Novartis (NVS) and Blackstone's (BX) Blackstone Life Sciences said Tuesday they have signed a deal for Novartis to acquire Anthos Therapeutics for up to $3.1 billion.

Novartis will make an upfront payment of $925 million at closing, and potential additional payments of up to $2.15 billion based on the achievement of regulatory and sales milestones.

Blackstone Life Sciences and Novartis launched Anthos in 2019 with exclusive international rights from Novartis to develop, produce and commercialize abelacimab, intended to prevent stroke and systemic embolism in patients with atrial fibrillation and to prevent blood clots recurrence in cancer patients. Abelacimab is currently in phase 3 development.

The transaction is expected to close in H1 this year, the companies said.