Sickle Cell DiseasePhase 1/2IMPACTNCT03997903

Imatinib for Pain in Sickle Cell Anemia

A Phase 1/2 study testing Imatinib Mesylate in people with Sickle Cell Disease, run by Indiana University at 2 sites in United States.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record

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Trial summary

Who is it for?: Ages 18 to 25 yearsHealthy volunteers can take part
Conditions the study is for: Sickle Cell Disease
What is being tested?: Imatinib Mesylate
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 7 participants
Where: 2 sitesUnited States
Study dates: 26 Feb 2020to 6 Aug 2024
Phase: Phase 1/2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 25 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

Age: patients must be ≥18 years of age and ≤25 years of age at the time of study entry.
Diagnosis: Patients must have documented diagnosis of sickle cell disease (Hemoglobin SS Disease or S-Beta 0 Thalassemia) by either high pressure liquid chromatography (HPLC) or Hemoglobin Electrophoresis
Disease status: Patients must have at least 2 documented episodes of vaso-occlusive pain in the prior year as defined by 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 opiates or with a parenteral nonsteroidal anti-inflammatory drug.
Performance Level: Karnofsky ≥80 for patients >10 years of age and Lansky ≥80 for patients ≤10 years of age. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.
Organ function requirements:
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
Informed Consent: All patients and/or their parents or legal guardians must sign a written informed consent. Assent, when appropriate, will be obtained according to institutional guidelines.

Who cannot join

Chronic transfusion protocol.
Patients currently on a chronic transfusion protocol are not eligible
Hydroxyurea Intolerance
Patients who are ineligible for hydroxyurea due to persistent marrow suppression (e.g. thrombocytopenia, neutropenia)
Pregnancy or Breast-Feeding
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.

Show all 22Show fewer

Concomitant Medications
Investigational Drugs: Patients who are currently receiving another investigational drug.
Anti-cancer agents: Patients who are currently receiving other anti-cancer agents.
The following CYP3A4 inducers are prohibited 14 days before the start of imatinib and during the study with imatinib: rifampin, rifabutin, carbamazepine, Phenobarbital, phenytoin, St. John's wort, efavirenz, and tipranavir.
The following CYP3A4 inhibitors are prohibited 7 days before the start of imatinib and during the study with imatinib: azole antifungals (itraconazole, ketoconazole); clarithromycin, erythromycin, diltiazem, verapamil, HIV protease inhibitors (indinavir, saquinavir, ritonavir, atazanavir, nelfainavir); delavirdine.
Patients who have an uncontrolled infection.
Prior use of Imatinib: Patients who have previously received imatinib are not eligible for study.
Patients who in the opinion of the investigator may not be able to comply with the safety monitoring requirements of the study.
Patient is < 5 years free of a malignancy. Existence of any other malignant disease is not allowed.
Patient with Grade III/IV cardiac problems as defined by the New York Heart Association Criteria. (i.e., congestive heart failure, myocardial infarction within 6 months of study).
Patients with a history of QT prolongation, need for concomitant use of anti-arrhythmics or other agents known to prolong QT interval, or electrolyte derangement that cannot be corrected to within normal limits prior to initiation of study drug.
Patients with a family history of sudden cardiac death.
Patient has a severe and/or uncontrolled medical disease other than sickle cell disease (i.e., uncontrolled diabetes, chronic renal disease, or active uncontrolled infection).
Patient has known chronic liver disease (i.e., chronic active hepatitis, and cirrhosis).
Patient has a known diagnosis of human immunodeficiency virus (HIV) infection.
Patient had a major surgery within 2 weeks prior to study entry.

Trial locations and contacts

2 sites in 1 country.

United States2 sites

Cincinnati Children's Hospital
Cincinnati, Ohio, 45229
Riley Hospital for Children at IU Health
Indianapolis, Indiana, 46202

Other trials in United States

About this study

Official title: IMatinib for PAin in Chronic Treatment of Sickle Cell Anemia (IMPACT SCA): A Pilot Study of Imatinib in Patients With Sickle Cell Anemia and Recurrent Vaso-occlusive Pain

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).

