The US Food and Drug Administration (FDA) recently granted “breakthrough therapy designation” status to Genentech’s investigational therapy ACE910, for the prophylactic treatment of individuals with hemophilia A who are 12 or older.
ACE910 is an artificial protein engineered to simultaneously bind factor proteins IXa and X, which mimics a function that factor VIII (FVIII) carries out as part of the clotting cascade, a series of chemical reactions that ensure culminate in clot formation. The therapy is designed to be effective even if the patient has developed inhibitor antibodies to FVIII. In addition, because ACE910 is structurally distinct from FVIII, it is not expected to trigger the formation of new inhibitors.
Drugs designated as “breakthrough” therapies are placed by the FDA on a fast-track approval program and given intensive guidance by the agency. ACE910 was granted this designation after positive data results from a small phase I clinical trial in which patients with severe hemophilia A, with and without inhibitors to FVIII, received the therapy prophylactically via weekly subcutaneous (under the skin) injections. The subcutaneous administration of this treatment represents a potential alternative to the traditional administration of factor replacement therapy via intravenous infusions of recombinant or plasma-derived FVIII.
Annual bleeding rates dropped significantly in all the patients enrolled in the study, regardless of their inhibitor status. Further, none of the patients developed inhibitor antibodies in response to the new therapy. Results from a successful follow-up phase I/II extension study among the same patients were presented at the International Society of Thrombosis and Haemostasis, June 20-25, 2015, in Toronto, Canada.
“People with hemophilia A may require regular and frequent infusions of replacement clotting factor to reduce the risk of dangerous bleeding, and they can develop inhibitors that make replacement ineffective,” said Sandra Horning, MD, chief medical officer and head of Global Product Development at Genentech. “We are pleased that the FDA has granted breakthrough therapy designation for ACE910, recognizing an unmet need for patients with inhibitors and the promise of these early data. Genentech has been developing antibody treatments for people with blood disorders for over 20 years, and we are excited to expedite the development of a potential new treatment for hemophilia A.”
According to a Genentech press release, the company will begin a phase III trial of ACE910 in patients with hemophilia A with FVIII inhibitors by the end of 2015, with a subsequent phase III trial in patients without inhibitors in 2016. Additionally, a trial in pediatric patients with hemophilia A is planned in 2016.
Source: Genentech press release dated September 3, 2015
