Boston Scientific Corp. enrolled more than 1,500 patients in the Platinum clinical trial of its Promus Element drug-eluting stent, two months ahead of schedule, setting the stage for approval applications to the Food & Drug Administration and the Japanese Ministry of Health, Labor and Welfare.

The Natick, Mass.-based medical devices giant said the workhorse trial is a global, randomized, pivotal controlled study of its platinum chromium Promus Element everolimus-eluting stent involving 1,532 patients at more than 140 sites worldwide.

The trial will compare the Promus Element with an earlier, cobalt chromium alloy Promus model that uses the same drug dose and polymer. A pair of parallel sub-trials will evaluate the Promus Element in small vessels and long lesions.

BoSci is also developing bare-metal and paclitaxel-eluting variations of the Element platform and has a pivotal trial under way comparing those devices, the Taxus Element and Taxus Express2. That trial, called Perseus, finished enrolling patients last October; primary endpoint results are due next year.