British pharmaceutical company Shire plc has agreed to acquire U.S.-based NPS Pharma for $5.2 billion, strengthening its capabilities in treating rare diseases and gastrointestinal disorders.

The deal — the biggest in Shire's history — comes less than three months after its planned sale to U.S. biopharmaceutical company AbbVie Inc fell through. AbbVie paid Shire a break fee of $1.6 billion to get out of that acquisition when the Treasury Department changed the rules on firms reincorporating in a country with lower taxes.

NPS Pharma is a commercial-stage biopharmaceutical company with a focus on treating rare diseases. Its first product, Gattex/Revestive (teduglutide [rDNA origin]) for injection, is approved in the United States and Europe to treat adults with short bowel syndrome (SBS). The company's second product, rhPTH -83 (Natpara/Natpar), is currently under review in the United States and Europe for the treatment for hypoparathyroidism (HPT).

Additionally, NPS Pharma has an ongoing Phase 2a study evaluating its lead pipeline candidate, NPSP795, for the treatment of adults with autosomal dominant hypocalcemia.

The acquisition has been approved by both boards of directors.

Welcoming the deal, Shire CEO Flemming Ornskov, MD, MPH, commented: "We look forward to accelerating the growth of the NPS Pharma portfolio based on our proven track record of maximizing value from acquired assets and commercial execution. The NPS Pharma organization will be a welcome addition to Shire as we continue to help transform the lives of patients with rare diseases."

The transaction is expected to add to Shire's non-GAAP EPS from 2016 onward.