Increasing the blood levels of HDL or 'good' cholesterol is known to reduce the risk of heart disease much more than consumption of statins.
A new study conducted with 1,623 patients investigated the safety of anacetrapib, a drug that inhibits a protein called CETP, which raises HDL, reports Nature.
The trial found with 94 percent confidence that anacetrapib does not harm patients - in contrast to the 15,000-patient trial of torcetrapib, also a CETP inhibitor.
When Pfizer halted that trial, many companies stopped working on CETP blockers. Researchers were left wondering whether torcetrapib's failure was down to unexpectedly high toxicity in that compound, whether the inhibition of CETP itself is harmful, or whether the idea that raising HDL levels lowers risk is flawed.
After 24 weeks on the drug anacetrapib, patients experienced a 138 percent increase in HDL levels. In contrast, exercising and changing diet might only raise HDL by 10 percent, said Christopher Cannon, a cardiovascular researcher at Brigham and Women's Hospital in Boston, Massachusetts.
The participants, all of whom were also on statins, experienced a further 40 percent reduction in LDL levels.
The researchers noted some positive trends: 3.3 percent of patients taking the drug experienced heart attacks, stroke or other kinds of cardiovascular events, compared with 5.3 percent of patients in the placebo group.
Prediman Shah, director of cardiology and atherosclerosis research at Cedars-Sinai Medical Center in Los Angeles, California, is happy with the results, but equally cautious.
Whether raising HDL really works won't become clear until data from larger studies begin to emerge, Shah said. An international, 30,000-patient trial testing anacetrapib's efficacy will begin next year, but results won't come in until at least 2014.