131I-apamistamab-based Conditioning for Hematopoietic Stem Cell Transplant (HSCT) in Advanced Sickle Cell Disease (SCD)

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. 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.

Conditions

• Sickling Disorder Due to Hemoglobin S

Interventions

DRUG

131I-apamistmab

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.

DRUG

Sirolimus

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.

DRUG

Campath

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.

DRUG

Total Body Irradiation

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.

PROCEDURE

Exchange Transfusion

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).

RADIATION

Planar gamma imaging

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.

Sponsors & Collaborators

• Actinium Pharmaceuticals

  collaborator INDUSTRY

• Columbia University

  lead OTHER

Principal Investigators

• Markus Y Mapara, MD · Columbia University

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

12 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-04-28

Primary Completion

2030-03-12

Completion

2032-03-12

FDA Drug

Yes

Countries

• United States

Study Locations