RecruitingPhase 2Drug trialDefibrotide Dose-escalation for SOS Post-HSCTThis research study is being done to determine the safety and tolerability of increasing doses of defibrotide within a single patient with sinusoidal obstructive syndrome (SOS)/veno-occlusive disease (VOD) after hematopoietic cell transplantation (HCT) associated with either kidney and/or lung impairment that has not obtained a complete response (CR) or progressed in severity with standard doses of defibrotide.