AbbVie raises offer for drugmaker Shire to $51 billion

(Bloomberg) — AbbVie Inc., the drugmaker split last year from Abbott Laboratories, made a fourth offer to buy Shire PLC, raising the price to about $51.5 billion in an effort to bring Shire to the negotiating table.

AbbVie increased the offer by about 11 percent to 51.15 pounds a share in cash and stock, the company said in a statement today. Previously, AbbVie made three bids.

“AbbVie has made a compelling offer to Shire that creates immediate and long-term value to shareholders of both companies,” Richard Gonzalez, AbbVie's CEO, said in the statement. “We think its shareholders should strongly encourage the Shire board to engage in constructive dialogue with AbbVie.”

Buying Shire would allow North Chicago, Illinois-based AbbVie to have its tax domicile in the U.K., which has a lower tax rate than the U.S. The addition of Shire's array of rare disease treatments and drugs for attention deficit hyperactivity disorder would also diversify AbbVie's product portfolio, which is currently dominated by a single medicine, the arthritis therapy Humira.

Besides rare disease treatments, Shire makes drugs for attention deficit including Vyvanse and Adderall XR. ADHD treatments accounted for about 39 percent of Shire's revenue last year.

While Shire's tax domicile is in Dublin, AbbVie has said the combined company would be domiciled in the U.K.