DDAB development in study DMP 754-017.

Patients with a negative DDAB prescreen using an in vitro platelet antibody elution technique (EDTA plasma) were treated with roxifiban continuously for up to 180 days. Additional antibody tests after platelet elution were performed on days 7, 10, and 14 (panels A-D; ●). Drug treatment in all 4 subjects was discontinued based on a developing antibody concentration. All subjects participated in follow-up antibody testing. In addition, a citrate plasma sample obtained in parallel with the EDTA sample was retrospectively analyzed for the presence of DDABs (○). The platelet count is indicated by ▪. (A) Patient 21013 developed severe thrombocytopenia on day 11. Drug treatment was stopped on day 9 based on a rapidly increasing antibody concentration. The patient was hospitalized for monitoring. (B) Patient 49007 was excluded from the study on day 11. (C) Patient 61003 was excluded from the study on day 11. (D) Patient 7013 was excluded from the study on day 11.