Sickle Cell DiseasePhase 2NCT07616154
Haploidentical Donor Hematopoietic Cell Transplant for Sickle Cell Disease
A Phase 2 study testing Cyclophosphamide 50mg, Abatacept and Alemtuzumab in people with Sickle Cell Disease, run by St. Jude Children's Research Hospital at 1 site in United States.
Trial summary
The purpose of this study it to evaluate a reduced toxicity conditioning regimen for haploidentical donor HCT followed by a GVHD prophylaxis regimen comprising of post-transplant cyclophosphamide, sirolimus and abatacept with the goal to improve the GVHD-free rejection-free survival (GRFS) to greater than 90% after… Read more about this study
- Who is it for?
- Ages Up to 22 years
- Conditions the study is for
- Sickle Cell Disease
- What is being tested?
- Cyclophosphamide 50mg, Abatacept and Alemtuzumab
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2026to Sep 2035
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
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 Up to 22 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Transplant Recipient
- Age less than or equal to 22 years.
- Patients without a suitable HLA-matched sibling donor but with a suitable single haplotype matched (≥ 3 of 6) family member donor. Potential donors do not need to undergo eligibility determination prior to the recipients enrolling on the study. As long as a potential donor is identified and willing to donate hematopoietic progenitor cells, recipients can enroll on the study.
- Patients with SCD (any genotype) who meet any ONE of the following criteria:
- History of an abnormal transcranial Doppler measurement defined as TCD velocity ≥200 cm/sec by the non-imaging technique (or ≥185 cm/sec by the imaging technique) measured at a minimum of two separate occasions.
- History of cerebral infarction on brain MRI (overt stroke, or silent cerebral infarct).
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- History of two or more episodes of acute chest syndrome (ACS) in the 2-years period preceding enrollment.
- History of two or more SCD related pain events requiring treatment with parenteral analgesics in the last 12 months.
- History of two or more episodes of priapism (erection lasting ≥4 hours or requiring emergent medical care).
- Administration of regular RBC transfusions (≥8 transfusions in the previous 12 months).
- Evidence of progressive end organ damage (eg. cardiomyopathy, nephropathy, pulmonary hypertension etc) that in the opinion of the treating hematologist is not responsive to medical management and may benefit from an HCT. Such a determination must be made in writing by at least two independent hematologists and documented in the patient's electronic medical record prior to enrollment.
- Donor
- An at least single haplotype matched (≥ 3 of 6) family member.
- HIV negative
- Not pregnant, as confirmed by negative serum or urine pregnancy test within 14 days prior to enrollment (if female).
- Not breast feeding.
- Donor should not have clinically significant hemoglobinopathy. Donors with sickle cell trait are acceptable.
- Regarding donation eligibility, is identified as either:
- Completed the process of donor eligibility determination as outlined in 21 CFR 1271 and agency guidance; OR.
- Does not meet 21 CFR 1271 eligibility requirements but has a declaration of urgent medical need completed by the principal investigator or physician sub-investigator per 21 CFR 1271.
Who cannot join
- Transplant Recipient
- Karnofsky or Lansky performance score <60.
- Pregnant, as confirmed by positive serum or urine pregnancy test within 14 days prior to enrollment (if female).
- Breast feeding.
- Uncontrolled bacterial, viral or fungal infections (undergoing appropriate treatment and with progression of clinical symptoms) within 1 month prior to conditioning. Patients with febrile illness or suspected minor infection should await clinical resolution prior to starting conditioning. Patients with confirmed seropositivity or positive NAAT for HIV are excluded.
- Serum conjugated (direct) bilirubin >3x upper limit of normal for age as per local laboratory. Participants with hyperbilirubinemia as the result of hyperhemolysis, or a severe drop in hemoglobin post blood transfusion, are not excluded as long as it downtrends and return to acceptable limits subsequently.
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- Left ventricular shortening fraction <25% or ejection fraction <40% by echocardiogram.
- Estimated creatinine clearance less than 50 mL/min/1.73m2.
- Diffusion capacity of carbon monoxide (DLCO) <35% (adjusted for hemoglobin) OR baseline oxygen saturation <85% or PaO2 <70.
- Presence of anti-donor specific HLA antibodies unresponsive to desensitization.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
St Jude Children's Research Hospital
Memphis, Tennessee, 38105
Akshay Sharma, MD, 866-278-5833, referralinfo@stjude.org
Akshay Sharma, MD
About this study
The purpose of this study it to evaluate a reduced toxicity conditioning regimen for haploidentical donor HCT followed by a GVHD prophylaxis regimen comprising of post-transplant cyclophosphamide, sirolimus and abatacept with the goal to improve the GVHD-free rejection-free survival (GRFS) to greater than 90% after haploidentical donor HCT in children and young adults with SCD.
