Sickling Disorder Due to Hemoglobin SPhase 1NCT07015684
131I-apamistamab-based Conditioning for Hematopoietic Stem Cell Transplant (HSCT) in Advanced Sickle Cell Disease (SCD)
A Phase 1 study testing 131I-apamistmab, Sirolimus and Campath in people with Sickling Disorder Due to Hemoglobin S, run by Columbia University at 1 site in United States.
Trial summary
The purpose of this study is to find the smallest amount of the 131 I-apamistamab needed for preparing patients with severe sickle cell disease (SCD) for a bone marrow transplant. Read more about this study
- Who is it for?
- Ages 12 to 50 years
- Conditions the study is for
- Sickling Disorder Due to Hemoglobin S
- What is being tested?
- 131I-apamistmab, Sirolimus and Campath
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Apr 2025to 12 Mar 2032
- Phase
- Phase 1
- 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 12 to 50 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Availability of an HLA-matched sibling donor
- Patients with sickle cell anemia (Hb SS, Sβ0 thalassemia or severe SC) who are 12 - 50 years of age inclusive AND who have 1 or more of the following:
- Clinically significant neurologic event (stroke) or any neurological deficit lasting at least 24 hours. Stroke will be defined as a clinically significant neurologic event that is accompanied by an infarct on cerebral MRI or cerebral arteriopathy requiring chronic transfusion therapy.
- History of two or more episodes of ACS in the 2-year period preceding enrollment despite supportive care measures (i.e. asthma therapy and/or hydroxyurea).
- History of three or more severe vaso-occlusive pain crises per year in the 2-year period preceding enrollment despite the institution of supportive care measures (i.e. a pain management plan and/or treatment with hydroxyurea).
- Administration of regular RBC transfusion therapy, defined as receiving 8 or more transfusions per year for 1 year or more to prevent vaso-occlusive clinical complications (i.e. pain, stroke, and ACS)
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- An echocardiographic finding of tricuspid valve regurgitant jet (TRJ) velocity > or equal to 2.7 m/sec or pulmonary hypertension diagnosed by right heart catherization.
- Sickle hepatopathy defined as EITHER ferritin >1000mcg/L OR direct bilirubin >0.4mg/dl but <5xULN AND platelet count <250,000/uL at baseline
- Adequate organ functions as defined as:
- ECOG performance status of 2 or better
- Cardiac function: LVEF of 40% or greater
- Pulmonary Function: Pulse oximetry with a baseline oxygen saturation of 85% or greater and corrected DLCO of 40% or greater
- Hepatic Function: Serum conjugated (direct) bilirubin less than 5x upper limit of normal for age as per local laboratory, ALT and AST less than 5 x upper limit of normal as per local laboratory. Patients whose hyperbilirubinemia is the result of hyperhaemolysis, or a sever drop in hemoglobin post blood transfusion are not excluded.
- Absence of liver cirrhosis, bridging fibrosis and active hepatitis as documented by liver biopsy for patients with evidence of iron overload by serum ferritin or MRI. The histological grading and scale described by Ishak and colleagues (1995) will be used.
- Donor Eligibility and Selection Criteria
- Donor should be evaluated for eligibility to donate by an independent physician not directly caring for the patient on study protocol.
- Donor is willing to sign informed consent allowing the use of the PBSC product for the HSCT of the recipient.
- Donor cannot be pregnant or lactating and must agree to contraception until after the donation procedure is complete.
- Testing negative for HIV and viral hepatitis
- Free of Hb S (defined as Hb S less than 50%) and other hemoglobinopathies that are symptomatic or of clinical significance.
- Targeted minimum stem cell dose of 5.0 x 10e6 CD34 cells/Kg of recipient weight
- Fulfills standard criteria for eligibility as a donor for HSCT.
- Note: HSCT can be deleterious for the developing fetus and pregnant mother due to the conditioning regimen, GVHD prophylaxis and treatment. Agents used in this study such as cyclophosphamide are pregnancy risk factor category D. Sirolimus is pregnancy risk factor category C. Radiotherapy also used (TBI) is a well-known teratogenic agent. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study and for at least 1 year post transplant.
- Finally, pregnancy and lactation restrictions and contraception requirements are also applicable to the donor. Filgrastim or other G-CSF analogous are pregnancy risk factor category C. The restriction lasts for 4 weeks after stem cell donation.
