Merck Reports Encouraging Results for Hepatitis C
By PETER LOFTUS
Merck & Co. said Wednesday the addition of its experimental hepatitis C drug to standard treatment improved patient outcomes in two clinical trials, compared with standard treatment alone.
The Whitehouse Station, N.J., company said it planned to submit the drug, boceprevir, for regulatory approval in the U.S. and Europe this year. Merck obtained boceprevir with its takeover of Schering-Plough last year.
"The data we announced today really reinforces our belief for the potential of this drug to help change the landscape for the treatment of hepatitis C," Peter Kim, president of Merck's research unit, said in an interview Wednesday.
But it's uncertain how Merck's drug will fare against a similar drug, telaprevir, under development by Vertex Pharmaceuticals Inc. and Johnson & Johnson. While the new Merck data are encouraging, analysts say telaprevir has generated more impressive data in separate clinical trials, and doctors may prefer telaprevir if it makes it to market. Vertex has said it plans to submit telaprevir for U.S. regulatory approval this year.
Both drugs are aimed at a potentially big market. Barclays has estimated protease inhibitors could generate $3 billion to $4 billion in peak annual sales, with boceprevir capturing about $1.5 billion of that. Other companies including Roche Holding AG also are studying protease inhibitors.
The hepatitis C virus is typically spread through contact with infected blood and can lead to cirrhosis and cancer of the liver. About 3.2 million Americans are living with chronic hepatitis C, according the U.S. Centers for Disease Control and Prevention.
Both the Merck and Vertex drugs are known as protease inhibitors, which are designed to block an enzyme that helps hepatitis C virus replicate. Standard treatment is a combination of the drug pegylated interferon and ribavirin. The hope is that protease inhibitors can improve cure rates versus standard treatment, and potentially shorten the duration of treatment.
Merck released top-line results of two late-stage studies of boceprevir Wednesday. One study, Respond-2, was in 403 patients who had failed prior therapy. The patients were divided into three groups: those taking standard treatment plus boceprevir for 48 weeks; those taking the same combination but who could shorten treatment duration to 36 weeks if their virus counts fell to certain levels; and those on standard treatment plus placebo for 48 weeks.
The primary goal was to measure "sustained virologic response," or SVR, which means undetectable virus levels 24 weeks after the end of treatment. The study found SVR rates of 66% in the boceprevir 48-week group, 59% in the shortened-duration arm and 21% in the standard-care group.
The second study, titled "Sprint-2," involved 1,097 patients who had no prior treatment. This study also had groupings similar to the Respond-2 study, though patients in the shortened-duration arm could stop treatment after 28 weeks. The study found SVR rates of 66% in the boceprevir 48-week arm, 63% in the shortened-duration arm and 38% in the standard-treatment arm.
Kim said the results showed that some patients were able to shorten treatment duration by 12 to 20 weeks.
The Sprint-2 study included an analysis of African-American patients because they have been shown to have a higher incidence of hepatitis C, and a lower rate of response to treatments. The analysis found higher SVR rates among black patients in the boceprevir-containing regimens than for standard of care.
The most common adverse events in the trials included fatigue, headache and nausea.
Merck plans to present the full data at a medical conference in November.
Baird analyst Thomas Russo, who follows Vertex, said the boceprevir data in previously untreated patients in the Sprint-2 study were "not all that impressive." The 66% SVR rate for boceprevir in this group compared with a 75% rate announced by Vertex for telaprevir in a separate study, Russo wrote in a note to clients. Vertex hasn't yet reported late-stage data for treatment-experienced patients.
Merck's Kim declined to make direct comparisons between boceprevir and telaprevir, noting they haven't been studied head-to-head in the same trial. But he noted that both of its studies had significant populations of difficult-to-treat patients.
A Vertex spokesman declined immediate comment. |
