Study Comparing Efficacy and Safety of Defibrotide vs Best Supportive Care in the Prevention of Hepatic Veno-Occlusive Disease in Adult and Pediatric Patients

Study Overview
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Brief Summary
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This study is to compare the efficacy and safety of defibrotide prophylaxis in addition to best supportive care versus best supportive care alone in the prevention of hepatic veno- occlusive disease (VOD) in adult and pediatric patients undergoing hematopoietic stem cell transplant who are at high risk or very high risk of developing VOD.

Official Title
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A Phase 3, Randomized, Adaptive Study Comparing the Efficacy and Safety of Defibrotide vs Best Supportive Care in the Prevention of Hepatic Veno-Occlusive Disease in Adult and Pediatric Patients Undergoing Hematopoietic Stem Cell Transplant

Conditions
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Veno-occlusive Disease

Intervention / Treatment
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* Drug: Defibrotide
* Other: Best Supportive Care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient must be above the age of 1 month as of the start date of study treatment. Patient must be scheduled to undergo allogeneic hematopoietic stem cell transplant (HSCT) (adults or pediatric patients) or autologous HSCT (pediatric patients only) and be at high risk or very high risk of developing veno-occlusive disease (VOD). Female patients (and female partners of male patients) of childbearing potential who are sexually active must agree to use a highly effective method of contraception with their partners during exposure to defibrotide and for 1 week after the last dose of defibrotide. Adult patients must be able to understand and sign a written informed consent. For minor patients, the parent/legal guardian or representative must be able to understand and sign a written informed consent. Assent, when appropriate, will be obtained according to institutional guidelines. Exclusion Criteria: Patient has hemodynamic instability within 24 hours before the start of study treatment. Patient has acute bleeding that is clinically significant within 24 hours before the start of study treatment. Patient used any medication that increases the risk of bleeding within 24 hours before the start of study treatment. Patient is using or plans to use an investigational agent for the prevention or treatment of VOD. Patient, in the opinion of the investigator, may not be able to comply with the safety monitoring requirements of the study. Patient or parent/legal guardian or representative has a psychiatric illness that would prevent the patient or parent/legal guardian or representative from giving informed consent and/or assent. Patient has a serious active disease or co-morbid medical condition, as judged by the investigator, which would interfere with the conduct of this study. Patient is pregnant or lactating and does not agree to stop breastfeeding. Patient has a known history of hypersensitivity to defibrotide or any of the excipients. Patient or parent/legal guardian or representative lacks the full mental capacity to understand and sign a written informed consent. Patient is receiving or plans to receive other investigational therapy during study.

Ages Eligible for Study
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Minimum Age: 1 Month

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Defibrotide<br>Defibrotide is administered intravenously at a dose of 25 mg/kg/day in addition to best supportive care on the day before the first day of the conditioning regimen and will continue (for those patients without a VOD diagnosis) for a recommended minimum of 21 days and end no later than Day +30 post HSCT | Drug: Defibrotide<br> <br> |
| Other: Best Supportive Care<br>Best supportive care alone (without the addition of defibrotide) according to institutional guidelines and patient need, is administered on the first day of conditioning and will continue until Day +30 post HSCT or hospital discharge, whichever is sooner, or diagnosis of VOD, if applicable | Other: Best Supportive Care<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Veno-occlusive Disease (VOD)-Free Survival by Day +30 Post-Hematopoietic Stem Cell Transplant (HSCT) Per the Independent Endpoint Adjudication Committee (EPAC) | VOD-free survival is a composite of survival status and VOD occurrence as determined by modified Seattle criteria adjudicated by a blinded independent EPAC. An event is defined as a VOD diagnosis (as assessed by the EPAC) or death, whichever, is earlier, up to and including Day +30 post-HSCT. The values reported below are participants who did not experience VOD or death by Day +30 post-HSCT. | Day +30 Post-HSCT | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Veno-Occlusive Disease (VOD)-Free Survival by Day +100 Post-Hematopoietic Stem Cell Transplant (HSCT) Per the Independent Endpoint Adjudication Committee (EPAC) | VOD-free survival is a composite of survival status and VOD occurrence as determined by modified Seattle criteria adjudicated by a blinded independent EPAC. An event is defined as a VOD diagnosis (as assessed by the EPAC) or death, whichever, is earlier, up to and including Day +100 post-HSCT. The values reported below are participants who did not experience VOD or death by Day +100 post-HSCT. | Day +100 Post-HSCT | 