Who cannot join
- Pulmonary dysfunction defined as DLCO (corrected for hemoglobin and alveolar volume) < 40% of predicted OR baseline oxygen saturation of <85% or PaO2 <70.
- Severe cardiac dysfunction defined as ejection fraction <35%.
- Impaired renal function defined as GFR <40.
- Hepatic dysfunction defined as bridging (portal to portal) fibrosis or cirrhosis of the liver OR transaminases >5x ULN for age.
- Clinical stroke within 6 months of anticipated transplant
- Karnofsky performance score < 50%
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- HIV infection
- Uncontrolled viral, bacterial, fungal, or protozoal infection at the time of study enrollment.
- Have circulating HAMA noted on initial screening.
- Have received prior radiation to maximally tolerated levels to any critical normal organs
- Patients with unspecified chronic toxicity serious enough to detrimentally affect the patient's capacity to tolerate HSCT.
- Patients' unable to understand the nature and risks inherent in the HSCT process.
- History of non-compliance severe enough in the estimation of the treating team to preclude the patient from undergoing unrelated donor transplantation.
- Patient is pregnant or lactating.
- Inability to provide adequate transfusion support or increased risk immunohematological complications due presence of anti-RBC antibody against stem cell donor.
- Patients with any history of radiation therapy.
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
Columbia University Irving Medical Center
New York, New York, 10032
Research Nurse Navigator, RN, 212-342-5162, cancerclinicaltrials@cumc.columbia.edu
Markus Y. Mapara, MD, PhD
About this study
Official title: Open-label, Single-Center, Phase 1 Study to Estimate the Minimum Effective Dose (MED) of 131I-apamistamab for Non-myeloablative Conditioning in Patients With Severe Sickle Cell Disease
The purpose of this study is to find the smallest amount of the 131 I-apamistamab needed for preparing patients with severe sickle cell disease (SCD) for a bone marrow transplant. This is the first time 131 I-apamistamab is being used for advanced Sickle Cell Disease (SCD) in the setting of allogeneic stem cell transplant. 131 I-apamistamab is an investigational product. This means that 131 I-apamistamab has not been approved by the Food and Drug Administration (FDA) for medical use in patients.
The study treatment that is given before the transplant is called the conditioning regimen. In this study, the investigators are adding a drug called 131 I-apamistamab instead of the conditioning regimen typically given before a stem cell transplant.
Read the detailed description
The purpose of this study is to research the minimum effective dose (MED) of 131 I-apamistamab conditioning for hematopoietic stem cell transplantation for patients with advanced SCD. 131 Iapamistamab is an investigational product. This means that 131 I-apamistamab has not been approved by the Food and Drug Administration (FDA) for medical use in patients.
The study treatment that is given before the transplant is called the conditioning regimen. In this study, investigators are adding 131 I-apamistamab instead of the conditioning regimen typically given before a stem cell transplant.
The current standard of care conditioning for allogeneic stem cell transplant in SCD is a combination of chemotherapy, total body irradiation and an antibody called Campath. This study is being done to see if the stem cell transplant for SCD can still be effective by eliminating total body irradiation from the conditioning as it has potential long term side effects such as secondary cancers, infertility, early cataracts and lung toxicity.
This is a single center, Phase I, dose finding study to estimate the MED of hematopoietic stem cell transplantation for patients with advanced sickle cell disease using 131I-apamistmab-based nonmyeloablative conditioning. The study will enroll 24 patients who are 12-50 years of age with sickle cell anemia (Hb SS, SC, or Sβ0 thalassemia) and have an available HLA-matched sibling donor.
- Conditions
- Sickling Disorder Due to Hemoglobin S
- Being tested
- 131I-apamistmab, Sirolimus, Campath, Total Body Irradiation, Exchange Transfusion
- Keywords
- severe sickle cell disease, severe SCD, sickle cell disease, sickle cell, advanced SCD, advanced sickle cell disease, anemia, sickle cell disorders, hemoglobin S (HbS) Disease, Hemoglobin S Disease
- Medical subject headings
- Anemia, Sickle Cell, Anemia, Sickle Cell Trait, Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
131I-apamistmabDrug
Also called Iodine (131I) apamistamab
131I-apamistamab is a drug construct consisting of the apamistamab monoclonal antibody (mAb) and radioactive isotope iodine 131 (131I). The study drug will be patient-specific and will be manufactured for dosing on a specific date. The antibody dose will be at least 0.5mg/kg, however the final antibody amount may be higher if necessary based on the target radioactivity level. The 131I-apamistamab study drug requires patient details such as height, weight, a calculation to determine weight for use in calculating antibody amount for the dose. 131I-apamistmab will be given via intravenous (IV) infusion.
