Allergan PLC said early Wednesday that it plans to file for U.S. approval of its acute migraine drug, ubrogepant, by the first quarter of 2019. If all goes as expected, the company said it expects the drug will be "the first oral CGRP receptor antagonist submitted in the U.S. for the acute treatment of migraine with or without aura." A slew of new drugs have recently been approved to prevent migraine -- a chronic, debilitating condition that millions of Americans suffer from -- but Allergan's drug takes a different approach, and is intended to for so-called "acute relief," or easing the painful attacks as they occur. Existing alternatives in this space include general pain drugs and popular migraine medications called triptans. Allergan has previously said that it plans to file for Food and Drug Administration approval of ubrogepant next year; the recent completion of two clinical studies should allow it to file by the first quarter, the company said. Company shares rose 0.5% in Wednesday premarket trade. Shares have surged 7% over the last three months, compared with a 0.01% rise in the S&P 500 and a 2.7% rise in the Dow Jones Industrial Average .