Roche group Genentech said its bispecific antibody ACE910 has picked up a ‘breakthrough’ designation in the US for the prophylactic treatment of haemophilia A patients with factor VIII inhibitors.

Patients with the condition experience repeated severe bleeding symptoms because a deficiency or functional disorder of coagulation factor VIII stops their blood from clotting. While factor VIII replacement therapy is widely used to prevent bleeding, this intravenous treatment may develop inhibitors which reduce its effectiveness, creating a high unmet need for these patients. 

ACE910 is an investigational humanised bispecific monoclonal antibody engineered by Roche group Chugai to mimic the function of blood coagulation factor VIII, and thus provide a new approach to treating the condition, regardless of whether patients have developed inhibitors. 

The breakthrough designation, a regulatory tool designed to speed up development and review of drugs for severe or life-threatening diseases that could offer an benefit over existing therapies, was based on data from a Phase I/II clinical study conducted with Japanese and Caucasian healthy volunteers as well as Japanese haemophilia A patients.

This showed that once-weekly subcutaneous injection of ACE910 demonstrated a prophylactic efficacy profile in all cohorts irrespective of the presence of inhibitors, with bleeding completely controlled in nine out of 18 patients during the drug’s administration.