Combination immunotherapy for metastatic colorectal cancer

Phase I/II Study of the Combination Immunotherapy Regimen: SX-682, TriAdeno Vaccine, Retifanlimab and IL-15 Agonist N-803 (STAR15) for Metastatic Colorectal Cancer (mCRC)

Phase1; Phase2 Interventional National Institutes of Health Clinical Center (CC) · NCT06149481

This study is testing a new combination of four experimental cancer drugs to see if they can help people with metastatic colorectal cancer that usually doesn't respond to standard treatments.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 120 Years
SexAll
SponsorNational Institutes of Health Clinical Center (CC) NIH
Drugs / interventionsbevacizumab, chemotherapy, immunotherapy, radiation, prednisone, retifanlimab, pembrolizumab
Locations1 site (Bethesda, Maryland)
Trial IDNCT06149481 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of a combination of four experimental anti-cancer drugs—retifanlimab, TriAdeno vaccine, N-803, and SX-682—in treating metastatic colorectal cancer (mCRC). Participants will undergo screening, including physical exams and imaging tests, and will receive two tumor biopsies during the study. The treatment regimen will involve either three or four of the drugs, with a detailed schedule provided to participants. The study seeks to enhance immune responses in patients with MSS mCRC, which typically does not respond to standard immune checkpoint inhibitors.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with histologically confirmed metastatic colorectal cancer who have received or refused standard systemic therapies.

Not a fit: Patients with early-stage colorectal cancer or those who have not received prior systemic therapies may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve survival rates and quality of life for patients with metastatic colorectal cancer.

How similar studies have performed: Other studies have shown promise with similar immunotherapy approaches, but this specific combination is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
* INCLUSION CRITERIA:
* Participants with histologically confirmed colorectal cancer and evidence of metastatic disease.
* Participants must have received, been ineligible to receive, or refused to receive two lines of standard systemic therapy i.e., a fluoropyrimidine with oxaliplatin or irinotecan with bevacizumab, regorafenib, trifluridine, and (if history of RAS wild-type) EGFR-targeted therapy. Participants must have received one line of systemic checkpoint inhibitor if history of advanced microsatellite instability-high \[MSI-H/dMMR\]) metastatic colon cancer.
* Participants who had progressive disease within 6 months before study treatment following standard adjuvant therapy are eligible if they have not received systemic therapy for metastatic disease. Participants with a history of MSI-H/dMMR must have also received one line of checkpoint inhibitor therapy.
* Age \>= 18 years.
* Measurable disease per RECIST 1.1.
* ECOG performance status \<= 2.
* Adequate organ and marrow as a function defined below:

  * absolute neutrophil count (ANC) \>= 1,500 cells/mm\^3
  * platelet count \>= 100,000 cells/mm\^3
  * hemoglobin (Hgb) \>= 9 g/dL
  * total bilirubin level \< 1.5 x upper limit of normal (ULN)
  * alanine aminotransferase (ALT) \<= 2.5 x ULN OR \<= 5 x ULN for participants with liver metastases
  * aspartate aminotransferase (AST) level \<= 2.5 x ULN OR \<= 5 x ULN for participants with liver metastases
  * creatinine clearance (CrCl) calculated by Cockroft-Gault formula \>= 50 mL/min
* Resolution of toxic effect(s) of prior anti-cancer therapy (except alopecia and neuropathy) to Grade \<=1 or to \<=2 if effective medical management of those toxicities is in place such that they are controlled per standard of care (e.g., grade 2 hypothyroidism requiring oral thyroid replacement).
* Participants with treated brain metastases are eligible if clinically appropriate follow-up brain imaging after central nervous system (CNS)-directed therapy shows no evidence of progression.
* Participants positive for human immunodeficiency virus (HIV) are eligible if they are compliant with appropriate anti-retroviral therapy for at least 6 months, have HIV viral load \<400 copies/mL, and a CD4 count \> 350 cells/microliter at screening.
* Participants positive for Hepatitis C virus (HCV) are eligible if they have completed definitive anti-viral therapy and have an undetectable viral load.
* Individuals of child-bearing potential (IOCBP) and individuals who can father children must agree to use an effective method of contraception (barrier, hormonal, intrauterine device \[IUD\], surgical sterilization) at study entry and up to 6 months after the last dose of the study drug(s).
* Breastfeeding participants must be willing to discontinue breastfeeding from study treatment initiation through 6 months after study treatment discontinuation.
* Participants must have lesion(s) accessible for biopsy (other than used for measurement of disease) and be willing to undergo mandatory study biopsies. Lesions to be biopsied will be determined safely accessible by the provider performing the biopsy (e.g. interventional radiology if a liver or lung biopsy) prior to performing the biopsy.
* Participants must be able to understand and willing to sign a written informed consent document.

EXCLUSION CRITERIA:

* Participants with prior investigational drug, chemotherapy, immunotherapy, or any prior therapeutic radiotherapy within 14 days prior to study treatment initiation.
* Participants with palliative radiotherapy performed within 7 days prior to study treatment initiation.
* Active autoimmune disease requiring systemic immunosuppression in excess of physiologic maintenance doses of corticosteroids (\> 10 mg/day of prednisone or equivalent) with the exception of:

  * intermittent use of bronchodilators, inhaled corticosteroids, or local corticosteroid injections in participants with asthma
  * using topical, ocular, intra-articular, or intranasal corticosteroids (with minimal systemic absorption
  * brief courses of corticosteroids for prophylaxis (e.g., contrast dye allergy).
* Evidence of interstitial lung disease, history of interstitial lung disease, or active, noninfectious pneumonitis. Participants with chronic post-radiation pulmonary changes/scarring that is asymptomatic are eligible.
* Active infections requiring systemic antibiotics or antifungal or antiviral treatment within 8 days prior to treatment initiation. Participants who have had appropriate antibiotics initiated but are still completing the treatment course are eligible if clinically improved or had minimal symptoms at presentation (e.g., urinary tract infection or pharyngeal streptococcal infection without evidence of systemic inflammatory response).

  * History of organ transplant, including allogeneic stem cell transplantation.
  * Participants who experienced immune-related toxicity during prior checkpoint inhibitor therapy for which permanent discontinuation of therapy was recommended (per product label or consensus guidelines) or any immune-related toxicity requiring systemic corticosteroids (with the exception of endocrinopathy that is well controlled on replacement hormones).
* History of allergic reactions attributed to compounds of similar chemical or biologic composition to the study drugs.
* Receipt of a live vaccine within 28 days prior to treatment initiation. Note: Examples of live vaccines include but are not limited to measles, mumps, rubella, varicella-zoster (chickenpox), yellow fever, rabies, BCG, and typhoid vaccines. Seasonal influenza vaccines for injection are generally killed-virus vaccines and are allowed; however, intranasal influenza vaccines are live, attenuated vaccines and are not allowed.
* History of infection with Hepatitis B virus (HBV) unless on suppressive therapy. Individuals with serologic evidence of a resolved prior HBV infection (i.e., HBsAgnegative and anti-HBc positive) are eligible.
* Pregnancy confirmed with Beta-human chorionic gonadotropin (Beta-HCG) serum or urine pregnancy test performed in IOCBP at screening.
* Uncontrolled intercurrent illness that would limit compliance with study requirements.

Where this trial is running

Bethesda, Maryland

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 Metastatic Colorectal CancerMonoclonal AntibodyBrachyuryMUC-1Immunoglobulin G cytokine fusion proteinchemokine antagonistSmall Molecule
Last reviewed 2026-06-13 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.