Novartis' $3.1 Billion Bet on Abelacimab: A Promising Stroke Prevention Asset

Novartis has agreed to acquire Anthos Therapeutics for up to $3.1 billion, securing the rights to abelacimab, a novel factor XI inhibitor with promising potential in stroke prevention and cancer-associated thrombosis. The acquisition, expected to close in the first half of 2025, aligns with Novartis' strategic focus on the cardiovascular therapeutic area and leverages the company's strength and expertise in this domain.

Anthos Therapeutics, launched by Blackstone Life Sciences and Novartis in 2019, has advanced abelacimab through clinical development under a license from Novartis. Abelacimab is a novel, highly selective, fully human monoclonal antibody designed to induce effective hemostasis-sparing anticoagulation through Factor XI inhibition. Phase 2 data showed a significant reduction in bleeding events in patients taking abelacimab versus a standard of care direct-oral anticoagulant in patients with atrial fibrillation (AZALEA1,2). Three Phase 3 clinical trials are ongoing for patients at risk of arterial and venous clots, one in patients with atrial fibrillation (LILAC-TIMI 763) and two in cancer associated thrombosis (ASTER4) and (MAGNOLIA5).



The acquisition includes an upfront payment of $925 million, with additional payments of up to $2.15 billion upon achievement of specified regulatory and sales milestones. This structure reflects Novartis' confidence in abelacimab's potential while managing risk through performance-based compensation. The transaction's timing is opportune, coming shortly after the publication of impressive clinical results in the New England Journal of Medicine showing abelacimab's superior safety profile with a 62% reduction in major bleeding compared to current standard of care.

The early termination of the AZALEA-TIMI 71 trial by the Independent Data Monitoring Committee due to overwhelming clinical benefit is a strong validation of abelacimab's safety profile. Factor XI inhibition represents a novel approach that could potentially decouple antithrombotic efficacy from bleeding risk, addressing one of the most significant challenges in current anticoagulation therapy. The ongoing phase 3 trials targeting both atrial fibrillation and cancer-associated thrombosis demonstrate the broad potential applications of this therapeutic approach, with data expected in the second half of 2026.

In conclusion, Novartis' acquisition of Anthos Therapeutics for up to $3.1 billion reflects the strategic value and potential of abelacimab in stroke prevention and cancer-associated thrombosis. The transaction aligns with Novartis' long-term growth strategy in the cardiovascular therapeutic area and demonstrates the company's commitment to advancing innovative therapies for patients with high unmet medical needs.