

Merck rose 29 cents, or less than 1 percent, to $34.33 at 4:15 p.m. in New York Stock Exchange composite trading. Vertex fell $1.33, or 2.7 percent, to $48.04 in Nasdaq Stock Market composite trading.

No Vaccine

About 170 million people worldwide have hepatitis C, a bloodborne disease that can lead to liver cirrhosis and cancer, according to the Centers for Disease Control and Prevention in Atlanta. No vaccine exists for the virus, which is commonly spread through needle-sharing and can be transmitted sexually in rare cases.

The current standard therapy for hepatitis C requires almost a year of treatment and cures less than half of patients, said Donald Jensen, director of the Center for Liver Diseases at the University of Chicago Medical Center.

That treatment combines the antiviral drug ribavirin with peginterferon, an immune-boosting protein sold by Merck as PegIntron and Roche Holding AG (ROG) as Pegasys. The FDA approved PegIntron in 2001 and Pegasys in 2002.

Merck’s drug, and a competing treatment from Vertex called telaprevir, “clearly have the ability to revolutionize the therapy for hepatitis C,” Jensen said April 19 in an interview.

Protease Inhibitors

Separate clinical trials showed both drugs, so-called protease inhibitors, cured more patients in less time when used in combination with standard therapy. Both medicines are likely to win FDA approval and may reach the market in May or June, said Geoffrey Porges, an analyst at Sanford C. Bernstein & Co. in New York.

A Merck-funded study found that almost half of patients on boceprevir were able to shorten their treatment duration by 12 to 20 weeks, Merck said March 30 in a statement. Merck’s research also concluded that boceprevir combined with standard therapy cured 64 percent of chronic hepatitis-C patients for whom previous treatments had failed, compared with 21 percent of those who took peginterferon and ribavirin alone.

Among hepatitis C patients who were new to treatment, 65 percent of those who took boceprevir, and 38 percent on standard therapy alone, were cured.

Vertex’s Drug

FDA staff plan to release a separate evaluation tomorrow of Vertex’s telaprevir. Vertex said March 31 that its drug cured 86 percent of patients in a trial who had previously relapsed after standard therapy, compared with 24 percent who only took peginterferon and ribavirin.

Another company-funded study found that the drug cured 75 percent of patients who were new to treatment and took it for 12 weeks, compared with 44 percent of those on standard therapy alone, Vertex said March 31 in a statement.

Merck’s drug, unlike Vertex’s, requires patients to first take peginterferon and ribavirin alone for four weeks. The protocol will help doctors gauge how well the new drug is likely to work in each patient and personalize treatment, said Eliav Barr, vice president of infectious diseases at Merck Research Laboratories.

“We were interested in making sure no patient gets boceprevir before we have the opportunity to know whether the patient can actually tolerate” the standard therapy, Barr said April 20 in an interview.

To contact the reporter on this story: Molly Peterson in Washington at mpeterson9@bloomberg.net

To contact the editor responsible for this story: Adriel Bettelheim at abettelheim@bloomberg.net

Bloomberg reserves the right to remove comments but is under no obligation to do so, or to explain individual moderation decisions.

Please enable JavaScript to view the comments powered by Disqus.