Radiation therapy before CAR T-cell treatment for advanced lymphoma

Plain-English translation of NCT05800405 on ClinicalTrials.gov ↗ · Source last updated February 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 approach to treating advanced large B-cell lymphoma by combining two proven therapies in a specific order: radiation therapy followed by CAR T-cell infusion. CAR T-cell infusion is an immunotherapy where doctors collect your immune cells, reprogram them in the lab to fight cancer, and return them to your body. The study will examine whether giving radiation to all visible cancer sites first makes the CAR T-cell treatment work better and whether this combination is safe to administer.

Large B-cell lymphoma that comes back after standard treatment or doesn't respond to it is difficult to cure, and many patients need better options. This trial explores whether combining radiation therapy with CAR T-cell infusion could improve outcomes by preparing the cancer sites before the immune cells arrive.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have been diagnosed with large B-cell lymphoma that has relapsed (come back) or is refractory (didn't respond to prior treatment)
you have 6 or fewer areas of cancer visible on PET scans that can be treated with radiation
you are planned to receive CAR T-cell infusion within 3 months of joining the study
you have recovered from side effects of prior cancer treatments (except hair loss)
you are in reasonably good general health with an ability to care for yourself

You likely don't qualify if…

you have received prior CD19-directed therapy (a specific type of targeted cancer treatment)
you have had radiation therapy within the past 21 days
you have cancer in your central nervous system (brain or spinal cord)
you have an active infection requiring antibiotics or other serious uncontrolled medical conditions
you are pregnant or breastfeeding

What participation looks like

You would undergo a procedure called leukapheresis to collect immune cells from your blood, which are sent to a lab to be processed. Then you would receive external beam radiation therapy targeted to all your cancer sites. After that, you would receive the modified CAR T-cell infusion as part of standard care. Throughout the study, you would have PET-CT scans, blood tests, and possibly MRI imaging to monitor your response and collect data for research. The entire process from enrollment to CAR T infusion would happen within about 3 months.

Radiation therapy before CAR T-cell treatment for advanced lymphoma

What is this trial?

Do you qualify?

What participation looks like

Trial locations(1 site)