Recruiting

Gene-corrected blood cell therapy for severe sickle cell disease

Plain-English translation of NCT04819841 on ClinicalTrials.gov ↗ · Source last updated March 2026 · Translation generated June 2026 · How we translate trials

Read our Sickle Cell Disease research guide →

Phase 1/2 — A combined trial that checks safety and dosing while also starting to look at whether the treatment works.

What is this trial?

This trial is testing a new treatment called nula-cel for people with severe sickle cell disease. Nula-cel is made from your own blood-forming stem cells, which doctors remove, fix the sickle cell mutation using gene-editing technology, and then give back to you through an IV infusion. The goal is to help your body produce healthy red blood cells instead of sickled ones.

People with severe sickle cell disease suffer from repeated, painful crises and organ damage that current treatments cannot fully prevent. This medication offers a new approach by fixing the root cause—the faulty gene—rather than just managing symptoms.

Do you qualify?

You likely qualify if…

you are between 12 and 40 years old
you have been diagnosed with severe sickle cell disease and have had at least 4 severe pain crises in the past 2 years, or at least 2 acute chest syndrome episodes in the past 2 years (with at least one in the past year)
you are in good enough overall health to undergo the treatment (performance status score of 80 or higher)
you do not have an identical or perfectly matched sibling donor available for a traditional stem cell transplant

You likely don't qualify if…

you have a 10 out of 10 HLA-matched sibling donor available
you have received a stem cell transplant or gene therapy in the past
you have a current or previous cancer diagnosis or bone marrow disorders
you are pregnant, breastfeeding, or have a serious active infection
you have certain genetic mutations that could increase your risk of developing certain blood cancers

What participation looks like

You will have your blood-forming stem cells collected and sent to a laboratory, where they will be corrected using gene-editing technology. You will then receive chemotherapy to prepare your body, followed by an infusion of your corrected cells back into your bloodstream. The trial will monitor you closely with blood tests and clinic visits over time to see how well the treatment works and track any side effects.

AI-generated summary from trial data · Jun 3, 2026 · Not medical advice

Trial locations(4 sites)

United States

Children's Hospital Los Angeles, Los Angeles, California

Lucile Packard Children's Hospital, Palo Alto, California

Washington University, St Louis, Missouri

Nationwide Children's Hospital, Columbus, Ohio