Merck (NYSE: MRK), known as MSD outside the United States and Canada, and Acceleron Pharma Inc. (Nasdaq: XLRN), a publicly traded biopharmaceutical company, have entered into a definitive agreement under which Merck, through a subsidiary, will acquire Acceleron for $180 per share in cash for an approximate total equity value of $11.5 billion.

“Strategic business development is a top priority for Merck as we look to drive sustainable growth and further bolster and balance our pipeline with breakthrough science,” said Rob Davis, chief executive officer and president, Merck. “Acceleron’s innovative research has yielded an exciting late-stage candidate that complements and strengthens our growing cardiovascular portfolio and pipeline and holds the potential to build upon Merck’s proud legacy in cardiovascular disease.”

“This agreement with Merck represents the culmination of decades of work by Acceleron researchers successfully leveraging our company’s deep scientific expertise in the biology of the TGF-beta superfamily and driven by an unwavering dedication to delivering life-changing medicines for patients,” said Habib Dable, chief executive officer and president, Acceleron. “We believe Merck is well-positioned to apply its industry-leading clinical and commercial capabilities to harness the potential of sotatercept as we join together to help make an impact on cardiopulmonary disease for the benefit of patients.”

Ropes & Gray advised Acceleron.