Primary Objective:
Read more
- To assess the GVHD-free and rejection free survival (GRFS) after haploidentical donor HCT in children and young adults with SCD.
Secondary Objectives:
- Assess the overall survival (OS) and disease-free survival (DFS) after haploidentical donor HCT for SCD.
- Estimate incidence and severity of acute and chronic GVHD after haploidentical donor HCT for SCD.
- Assess the neutrophil and platelet engraftment kinetics after haploidentical donor HCT for SCD.
- Conditions
- Sickle Cell Disease
- Being tested
- Cyclophosphamide 50mg, Abatacept, Alemtuzumab, Hydroxyurea, Thiotepa
- Keywords
- Sickle Cell, Hematopoietic Cell Transplant
- 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.
Cyclophosphamide 50mgDrug
IV
AbataceptDrug
IV
AlemtuzumabDrug
IV
HydroxyureaDrug
IV
ThiotepaDrug
IV
FilgrastimDrug
IV
SirolimusDrug
IV
AzathioprineDrug
IV
TBIRadiation
Radiaiton therapy
Hematopoietic Progenitor Cell InfusionProcedure or surgery
Hematopoietic Progenitor Cell Infusion
| Study group | Role | What they receive |
|---|---|---|
| HAPSCD Treatment | Experimental | Not described Receives: Drug: Cyclophosphamide 50mg; Drug: Abatacept; Drug: Alemtuzumab; Drug: Hydroxyurea; Drug: Thiotepa; Drug: Filgrastim; Drug: Sirolimus; Drug: Azathioprine; Radiation: TBI; Procedure: Hematopoietic Progenitor Cell Infusion |
What is being measured
The primary outcome is the main question the study is designed to answer.
GVHD-free and rejection free survival (GRFS)
GRFS is defined as the time interval from transplant (graft infusion) until the first of grade III-IV acute GVHD, moderate or severe chronic GVHD, primary or secondary graft failure requiring second definitive therapy, and death occurs. GRFS will be calculated at 1-year, and 3-year post-transplant and reported as a percentage of the enrolled patients.
Measured: Up to 3 years after HCT
Secondary outcomes (4)
Overall survival (OS)
Event for OS will include death due to any cause. OS will be evaluated and reported at 1 year and 3 years after HCT as a percentage of the enrolled patients.
Measured: Up to 3 years after HCT
Disease-free survival (DFS)
Events for DFS will include death due to any cause and recurrence of SCD symptoms or graft failure after HCT. DFS will be evaluated and reported at 1 year and 3 years after HCT as a percentage of the enrolled patients.
Measured: Up to 3 years after HCT
Incidence and severity of acute and chronic GVHD
Incidence of acute GVHD will be evaluated and reported at 1 month and, 3 months, and 6 months after HCT as a percentage of the enrolled patients. Incidence of chronic GVHD will be evaluated and reported at 6 months, 1 year and 3 years after HCT as a percentage of the enrolled patients
Measured: Up to 3 years after HCT
Neutrophil and platelet engraftment
The time to neutrophil and platelet engraftment will be reported in aggregate for all the participants using summary statistics.
Measured: Up to 6 months after HCT
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2026
- Study startSep 2026 (estimated)
- Primary completionSep 2034 (estimated)
- Study completionSep 2035 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
- More trials run by St. Jude Children's Research HospitalThe sponsor's other registered studies.
- 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- St. Jude Children's Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Akshay Sharma, MD, Principal investigator, St. Jude Children's Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07616154
- Sponsor's protocol ID
- HAPSCD
- Status last verified
- Jul 2026
- First submitted
- 17 May 2026
- Last updated
- 23 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant de-identified datasets containing the variables analyzed in the published article will be made available (related to the study primary or secondary objectives contained in the publication). Supporting documents such as the protocol, statistical analyses plan, and informed consent are available through the CTG website for the specific study. Data used to generate the published article will be made available at the time of article publication. Investigators who seek access to individual level de-identified data will contact the computing team in the Department of Biostatistics (ClinTrialDataRequest@stjude.org) who will respond to the data request.
Study at a glance
From the registry record, last updated by the sponsor on 23 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Haploidentical Donor Hematopoietic Cell Transplant for Sickle Cell Disease
- ClinicalTrials.gov ID
- NCT07616154
- Acronym / sponsor ID
- HAPSCD
- Conditions
- Sickle Cell Disease
- Keywords
- Sickle Cell, Hematopoietic Cell Transplant
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- St. Jude Children's Research HospitalUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Sep 2034 (estimated)
- Study completion
- Sep 2035 (estimated)
- First posted
- 1 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study it to evaluate a reduced toxicity conditioning regimen for haploidentical donor HCT followed by a GVHD prophylaxis regimen comprising of post-transplant cyclophosphamide, sirolimus and abatacept with the goal to improve the GVHD-free rejection-free survival (GRFS) to greater than 90% after haploidentical donor HCT in children and young adults with SCD.
