Testing a new radiation treatment to prepare for stem cell transplant in severe sickle cell disease

Plain-English translation of NCT07015684 on ClinicalTrials.gov ↗ · Source last updated June 2026 · Translation generated June 2026 · How we translate trials

Phase 1 — Testing in a small group (usually 20–80 people) to find a safe dose and watch for side effects.

What is this trial?

This trial is testing a new medication called 131I-apamistamab as part of the preparation process before receiving a stem cell transplant. The medication is designed to help make room for donor stem cells without requiring full-body radiation, which can cause serious long-term problems like cancer, infertility, and vision loss. Researchers want to find the right dose of this medication that works best for people with severe sickle cell disease.

Currently, doctors use a combination of chemotherapy, full-body radiation, and antibodies to prepare patients for stem cell transplant. However, full-body radiation carries real risks of long-term harm—including secondary cancers, infertility, and cataracts. This trial explores whether the new treatment can be just as effective while eliminating full-body radiation and its dangerous side effects.

Do you qualify?

You likely qualify if…

you are between 12 and 50 years old
you have been diagnosed with sickle cell anemia (HbSS, SC, or sickle beta-zero thalassemia)
you have experienced serious complications from sickle cell disease, such as a stroke, repeated acute chest syndrome, severe pain crises, or pulmonary hypertension
you have an HLA-matched sibling who is willing to donate stem cells for you
your heart, lungs, and liver function is adequate to tolerate the transplant procedure

You likely don't qualify if…

you do not have an available matched sibling donor
your heart function is severely reduced (ejection fraction below 40%)
your lung function is severely impaired (oxygen saturation below 85% or corrected DLCO below 40%)
you have advanced liver disease, such as cirrhosis or bridging fibrosis
you are pregnant, breastfeeding, or unwilling to use contraception during the donation process

What participation looks like

If you qualify and enroll, you will receive an infusion of the new medication through a vein in your arm about 10 days before your stem cell transplant. The medication is given once and is prepared at a specific dose level (100 or 150 millicuries, depending on which dose group you're in). After the infusion, you will proceed with the standard stem cell transplant process, including receiving donor stem cells and the supportive care that follows. The trial involves close monitoring at Columbia University Medical Center to track how you respond to the treatment.

AI-generated summary from trial data · Jun 10, 2026 · Not medical advice

Testing a new radiation treatment to prepare for stem cell transplant in severe sickle cell disease

What is this trial?

Do you qualify?

What participation looks like

Trial locations