Analysis of thrombosis before and during eculizumab therapy. Comparison of the number and frequency of thromboses in patients in all of the eculizumab studies. (A) The analysis has been restricted to compare the same time period for each patient before they started eculizumab to the time they have spent on therapy. The aim is to remove a bias introduced due to the prolonged time for many patients between diagnosis and commencing therapy. (B) Demonstrates that thromboses are often seen even when patients are anticoagulated with warfarin or heparin and that these are reduced by eculizumab.