A Phase 3 interventional study of short-course radiotherapy and Serplulimab in Locally Advanced Colon Cancer and pMMR, sponsored by Fudan University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Fudan University · Phase 3, Interventional, and Treatment
Locally advanced colon cancer, particularly T4 disease or colon cancer with bulky nodes, carries a poor prognosis and limited efficacy with neoadjuvant chemotherapy. In our previous small-sample phase II study, PD-1 inhibitor plus CAPOX chemotherapy combined with short-course radiotherapy yielded a marked improvement in the pCR rate compared with neoadjuvant CAPOX alone, though survival outcomes remain under follow-up. This prospective, multicentre, randomised, three-arm phase III study enrolls 480 patients with pMMR/MSS locally advanced high-risk colon cancer. Participants are randomised in a 2:2:1 ratio to three arms: short-course radiotherapy combined with chemotherapy and PD-1 inhibitor (25 Gy in 5 fractions of radiotherapy, followed by 4 cycles of CAPOX plus the PD-1 inhibitor serplulimab); chemotherapy plus PD-1 inhibitor (4 cycles of CAPOX combined with serplulimab); and chemotherapy alone (4 cycles of CAPOX). The primary endpoint is the 3-year event-free survival (EFS) rate. Secondary endpoints include the pCR rate, 5-year overall survival rate (5y OS), R0 resection rate, toxicity, surgical complications and quality of life.
1,485 studies on the registry are indexed under Colonic Neoplasms; 362 are open to participants now.
This study's planned enrollment of 480 is above the median of 89 across 1,067 interventional studies indexed under Colonic Neoplasms.
Browse Colonic Neoplasms studies →Fudan University is the lead sponsor of 1,308 studies on the registry; 637 are open to participants now.
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1. Aged ≥18 years, of any gender. 2. Colon adenocarcinoma confirmed by histopathology, with the tumour located >15 cm from the anal verge on colonoscopy.
3. Locally high-risk disease demonstrated by contrast-enhanced abdominal CT or MRI, defined as tumour invasion beyond the serosa or into adjacent organs (cT4), or high-risk lymph nodes and tumour deposits. No distant metastasis (M0) identified on chest CT plus contrast-enhanced pelvic CT/MRI, or whole-body PET-CT.
4. pMMR or MSS status confirmed by immunohistochemistry or genetic testing. 5. No prior anti-tumour therapy. 6. ECOG performance status 0-1, with an expected survival of ≥3 months. Patients must be willing to cooperate with adverse event and efficacy assessments.
7. Adequate organ function:
8. No severe concomitant disease that would limit life expectancy to less than 5 years.
9. Female subjects of childbearing potential must have a negative pregnancy test; female subjects without childbearing potential are also eligible.
10. Male patients of childbearing potential and female patients with childbearing potential and pregnancy risk must agree to use adequate contraception throughout the study period and for 12 months after completion of study treatment.
11. Signed and dated informed consent form, indicating that the patient has been informed of all relevant aspects of the study.
12. Patients who are willing and able to comply with scheduled visits, treatment plans, laboratory tests and other study procedures.
Exclusion Criteria:
1. Histopathological diagnosis of other colonic neoplasms, such as gastrointestinal stromal tumour, lymphoma, etc.
2. Prior treatment with PD-1 antibody, PD-L1 antibody or CTLA-4 antibody. 3. Previous or concurrent malignancy, except for adequately treated non-melanoma skin cancer, cervical carcinoma in situ and papillary thyroid carcinoma.
4. Active autoimmune disease or a history of autoimmune disease (including but not limited to interstitial pneumonia, colitis, hepatitis, hypophysitis, vasculitis, nephritis, hyperthyroidism and hypothyroidism). Exceptions include autoimmune-mediated hypothyroidism treated with a stable dose of thyroid replacement hormone; type 1 diabetes mellitus managed with stable-dose insulin; vitiligo; or childhood asthma/allergy that has resolved and requires no intervention in adulthood.
5. History of immunodeficiency, including positive HIV test, other acquired or congenital immunodeficiency disorders, or a history of solid organ transplantation and allogeneic bone marrow transplantation.