| Percentage of Participants With Veno-Occlusive Disease (VOD) by Day +30 Post-Hematopoietic Stem Cell Transplant (HSCT) | The number of participants who were diagnosed with VOD based on the Modified Seattle Criteria as per blinded EPAC assessment. The percentage was calculated out of the total number of participants in each arm of the study. The values reported below are the numbers and percentages of participants who experienced VOD by Day +30 post-HSCT. | Day +30 Post-HSCT | 
| Veno-Occlusive Disease (VOD)-Free Survival Rate by Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | VOD-free survival is a composite of survival status and VOD occurrence as determined by modified Seattle criteria. An event is defined as a VOD diagnosis or death, whichever, is earlier, up to and including Day +180 post-HSCT. The diagnosis of VOD through Day +100 post-HSCT was based on Endpoint Adjudication Committee (EPAC), and the diagnosis of VOD after Day +100 post-HSCT was based on investigator assessments. The values reported below are participants who did not experience VOD or death by Day +180 post-HSCT. | Day +180 Post-HSCT | 
| Non-Relapse Mortality (NRM) for Defibrotide (DP) and Best Supportive Care (BSC) by Days +100 and +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | NRM is defined as death that occurs after HSCT in participants who were noted as having malignant primary disease on the disease history electronic case report form (eCRF) and do not have primary disease relapse post-HSCT. | Days +100 and +180 Post-HSCT | 
| Percentage of Participants With Veno-Occlusive Disease (VOD)-Associated Multi-Organ Dysfunction (MOD) by Days +30 and Days +100 Post-Hematopoietic Stem Cell Transplant (HSCT) in Patients Who Developed VOD | VOD-associated MOD is defined for participants as occurring if the investigator answers Yes to the question Has the participant been diagnosed with VOD associated MOD? in the electronic case report form (eCRF). The values below are the number of participants who received the answer, Yes. | Days +30 and +100 Post-HSCT | 
| Percentage of Participants Who Had Resolution of Veno-Occlusive Disease (VOD) by Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | The proportion of participants who had resolution of VOD by Day +180 post-HSCT is reported as a percentage. | Day +180 Post-HSCT | 
| Time to Resolution of Veno-Occlusive Disease (VOD) by Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | Time to Resolution of VOD is calculated as follows: Time to Resolution of VOD= [Date of VOD resolution] - [Date of VOD diagnosis by investigator]. | Day +180 Post-HSCT | 
| Percentage of Participants With Veno-Occlusive Disease (VOD) After Day +30 Post-Hematopoietic Stem Cell Transplant (HSCT) up to Days +100 and +180 Post-HSCT | The values shown are the number and percentage of participants with VOD after day +30 post-HSCT and on or before Days +100 and +180 post-HSCT. The diagnosis of VOD through Day +100 post-HSCT was made by Endpoint Adjudication Committee (EPAC), and the diagnosis of VOD after Day +100 post-HSCT was based on investigator assessments. | Days +100 and +180 Post-HSCT | 
| Change in 5-Level EuroQol-5D (EQ-5D-5L) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Adult Participants Age ≥ 16 Years: Mobility | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-5L, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 Post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in 5-Level EuroQol-5D (EQ-5D-5L) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Adult Participants Age ≥ 16 Years: Self-Care | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-5L, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 Post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in 5-Level EuroQol-5D (EQ-5D-5L) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Adult Participants Age ≥ 16 Years: Activity | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-5L, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 Post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in 5-Level EuroQol-5D (EQ-5D-5L) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Adult