A Phase 1/2 interventional study of Imatinib Mesylate in Sickle Cell Disease, sponsored by Indiana University. Terminated at 2 sites in United States. Open to participants aged 18 Years to 25 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-29.
Sponsored by Indiana University · Phase 1/2, Interventional, and Basic science
In this protocol, the investigators propose to evaluate the biochemical effects of imatinib on sickle red blood cells (RBCs). Patients will be administered imatinib mesylate orally following the guidelines previously established for use of imatinib in other disorders. The biochemical effects of imatinib on sickle RBCs will be examined, including changes in their levels of band 3 tyrosine phosphorylation and the abundances of RBC-derived microparticles in their blood. In addition, the patients will be monitored for symptoms of sickle cell disease (SCD). The investigators expect band 3 tyrosine phosphorylation to decrease dramatically in patients treated with imatinib. The investigators also anticipate a reduction in the numbers of RBC-derived microparticles in circulation (quantitated by assaying the number of glycophorin A positive microparticles in peripheral blood samples by flow cytometry. Most importantly, the investigators expect to see a reduction in the frequency of vaso-occlusive crises, and possibly acute chest syndrome and utilization of opioids. The study duration is planned as 6 months in order to provide adequate time for potential change in the primary endpoints (e.g. percent irreversibly sickled cells).
1,103 studies on the registry are indexed under Anemia, Sickle Cell; 235 are open to participants now.
This study's enrollment of 7 is below the median of 40 across 750 interventional studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell studies →Indiana University is the lead sponsor of 958 studies on the registry; 200 are open to participants now.
Of its 142 completed or terminated interventional studies of FDA-regulated products, 112 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Organ function requirements:
a. Adequate bone marrow function defined as i. Peripheral absolute neutrophil count (ANC) ≥1000/µL ii. Platelet count ≥100,000/ µL (transfusion independent) b. Adequate renal function defined as i. Creatinine clearance or radioisotope glomerular filtration rate (GFR) ≥70 mL/min/1.73 m2 or ii. A serum creatinine based on age/gender c. Adequate Liver Function Defined As: i. Total bilirubin (sum of conjugated + unconjugated) ≤1.5 times upper limit of normal (ULN) for age, and ii. serum glutamate pyruvate transaminase (SGPT or ALT) \<2.5 upper limit of normal. For the purpose of this study, the ULN for SGPT is 45 U/L iii. Serum albumin ≥2 g/dL d. Adequate cardiac function defined as: i. Shortening fraction or ejection fraction greater than the institutional norm, and ii. Corrected QT interval ≤450 msec
Exclusion Criteria:
Chronic transfusion protocol.
a. Patients currently on a chronic transfusion protocol are not eligible
Hydroxyurea Intolerance
a. Patients who are ineligible for hydroxyurea due to persistent marrow suppression (e.g. thrombocytopenia, neutropenia)
Pregnancy or Breast-Feeding
a. Pregnancy tests must be obtained in girls who are post-menarchal. Males or females of reproductive potential may not participate unless they have agreed to use an effective contraceptive method.
Concomitant Medications
Drug: Imatinib Mesylate
The starting dose for subjects will be 340 mg/m2/day with a maximum dose of 600 mg daily. Patients will receive Imatinib orally once daily for 6 months.
Changes in Biochemical Effects - Band 3 Phosphorylation
Percent change in Band 3 Phosphorylation tested in red blood cells. Band 3 is a protein found on the membrane of red blood cells.
Time frame: Change from baseline Band 3 Phosphorylation at 7 months
Change in Amount of Microparticles Released From Red Blood Cells
Change in Microparticles released from red blood cells. Microparticles are small vesicles released from red blood cells during aging, stress, or other types of damage that contain various proteins from inside the red blood cell, as well as from its membrane.
Time frame: change from baseline microparticle release at 7 months
Change in Percent Irreversibly Sickled Cells
Functional RBCs is analyzed by two components, one of which is percent irreversibly sickled cells. The percent of irreversibly sickled cells is measure by ektacytometry. Red blood cells that sickle and then cannot revert back to its normal shape are considered irreversibly sickled, increasing the likelihood of adhesion to vessel walls, as well as breakdown or hemolysis. Understanding the point of susceptibility of sickling helps us at what partial pressure of oxygen the red blood cell will sickle. The higher the partial pressure, the more resistant the red blood cell is to sickling/breakdown.
Time frame: Change from baseline of percent irreversibly sickled cells at 7 months
Change in Point of Susceptibility to Sickling by OxygenScan
Functional RBCs is analyzed by two components, one of which is Change in Point of Susceptibility to Sickling. This is measured by OxygenScan. The point of susceptibility of sickling shows at what partial pressure of oxygen (mmHg) the red blood cell will sickle. The higher the partial pressure, the more resistant the red blood cell is to sickling/breakdown.
Time frame: Change from baseline of point of susceptibility of sickling at 7 months
Number of Instances of Vaso-occlusive Crisis (VOC)
Defined as an acute episode of pain lasting greater than 24 hours, with no medically determined cause other than a vaso-occlusive event that resulted in treatment with oral or parenteral opiate agents and/or parenteral nonsteroidal anti-inflammatory agents. Degree of pain was measured by the standard numerical pain scale (0 being little to no pain, 10 being the worst pain).
Time frame: Assessed monthly from treatment start up to 7 months
Number of Instances of Acute Chest Syndrome (ACS)
Defined as respiratory distress (hypoxia, shortness of breath, chest pain, tachypnea) with evidence of an infiltrate on chest x-ray Measured with clinical evaluation.
Time frame: Assessed monthly from treatment start up to 7 months
Opioid Use
Defined as oral opioid use. Oral use will be documented in pain diary by patient/guardian and reviewed at each visit.
