N-803 for Synovial Sarcoma and Myxoid/Round Cell Liposarcoma
This study is testing a treatment called N-803 for people with synovial sarcoma or myxoid/round cell liposarcoma that has continued to grow or spread after previous adoptive cellular therapy (ACT) using T-cell receptor therapy (TCR-T). N-803 is an immunotherapy, meaning it helps your body's immune system fight cancer. It uses a natural protein to help immune cells grow and become active. Researchers want to see if N-803 is safe and if it helps expand the T-cells from your previous treatment. They will also look for signs that the treatment is working to shrink tumors. You may be eligible if you are 18-80 years old and have one of these cancers that has progressed after TCR-T treatment. The study status is currently unclear.
- Study design
- This is an early-phase interventional study with a planned enrollment of 8 participants. It is designed to evaluate the safety and effects of N-803.
- What's involved
- You would undergo blood sample collection, CT scans, leukapheresis (a procedure to collect white blood cells), and MRI scans. N-803 will be given as an injection under the skin.
- Compensation
- Not stated in the trial record.
- Follow-up
- Your safety will be monitored for up to 30 days after your last dose of N-803. The expansion of T-cells will be measured before and after eight weeks of N-803 therapy.
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NCT07261657
N-803 in Patients With Progressive Synovial Sarcoma and Myxoid/Round Cell Liposarcoma Previously Treated With Adoptive Cellular Therapy
Recruiting
EARLY_PHASE1Ages 18–80InterventionalTreatmentSeth PollackInvestigator-initiated
~8 participants
Updated 2026-08-27 on ClinicalTrials.gov
What's tested:Biospecimen CollectionComputed TomographyLeukapheresisMagnetic Resonance ImagingNogapendekin Alfa InbakiceptX-Ray Imaging
At a glance
Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
The expansion of rare persisting transferred T-cell receptor therapy
Measured over Before and after eight weeks of N-803 therapy
+1 more outcome measured
Conditions
Where it's being run
1 sites across 1 statesIllinois1
Study leadership
- Seth M Pollack, MD · PRINCIPAL_INVESTIGATOR · Northwestern University
Who to contact
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Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
Patients must have histologically or cytologically confirmed Synovial Sarcoma (SS) and/or Myxoid/Round Cell Liposarcoma (MRCL) who have progressed after ACT using TCR-T.
Patients must have been treated with a TCR-T product that can be assessed per medical history and/or discretion of the principal investigator. This includes the FDA approved Afamitresgene autoleucel but also other products at the discretion of the principal investigator.
Patients must have measurable disease according to RECIST v1.1. See Appendix A for RECIST v1.1 criteria.
Patients must have shown clinical benefit on at least one scan post ACT using TCR-T, (SD, PR, CR), as determined by the treating investigator.
Patients must be aged ≥ 18 to 80 at time of registration.
Patients must have a performance status of \>70% on the Karnofsky Scale (see Appendix A) or \< 2 on the ECOG Performance Scale (see Appendix B).
Patients must be able to undergo leukapheresis per institutional standards. For patients receiving leukapheresis at the Rube Walker Blood Center, see Appendix F for reference document guidance and Rube Walker Blood Center leukapheresis eligibility criteria.
Patients must have adequate organ and bone marrow function as defined below within screening window of 28 days up until Pre-Dose Leukapheresis:
Has not undergone a hysterectomy or bilateral oophorectomy
Has had menses at any time in the preceding 12 consecutive months (and therefore has not been naturally postmenopausal for \> 12 months)
POCBP must have a negative pregnancy test during screening and per the study schedule. See Study Procedures in Section 5 for more information.
Patients must have the ability to understand and the willingness to sign a written informed consent document and comply with the study requirements.
Exclusion
Patients who have not recovered from adverse events due to prior anti-cancer therapy (i.e., have residual toxicities \> Grade 1) with the exception of alopecia, neuropathy and other non-significant adverse events per NCI CTCAE v 5.0 as deemed by the principal investigator.
Patients with high risk of bleeding, as determined by treating investigator. Note: If patients are on anticoagulants, the investigator will determine if patient can continue anticoagulants throughout the study, or if their dosage needs to be changed until completion of both leukapheresis procedures.
Patients who have received other IL-15 treatments since receiving TCR-T cells to the start of study treatment (C1D1).
Patients with new or progressing brain metastases. Note: Patients with treated brain metastases that are stable in the opinion of the treating investigator are eligible.
Known significant cardiovascular disease, such as New York Heart Association cardiac disease (Class II or greater, see Appendix C), myocardial infarction within 3 months prior to Pre-Dose Leukapheresis, unstable arrhythmias, or unstable angina. To be eligible for this trial, patients should be class 2B or better. See Appendix C for more information.
Patients who have a history of allergic reactions attributed to compounds of similar chemical or biologic composition to N-803 or history of severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric or humanized antibodies or fusion proteins.
