Effect of GDXa after 1 min and 1 h of incubation at 37°C in a severe hemophilic plasma. A severe hemophilia A plasma was spiked with 50 nM GDXa and incubated at 37°C for 1 h. Aliquots were removed both immediately and after 1 h for testing in thrombin generation assays. By definition, all values were set at zero for hemophilic plasma because no thrombin was generated.