Alnylam Pharmaceuticals and Sanofi Genzyme announced the initiation of the ATLAS Phase 3 clinical program for fitusiran. The global, multicenter program is designed to evaluate the safety and efficacy of fitusiran in three separate trials, including patients with hemophilia A and B with or without inhibitors and patients receiving prophylactic therapy. Fitusiran is an investigational RNAi therapeutic targeting antithrombin (AT) for the treatment of patients with hemophilia A and B, that is designed to lower levels of AT with the goal of promoting sufficient thrombin generation to restore hemostasis and prevent bleeding.
“ATLAS will include patients with hemophilia A and B with or without inhibitors, and patients previously receiving on-demand or prophylactic therapy with replacement factors or bypassing agents,” said Akin Akinc, Ph.D., Alnylam’s Vice President and General Manager, Fitusiran. “We expect top-line data from the ATLAS trials in mid-to-late 2019.”
The three separate trials are:
ATLAS-INH, a nine-month, open-label, randomized, active-controlled trial designed to enroll approximately 50 patients with hemophilia A or B with inhibitors receiving prior on-demand therapy. The study’s primary endpoint is the annualized bleeding rate (ABR), and key secondary endpoints include the annualized spontaneous bleeding rate, annualized joint bleeding rate, and quality of life as measured by the Haem-A-QOL score.
ATLAS-A/B, a nine-month, open-label, randomized, active-controlled trial designed to enroll approximately 100 patients with hemophilia A or B without inhibitors receiving prior on-demand therapy. The study’s primary endpoint is the ABR, and key secondary endpoints include the annualized spontaneous bleeding rate, annualized joint bleeding rate, and quality of life as measured by the Haem-A-QOL score.
ATLAS-PPX, an open-label, one-way crossover study designed to enroll approximately 100 patients with hemophilia A or B with or without inhibitors receiving prophylaxis therapy as prior standard of care. In this study, patients will receive standard of care prophylaxis for six months and then transition to fitusiran treatment for seven months. The ABR will be prospectively measured in both periods. The study’s primary endpoint is the ABR in the fitusiran period and in the factor/bypassing agent prophylaxis period. Key secondary endpoints include the annualized spontaneous bleeding rate, annualized joint bleeding rate, and quality of life as measured by the Haem-A-QOL score.
Hemophilia is a hereditary bleeding disorder characterized by an underlying defect in the ability to generate adequate levels of thrombin needed for effective clotting, thereby resulting in recurrent bleeds into joints, muscles, and major internal organs. There are approximately 200,000 persons diagnosed worldwide with hemophilia A and hemophilia B.
Standard treatment for people with hemophilia currently involves replacement of the deficient clotting factor either as prophylaxis or “on-demand” therapy which can lead to a temporary restoration of thrombin generation capacity. However, as many as one third of people with severe hemophilia A will develop a neutralizing antibody to their replacement factor – a very serious complication; individuals with these ‘inhibitors’ become refractory to standard replacement factor therapy.