Kaplan–Meier curves of progression free survival according to (A) cyclophosphamide clearance following dose 1, (B) cyclophosphamide clearance following dose 5, (C) DCCP AUC0–6h following dose 1 and (D) DCCP AUC0–6h following dose 5. Patients with values above and below the median are displayed as dashed lines and solid lines, respectively. DCCP, dechloroethylcyclophosphamide; AUC, area under the plasma concentration-time curve.