NEW YORK Allergan Inc (AGN.N) on Wednesday said it would buy Vitae Pharmaceuticals (VTAE.O), which is testing an experimental drug to treat psoriasis and other autoimmune disorders, for $639 million in cash.
Vitae is also testing a potential treatment for atopic dermatitis.
The acquisition would expand the main dermatology business at Allergan, which is best known for its widely used Botox treatment.
The company is paying $21 per share in cash for Vitae, whose stock jumped to $20.89 in premarket trading from $8.10 at Tuesday's close. The previous year high was $18.71 on Dec. 30.
Allergan shares closed at $240.10 on Tuesday.
(Reporting by Caroline Humer; Editing by Lisa Von Ahn)