Baxalta Incorporated, a global biopharmaceutical leader, reported positive results from a phase 1 open-label, dose escalation study assessing the safety and pharmacokinetic (PK) profile of BAX 930, an investigational recombinant ADAMTS13 for the treatment of patients with severe hereditary thrombotic thrombocytopenic purpura (hTTP). These findings on BAX 930 were presented during a poster session at the 62nd annual Scientific and Standardization Committee (SSC) meeting of the International Society on Thrombosis and Haemostatis (ISTH) in Montpellier, France.

“As a recombinant ADAMTS13, BAX 930 may provide an alternative treatment option for patients with hTTP and these phase 1 results showed potential advantages of BAX 930 compared to conventional plasma infusions,” said John Orloff, M.D., head of Research & Development and chief scientific officer, Baxalta. “The positive results from the phase 1 study demonstrated a favorable PK and safety profile for BAX 930 and provide the basis for proceeding to phase 3 as we advance this innovative therapy for patients.”

BAX 930 is designed to provide an alternative to the current replacement of ADAMTS13 using large volumes of fresh frozen plasma that contain variable amounts of ADAMTS13 and typically require two hours or more for the preparation and infusion. In contrast, BAX 930 can be quickly reconstituted, and may thus be suitable for treatment in the patient’s home.

The phase 1 data included results from fifteen patients with severe hTTP who completed the multicenter study. Each patient received a single dose of BAX 930 in one of three dosing cohorts. PK data demonstrated a consistent half-life across the BAX 930 doses and a linear dose response. No serious adverse events were reported. In the highest dosing cohort, three subjects reported three possibly related adverse events, nausea, flatulence and decreased VWF activity; all of these reported adverse events resolved quickly without medication. Immunogenicity tests performed at screening, pre-dose and upon study completion, were negative in all subjects.

hTTP is a rare, life-threatening blood clotting disease in which individuals are congenitally deficient in ADAMTS13, an enzyme that cleaves the von Willebrand factor (VWF) protein involved in blood clotting. Baxalta has been granted Orphan Drug Designation for BAX 930 by the U.S. Food and Drug Administration and by the European Medicines Agency.