AstraZeneca's biologics research and development arm MedImmune has signed over global rights to its experimental Crohn's disease drug MEDI2070 to Allergan, in a deal potentially worth $1.52 billion.

MEDI2070 is an IL-23 monoclonal antibody currently being assessed in a Phase IIb clinical trial for moderate-to-severe Crohn's disease and on the brink of entering Phase II for ulcerative colitis.

As these diseases fall outside of AZ' three main therapy areas - Respiratory, Cardiovascular & Metabolic Diseases, and Oncology - the group is handing over rights in return for an upfront payment of $250 million.

The firm also stands to receive potential additional payments of up to $1.27 billion if certain success-based development and sales-related milestones are achieved, as we as tiered royalties on sales.

MedImmune has been leading the clinical development for MEDI2070 under a collaboration agreement between AZ and Amgen, which, as such, will receive one-third of all payments and royalties coming from Allergan, as well as a single-digit percentage inventor royalty on the drug.

"This agreement demonstrates our sharp focus on three main therapy areas while creating value from the increased R&D productivity and innovative science in our pipeline through collaborations," said MedImmune's executive vice president, commenting on the move.