Merck heart drug surprises with positive result; questions linger

The drugmaker reported only that the drug, anacetrapib, met the main goal in the 4-year trial of about 30,000 high-risk heart patients already on cholesterol-lowering statins. It showed a statistically significant reduction in the combined risk of heart attacks, heart-related death and need for repeat artery-clearing procedures.

While announcing the positive result few had expected, given the checkered past of similar medicines, Merck said it plans to review the data with external experts and consider whether to file applications seeking approval.

"When they make a statement that we haven't decided whether to file a new drug application it sends a very strong message," said Dr. Steven Nissen, chief of cardiology at the Cleveland Clinic, who has studied other drugs in the class known as CETP inhibitors. "The fact that they're hedging their bets ... suggests that the treatment effect may have been relatively small."

Full details of the trial will be presented at a major European heart meeting on Aug. 29.

Merck shares, which initially rose more than 2 percent in pre-market trading, were up just 3 cents at $65.95 as uncertainty over the medicine's future weighed on investors.

"We believe it is more prudent to wait for the full data release before drawing broad conclusions on the product’s commercial potential," Credit Suisse analyst Vamil Divan said.

A little over a decade ago, CETP inhibitors were hailed as the next big heart drug due to their ability to dramatically raise HDL, the so-called good cholesterol.

Pfizer had been banking on its torcetrapib to replace lost revenue when Lipitor, then the world's top-selling medicine, lost patent protection. Analysts had forecast more than $10 billion in eventual annual sales.

But it became the most expensive failure in pharmaceutical history in late 2006, when Pfizer had to pull the plug on its $800 million Phase III program over an imbalance in deaths and other safety issues.

CETP inhibitors from Roche and Eli Lilly and Co subsequently failed due to lack of sufficient efficacy, and other drugs that raise HDL by other mechanisms also failed to show benefit.

Merck's anacetrapib does also lower "bad" LDL cholesterol, which has proven to cut heart attacks and deaths.

(Reporting by Bill Berkrot; Additional reporting by Akankshita Mukhopadhyay in Bengaluru; Editing by Sriraj Kalluvila and Dan Grebler)