Mesoblast, the Australian adult stem cell developer, has partnered with Cephalon in what is the largest regenerative medicine deal to date. Under the terms of the agreement, which is potentially worth more than US$2 B, Cephalon will attain rights to commercialise specific products for certain degenerative diseases that were developed by Mesoblast based on its adult mesenchymal precursor stem cell platform. Cephalon also agreed to buy 19.99% of Mesoblast’s stock for a sizeable 45% premium to the company’s 30-day average price.