SirolimusDrug
Also called Rapamycin, Rapamune
Sirolimus is a macrocyclic lactone produced by Streptomyces hygroscopicus. It is an immunosuppressant agent. Sirolimus is to be given orally either as tablet or solution form. Dosage will be adjusted to a therapeutic target of 10-15 ng/mL in first 6 months post-transplant and 5-10 ng/mL after 6 months.
CampathDrug
Also called Alemtuzumab
Campath is a recombinant DNA-derived humanized monoclonal antibody that is directed against the 21-28 kD cell surface glycoprotein, CD52. CD52 is expressed on the surface of normal and malignant B and T lymphocytes, NK cells, monocytes, macrophages, and tissues of the male reproductive system. Campath will be given via IV at a total dose of 1 mg per kilogram of body weight.
Total Body IrradiationRadiation
Also called TBI
Radiation dose is 3Gy (Gy is a radiation unit of measurement). Radiation source and dose rates will be according to institutional practice. Total Body Irradiation (TBI) may be delivered from either linear accelerator or Cobalt sources.
Exchange TransfusionProcedure or surgery
Patient will undergo a red blood cell (RBC) exchange transfusion to achieve a Hemoglobin S (HgbS) level < 20% prior to starting therapy to prevent the development of a vaso-occlusive Crisis (VOC).
Planar gamma imagingRadiation
Also called therapeutic radiation
Dosimetric imaging will be performed using quantitative planar gamma camera acquisition. Planar gamma imaging is a technique used in medical imaging to take pictures of the inside of the body, particularly to look at how certain organs or tissues are functioning. This allows the study doctor to evaluate how the study drugs are absorbed into the body.
| Study group | Role | What they receive |
|---|---|---|
| 131I-apamistmab-based nonmyeloablative conditioning | Experimental | Ten days before participants receive donor stem cell infusion, they will receive a dose of 131 I-apamistamab as an intravenous (IV) infusion into a vein in the arm. The 131 I-apamistamab product will be formulated in advance of the anticipated infusion date, for infusion on a specific date, based on target dose (100 mCi or 150 mCi, based on dose level). Receives: Drug: 131I-apamistmab; Drug: Sirolimus; Drug: Campath; Radiation: Total Body Irradiation; Procedure: Exchange Transfusion; Radiation: Planar gamma imaging |
What is being measured
The primary outcome is the main question the study is designed to answer.
Graft failure rate
Graft failure defined as having had a primary or secondary graft failure by 42 days after blood stem cell (PB) transplantation. Primary graft failure is defined as failure to achieve an absolute neutrophil count (ANC) of >500/ μL by 42 days after blood stem cell (PB) transplantation or a total donor chimerism of >5%. Secondary graft failure is defined as cytopenias after initial engraftment (ANC <500/μL) and a total donor cell chimerism decreasing to less than 5%.
Measured: 42 days after blood stem cell (PB) transplantation
Secondary outcomes (13)
Event-free survival (EFS) Rate
Event-free survival is defined as the time from treatment initiation to the occurrence of primary graft failure, death, Graft-versus-Host Disease (GVHD) Grade III-IV, whichever comes first. Patients without events will be censored at the time of last follow-up assessment.
Measured: Duration of study, up to 7 years
Time to engraftment of Neutrophils
Time to neutrophil engraftment is defined as the first of 3 measurements on consecutive days when the patient has an absolute neutrophil count of 500/μL after conditioning.
Measured: Up to 7 years
Time to engraftment of Platelets
Time to platelet engraftment will be defined as the first day of a minimum of 3 measurements on different days that the patient has achieved a platelet count > 50,000/μL AND did not receive a platelet transfusion in the previous 7 days. The exception is the case in which a subject is given a platelet transfusion specifically to achieve a platelet threshold to allow an elective invasive procedure, such as a central catheter removal. Time from treatment initiation to successful donor cell engraftment defined as having achieved > 50% total Peripheral Blood Mononuclear Cells (PMC) donor cell chimerism upon successful engraftment at day +30 or upon meeting ANC and Plt engraftment whatever occurs first.