Participants who, in the opinion of the investigator, are unable to safely or feasibly receive subcutaneous injections of N-803. Examples include:
Absence of suitable subcutaneous tissue for injection (e.g., due to cachexia, scarring, or anatomical limitations).
Known history of allergic reactions attributed to compounds of similar chemical or biologic composition to N-803, or history of severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric or humanized antibodies or fusion proteins.
Active skin conditions or infections at potential injection sites.
Physical or psychological inability to tolerate subcutaneous injection procedures (e.g., severe needle phobia, movement disorders).
Medical contraindications to subcutaneous administration (e.g., bleeding disorders, severe dermatologic conditions).
Any other factors that, in the judgment of the investigator, would interfere with safe and feasible administration of subcutaneous injections.
Major surgical procedure (as defined in Appendix E, e.g., GI surgery, removal or biopsy of brain metastasis), other than for diagnosis or known need for a major surgical procedure while on study treatment.
Systemic autoimmune disease currently requiring treatment (e.g., lupus erythematosus, rheumatoid arthritis, Addison's disease, or autoimmune disease associated with lymphoma). The patient must have been off treatment for 90 days from registration.
History of organ transplant requiring immunosuppression; or history of pneumonitis or interstitial lung disease requiring treatment with systemic steroids; or a history of receiving systemic steroid therapy or any other immunosuppressive medication ≤ 3 days prior to study initiation. Daily steroid replacement therapy (e.g., prednisone or hydrocortisone at doses of ≤ 10 mg/day of prednisone (or equivalent)) and corticosteroids used to manage AEs are permitted.
Use of physiologic doses of systemic steroid replacement is permitted at doses of ≤ 10 mg/day of prednisone (or equivalent, e.g., dexamethasone 1.5 mg, methylprednisolone 8 mg, or hydrocortisone 40 mg).
Local steroids, including topical steroids (e.g., hydrocortisone, clobetasol), nasal steroids (e.g., fluticasone, mometasone), or inhaled steroids (e.g., budesonide, beclomethasone).
Limited courses (\< 1 week) of systemic steroids (≤ 10 mg/day of prednisone or equivalent) (e.g, in patients with exacerbations of reactive airway disease or anaphylaxis in patients who have known contrast allergies).
Immunosuppressive treatments to optimally manage immune-related AEs as clinically indicated
Serious uncontrolled concomitant disease that would contraindicate the use of the investigational drug used in this study or that would put the patient at high risk for treatment-related complications.
Patients who have an uncontrolled intercurrent illness including, but not limited to any of the following:
Hypertension that is not controlled on medication
Ongoing or active infection requiring systemic treatment including:
Known active infection with acute or chronic hepatitis B or C, known active human immunodeficiency virus (HIV), or acquired immunodeficiency syndrome
Exception: uncomplicated urinary tract infections (or sinus infections and are on antibiotics)
(AIDS)-related illness
Symptomatic congestive heart failure
Unstable angina pectoris
Cardiac arrhythmia
Psychiatric illness/social situations that would limit compliance with study requirements
Any other illness or condition that the treating investigator feels would interfere with study compliance or would compromise the patient's safety or study endpoints
Patients with a prior or concurrent malignancy whose natural history or treatment has the potential to interfere with the safety or efficacy assessment of the investigational regimen except the following:
Basal cell carcinoma of the skin
Squamous cell carcinoma of the skin
In situ cervical cancer that has undergone potentially curative therapy - Patient is pregnant or nursing. Note: Pregnant patients are excluded from this study because N-803 is an interleukin-15 (IL-15) receptor agonist with potential for teratogenic or abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with N-803, breastfeeding should be discontinued if the mother is treated with N-803.
Other conditions which, in the opinion of the Investigator, would compromise the safety of the patient or the patient's ability to complete the study.
Patients who need to be on concurrent anticancer treatment (e.g., chemotherapy, immunotherapy, cytokine therapy \[except erythropoietin\]) throughout participation in the study.
Patients who have had prior use of narrow therapeutic index drugs that are substrates of major CYP450 enzymes within 14 days of first study drug administration per discretion of the treating investigator, including but not limited to:
Tacrolimus
Cyclosporine
Sirolimus
Everolimus
Warfarin
Phenytoin
Midazolam
Tamoxifen
Codeine
Erlotinib
Patients who have had prior use concomitant medications that prolong the QT/QTc interval within 14 days of first study drug administration visit per discretion of the treating investigator.
Patients who have had prior biologic therapies or chemotherapy within 28 days of Pre-Dose Leukapheresis visit, or radiation therapy within 14 days of Pre-Dose Leukapheresis visit.
What this trial measures
- The expansion of rare persisting transferred T-cell receptor therapyBefore and after eight weeks of N-803 therapy
Will be assessed using T-cell receptor sequencing or flow cytometry.
- Incidence of adverse eventsUp to 30 days after the last administration of N-803
Will be determined by the incidence, severity, and attribution of adverse events graded per National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.