Trial Outcomes & Findings for Using Fostamatinib to Treat Post-Hematopoietic Stem Cell Transplant Immune-mediated Cytopenias (NCT NCT05502783)

Last Updated: 2025-12-05

Results Overview

Stable hematologic recovery (improvement documented in 2 consecutive available readings) without recent blood product transfusion support (in the past 48-72 hours). Hematologic recovery is defined as: * Hemoglobin =10 g/dL (or at least =2 g/dL above baseline) in participants enrolled with posttransplant anemia. In participants with symptomatic anemia, a hemoglobin increase of at least =2 g/dL above baseline is required OR * Platelets = 50 x 10\^9/L (or at least =20 x 10\^9/L above baseline) in participants enrolled with posttransplant thrombocytopenia OR * Both of the above criteria in participants with posttransplant Evans syndrome

Recruitment status

TERMINATED

Study phase

PHASE2

Target enrollment

1 participants

Primary outcome timeframe

Baseline, Week 2, Week 4, Week 6, Week 8, Week 10

Results posted on

2025-12-05

Participant Flow

Participant milestones

Participant milestones
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Overall Study STARTED	1
Overall Study COMPLETED	0
Overall Study NOT COMPLETED	1

Reasons for withdrawal

Reasons for withdrawal
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Overall Study Lack of Efficacy	1

Baseline Characteristics

Using Fostamatinib to Treat Post-Hematopoietic Stem Cell Transplant Immune-mediated Cytopenias

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Age, Categorical <=18 years	0 Participants n=37 Participants
Age, Categorical Between 18 and 65 years	1 Participants n=37 Participants
Age, Categorical >=65 years	0 Participants n=37 Participants
Sex: Female, Male Female	1 Participants n=37 Participants
Sex: Female, Male Male	0 Participants n=37 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=37 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	0 Participants n=37 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=37 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=37 Participants
Race (NIH/OMB) Asian	0 Participants n=37 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=37 Participants
Race (NIH/OMB) Black or African American	0 Participants n=37 Participants
Race (NIH/OMB) White	0 Participants n=37 Participants
Race (NIH/OMB) More than one race	0 Participants n=37 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=37 Participants
Region of Enrollment United States	1 participants n=37 Participants

PRIMARY outcome

Timeframe: Baseline, Week 2, Week 4, Week 6, Week 8, Week 10

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Number of Participants Who Were Able to Maintain Hematologic Recovery	0 Participants

SECONDARY outcome

Timeframe: Up to 10 weeks

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Objective hematologic recovery defined as: * Hemoglobin =9 g/dL (or at least =1 g/dL above baseline) in participants enrolled with anemia or at least =1 g/dL above baseline in participants with symptomatic anemia OR * Platelets = 30 x 10\^9/L (or at least =20 x 10\^9/L above baseline) in participants enrolled with thrombocytopenia OR * Both of the above criteria in participants with Evans syndrome

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Number of Participants Who Achieve Objective Hematologic Recovery	0 Participants

SECONDARY outcome

Timeframe: Baseline, Week 2, Week 4, Week 6, Week 8, Week 10

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Median change in requirement of weekly transfused blood component or growth factor injections requirement (total units of Packed Red Blood Cells or Platelets). Data from the specified time points were aggregated and summarized to calculate the median value.

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Median Change in Requirement of Transfused Blood Component Packed Red Blood Cells	1.0 Units Interval 1.0 to 1.0
Median Change in Requirement of Transfused Blood Component Platelet	12.0 Units Interval 12.0 to 12.0

SECONDARY outcome

Timeframe: Baseline, Week 2, Week 4, Week 6, Week 8, Week 10

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Median change in requirement of weekly growth factor injections. Data from the specified time points were aggregated and summarized to calculate the median value.

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Median Change in Requirement of Growth Factor Injections	1.0 Number of Growth Factor Injections Interval 0.0 to 1.0

SECONDARY outcome

Timeframe: Baseline, Week 2, Week 4, Week , Week 8, Week 10

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Median Change in requirement corticosteroid dose (Prednisone) , measured by median daily weight-based prednisone-equivalent corticosteroid dose from week 1 to week 12. Data from the specified time points were aggregated and summarized to calculate the median value.

