Bristol-Myers Squibb Co.’s and AstraZeneca PLC’s three-step deal to acquire Amylin Pharmaceuticals Inc. for $7 billion reaffirms the partners’ commitment to the vast and growing type 2 diabetes market, despite intense competition and the mixed track record of their five-year-old alliance. It also underscores the importance to pharma of risk-sharing deals in tackling large therapeutic areas.
The deal puts a key diabetes franchise, Amylin’s first-in-class glucagon-like peptide-1 agonist (GLP-1) Byetta (exenatide) and its long-acting follow-on Bydureon,...