Novartis Acquires Anthos Therapeutics for $925 Million, Bringing Abelacimab Back In-House

Novartis has announced a deal to acquire Anthos Therapeutics for $925 million upfront, with potential additional payments of up to $2.15 billion in regulatory and sales milestones. The acquisition, expected to close in the first half of 2025, brings the late-stage anticoagulant antibody abelacimab back under Novartis' control.

Abelacimab: A Potential Game-Changer in Blood Thinners

Abelacimab, a fully human monoclonal antibody targeting Factor XI, represents a new approach to anticoagulation. The drug is designed to prevent blood clots without increasing the risk of bleeding, a common side effect of current anticoagulants like Xarelto and Eliquis.

Recent Phase IIb data published in the New England Journal of Medicine demonstrated abelacimab's potential superiority over existing treatments. The AZALEA-TIMI 71 study showed that monthly 150-mg doses of abelacimab achieved a 99% median inhibition of Factor XI, sustaining this effect for over two years. Importantly, patients treated with abelacimab experienced a 62% reduction in major or clinically relevant non-major bleeding compared to those on Xarelto, with the difference being statistically significant (p<0.001).

Strategic Implications and Market Potential

The acquisition of Anthos Therapeutics marks a significant move for Novartis in the competitive anticoagulant market. With Eliquis facing potential generic competition as early as 2026, the timing of this deal could position Novartis favorably in the evolving landscape of blood thinners.

Abelacimab is currently undergoing evaluation in three Phase III trials: one for stroke prevention in atrial fibrillation and two for cancer-associated thrombosis. These studies, with expected completion dates in 2026, will be crucial in determining the drug's future market potential.

David Soergel, head of Novartis' cardiovascular, renal and metabolism development unit, stated, "We are proud that this medicine originated at Novartis and have been impressed with the Anthos Therapeutics team's expertise and dedication and with the great progress they have made on the program. Now is the right time to bring abelacimab back into the Novartis CRM pipeline."

Industry Context and Competition

The development of Factor XI inhibitors has seen mixed results across the pharmaceutical industry. Bayer recently terminated its Phase III OCEANIC-AF study of asundexian due to inferior efficacy compared to Eliquis. Johnson & Johnson and Bristol Myers Squibb also faced setbacks with their candidate milvexian in 2022.

Despite these challenges, the acquisition of Anthos by Novartis suggests continued interest and potential in the Factor XI inhibitor class. The deal also aligns with a broader trend of pharmaceutical companies acquiring promising assets from smaller biotechs, as evidenced by recent acquisitions such as GSK's purchase of IDRx and Johnson & Johnson's acquisition of Intra-Cellular.

As the pharmaceutical landscape continues to evolve, the success of abelacimab could significantly impact the future of anticoagulant therapy and Novartis' position in this crucial market segment.