6. History of interstitial lung disease (excluding radiation pneumonitis not treated with steroids) or non-infectious pneumonitis.
7. Subjects with active pulmonary tuberculosis identified by medical history or CT scan; those with a history of active pulmonary tuberculosis within 1 year prior to enrollment; or those with a history of active pulmonary tuberculosis more than 1 year previously who did not receive standard anti-tuberculosis treatment.
8. Subjects with active hepatitis B (HBV DNA ≥2000 IU/mL or 10⁴ copies/mL) or hepatitis C (positive hepatitis C antibody with HCV-RNA above the lower limit of quantification of the assay).
9. Severe impairment of cardiac, pulmonary, renal or hepatic function. 10. Uncontrolled hypertension despite antihypertensive medication (systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg).
11. History of psychoactive substance abuse, alcoholism or illicit drug use. 12. Other factors judged by the investigator to compromise subject safety or trial compliance. Examples include severe diseases requiring concomitant treatment (including psychiatric disorders), significant laboratory abnormalities, or other familial or social factors.
Group A receives 25 Gy in 5 fractions of radiotherapy, followed by 4 cycles of CAPOX plus the PD-1 inhibitor serplulimab
Radiation: short-course radiotherapy · Drug: Serplulimab · Drug: CapOx(Capecitabine+ Oxaliplatin)
Group B receives 4 cycles of CAPOX plus the PD-1 inhibitor serplulimab
Drug: Serplulimab · Drug: CapOx(Capecitabine+ Oxaliplatin)
Group C receives 4 cycles of CAPOX
Drug: CapOx(Capecitabine+ Oxaliplatin)
short-course radiotherapy with 25 Gy in 5 Fractions (25 Gy/5Fx)
A fixed dose of 300 mg is administered by intravenous infusion on Day 1 (D1), once every 3 weeks (Q3W).
Also known as: immunotherapy, PD-1 inhibitor
Oxaliplatin (130 mg/m²) is administered by intravenous infusion on Day 1. Capecitabine 1000 mg/m² is given orally twice daily (bid) from Day 1 to Day 14, repeated every 3 weeks (Q3W).
Also known as: chemotherapy
3-year event-free survival
rate of 3-year event-free survival
Time frame: From the date of randomization until the date of first documented disease progression or toxicity during neoadjuvant therapy that prevent surgery, local regional recurrence, distant metastasis, or death, whichever came first, assessed up to 36 months.
pathological complete response （pCR）
Defined as the proportion of patients in the arm with no residual viable tumour cells in the primary lesion and lymph nodes on surgical specimens.
Time frame: one month after surgery
R0 resection rate
Defined as the proportion of patients in the trial arm who achieve curative resection with microscopically negative resection margins.
Time frame: one month after surgery
Organ preservation rate:
Defined as the proportion of patients in the trial arm without combined organ resection.
Time frame: one month after surgery
5-year overall survival
Defined as the proportion of patients in the trial arm who are still alive at 5 years from randomisation.
Time frame: From the time of randomisation to 5 years.
Grade ≥3 toxicity rate
Defined as the proportion of all enrolled patients who experience grade 3 or higher adverse events related to radiotherapy, chemotherapy and immunotherapy during and after the combined treatment.
Time frame: From the time of randomization to 1 year after complete treatment
Surgical complication rate
Defined as the proportion of operated patients who develop surgical-related complications including wound infection, anastomotic leak, haemorrhage and others after surgery.
Time frame: From the time of surgery to 1 month after surgery
Plan to share: No — Individual participant data (IPD) from this study will not be shared. The rationale includes restrictions imposed by the institutional review board, Chinese national data protection regulations, and patient privacy requirements. In addition, the study dataset contains sensitive clinical and genomic information of participants, and the research team has not established a dedicated data sharing platform for external IPD access. Study summary results will be published in peer-reviewed journals upon completion of the trial.
Start is estimated for Oct 2026; primary completion for Dec 2029, 38 months later.
Of 50 phase 3 interventional studies under Colonic Neoplasms, half reached primary completion within 87 months of starting (the median), counting those still running; a quarter within 48 and three quarters within 128. This study's planned 38 months is below that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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