In a US$63 billion deal, US pharmaceutical company Abbvie has announced it is to takeover fellow pharma giant, Irish-based Allergan.

Abbvie Chairman and CEO Richard Gonzalez will continue to lead the company from its executive offices in Chicago and two members of Allergan's Board, including chairman and CEO Brent Saunders, will join Abbvie's board.

Gonzalez said: “With our enhanced growth platform to fuel industry-leading growth, this strategy allows us to diversify Abbvie's business while sustaining our focus on innovative science and the advancement of our industry-leading pipeline well into the future."

The combined company will consist of several franchises with leadership positions across immunology, hematologic oncology, medical aesthetics, neuroscience, women's health, eye care and virology, according to Abbvie’s statement, which added, “Allergan's product portfolio will be enhanced by Abbvie's commercial strength, expertise and international infrastructure.”