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Median Change in Requirement Corticosteroid Dose (Prednisone)	5 mg Interval 5.0 to 5.0

SECONDARY outcome

Timeframe: Baseline, Week 2, Week 4, Week 6, Week 8, Week 10, Week 12

Population: Participant was not on immunosuppressants during this study, therefore data could not be collected

Median Change in other immunosuppressant dose, measured by median daily dose of the immunosuppressant. Data from the specified time points were aggregated and summarized to calculate the median value.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to 10 weeks

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Number of Participants Who Developed Mild, Moderate or Severe Chronic Graft vs Host Disease (GVHD) according to 2014 NIH Consensus Criteria Diagnosis is based on organ involvement and severity scoring, with criteria for skin, mouth, eyes, liver, lungs, gastrointestinal tract, joints/fascia, and genital tract, though criteria have been revised to exclude findings clearly attributable to non-GVHD causes. Severity is categorized as mild, moderate, or severe based on the number of organs involved and the specific severity score for each organ (0-3), with lungs requiring specific pulmonary function tests for scoring. Mild: Involves 1 or 2 organs with a score of no more than 1 for each (lung score must be 0). Moderate: Involves 3 or more organs with a score of no more than 1 for each; OR at least 1 organ (not the lung) has a score of 2; OR the lung score is 1. Severe: Involves at least 1 organ with a score of 3; OR the lung score is 2 or 3.

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Number of Participants Who Developed Mild, Moderate or Severe Chronic Graft vs Host Disease (GVHD) According to 2014 NIH Consensus Criteria Mild	0 Participants
Number of Participants Who Developed Mild, Moderate or Severe Chronic Graft vs Host Disease (GVHD) According to 2014 NIH Consensus Criteria Moderate	0 Participants
Number of Participants Who Developed Mild, Moderate or Severe Chronic Graft vs Host Disease (GVHD) According to 2014 NIH Consensus Criteria Severe	0 Participants

SECONDARY outcome

Timeframe: Up to Week 10

Population: One participant withdrew at week 10 from the study due to lack of efficacy, therefore no data was collected up to week 12.

Number of patients who achieved 50% steroid dose reduction by week 12 compared to week 1

Outcome measures

Outcome measures
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 Participants Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Number of Patients Who Achieved 50% Steroid Dose Reduction	0 Participants

Adverse Events

Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Fostamatinib in Participants Post-Hematopoietic Stem Cell Transplant With Immune-Mediated Cytopenias n=1 participants at risk Participants Post-Hematopoietic Stem Cell Transplant with Immune-Mediated Cytopenias will receive fostamatinib 100 mg BID by mouth for 4 weeks. On the 4-week evaluation, a) if cytopenia improves (hemoglobin =10 g/dL, platelets = 50 x 109/L), patients will continue the same dose for a total of 12 weeks, b) if refractory cytopenias persist (hemoglobin \< 10 g/dL, platelets \< 50 x 109/L), the dose will be increased to 150 mg BID. Subjects with persistent (=2 readings, 2 weeks apart) loss of hematologic response after week 5 can increase their dose to 150 mg BID until at end of the study on week 12.
Investigations Alanine aminotransferase increased	100.0% 1/1 • Number of events 1 • up to 10 weeks
Investigations Aspartate aminotransferase increased	100.0% 1/1 • Number of events 4 • up to 10 weeks
Investigations Blood lactate dehydrogenase increased	100.0% 1/1 • Number of events 1 • up to 10 weeks
Cardiac disorders Tachycardia	100.0% 1/1 • Number of events 2 • up to 10 weeks
Respiratory, thoracic and mediastinal disorders Cough	100.0% 1/1 • Number of events 1 • up to 10 weeks
Gastrointestinal disorders Diarrhea	100.0% 1/1 • Number of events 1 • up to 10 weeks
General disorders Generalied edema	100.0% 1/1 • Number of events 1 • up to 10 weeks
Investigations Haptoglobin decreased	100.0% 1/1 • Number of events 1 • up to 10 weeks
Vascular disorders Hypertension	100.0% 1/1 • Number of events 1 • up to 10 weeks
Metabolism and nutrition disorders Hypoalbuminemia	100.0% 1/1 • Number of events 2 • up to 10 weeks
Metabolism and nutrition disorders Hypocalcemia	100.0% 1/1 • Number of events 2 • up to 10 weeks
Metabolism and nutrition disorders Hypokalemia	100.0% 1/1 • Number of events 7 • up to 10 weeks
Metabolism and nutrition disorders Hypomagnesemia	100.0% 1/1 • Number of events 4 • up to 10 weeks
Metabolism and nutrition disorders Hyponatremia	100.0% 1/1 • Number of events 3 • up to 10 weeks
Gastrointestinal disorders Nausea	100.0% 1/1 • Number of events 1 • up to 10 weeks
Investigations Neutrophil count decreased	100.0% 1/1 • Number of events 6 • up to 10 weeks
General disorders Pain	100.0% 1/1 • Number of events 1 • up to 10 weeks
Investigations White blood cell decreased	100.0% 1/1 • Number of events 4 • up to 10 weeks

Additional Information

Dr. Georg Aue

National Heart, Lung, and Blood Institute (NHLBI) at National Institutes of Health (NIH)

Phone: 301.547.9490

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place