Blackstone Life Sciences’ substantial $250 million investment in Anthos Therapeutics’ abelacimab, formerly known as MAA868 has yielded promising results. Novartis initially introduced the drug to address pressing medical needs, only to withdraw abruptly, leaving Anthos Therapeutics to take the reins. Since then, abelacimab has shown remarkable promise, delivering impressive reductions in both venous thromboembolism and bleeding events.
Novartis initially introduced the anti-Factor XI/XIa antibody, MAA868, with hopes of addressing critical medical issues such as atrial fibrillation and clot prevention in patients undergoing knee replacement surgery. However, Novartis abruptly withdrew from these trials before enrolling any patients, leaving the promising drug candidate in limbo. It was at this juncture that Blackstone Life Sciences seized the opportunity, licensing the asset and creating Anthos Therapeutics to spearhead its development.
Since Anthos took over the project, it has embarked on a relentless quest to demonstrate a potential medical breakthrough. Their efforts have not gone unnoticed. In 2021, the biotech reported an astonishing 80% reduction in venous thromboembolism compared to enoxaparin, a standard treatment. Their latest triumph, however, lies in the realm of bleeding reduction, further solidifying abelacimab’s potential as a groundbreaking innovation in anticoagulant therapy.
The Achilles’ heel of existing anticoagulant drugs is their tendency to increase the risk of bleeding. Anthos Therapeutics recognized this inherent dilemma and set out to develop abelacimab as a solution that could dissociate thrombosis from hemostasis. In simpler terms, they aimed to prevent clot formation without causing the same degree of bruising and bleeding associated with traditional therapies.
Their Phase 2 trial, involving 1,287 atrial fibrillation patients at moderate to high risk of stroke, brought forth the moment of truth. Participants were divided into two groups, one receiving Xarelto, a well-established anticoagulant, and the other receiving one of two abelacimab doses via subcutaneous injection once a month. The outcomes established a substantial decrease in significant or clinically significant non-major bleeding events associated with the experimental antibody. These encouraging results led Anthos to prematurely discontinue the study, providing Xarelto patients with the opportunity to transition to abelacimab if they wish.
While Anthos has not yet released the full dataset from the Phase 2 trial, preliminary indicators of abelacimab’s effectiveness in reducing bleeding have been promising. The biotech has described the reduction as “overwhelming” and “unprecedented.” The complete dataset is eagerly awaited and will be presented at an upcoming scientific congress.
In light of these promising outcomes, Anthos has swiftly moved abelacimab into three Phase 3 clinical trials. These trials will focus on atrial fibrillation patients and individuals with cancer who are at risk of venous thromboembolism. This development positions abelacimab as a frontrunner in the race to tackle Factor XI, alongside competitors such as milvexian by Bristol Myers Squibb and asundexian by Bayer, both of which are administered orally.