Shire says it intends to acquire the Belgian gastrointestinal specialist Movetis for $560 million (€428 million), adding a valuable constipation drug to its portfolio and the expertise it needs to further develop its gastrointestinal business.

Chief among the spoils for Shire would be the constipation drug, Resolor. The medicine is already approved in Europe for women suffering chronic constipation. Furthermore, it has patent protection through 2020 and could deliver peak sales of $397 million (€300 million) according to Shire, which expects to see immediate revenue from the drug if the acquisition is approved.

In addition to Resolor, the Movetis buy would also deliver two mid-stage gastrointestinal medicines and two “prioritized” compounds in preclinical development, addressing gastrointestinal ailments including ascites, pediatric reflux, refractory gastroesophageal reflux disease, and severe forms of irritable bowel syndrome.

A Movetis acquisition supports Shire's international expansion strategy says Mike Cola, president of Shire's specialty pharma business. Resolor has broad approval in Europe where the European Medicines Agency granted marketing authorization for the drug. It has also won draft approval on August 3 from the U.K.'s National Institute for Health and Clinical Excellence. A marketing authorization for the drug is still under review in Switzerland.

Movetis was founded in November 2006 as a spin-off of Johnson & Johnson. It launched a successful IPO in December 2009. J&J still has rights to Resolor outside Europe, but Movetis is entitled to receive royalties on those sales.

Shire's acquisition of the company still needs to be approved by 90 percent of Movetis shareholders. They'll get a chance to voice their opinion in September. But Shire has already lined up support for the acquisition from institutional shareholders, who own about 40 percent of the company's shares and Movetis' board of directors unanimously support the offer.

Shire will fund the acquisition from its existing cash resources, and expects that the acquisition will be accretive to its earnings after 2012.