Measured: Up to 7 years
Incidence of Graft-versus-Host Disease (GVHD) of any grade
Incidence of acute and chronic GVHD of any grade as evaluated according to The Center for International Blood and Marrow Transplant Research (CIBMTR) and National Institutes of Health (NIH) criteria respectively.
Measured: Up to 7 years
Incidence of other transplant related toxicities
Incidence of other transplant related toxicities, including Veno-occlusive disease (VOD), Idiopathic pneumonia syndrome (IPS), Central nervous system (CNS) toxicity, or Posterior reversible encephalopathy syndrome (PRES).
Measured: 12 Months Post Stem Cell Transplant
Incidence of significant transplant-related infections
Significant infections will be recorded including but not limited to bacterial or fungal sepsis, cytomegalovirus (CMV) reactivation with/without clinical disease, adenovirus infection, Epstein-Barr virus (EBV) reactivation with or without post-transplant lymphoproliferative disorder (PTLD), other significant viral reactivations or community-acquired viral infections and invasive mold infections.
Measured: 12 Months Post Stem Cell Transplant
Number of participants with donor chimerism >5%
Chimerism is a measure of the engraftment of donor cells within the recipient and is expressed as the percentage ratio between the number of donor cells and recipient cells. Chimerism will be determined by Short Tandem Repeat analysis.
Measured: 100 days post-transplant and 1 year post transplant
Percentage of Participants who Achieve Immune Reconstitution
Peripheral blood quantitative assessment of CD3+, CD4+, CD8+, CD19+, and CD16+/56+ lymphocytes will be assessed by flow cytometry. In addition, quantitative immunoglobulins will be measured for IgA, IgM and IgG. These will be performed at Day +60 (±10 days) as well as at 1 year (+/- 2 weeks) and after long term follow up at the discretion of the investigator. Descriptive statistics will be used to describe the percentage of patients who are able to achieve reconstitution of important lymphocyte subsets and B cell function at the defined timepoint above.
Measured: 12 Months Post Stem Cell Transplant
Follicle-stimulating hormone (FSH) titer
To assess the impact of the conditioning on fertility, FSH titers will be measured.
Measured: At study inclusion and at 1 year post-transplant
Luteinizing hormone (LH) titer
To assess the impact of the conditioning on fertility, LH titers will be measured.
Measured: At study inclusion and at 1 year post-transplant
Anti-Müllerian Hormone (AMH) titer
To assess the impact of the conditioning on fertility, AMH titers will be measured
Measured: At study inclusion and at 1 year post-transplant
Testosterone titer
To assess the impact of the conditioning on fertility, testosterone titers will be measured.
Measured: At study inclusion and at 1 year post-transplant
Sperm titer
To assess the impact of the conditioning on fertility, sperm titers will be measured.
Measured: At study inclusion and at 1 year post-transplant
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2025
- Study start28 Apr 2025
- Primary completion12 Mar 2030 (estimated)
- Study completion12 Mar 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickling Disorder Due to Hemoglobin SStudies of the same condition, open and under way.
- More trials run by Columbia UniversityThe 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 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Columbia University
- Sponsor type
- University, hospital or other
- Collaborators
- Actinium Pharmaceuticals
- Responsible party
- Principal investigator, Markus Mapara, Columbia University
- Investigators
- Markus Y Mapara, MD, Principal investigator, Columbia University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07015684
- Sponsor's protocol ID
- AAAV1172
- Status last verified
- Jun 2026
- First submitted
- 3 Jun 2025
- Last updated
- 10 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-label, Single-Center, Phase 1 Study to Estimate the Minimum Effective Dose (MED) of 131I-apamistamab for Non-myeloablative Conditioning in Patients With Severe Sickle Cell Disease
- ClinicalTrials.gov ID
- NCT07015684
- Acronym / sponsor ID
- AAAV1172
- Conditions
- Sickling Disorder Due to Hemoglobin S
- Keywords
- severe sickle cell disease, severe SCD, sickle cell disease, sickle cell, advanced SCD, advanced sickle cell disease, anemia, sickle cell disorders
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- Columbia UniversityUniversity, hospital or other
- Collaborators
- Actinium Pharmaceuticals
- Study start
- 28 Apr 2025 (actual)
- Primary completion
- 12 Mar 2030 (estimated)
- Study completion
- 12 Mar 2032 (estimated)
- First posted
- 11 Jun 2025 (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 is to find the smallest amount of the 131 I-apamistamab needed for preparing patients with severe sickle cell disease (SCD) for a bone marrow transplant. This is the first time 131 I-apamistamab is being used for advanced Sickle Cell Disease (SCD) in the setting of allogeneic stem cell transplant. 131 I-apamistamab is an investigational product. This means that 131 I-apamistamab has not been approved by the Food and Drug Administration (FDA) for medical use in patients.