Participants Age ≥ 16 Years: Pain | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-5L, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 Post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in 5-Level EuroQol-5D (EQ-5D-5L) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Adult Participants Age ≥ 16 Years: Anxiety | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-5L, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 Post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 4 and ≤ 7 Years: Mobility | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 4 and ≤ 7 Years: Self-Care | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 4 and ≤ 7 Years: Activity | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 4 and ≤ 7 Years: Pain | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 4 and ≤ 7 Years: Anxiety | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 8 and ≤ 15 Years: Mobility | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 8 and ≤ 15 Years: Self-Care | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 8 and ≤ 15 Years: Activity | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 8 and ≤ 15 Years: Pain | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Change in EuroQol-5D for Youth (EQ-5D-Y) Dimensions From Baseline to Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) for Pediatric Participants Age ≥ 8 and ≤ 15 Years: Anxiety | For each of the five dimensions of mobility, self-care, activity, pain, and anxiety based on the descriptive system of the EQ-5D-Y, self-report version, the numbers and percentages of participants for all categories (the three levels of reported problems and question not completed) at Day +180 post-HSCT was assessed. Each dimension was categorized as follows: Condition improved, if the reported level of problem is lower at the assessment than baseline; condition unchanged, if the reported level of problem remains the same; condition deteriorated, if the reported level of problem is higher at that assessment than at baseline; and unknown, if the reported level of problem is missing either at baseline or at that assessment. | Day +180 Post-HSCT | 
| Maximum Plasma Concentration (Cmax) of Defibrotide Prophylaxis During the Prophylaxis Phase | Cmax is the maximum defibrotide plasma concentration, obtained directly from the observed data. Cmax is a summary statistic and it is not reported on an hourly basis. If veno-occlusive disease (VOD) occurs, the prophylaxis phase starts on the baseline date and ends on the day before the start date of rescue defibrotide. If VOD does not occur, the prophylaxis phase starts on the baseline date and ends on the date of study completion/early termination. | Day +1 and +7 Post-HSCT | 
| Area Under the Defibrotide Concentration-Time Curve (AUClast) of Defibrotide Prophylaxis During the Prophylaxis Phase | AUClast is the area under the defibrotide concentration-time curve from 0 (pre-dose) to time of last quantifiable defibrotide concentration at time t. AUClast is a summary statistic and it is not reported on an hourly basis. If veno-occlusive disease (VOD) occurs, the prophylaxis phase starts on the baseline date and ends on the day before the start date of rescue defibrotide. If VOD does not occur, the prophylaxis phase starts on the baseline date and ends on the date of study completion/early termination. | Day +1 and +7 Post-HSCT | 
| Mean Clearance of Defibrotide Prophylaxis During the Prophylaxis Phase | Mean systemic clearance after intravenous dosing. Mean clearance is a summary statistic and it is not reported on an hourly basis. If veno-occlusive disease (VOD) occurs, the prophylaxis phase starts on the baseline date and ends on the day before the start date of rescue defibrotide. If VOD does not occur, the prophylaxis phase starts on the baseline date and ends on the date of study completion/early termination. | Day +1 and +7 Post-HSCT | 
| Volume of Distribution of Defibrotide Prophylaxis During the Prophylaxis Phase | Mean volume of distribution following intravenous dosing. Mean volume of distribution is a summary statistic and it is not reported on an hourly basis.If veno-occlusive disease (VOD) occurs, the prophylaxis phase starts on the baseline date and ends on the day before the start date of rescue defibrotide. If VOD does not occur, the prophylaxis phase starts on the baseline date and ends on the date of study completion/early termination. | Day +1 and +7 Post-HSCT | 
| Maximum Plasma Concentration (Cmax) of Defibrotide Prophylaxis During the Rescue Phase | Cmax is the maximum defibrotide plasma concentration, obtained directly from the observed data. Cmax is a summary statistic and it is not reported on an hourly basis. For the subset of participants who developed veno-occlusive disease (VOD) and received rescue defibrotide, the rescue treatment phase begins on the start date of rescue defibrotide and ends on the date of study completion/early termination. | Day +14 Post-VOD Treatment | 
