Treatment for relapsed or refractory diffuse large B-cell lymphoma using IOMAB-ACT and CAR-T cell therapy

IOMAB-ACT: A Phase Ib/II Multi-institutional Study of 131 I-Apamistamab Followed by CD19-Targeted CAR-T Cell Therapy for Patients With Relapsed or Refractory (R/R) Diffuse Large B-cell Lymphoma (DLBCL)

Phase1; Phase2 Interventional University of Texas Southwestern Medical Center · NCT06768905

This study is testing a new treatment combining a special radioactive drug and CAR-T cell therapy to see if it helps people with relapsed or hard-to-treat diffuse large B-cell lymphoma.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Texas Southwestern Medical Center Academic / other
Drugs / interventionsApamistamab, CAR-T
Locations1 site (Dallas, Texas)
Trial IDNCT06768905 on ClinicalTrials.gov

What this trial studies

This study evaluates the safety and efficacy of a single dose of 131I-Apamistamab followed by CAR-T cell therapy in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). It is an open-label, single-cohort, multi-institutional trial where patients will receive the 50 mCi dose of 131I-Apamistamab as a lymphodepleting conditioning before CAR-T cell infusion. A safety run-in phase will involve six patients to assess the treatment's safety profile.

Who should consider this trial

Good fit: Ideal candidates are patients with relapsed or refractory diffuse large B-cell lymphoma who have undergone prior chemoimmunotherapy and are eligible for CAR-T therapy.

Not a fit: Patients with non-relapsed DLBCL or those who have not received prior treatment may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with difficult-to-treat relapsed or refractory DLBCL.

How similar studies have performed: Other studies have shown promising results with CAR-T cell therapies, indicating potential success for this novel approach combining IOMAB-ACT.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Patients with diffuse large B-cell lymphoma (de novo or DLBCL transformed from an indolent lymphoma (follicular lymphoma, chronic lymphocytic leukemia \[Richter syndrome\]) or high-grade B-cell lymphoma (HGBL): ("DLBCL patients")

   * Defined as relapsed or refractory DLBCL or high-grade B-cell lymphoma (HGBL) following at least one or more prior chemoimmunotherapy regimen (with at least one course including an anthracycline and CD20-directed therapy) following diagnosis of de novo DLBCL/HGBL or DLBCL arising from indolent lymphoma and requiring further treatment and deemed to be candidates for standard of care CAR-T therapy. This includes patients with primary refractory disease (failure to achieve complete response (CR) to first-line therapy), relapsed disease within 12 months of first line chemoimmunotherapy or relapsed/refractory disease after 2 or more prior lines of systemic therapy.
   * Relapsed or refractory disease must be confirmed with a repeat biopsy within the last 12 months.
2. Age ≥ 18 years of age
3. Creatinine clearance ≥50 mL/min as calculated by the Cockroft-Gault formula.
4. Total bilirubin ≤1.5x upper limit of normal , AST and ALT ≤3x upper limit of normal (ULN), unless liver dysfunction is thought to be related to underlying malignancy or secondary to Gilbert's disease in which case the direct bilirubin should be ≤3.0 mg/dL, and AST and ALT ≤5x ULN.
5. Adequate pulmonary function as assessed by ≥92% oxygen saturation on room air or per institutional guidelines.
6. Thyroid function tests (TSH, FT4) ≤2x upper limit of normal (ULN)
7. Adequate bone marrow function meeting the following criteria as defined below, without requiring blood product or granulocyte-colony stimulating factor support in the 7 days prior to screening and start of 131I-Apamistamab treatment.

   1. Absolute neutrophil count ≥1.0k/µL,
   2. Platelets ≥50k/µL,
   3. Hemoglobin ≥8g/dL.
8. Performance status: ECOG performance status 0-2.
9. All men, as well as women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control, and/or abstinence) prior to study entry, and for the duration of study treatment, and for 30 days following completion of therapy. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.

   A female of child-bearing potential is any woman (regardless of sexual orientation, marital status, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:
   * Has not undergone a hysterectomy or bilateral oophorectomy; or
   * Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).
10. Ability to understand and the willingness to sign a written informed consent.
11. For patients undergoing bridging therapy after leukapheresis and prior to 131I-Apamistamab infusion a repeat PET or CT scan will be performed 10-14 days prior to the 131I-Apamistamab infusion. They will also be required to meet inclusion criteria number 1 and 7 above within 10-14 days prior to the planned infusion of 131I-Apamistamab. This will be considered eligibility Screening 2 and will be approved by the Sponsor-Investigator.

Exclusion Criteria:

1. Pregnant or lactating patients.
2. Impaired cardiac function (LVEF \<40%) as assessed by echocardiogram or MUGA scan.
3. Patients with active graft versus host disease following allogeneic hematopoietic cell transplantation requiring systemic T-cell suppressive therapy are ineligible.
4. Patients with active autoimmune disease requiring systemic T-cell suppressive therapy are ineligible.
5. Patients with the following cardiac conditions will be excluded:

   1. New York Heart Association (NYHA) stage III or IV congestive heart failure
   2. Myocardial infarction ≤6 months prior to enrollment
   3. Any history of clinically significant ventricular arrhythmia or unexplained syncope, not believed to be vasovagal in nature or due to dehydration.
6. Have current or prior positive test results for human immunodeficiency virus (HIV) or hepatitis B (HBV) or C (HCV), with the following exceptions:

   1. Patients who have positive HBV test results due to having been previously vaccinated against hepatitis B, as evidenced by negative hepatitis B surface antigen (HbsAg), negative anti- hepatitis B core protein (HBc) and positive antibody to the HbsAg (anti-HBs) are not excluded.
   2. Patients who have antibodies to HCV or who have hepatitis B core antibody, with undetectable viremia by PCR, and with adequate organ function as defined in the protocol, are not excluded.
7. Patients with uncontrolled systemic fungal, bacterial, viral, or other infections are ineligible.
8. Patients with any concurrent active malignancies as defined by malignancies requiring any therapy other than expectant observation or hormonal therapy, with the exception of squamous and basal cell carcinoma of skin.
9. Patients with history or presence of clinically significant neurological disorders such as epilepsy, generalized seizure disorder, severe brain injuries are ineligible.
10. Any other issue which, in the opinion of the treating physician, would make the patient ineligible for the study.
11. Patients with circulating human anti-mouse antibodies (HAMA) to BC8. The results of HAMA testing will need to be available prior to 131I-Apamistamab infusion.
12. Patients with prior history of treatment with radiopharmaceuticals for lymphoma treatment indication.
13. Patients with QTcF \>470mSec on EKG

Where this trial is running

Dallas, Texas

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Non Hodgkin LymphomaDiffuse Large B Cell Lymphoma
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.