The study treatment that is given before the transplant is called the conditioning regimen. In this study, the investigators are adding a drug called 131 I-apamistamab instead of the conditioning regimen typically given before a stem cell transplant.
Detailed description
The purpose of this study is to research the minimum effective dose (MED) of 131 I-apamistamab conditioning for hematopoietic stem cell transplantation for patients with advanced SCD. 131 Iapamistamab is an investigational product. This means that 131 I-apamistamab has not been approved by the Food and Drug Administration (FDA) for medical use in patients.
The study treatment that is given before the transplant is called the conditioning regimen. In this study, investigators are adding 131 I-apamistamab instead of the conditioning regimen typically given before a stem cell transplant.
The current standard of care conditioning for allogeneic stem cell transplant in SCD is a combination of chemotherapy, total body irradiation and an antibody called Campath. This study is being done to see if the stem cell transplant for SCD can still be effective by eliminating total body irradiation from the conditioning as it has potential long term side effects such as secondary cancers, infertility, early cataracts and lung toxicity.
This is a single center, Phase I, dose finding study to estimate the MED of hematopoietic stem cell transplantation for patients with advanced sickle cell disease using 131I-apamistmab-based nonmyeloablative conditioning. The study will enroll 24 patients who are 12-50 years of age with sickle cell anemia (Hb SS, SC, or Sβ0 thalassemia) and have an available HLA-matched sibling donor.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| 131I-apamistmab-based nonmyeloablative conditioning | Experimental | Drug: 131I-apamistmab, Drug: Sirolimus, Drug: Campath, Radiation: Total Body Irradiation, Procedure: Exchange Transfusion, Radiation: Planar gamma imagingTen days before participants receive donor stem cell infusion, they will receive a dose of 131 I-apamistamab as an intravenous (IV) infusion into a vein in the arm. The 131 I-apamistamab product will be formulated in advance of the anticipated infusion date, for infusion on a specific date, based on target dose (100 mCi or 150 mCi, based on dose level). |
Who may qualify
- Ages
- 12 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (24 listed)
- Availability of an HLA-matched sibling donor
- Patients with sickle cell anemia (Hb SS, Sβ0 thalassemia or severe SC) who are 12 - 50 years of age inclusive AND who have 1 or more of the following:
- Adequate organ functions as defined as:
- Donor Eligibility and Selection Criteria
- Donor should be evaluated for eligibility to donate by an independent physician not directly caring for the patient on study protocol.
Key exclusion criteria (16 listed)
- Pulmonary dysfunction defined as DLCO (corrected for hemoglobin and alveolar volume) < 40% of predicted OR baseline oxygen saturation of <85% or PaO2 <70.
- Severe cardiac dysfunction defined as ejection fraction <35%.
- Impaired renal function defined as GFR <40.
- Hepatic dysfunction defined as bridging (portal to portal) fibrosis or cirrhosis of the liver OR transaminases >5x ULN for age.