Conditions: Sickle Cell Disease
Being tested: Imatinib Mesylate
Medical subject headings: Anemia, Sickle Cell

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Imatinib MesylateDrug
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.

Study groups in NCT03997903
Study group	Role	What they receive
Imatinib Intervention	Experimental	Not described Receives: Drug: Imatinib Mesylate

What is being measured

The primary outcome is the main question the study is designed to answer.

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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Change from baseline of point of susceptibility of sickling at 7 months

Secondary outcomes (5)

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).
Measured: 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.
Measured: 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.
Measured: 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).
Measured: 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
Measured: Assessed monthly from treatment start up to 7 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

26 Feb 20206 Aug 2024

First posted25 Jun 2019
Study start26 Feb 2020
Primary completion6 Aug 2024
Study completion6 Aug 2024

Why it stopped: low accrual

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1/2
Primary purpose: Basic science
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Enrolment: 7 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03997903
Sponsor's protocol ID: IMPACT SCA
Acronym: IMPACT
Status last verified: Jan 2026
First submitted: 16 Jun 2019
Last updated: 29 Jan 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

RecruitingObservational study
Blood Sampling for Research Related to Sickle Cell Disease
Sickle Cell Trait, Sickle Cell Disease
Active, not recruitingPhase 2/3
A Study Evaluating the Efficacy and Safety of Mitapivat (AG-348) in Participants With Sickle Cell Disease (RISE UP)
Sickle Cell Disease
Enrolling by invitationObservational study
Blood Collection for Research Related to Certain Diseases Involving Blood Vessels
Sickle Cell Disease
RecruitingPhase 1/2
Repeat Peripheral Blood Stem Cell Transplantation for Patients With Sickle Cell Disease and Falling Donor Myeloid Chimerism Levels
Myeloid Chimerism
Not yet recruitingObservational study
MENA/Levant Epidemiological, Registry of Immunological & Clinical Traits (MERIT)
Antiphospholipid (aPL)-Positive, Rheumatic Arthritis

All Sickle Cell Disease trials

Study at a glance

From the registry record, last updated by the sponsor on 29 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: IMatinib for PAin in Chronic Treatment of Sickle Cell Anemia (IMPACT SCA): A Pilot Study of Imatinib in Patients With Sickle Cell Anemia and Recurrent Vaso-occlusive Pain
ClinicalTrials.gov ID: NCT03997903
Acronym / sponsor ID: IMPACT / IMPACT SCA
Conditions: Sickle Cell Disease
Phase: Phase 1/2
Study type: Interventional
Recruitment status: TerminatedReason stopped: low accrual
Enrolment: 7 participants (actual)
Lead sponsor: Indiana UniversityUniversity, hospital or other
Collaborators: Purdue University, Children's Hospital Medical Center, Cincinnati
Study start: 26 Feb 2020 (actual)
Primary completion: 6 Aug 2024 (actual)
Study completion: 6 Aug 2024 (actual)
First posted: 25 Jun 2019 (actual)
Results: Posted 29 Jan 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose: Basic science
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1

Arm	Type	Receives
Imatinib Intervention	Experimental	Drug: Imatinib Mesylate

Who may qualify

Ages: 18 to 25 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (7 listed)

Age: patients must be ≥18 years of age and ≤25 years of age at the time of study entry.
Diagnosis: Patients must have documented diagnosis of sickle cell disease (Hemoglobin SS Disease or S-Beta 0 Thalassemia) by either high pressure liquid chromatography (HPLC) or Hemoglobin Electrophoresis
Disease status: Patients must have at least 2 documented episodes of vaso-occlusive pain in the prior year as defined by 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 opiates or with a parenteral nonsteroidal anti-inflammatory drug.
Performance Level: Karnofsky ≥80 for patients >10 years of age and Lansky ≥80 for patients ≤10 years of age. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.
Organ function requirements:

Key exclusion criteria (22 listed)

Chronic transfusion protocol.
Hydroxyurea Intolerance
Pregnancy or Breast-Feeding
Concomitant Medications
Patients who have an uncontrolled infection.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Imatinib MesylateThe 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.	Drug	Imatinib Intervention

Primary outcome

Changes in Biochemical Effects - Band 3 Phosphorylation
Time frame: Change from baseline Band 3 Phosphorylation at 7 months
Percent change in Band 3 Phosphorylation tested in red blood cells. Band 3 is a protein found on the membrane of red blood cells.
Change in Amount of Microparticles Released From Red Blood Cells
Time frame: change from baseline microparticle release at 7 months
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.
Change in Percent Irreversibly Sickled Cells
Time frame: Change from baseline of percent irreversibly sickled cells at 7 months
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.
Change in Point of Susceptibility to Sickling by OxygenScan
Time frame: Change from baseline of point of susceptibility of sickling at 7 months
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.

