Antithrombin Assay Supports Fitusiran Therapy

Here’s a link to our 1 April 2025 Sanofi announcement about the FDA approval of Fitusiran® therapy. Sanofi provides the Siemens Healthineers’ INNOVANCE Antithrombin® assay, a chromogenic substrate method, as a companion diagnostic tool to support Fitusiran dosing. A Sanofi-supported study compared eight antithrombin activity assay kits on seven coagulometers to indicate the reagent-instrument combinations that provide the best detection limits and precision. The antithrombin level that provides the best outcomes in hemophilia ranges from 15–35%. Thanks to Dr. Ali Sadeghi-Khomami for drawing our attention to this study. Chhabra ES, Sadeghi-Khomami A, Liu Met al. Global comparative antithrombin field study: impact of laboratory assay variability on the assessment of antithrombin activity measurement at Fitusiran clinical decision-making points. Haemophilia. 2025 doi: 10.1111/hae.70045. Epub ahead of print. PMID: 40254822.