- Clinical stroke within 6 months of anticipated transplant
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 |
|---|---|---|
| 131I-apamistmabAlso: Iodine (131I) apamistamab131I-apamistamab is a drug construct consisting of the apamistamab monoclonal antibody (mAb) and radioactive isotope iodine 131 (131I). The study drug will be patient-specific and will be manufactured for dosing on a specific date. The antibody dose will be at least 0.5mg/kg, however the final antibody amount may be higher if necessary based on the target radioactivity level. The 131I-apamistamab study drug requires patient details such as height, weight, a calculation to determine weight for use in calculating antibody amount for the dose. 131I-apamistmab will be given via intravenous (IV) infusion. | Drug | 131I-apamistmab-based nonmyeloablative conditioning |
| SirolimusAlso: Rapamycin, RapamuneSirolimus is a macrocyclic lactone produced by Streptomyces hygroscopicus. It is an immunosuppressant agent. Sirolimus is to be given orally either as tablet or solution form. Dosage will be adjusted to a therapeutic target of 10-15 ng/mL in first 6 months post-transplant and 5-10 ng/mL after 6 months. | Drug | 131I-apamistmab-based nonmyeloablative conditioning |
| CampathAlso: AlemtuzumabCampath is a recombinant DNA-derived humanized monoclonal antibody that is directed against the 21-28 kD cell surface glycoprotein, CD52. CD52 is expressed on the surface of normal and malignant B and T lymphocytes, NK cells, monocytes, macrophages, and tissues of the male reproductive system. Campath will be given via IV at a total dose of 1 mg per kilogram of body weight. | Drug | 131I-apamistmab-based nonmyeloablative conditioning |
| Total Body IrradiationAlso: TBIRadiation dose is 3Gy (Gy is a radiation unit of measurement). Radiation source and dose rates will be according to institutional practice. Total Body Irradiation (TBI) may be delivered from either linear accelerator or Cobalt sources. | Radiation | 131I-apamistmab-based nonmyeloablative conditioning |
| Exchange TransfusionPatient will undergo a red blood cell (RBC) exchange transfusion to achieve a Hemoglobin S (HgbS) level < 20% prior to starting therapy to prevent the development of a vaso-occlusive Crisis (VOC). | Procedure or surgery | 131I-apamistmab-based nonmyeloablative conditioning |
| Planar gamma imagingAlso: therapeutic radiationDosimetric imaging will be performed using quantitative planar gamma camera acquisition. Planar gamma imaging is a technique used in medical imaging to take pictures of the inside of the body, particularly to look at how certain organs or tissues are functioning. This allows the study doctor to evaluate how the study drugs are absorbed into the body. | Radiation | 131I-apamistmab-based nonmyeloablative conditioning |
Primary outcome
Graft failure rate
Time frame: 42 days after blood stem cell (PB) transplantation
Graft failure defined as having had a primary or secondary graft failure by 42 days after blood stem cell (PB) transplantation. Primary graft failure is defined as failure to achieve an absolute neutrophil count (ANC) of >500/ μL by 42 days after blood stem cell (PB) transplantation or a total donor chimerism of >5%. Secondary graft failure is defined as cytopenias after initial engraftment (ANC <500/μL) and a total donor cell chimerism decreasing to less than 5%.
13 secondary outcomes
Event-free survival (EFS) Rate
Time frame: Duration of study, up to 7 years
Time to engraftment of Neutrophils
Time frame: Up to 7 years
Time to engraftment of Platelets
Time frame: Up to 7 years
Incidence of Graft-versus-Host Disease (GVHD) of any grade
Time frame: Up to 7 years
Incidence of other transplant related toxicities
Time frame: 12 Months Post Stem Cell Transplant
Incidence of significant transplant-related infections
Time frame: 12 Months Post Stem Cell Transplant
Number of participants with donor chimerism >5%
Time frame: 100 days post-transplant and 1 year post transplant
Percentage of Participants who Achieve Immune Reconstitution
Time frame: 12 Months Post Stem Cell Transplant
Follicle-stimulating hormone (FSH) titer
Time frame: At study inclusion and at 1 year post-transplant
Luteinizing hormone (LH) titer
Time frame: At study inclusion and at 1 year post-transplant
Anti-Müllerian Hormone (AMH) titer
Time frame: At study inclusion and at 1 year post-transplant
Testosterone titer
Time frame: At study inclusion and at 1 year post-transplant
Sperm titer
Time frame: At study inclusion and at 1 year post-transplant
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 10 Jun 2026.
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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.
Markus Y Mapara, MD principal investigator
Columbia University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing 131I-apamistmab, Sirolimus and Campath in people with Sickling Disorder Due to Hemoglobin S, run by Columbia University 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 24 inclusion and 16 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 10 Jun 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 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.
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 Central Nurse Navigator, RN ((212) 342 5162, cancerclinicaltrials@cumc.columbia.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Graft failure rate (time frame: 42 days after blood stem cell (PB) transplantation). 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 10 Jun 2026.