TRENTON:  So-so results for a new type of cholesterol drug have left Merck in a quandary: Does the company try to bring it to market or scrap it?

A large, long-term study of the drug showed that it prevents heart attacks and reduces the need for heart procedures, while three similar drugs developed by rivals failed. But the drug, anacetrapib, only reduced those complications by 9 percent.

Now Merck, which has spent 13 years and likely hundreds of millions of dollars testing the drug, has to decide whether to spend even more to seek approval from regulators and convince people to buy it in a market full of cholesterol drugs.

The results of the 30,450-patient study were announced Tuesday at a conference of heart specialists in Barcelona, Spain and published in the New England Journal of Medicine. The study found that anacetrapib is safe and somewhat effective.

That kind of result is normally enough to seek approval to market a new medicine, especially for heart disease, which is the top killer in many developed countries. Yet even after seeing the results weeks ago, Merck says its executives are still consulting with medical experts and regulators on whether to go through the costly process of applying for approval.

Analyst Steve Brozak, president of WBB Securities, predicts Merck will do so, given anacetrapib’s safety, the huge pool of potential patients and all the resources Merck has poured into the drug.

“This will get used,” Brozak said.

Merck would likely price the bill somewhere between the two extremes that now define the market for cholesterol drugs.

Generic versions of brand-name statin cholesterol pills including Lipitor, Crestor and Merck’s own Zocor now cost $10 to $20 a month. Repatha and Praluent, two new injected medicines in a different drug category that have been shown to dramatically reduce cholesterol, cost $14,000 a year.

Georgetown University cardiologist Dr. Allen J. Taylor said he thinks the drug would be approved by the Food and Drug Administration despite its “relatively weak benefit.”

“If you were discussing this with patients,” Taylor said, “you would have to tell them that when you start this, you’ll have to take it for four years to have a 1 percent chance of preventing an event,” meaning a heart attack or a procedure such as bypass surgery or implanting a stent to keep an artery open.

Taylor said it’s still unclear how anacetrapib controls cholesterol, which would make it hard for doctors to determine which patients would benefit much from it. But he and Brozak praised the company for doing such an exhaustive, expensive study in an era when many studies are quick and relatively small, sometimes producing unclear results.

In the study, patients getting anacetrapib plus a statin for four years had, on average, lower levels of bad cholesterol and other fats, and higher levels of good cholesterol, compared to a group getting a statin and a dummy pill. But Merck’s drug didn’t prevent any deaths from heart attacks or other cardiac problems.

Anacetrapib’s only worrisome side effect was a long-term accumulation of the drug in patients’ fatty tissue. It’s unknown if that will cause problems, so Merck plans to study that by following some participants for two years after they stop taking the drug.