A Phase 1 interventional study of 131I-apamistmab and Sirolimus in Sickling Disorder Due to Hemoglobin S, sponsored by Columbia University. Recruiting at 1 site in United States. Open to participants aged 12 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-06-10.
Sponsored by Columbia University · Phase 1, Interventional, and Treatment
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.
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.
1,134 studies on the registry are indexed under Anemia, Sickle Cell; 238 are open to participants now.
This study's planned enrollment of 24 is below the median of 40 across 769 interventional studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell studies →Columbia University is the lead sponsor of 1,136 studies on the registry; 195 are open to participants now.
Of its 180 completed or terminated interventional studies of FDA-regulated products, 148 (82%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients with sickle cell anemia ( 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
Note: HSCT can be deleterious for the developing fetus and pregnant mother due to the conditioning regimen, 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.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Allogeneic and autologous transplant
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GVHD (graft-versus-host disease)
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Karnofsky performance status (KPS)
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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).
Drug: 131I-apamistmab · Drug: Sirolimus · Drug: Campath · Radiation: Total Body Irradiation · Procedure: Exchange Transfusion · Radiation: Planar gamma imaging
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.
Also known as: Iodine (131I) apamistamab
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.
Also known as: Rapamycin, Rapamune
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.
Also known as: Alemtuzumab
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.
Also known as: TBI
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).
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.
Also known as: therapeutic radiation
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%.
Time frame: 42 days after blood stem cell (PB) transplantation
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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).
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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
Time frame: 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.
Time frame: 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.
Time frame: At study inclusion and at 1 year post-transplant
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