Primary Objective:
- To assess the GVHD-free and rejection free survival (GRFS) after haploidentical donor HCT in children and young adults with SCD.
Secondary Objectives:
- Assess the overall survival (OS) and disease-free survival (DFS) after haploidentical donor HCT for SCD.
- Estimate incidence and severity of acute and chronic GVHD after haploidentical donor HCT for SCD.
- Assess the neutrophil and platelet engraftment kinetics after haploidentical donor HCT for SCD.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| HAPSCD Treatment | Experimental | Drug: Cyclophosphamide 50mg, Drug: Abatacept, Drug: Alemtuzumab, Drug: Hydroxyurea, Drug: Thiotepa, Drug: Filgrastim, Drug: Sirolimus, Drug: Azathioprine, Radiation: TBI, Procedure: Hematopoietic Progenitor Cell Infusion |
Who may qualify
- Ages
- Up to 22 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (20 listed)
- Transplant Recipient
- Age less than or equal to 22 years.
- Patients without a suitable HLA-matched sibling donor but with a suitable single haplotype matched (≥ 3 of 6) family member donor. Potential donors do not need to undergo eligibility determination prior to the recipients enrolling on the study. As long as a potential donor is identified and willing to donate hematopoietic progenitor cells, recipients can enroll on the study.
- Patients with SCD (any genotype) who meet any ONE of the following criteria:
- History of an abnormal transcranial Doppler measurement defined as TCD velocity ≥200 cm/sec by the non-imaging technique (or ≥185 cm/sec by the imaging technique) measured at a minimum of two separate occasions.
Key exclusion criteria (10 listed)
- Transplant Recipient
- Karnofsky or Lansky performance score <60.
- Pregnant, as confirmed by positive serum or urine pregnancy test within 14 days prior to enrollment (if female).
- Breast feeding.
- Uncontrolled bacterial, viral or fungal infections (undergoing appropriate treatment and with progression of clinical symptoms) within 1 month prior to conditioning. Patients with febrile illness or suspected minor infection should await clinical resolution prior to starting conditioning. Patients with confirmed seropositivity or positive NAAT for HIV are excluded.
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 |
|---|---|---|
| Cyclophosphamide 50mgIV | Drug | HAPSCD Treatment |
| AbataceptIV | Drug | HAPSCD Treatment |
| AlemtuzumabIV | Drug | HAPSCD Treatment |
| HydroxyureaIV | Drug | HAPSCD Treatment |
| ThiotepaIV | Drug | HAPSCD Treatment |
| FilgrastimIV | Drug | HAPSCD Treatment |
| SirolimusIV | Drug | HAPSCD Treatment |
| AzathioprineIV | Drug | HAPSCD Treatment |
| TBIRadiaiton therapy | Radiation | HAPSCD Treatment |
| Hematopoietic Progenitor Cell InfusionHematopoietic Progenitor Cell Infusion | Procedure or surgery | HAPSCD Treatment |
Primary outcome
GVHD-free and rejection free survival (GRFS)
Time frame: Up to 3 years after HCT
GRFS is defined as the time interval from transplant (graft infusion) until the first of grade III-IV acute GVHD, moderate or severe chronic GVHD, primary or secondary graft failure requiring second definitive therapy, and death occurs. GRFS will be calculated at 1-year, and 3-year post-transplant and reported as a percentage of the enrolled patients.
4 secondary outcomes
Overall survival (OS)
Time frame: Up to 3 years after HCT
Disease-free survival (DFS)
Time frame: Up to 3 years after HCT
Incidence and severity of acute and chronic GVHD
Time frame: Up to 3 years after HCT
Neutrophil and platelet engraftment
Time frame: Up to 6 months after HCT
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jul 2026.
- St. Jude Children's Research HospitalLink provided by the sponsor.
- Clinical Trials Open at St. JudeLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Individual participant de-identified datasets containing the variables analyzed in the published article will be made available (related to the study primary or secondary objectives contained in the publication). Supporting documents such as the protocol, statistical analyses plan, and informed consent are available through the CTG website for the specific study. Data used to generate the published article will be made available at the time of article publication. Investigators who seek access to individual level de-identified data will contact the computing team in the Department of Biostatistics (ClinTrialDataRequest@stjude.org) who will respond to the data request.
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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.
Akshay Sharma, MD principal investigator
St. Jude Children's Research Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Cyclophosphamide 50mg, Abatacept and Alemtuzumab in people with Sickle Cell Disease, run by St. Jude Children's Research Hospital at 1 site 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 20 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 23 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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 phase mean?
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Akshay Sharma, MD (8662785833, referralinfo@stjude.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
GVHD-free and rejection free survival (GRFS) (time frame: Up to 3 years after HCT). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Jul 2026.