The Phoenix Trial: Cemiplimab for Localized dMMR Colon Cancer
This study, called The Phoenix Trial, is looking at how well a drug called cemiplimab works for people with localized colon cancer that has a specific biomarker (a biological sign in your body) called dMMR (deficient mismatch repair). You may be able to join if you are 18 or older and have colon adenocarcinoma confirmed by a pathology review. The main goal is to see if cemiplimab can help manage the cancer without surgery, and to understand its safety. The study plans to enroll 50 participants, but its current recruitment status is unclear.
- Study design
- This is an interventional study, meaning participants will receive a specific treatment. It is a Phase II trial, and it plans to enroll 50 participants.
- What's involved
- Not specified in the trial record.
- Compensation
- Not stated in the trial record.
- Follow-up
- Adverse events will be measured through study completion, which is an average of 1 year.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
NCT05961709
The Phoenix Trial: Phase II Trial of Cemiplimab for the Non-operative Management of Localized dMMR Colon Cancer
Active, Not Recruiting
PHASE2Ages 18+InterventionalTreatmentM.D. Anderson Cancer CenterInvestigator-initiated
~50 participants
Updated 2026-05-04 on ClinicalTrials.gov
What's tested:Cemiplimab
At a glance
Recruiting sites
0 of 5 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Incidence of Adverse Events, Graded According to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Version (v) 5.0
Measured over Through study completion; an average of 1 year
Conditions
NCT05961709
Where you'd take part
This study runs at 5 sites. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.
Banner - MD Anderson Cancer
Gilbert, Arizonano site contact published
Baptist - MD Anderson Cancer Center
Jacksonville, Floridano site contact published
Cooper University Medical Center
Camden, New Jerseyno site contact published
M D Anderson Cancer Center
Houston, Texasno site contact published
Ochsner
New Orleans, Louisianano site contact published
Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.
Study leadership
- Michael Overman, MD · PRINCIPAL_INVESTIGATOR · M.D. Anderson Cancer Center
Who to contact
This trial hasn't published a contact. View it on ClinicalTrials.gov
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Eligibility criteria
Inclusion
Age ≥18 years
Histological confirmation of colon adenocarcinoma, as determined by pathology review (inferior colon margin defined as \>10 cm from anal verge).
Colon cancer that is deficient in mismatch repair (dMMR) or microsatellite Instability high (MSI-H) as determined by one of three methods:
Immunohistochemistry-determined dMMR by complete tumor nuclear loss of MLH1, PMS2, MSH2 or MSH6
PCR-determined MSI at \>30% of tested microsatellites
Next-generation-determined MSI-H based upon instability at multiple microsatellites as determined by the specific next generation sequencing panel
Localized colon cancer with (1) radiological staging of T3 or T4 or lymph node positive (stage II or III) OR (2) locally recurrent with luminal component OR (3) stage I with a surgical mortality defined as \>5% by American College of Surgeons (ACS) National Surgery Quality Improvement Program
Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1.
Primary tumor that is deemed to be accessible by endoscopic intervention and willingness to undergo repeated endoscopic evaluations
Measurable or non-measurable disease by cross-sectional imaging per RECIST v1.1 criteria
Laboratory values (obtained within 7 days prior to registration) meeting the following criteria:
Absolute neutrophil count (ANC) ≥1000/mme
Platelet count \>80,000/mm3
Hemoglobin \>8 g/dL
Total bilirubin ≤1.5 x upper limit of normal (ULN) \[for patients with Gilberts disease criteria is direct bilirubin ≤1.5 x ULN\]
Alanine aminotransferase (ALT) and aspartate transaminase (AST) ≤3 x ULN
Creatinine \<2.0 mg/dL
Negative urine or serum pregnancy test done ≤7 days prior to registration (women of childbearing potential only). NOTE: If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.
The effects of cemiplimab on the developing human fetus are unknown. For this reason, women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation and 4 months after the last dose of cemiplimab. (Refer to Pregnancy Assessment Policy MD Anderson Institutional Policy # CLN1114). This includes all female patients, between the onset of menses (as early as 8 years of age) and 55 years unless the patient presents with an applicable exclusionary factor which may be one of the following:
Postmenopausal (no menses in greater than or equal to 12 consecutive months).
History of hysterectomy or bilateral salpingo-oophorectomy.
Ovarian failure (Follicle Stimulating Hormone and Estradiol in menopausal range, who have received Whole Pelvic Radiation Therapy).
History of bilateral tubal ligation or another surgical sterilization procedure.
Approved methods of birth control are as detailed in Appendix 4.
Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 4 months after completion of cemiplimab administration.
Willingness to return to enrolling institution for follow-up.
Willingness to provide mandatory blood specimens for correlative research (not applicable to external sites: Cancer Network sites and LBJ Hospital)
Ability to understand and the willingness to sign a written informed consent document.
Willing and able to comply with clinical trial instructions and requirements. Individuals lacking the ability, based on reasonable medical judgment, to understand and appreciate the nature and consequences of participation in this study will not be eligible for participation.
Exclusion
Failure to recover from acute, reversible effects of prior therapy regardless of interval since last treatment. EXCEPTION: Grade 1 or 2 peripheral (sensory) neuropathy or alopecia
Comorbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens; conditions including but not limited to:
symptomatic congestive heart failure
unstable angina pectoris
cardiac arrhythmia
ongoing or active infection
psychiatric illness/social situations
dyspnea at rest due to complications of advanced malignancy or other disease that requires continuous oxygen therapy
any other conditions that would limit compliance with study requirements
Immunocompromised patients and patients known to be HIV positive and currently receiving antiretroviral therapy without undetectable viral load. NOTE: Patients known to be HIV positive, but without clinical evidence of an immunocompromised state, are eligible for this trial.
Receiving any other investigational agent, chemotherapy or other targeted therapy that would be considered as a treatment for the colon cancer.
Because this study involves an investigational agent whose genotoxic, mutagenic and teratogenic effect on the developing fetus and newborn are unknown, the following are not eligible for participation in this trial:
Pregnant persons
Nursing persons
Persons who are breastfeeding
Persons of childbearing potential who are unwilling to employ adequate contraception
Persons expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of trial treatment.
Any of the following prior therapies, if applicable:
Surgery ≤3 weeks prior to study treatment
Chemotherapy ≤2 weeks prior to study treatment
Radiation therapy ≤2 weeks prior to study treatment
Patients who have received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., CTLA-4, OX 40, CD137) for colon cancer
Patients with a prior or concurrent malignancy whose natural history or treatment have the potential to interfere with the safety or efficacy assessment of the investigational regimen
Patient has known metastatic sites of disease. Note: locoregional lymph nodes or tumor deposits are not considered metastatic disease. Also, locally recurrent disease is allowed.
Patient has active autoimmune disease that has required systemic treatment in the past year (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (e.g.., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment.
Patient has a history of (non-infectious) pneumonitis that required steroids or has current pneumonitis
What this trial measures
- Incidence of Adverse Events, Graded According to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Version (v) 5.0Through study completion; an average of 1 year