5 secondary outcomes

Number of Instances of Vaso-occlusive Crisis (VOC)
Time frame: Assessed monthly from treatment start up to 7 months
Number of Instances of Acute Chest Syndrome (ACS)
Time frame: Assessed monthly from treatment start up to 7 months
Opioid Use
Time frame: Assessed monthly from treatment start up to 7 months
Number of Hospitalizations
Time frame: Assessed monthly from treatment start up to 7 months
Assessment of Toxicities of Imatinib in Patients With Sickle Cell Anemia
Time frame: Assessed monthly from treatment start up to 7 months

Results and safety

Results posted to the registry on 29 Jan 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Imatinib Intervention	3	1
Control Group for Blood Draws	4	4

Primary outcome: Changes in Biochemical Effects - Band 3 Phosphorylation

Time frame: Change from baseline Band 3 Phosphorylation at 7 months. Number

Population analysed: Baseline samples for 2 of the 3 participants were processed but were not measurable (possible damage during transportation). 2 of the 3 participants did not have month 7 samples collected. 1 was collected by were not measurable (possible damage during transportation).

Primary outcome: Change in Amount of Microparticles Released From Red Blood Cells

Time frame: change from baseline microparticle release at 7 months. Number. Unit: Microparticles per microliter of plasma

Measure	Imatinib Intervention n = 1
Value	-48

Population analysed: Change in microparticle release from baseline to 7 months was calculated for the one participant that completed the study

Primary outcome: Change in Percent Irreversibly Sickled Cells

Time frame: Change from baseline of percent irreversibly sickled cells at 7 months. Number. Unit: percent

Measure	Imatinib Intervention n = 1
Value	0.32

Population analysed: Only one participant completed 7 months of the study to be analyzed

Primary outcome: Change in Point of Susceptibility to Sickling by OxygenScan

Time frame: Change from baseline of point of susceptibility of sickling at 7 months. Number. Unit: mmHg

Measure	Imatinib Intervention n = 1
Value	-6.39

Population analysed: Only 1 participant completed 7 months of the study to be analyzed.

5 secondary outcomes are reported in the full results.

Adverse events

Time frame: 3 years. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Imatinib Intervention	2 of 3 (66.7%)	3 of 3 (100%)	0 of 3

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 29 Jan 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Sickle Cell Disease

RecruitingObservational study
Blood Sampling for Research Related to Sickle Cell Disease
Sickle Cell Trait, Sickle Cell Disease
Active, not recruitingPhase 2/3
A Study Evaluating the Efficacy and Safety of Mitapivat (AG-348) in Participants With Sickle Cell Disease (RISE UP)
Sickle Cell Disease
Enrolling by invitationObservational study
Blood Collection for Research Related to Certain Diseases Involving Blood Vessels
Sickle Cell Disease
RecruitingPhase 1/2
Repeat Peripheral Blood Stem Cell Transplantation for Patients With Sickle Cell Disease and Falling Donor Myeloid Chimerism Levels
Myeloid Chimerism
Not yet recruitingObservational study
MENA/Levant Epidemiological, Registry of Immunological & Clinical Traits (MERIT)
Antiphospholipid (aPL)-Positive, Rheumatic Arthritis

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

The record lists no contact. Use the official record to reach the sponsor.

2 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing Imatinib Mesylate in people with Sickle Cell Disease, run by Indiana University at 2 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 22 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 29 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 29 Jan 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in Biochemical Effects - Band 3 Phosphorylation (time frame: Change from baseline Band 3 Phosphorylation at 7 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03997903.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jan 2026.