NCT06898905 · Yale University
Hyperfractionated Dual Equivalent Fractionated Radiation Therapy
(HyDEF)
What this study is about
This study evaluates the feasibility and safety of bridging radiation therapy, including a novel method for comparing the effectiveness of hypofractionated versus hyperfractionated radiation therapy in participants with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) undergoing T-cell redirection therapies (CAR T-cell therapy or bispecific antibodies).
View original scientific description
This study evaluates the feasibility and safety of bridging radiation therapy, including a novel method for comparing the effectiveness of hypofractionated versus hyperfractionated radiation therapy in participants with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) undergoing T-cell redirection therapies (CAR T-cell therapy or bispecific antibodies).
Interventions
OTHER
Bridging Radiation Therapy
Study seeks to compare the hypofractionated radiation therapy with hyperfractionated treatment within the same tumor. Each participant will be serving as their own control; half their tumor will receive once daily hypofractionated (QD) bridging radiotherapy, and the other half of their tumor will receive twice daily hyperfractionated (BID) bridging radiotherapy. Either schedule is considered standard of care and this study aims to determine which schedule may prove superior between the two standards.
Primary outcome measures
Feasibility Assessment of Bridging Radiation Therapy
Time frame: Approximately one year
Feasibility will be assessed by the proportion of enrolled participants who are successfully treated according to the proposed bridging radiation therapy schema.
Safety analysis of Bridging Radiation Therapy
Time frame: Throughout the study, approximately two years
Safety will be assessed by analyzing the incidence of severe (grade ≥ 3) acute toxicities. The therapy will be considered safe if fewer than 30% of study participants receiving dual fractionated radiation therapy experience these toxicities.
Dynamics of Circulating Tumor DNA (ctDNA) as a Marker of Minimal Residual Disease
Time frame: Baseline (0-7 days prior to radiation therapy) to post-radiation therapy (prior to initiation of lymphodepleting chemotherapy)
Changes in serum ctDNA levels will be measured at baseline and after radiation therapy (RT) to characterize ctDNA dynamics and assess minimal residual disease. Comparisons will focus on quantitative shifts in ctDNA burden in relation to treatment response.
Biomarkers of Hypoxia and Immune Exhaustion in Relation to Treatment Response
Time frame: Baseline (0-7 days prior to radiation therapy) to post-radiation therapy (prior to initiation of lymphodepleting chemotherapy).
Serum biomarkers associated with tumor hypoxia and immune exhaustion will be evaluated at baseline and after radiation therapy (RT). Changes in these biomarkers will be compared to characterize biological responses to treatment and their relationship to clinical outcomes.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Provision of signed and dated informed consent form.
- Stated willingness to comply with all study procedures and availability for the duration of the study.
- Adult aged 18 years or older.
- Histologically confirmed diagnosis of R/R DLBCL with plan for CAR T or BsAb therapy at Yale New Haven Hospital.
- ECOG performance status 0 to 3.
- Ability to present for once or twice daily (M-F) fractionated radiation therapy, without contraindications for radiotherapy as determined by the treating radiation oncologist.
- Women of childbearing potential must have a negative serum or urine pregnancy test at screening and at time of radiation treatment planning, per standard of care and departmental standard operating procedure. Participants must agree to take appropriate precautions to avoid pregnancy (with at least 99% certainty) from screening through safety follow-up. Permitted methods that are at least 99% effective in preventing pregnancy should be communicated to the participants and their understanding confirmed.
Exclusion criteria
- Participants who meet any of the following criteria will be disqualified from entering the study:
- Participants who are pregnant or currently breastfeeding. a. Females who have undergone surgical sterilization or who have been postmenopausal for at least 12 months are not considered to be of childbearing potential.
- Participants with history of prior radiation exposure for research purposes within the past year, such that participation in this study would place them over the FDA limits for annual radiation exposure.
- Participants who are unable to safely receive FDG PET tracer.
- Any condition that would, in the investigator's judgment, interfere with full participation in the study and attending required study visits (if outpatient); pose a significant risk to the participant; or interfere with interpretation of study data.
- Participants who would not be anticipated to derive any clinical benefit from bridging radiotherapy, are unable to participate in twice daily radiotherapy, or have clinical contraindications to radiation therapy per treating investigator.
Where
- New Haven, Connecticut
Collaborators
American Cancer Society, Inc.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 22, 2026 · Source of record for eligibility and locations