Time frame: Assessed monthly from treatment start up to 7 months
Number of Hospitalizations
Defined as an emergency room or clinic visit resulting in an inpatient admission or observation for a sickle cell-related event (e.g. vaso-occlusive pain, acute chest syndrome, etc).
Time frame: Assessed monthly from treatment start up to 7 months
Assessment of Toxicities of Imatinib in Patients With Sickle Cell Anemia
Assessment of toxicities based on clinical and laboratory evaluation
Time frame: Assessed monthly from treatment start up to 7 months
| Milestone | Imatinib Intervention | Control Group for Blood Draws |
|---|---|---|
| Started | 3 | 4 |
| Completed | 1 | 4 |
| Not completed | 2 | 0 |
Percent change in Band 3 Phosphorylation tested in red blood cells. Band 3 is a protein found on the membrane of red blood cells.
No measurements were reported for this outcome.
Change in Microparticles released from red blood cells. Microparticles are small vesicles released from red blood cells during aging, stress, or other types of damage that contain various proteins from inside the red blood cell, as well as from its membrane.
| Microparticles per microliter of plasma | Imatinib Intervention |
|---|---|
| Change in Amount of Microparticles Released From Red Blood Cells | -48 |
Functional RBCs is analyzed by two components, one of which is percent irreversibly sickled cells. The percent of irreversibly sickled cells is measure by ektacytometry. Red blood cells that sickle and then cannot revert back to its normal shape are considered irreversibly sickled, increasing the likelihood of adhesion to vessel walls, as well as breakdown or hemolysis. Understanding the point of susceptibility of sickling helps us at what partial pressure of oxygen the red blood cell will sickle. The higher the partial pressure, the more resistant the red blood cell is to sickling/breakdown.
| percent | Imatinib Intervention |
|---|---|
| Change in Percent Irreversibly Sickled Cells | 0.32 |
Functional RBCs is analyzed by two components, one of which is Change in Point of Susceptibility to Sickling. This is measured by OxygenScan. The point of susceptibility of sickling shows at what partial pressure of oxygen (mmHg) the red blood cell will sickle. The higher the partial pressure, the more resistant the red blood cell is to sickling/breakdown.
| mmHg | Imatinib Intervention |
|---|---|
| Change in Point of Susceptibility to Sickling by OxygenScan | -6.39 |
Defined as an acute episode of pain lasting greater than 24 hours, with no medically determined cause other than a vaso-occlusive event that resulted in treatment with oral or parenteral opiate agents and/or parenteral nonsteroidal anti-inflammatory agents. Degree of pain was measured by the standard numerical pain scale (0 being little to no pain, 10 being the worst pain).
| events | Imatinib Intervention |
|---|---|
| Number of Instances of Vaso-occlusive Crisis (VOC) | 4 |
Defined as respiratory distress (hypoxia, shortness of breath, chest pain, tachypnea) with evidence of an infiltrate on chest x-ray Measured with clinical evaluation.
| event | Imatinib Intervention |
|---|---|
| Number of Instances of Acute Chest Syndrome (ACS) | 1 |
Defined as oral opioid use. Oral use will be documented in pain diary by patient/guardian and reviewed at each visit.
No measurements were reported for this outcome.
Defined as an emergency room or clinic visit resulting in an inpatient admission or observation for a sickle cell-related event (e.g. vaso-occlusive pain, acute chest syndrome, etc).
| hospitalizations | Imatinib Intervention |
|---|---|
| Number of Hospitalizations | 5 |
Assessment of toxicities based on clinical and laboratory evaluation
| events | Imatinib Intervention |
|---|---|
| Assessment of Toxicities of Imatinib in Patients With Sickle Cell Anemia | 21 |
Collected over 3 years. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Imatinib Intervention | 0/3 (0%) | 2/3 (66.7%) | 3/3 (100%) |
| Event | Imatinib Intervention |
|---|---|
| Grade 3 Non Cardiac Chest PainMusculoskeletal and connective tissue disorders | 1/3 |
| Grade 3 Lung InfectionRespiratory, thoracic and mediastinal disorders | 1/3 |
| Grade 3 Pain in ExtremityMusculoskeletal and connective tissue disorders | 1/3 |
| Event | Imatinib Intervention |
|---|---|
| AnemiaBlood and lymphatic system disorders | 2/3 |
| Alanine Aminotransferase IncreasedHepatobiliary disorders | 2/3 |
| Aspartate Aminotransferase IncreasedHepatobiliary disorders | 2/3 |
| VomitingGastrointestinal disorders | 2/3 |
| HeadacheNervous system disorders | 2/3 |
| HyperbilirubinemiaHepatobiliary disorders | 2/3 |
| NauseaGastrointestinal disorders | 2/3 |
| HypoglycemiaMetabolism and nutrition disorders | 1/3 |
| HypokalemiaMetabolism and nutrition disorders | 1/3 |
| Nasal CongestionEar and labyrinth disorders | 1/3 |
Baseline data were not collected for the Control Group.
| Age, Categorical(Participants) | Imatinib Intervention |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 3 |
| >=65 years | 0 |
| Sex: Female, Male(Participants) | Imatinib Intervention |
|---|---|
| Female | 1 |
| Male | 2 |
| Race (NIH/OMB)(Participants) | Imatinib Intervention |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 3 |
| White | 0 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Sickle Cell Genotype: HbSS(participants) | Imatinib Intervention |
|---|---|
| Number | 3 |
| Disease Status(Participants) | Imatinib Intervention |
|---|---|
| Count of participants | 3 |
| Performance Level(Participants) | Imatinib Intervention |
|---|---|
| Count of participants | 3 |
| Organ Function(Participants) | Imatinib Intervention |
|---|---|
| Count of participants | 3 |
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