UPDATE 1-U.S. FDA approves AbbVie's migraine prevention drug

(Adds details on the drug)

Sept 28 (Reuters) - AbbVie Inc said on Tuesday the U.S. health regulator approved its once-daily oral medicine for preventive treatment of migraine in adults, adding a third drug to the drugmaker's arsenal of therapies for severe headaches.

The drug, Qulipta, which AbbVie will launch in early October, will enter a crowded market for migraine prevention drugs such as Eli Lilly's Emgality, Amgen Inc's Aimovig and Biohaven Pharmaceutical Holding Co Ltd's Nurtec ODT.

Analysts expect the drug to bring in sales of over $640 million by 2025, according to Refinitiv data.

AbbVie acquired Qulipta in 2020 as part of its $63 billion deal for Allergan, along with anti-wrinkle and chronic migraine treatment Botox and acute migraine drug Ubrelvy.

Qulipta belongs to a class of drugs called calcitonin gene-related peptide (CGRP) receptor antagonists, also called "gepants", which act by blocking a pathway that seemingly plays a role in migraine activation.

The Food and Drug Administration's approval of Qulipta is supported by data from a late-stage study, which showed the drug caused a statistically significant reduction in average monthly headache days in patients compared to placebo.

Migraine, characterized by severe headache and other symptoms such as light sensitivity and nausea, affects about 39 million people in the United States, AbbVie said. (Reporting by Manojna Maddipatla in Bengaluru; Editing by Krishna Chandra Eluri)