That early termination caused some critics to question the impact of the results.
Dr. Roger S. Blumenthal of Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, said that since the trial was originally designed as a 360-patient study, continuing the study until all patients had completed the trial would have provided more compelling evidence.
"The absolute difference might have gotten smaller, or it might have gotten bigger," Blumenthal told MedPage Today.
He made that same point in an editorial that was published along with the study.
The premature termination, as he and his Hopkins colleague Dr. Erin D. Michos, wrote, "was unfortunate and may exaggerate the potential benefit of niacin therapy."
But Blumenthal agreed that Taylor made a valid point about the lack of clinical equipoise and said the investigators clearly had a right to terminate the study.
Dr. John J. P. Kastelein of the Academic Medical Center in Meibergdreef, the Netherlands, also faulted the early termination of the trial. Kastelein, who served as discussant for the trial, also co-authored a second editorial NEJM editorial that was published along with the trial results.
At a press conference, Kastelein said early termination opened the door to "random results."
Because of his leading role in trials that have investigated ezetimibe, Kastelein's NEJM editorial offered what where arguably the most interesting comments about ARBITER 6-HALTS
He was lead author and prinicipal investigator of the ENHANCE trial, another study that sought to prove a benefit for ezetimibe in slowing plaque progression. ENHANCE, like ARBITER, relied on measurement of the artery wall to compare the efficacy of a statin (simvastatin) alone to the combination of ezetimibe and simvastatin marketed as Vytorin.
That trial was also negative. and when it was reported at the American College of Cardiology and simultaneously published in NEJM, Taylor wrote an editorial suggesting that ezetimibe was being overused.
In his turn as editorialist, Kastelein agreed with the ARBITER 6-HALTS investigators, writing that the results "available to date provide support for the concept that the use of statins to reduce LDL cholesterol to target levels with the subsequent addition of a drug to raise HDL cholesterol levels (niacin), rather than a drug to lower LDL cholesterol levels (ezetimibe), is a more effective treatment for patient at high cardiovascular risk."
Ezetimibe and the ezetimibe/simvastatin combo pill were developed by Merck/Schering-Plough, a joint development agreement that has now evolved into a merger between the two pharmaceutical giants.
Early Saturday morning, Merck issued a press release confirming completion of the merger, stating, "Merck today confirms and underscores its commitment to marketing and developing cardiovascular medicines for a range of cardiovascular disorders."
In response to ARBITER 6-HALTS, Merck issued a seven-page statement confirming its continued support of its ezetimibe products.
"The results of the small ARBITER 6 study do not, in any way, change our view of Zetia and Vytorin as effective medicines for fighting LDL cholesterol," said Peter S. Kim, president of Merck Research Laboratories.
Dr. Douglas Weaver, immediate past president of the American College of Cardiology, called niacin "an effective, but underutilized drug."