New drugs for hepatitis C and superhigh cholesterol succeeded in late-stage clinical trials, the developers of the products announced on Wednesday. But both drugs have side effects that could dampen sales, analysts said.
Merck said that its drug boceprevir, when added to the existing therapy, effectively cured about two-thirds of patients with hepatitis C. That was far better than the cure rate with the existing therapy alone.
Isis Pharmaceuticals and Genzyme said its drug mipomersen significantly lowered LDL, the so-called bad cholesterol, in patients who still had very high cholesterol levels despite taking the highest tolerable dose of statins.
Merck is in a heated race with Vertex Pharmaceuticals to bring to market the first of a new class of hepatitis C drugs that are expected to make treatment far more effective and possibly shorter in duration. The existing treatment, using alpha interferon and ribavirin, takes nearly a year, causes severe side effects and succeeds in eradicating the virus only about half the time.
The initial reading of Wall Street was that boceprevir might be a bit less attractive than Vertex’s candidate, telaprevir, in part because Merck’s drug caused fairly high rates of anemia.
Shares of Vertex rose $1.02, or 2.9 percent, Wednesday to $36.26. Shares of Merck closed up 37 cents, or 1 percent, to $35.19.
Merck said that in one trial of 1,097 patients getting treatment for hepatitis C for the first time, 66 percent of those who had a 48-week regimen that included boceprevir had a sustained virologic response. That compared with 38 percent for those who got the existing therapy plus a placebo.
The corresponding figures from Vertex’s Phase 3 trial were 75 percent and 44 percent.
A sustained virologic response means the virus was undetectable in the patient’s blood 24 weeks after treatment ended. Many doctors consider that a cure.
Merck’s other trial involved about 400 patients for whom previous treatment had been unsuccessful. About 66 percent of those who received boceprevir in the 48-week regimen were effectively cured, triple the 21 percent rate in the control group.
Vertex is expected to report its Phase 3 results in previously treated patients in September.
“This is a compelling profile for boceprevir,” said Peter S. Kim, president of Merck Research Laboratories. He said that Merck would complete its application to the Food and Drug Administration by the end of this year.
Isis and Genzyme said they would apply for approval of their cholesterol-lowering drug in the first half of 2011.
Mipomersen would be Isis’s first big product and would validate its “anti-sense” technology for turning off genes. Genzyme could cite the promise of mipomersen to demand a higher price from Sanofi-Aventis, which is interested in buying Genzyme.
In one trial, patients who took mipomersen had an average reduction of 36 percent in LDL after 26 weeks, while those getting a placebo had a 13 percent increase. In the other study, those who got the drug had a reduction of 37 percent versus a reduction of 5 percent for a placebo.
Yet more than 20 percent of the patients in each of the trials dropped out because of side effects. The biggest concern is that the drug might cause liver damage.
“Efficacy looks good but safety remains a key risk,” Geoffrey Meacham, an analyst at J. P. Morgan, wrote in a note to clients Wednesday.
Shares of Isis fell 56 cents, or 5.6 percent, to $9.43. Shares of Genzyme fell 79 cents, or 1 percent, to $69.41.
The companies are initially aiming mipomersen at a relatively small number of patients who have a genetic disorder that leads to extremely high levels of cholesterol. But the companies hope to eventually expand to broader markets, if safety allows that.
Source :nytimes.com