So far, at least. The drugmaker is reporting that its experimental cholesterol med, which is in the same class as Pfizer’s fabulous flop, had dramatic results in a small clinical trial, and didn’t exhibit the sort of safety problems that killed torcetrapib. Merck’s CETP inhibotor raised HDL by 139 percent and cut LDL levels by 40 percent during an 8-week trial, in 589 patients, according to data presented at the Drugs Affecting Lipid Metabolism meeting in New York.

By contrast, the current best-selling drugs to boost HDL - whose active ingredient is niacin - typically raise good cholesterol by only 20 to 30 percent, Reuters reminds us. Just as significant, the Merck drug - code-named MK-859 - didn’t cause a rise in blood pressure, which was a big issue with Pfizer’s torcetrapib and may have caused an increased number of deaths that ultimately ended further development.

“As hard as we looked, we couldn’t find any increase in blood pressure,” Daniel Bloomfield, a senior Merck research told Reuters. “The data really point out you can inhibit CETP with MK-859, and substantially reduce LDL and increase HDL, and importantly not raise blood pressure…The data suggest any does would be safe to go forward with.” Four doses - 10 mg, 40 mg, 150 mg and 300 mg, were tested against placebo.

The incidence of side effects among patients taking the Merck drug, at whatever dose, was similar to those seen among patients given placebos. But Bloomfield cautioned that the safety won’t really be known until the drug goes through much larger studies, which typically take 4 to 7 years and focus on the risk of heart attacks and death. And despite the effects on LDL and HDL cholesterol, he believes the FDA is unlikely to approve MK-859 until such studies are completed.

Pfizer saw an $800 million late stage development program for torcetrapib go down in flames last December when safety monitors shut it down after finding increased deaths among patients taking the drug in clinical trials. The drug had been expected to replace Pfizer’s $13 billion a year Lipitor when the world’s most widely prescribed medicine faces generic competition as soon as 2010.

Torcetrapib’s sensational failure left researchers and investors anxious to find out if its dangers might crop up with other CETP inhibitors in development or if they were specific to the Pfizer drug. Roche and its partner Japan Tobacco said earlier this week they would decide later this year whether to move their own CETP inhibitor into late stage trials.

In Merck’s trial, HDL levels rose by 44 percent and 86 percent, respectively, among patients taking daily 10 milligram and 40 milligram doses of MK-859, while results seen with the highest 300 mg dose were similar to those of the 150 mg group. Levels of LDL cholesterol fell 16 percent and 27 percent, respectively, among those receiving the two smallest doses of the drug, and fell 39 percent in the highest-dose group. HDL levels rose only 4 percent in the placebo group, while LDL levels rose 2 percent.

The Merck drug was also tested at all doses in combination with 20 mg doses of Lipitor. The combination didn’t have any additional impact on raising HDL. But it magnified the impact on LDL, lowering it as much as 68 percent at the highest dose of MRK-859.