Anthos Acquired by Novartis for $925 Million

Cambridge-based Anthos Therapeutics and its parent company, private investment platform Blackstone Life Sciences, have entered into an agreement with Novartis to acquire Anthos for up to $3.1 billion. Anthos was founded by Blackstone Life Sciences and Novartis in 2019 with the exclusive global rights from Novartis to develop, manufacture, and commercialize abelacimab, a novel factor XI inhibitor that originated at Novartis.

Anthos shareholders will receive an upfront payment of $925 million upon closing of the transaction. In addition, Anthos shareholders are entitled to receive payments in the event certain regulatory and commercial milestones are achieved. Completion of the transaction is expected in the first half of 2025.

Abelacimab is a novel, investigational, highly selective, fully human monoclonal antibody that binds tightly to Factor XI to block its activation and prevent the generation of the activated form (Factor XIa). This mimics natural Factor XI deficiency, which is associated with protection from thromboembolic disease.

Abelacimab received a Fast Track Designation from the FDA in July 2022 for the treatment of thrombosis associated with cancer. In September 2022, abelacimab was also granted a Fast Track Designation for the prevention of stroke and systemic embolism in patients with atrial fibrillation.

“We are proud to have launched and helped grow Anthos by acquiring the rights to abelacimab, assembling a world class team, designing the clinical plan and financing its development,” said Dr. Nicholas Galakatos, Chairman of Anthos’ Board of Directors and Global Head of Blackstone Life Sciences. “We believe abelacimab has the potential to be a leader in the new class of Factor XI anticoagulants and are pleased to have Novartis as a committed partner to advance the development and commercialization of abelacimab as a potential treatment option for the millions of patients at risk of strokes. This transaction is an affirmation of Blackstone Life Sciences’ ownership investment strategy, where we seek to find innovative products and build companies around them to meet unmet patient needs.” (Source: Anthos Therapeutics Website, 11 February, 2025)