August 4, 2010

Hepatitis, Cholesterol Drugs Show Promise

August 4, 2010, 11:46 am
By ANDREW POLLACK

New drugs for hepatitis C and for super-high cholesterol succeeded in late-stage clinical trials and could be on their way to market, the drugs developers announced Wednesday morning.

Merck said that its antiviral drug boceprevir, when added to 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 their drug for super-high cholesterol significantly lowered LDL, the so-called “bad cholesterol’’ in patients, who still had very high cholesterol levels despite taking the highest statin doses they could tolerate.

Still, investors had concerns with both drugs. For the cholesterol drug, called mipomersen, some patients had elevated liver enzymes, a sign the drug might damage the liver.

“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, a biotechnology company in Carlsbad, Calif. were down more than 3 percent at about 10 a.m.

Mipomersen, which is injected, is not likely to compete directly with statins like Pfizer’s Lipitor. It is intended initially for a relatively small number of patients with a genetic disorder that leads to extremely high levels of cholesterol.

But the two companies hope to gradually expand it to broader populations, if safety concerns do not stand in the way. Genzyme said it would file for the initial approval from the F.D.A. in the first half of 2011.

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 also possibly shorter in duration. The existing treatment — with alpha interferon and ribavirin – can take nearly a year, causes severe side effects and succeeds in eradicating the hepatitis C virus only about half the time.

“This is a compelling profile for boceprevir,’’ Peter S. Kim, president of Merck Research Laboratories, said on a conference call with analysts Wednesday. He said the company would complete its application to the F.D.A. for regulatory approval by the end of this year.

The early read by Wall Street was that Vertex’s drug would not be blown out of the water by boceprevir. Shares of Merck, a huge company, barely budged. Those of Vertex, whose future is heavily dependent on the success of its hepatitis C drug, were up about 5 percent.

Merck, which obtained boceprevir when it acquired Schering-Plough, announced the results of two clinical trials, which were somewhat complicated in their structure.

In a trial involving 1,097 patients who were undergoing treatment for the first time, 66 percent of those who got boceprevir plus standard therapy for 48 weeks had a so-called sustained virologic response, compared to 38 percent of those getting the standard therapy plus a placebo.

In Vertex’s phase 3 trial, the corresponding rates for its drug, telaprevir, were 75 percent and 44 percent.

A sustained virologic response means there was no detectable hepatitis C virus in the patient’s blood 24 weeks after the treatment ended. Many doctors say that is essentially a cure.

Merck’s other trial involved about 400 patients for whom prior treatment had been unsuccessful. For those who got boceprevir in a 48-week treatment regimen, 66 percent had a sustained virologic response, triple the 21 percent for those in the control arm.

Vertex has not yet reported phase 3 results for patients who have failed prior therapy.

Both Merck trials also looked at schemes in which treatment with boceprevir could be stopped at either 28 weeks or 36 weeks if patients had no detectable virus in their blood. The cure rates for those patients was nearly as good as for the full 48-week regimen. Merck did not say, however, how many patients were able to shorten the duration of treatment.

Merck said 15 percent of the patients in the trial testing initial therapy were blacks, a group that has a higher rate of hepatitis C than the rest of the nation’s population and also do less well on the existing therapy.

In the trial 53 percent of the blacks getting the 48-week treatment with boceprevir had a sustained virologic response compared to 23 percent for those in the control group.

The key safety issue for boceprevir appears to be anemia. That is already a side effect of ribarvirin, one of the two drugs now used to treat hepatitis. But the boceprevir seems to make it worse.

Merck executives said that anemia could be controlled using drugs like Procrit or Aranesp.

Both boceprevir and telaprevir inhibit the protease enzyme made by the virus. Both are taken orally three times a day. The patients in both Merck’s and Vertex’s trials had a strain of hepatitis C called genotype 1, which is the most common strain in the United States and Western Europe and is particularly hard to treat.

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