| Area Under the Defibrotide Concentration-Time Curve (AUClast) of Defibrotide Prophylaxis During the Rescue Phase | AUClast is the area under the defibrotide concentration-time curve from 0 (pre-dose) to time of last quantifiable defibrotide concentration at time t. AUClast is a summary statistic and it is not reported on an hourly basis. For the subset of participants who developed veno-occlusive disease (VOD) and received rescue defibrotide, the rescue treatment phase begins on the start date of rescue defibrotide and ends on the date of study completion/early termination. | Day +14 Post-VOD Treatment | 
| Volume of Distribution of Defibrotide Prophylaxis During the Rescue Phase | Mean volume of distribution following intravenous dosing. Mean volume of distribution is a summary statistic and it is not reported on an hourly basis. For the subset of participants who developed veno-occlusive disease (VOD) and received rescue defibrotide, the rescue treatment phase begins on the start date of rescue defibrotide and ends on the date of study completion/early termination. | Day +14 Post-VOD Treatment | 
| Percentage of Participants With Grades 2, 3, and 4 Acute Graft-Versus-Host-Disease (GvHD) by Days +30, +100, and +180 Post-Hematopoietic Stem Cell Transplant (HSCT) in the Prophylaxis Phase | The number and percentage of participants with Grade 2-4 acute GvHD in the prophylaxis phase. Grade 2 is defined as Skin stage = 3, or Liver stage = 1, or GI stage = 1. Grade 3 is defined as Skin stage = 3, or Liver stage = 2-3, or GI stage = 2-4. Grade 4 is defined as a Skin stage = 4, or Liver stage = 4, or GI stage = 2-4. | Days +30, +100, and +180 Post-HSCT | 
| Percentage of Participants With Grades 2, 3, and 4 Acute Graft-Versus-Host-Disease (GvHD) by Days +30, +100, and +180 Post-Hematopoietic Stem Cell Transplant (HSCT) in the Rescue Phase | The number and percentage of participants with Grade 2-4 acute GvHD in the rescue phase. Grade 2 is defined as Skin stage = 3, or Liver stage = 1, or GI stage = 1. Grade 3 is defined as Skin stage = 3, or Liver stage = 2-3, or GI stage = 2-4. Grade 4 is defined as a Skin stage = 4, or Liver stage = 4, or GI stage = 2-4. | Days +30, +100, and +180 Post-HSCT | 
| Percentage of Participants With Chronic Graft-Versus-Host-Disease (GvHD) by Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | The values shown are the number and percentages of participants who developed chronic GvHD by Day +180 post-HSCT in the prophylaxis phase and rescue phase. | Day +180 Post-HSCT | 
| Number of Participants With Graft Failure During the Prophylaxis Phase and Rescue Phase | Graft failure is defined as participants that after hematopoietic stem cell transplant (HSCT) never reached an absolute neutrophil count >0.5 x 10^9/L that is maintained for three consecutive days or a platelet count >20 x 10^9/L without a platelet transfusion in the preceding seven days. If veno-occlusive disease (VOD) occurs, the prophylaxis phase starts on the baseline date and ends on the day before the start date of rescue defibrotide. If VOD does not occur, the prophylaxis phase starts on the baseline date and ends on the date of study completion/early termination. For the subset of participants who developed VOD and received rescue defibrotide, the rescue treatment phase begins on the start date of rescue defibrotide and ends on the date of study completion/early termination. | Day +180 Post-HSCT | 
| Number of Participants With Neutrophil Engraftment by Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | The date of neutrophil engraftment was recorded on the electronic case report form (eCRF) and is defined as the first date after HSCT of an absolute neutrophil count >0.5 x 10^9/L that is maintained for three consecutive days. The definition of absolute neutrophil count includes both segmented neutrophils and bands, immature neutrophils. The number of participants with neutrophil engraftment was assessed. | Day +180 Post-HSCT | 
| Number of Participants With Platelet Engraftment by Day +180 Post-Hematopoietic Stem Cell Transplant (HSCT) | The date of platelet engraftment was recorded on the electronic case report form (eCRF) and is defined as the first date after HSCT of a platelet count >20 x 10^9/L without a platelet transfusion in the preceding seven days. The number of participants with platelet engraftment was assessed. | Day +180 Post-HSCT | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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stem cell transplant, hematopoietic stem cell transplant (HSCT), veno-occlusive disease (VOD), sinusoidal obstruction syndrome (SOS)