Radiotherapy Combined With Capeox Chemotherapy, Sintilimab and Suvemcitug in Locally Advanced pMMR Rectal Cancer:a Prospective Clinical Trial

NCT07774754 | Not Yet Recruiting Phase 2

• 1 other identifier: B2026-381-01
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

This study is a prospective, single-arm clinical trial with a dose-reduction design, which is expected to enrol 18 patients with locally advanced rectal cancer with pMMR status. The aim is to investigate the safety and efficacy of neoadjuvant chemoradiotherapy combined with sintilimab and suvecitib. Patients will receive long-course chemoradiotherapy (concurrent capecitabine, 1000 mg/m², twice daily, days 1-14, Q3W, 2 cycles; sintilimab, 200 mg, d1, IV drip, Q3W, 2 cycles), followed by 6 cycles of the Capeox regimen in combination with sintilimab and suvecitib, namely oxaliplatin 130 mg/m², d1, IV infusion, every 3 weeks; and capecitabine 1,000 mg/m², twice daily, days 1-14, every 3 weeks; sintilimab, 200 mg, Day 1, IV drip, every 3 weeks; suvectitumab (anti-angiogenic agent), 2.0/1.5/1.0 mg/kg, Day 1, IV drip, every 3 weeks. A total of 8 cycles of sintilimab and 6 cycles of suvectitumab were administered during the neoadjuvant treatment period. If, following completion of neoadjuvant therapy, the subject has not achieved cCR/near-cCR status, TME surgery or other therapeutic surgery shall be performed; the interval between the final dose of suvectitumab and surgery should be ≥6 weeks. If cCR/near-cCR status is achieved, watchful waiting or other treatment options shall be discussed with the patient. The adjuvant treatment regimen following surgery shall be determined by the investigator based on the patient's pathological results.

Conditions

Rectal Cancer

Outcome Measures

Primary Outcomes (1)

• Serious Adverse Effects of Neoadjuvant Therapy

  During neoadjuvant therapy

Secondary Outcomes (9)

• Complete response (CR) rate

  The proportion of participants who achieved either of the following outcomes following neoadjuvant therapy: pathological complete response (pCR) or clinical complete response (cCR)

• major pathological response and tumor regression grade

  At the time of surgical pathological assessment

• R0 rate

  At the time of surgical pathological assessment

• Long-Term Quality of Life

  From date of randomization , assessed up to 60 months.

• Incidence of Surgical Complications

  the surgical complications were assessed up to 1 year from the surgery.

Study Arms (1)

Treatment Arm

EXPERIMENTAL

This study is expected to enroll 18 patients with pMMR locally advanced rectal cancer. Patients will receive long-term chemoradiotherapy (concurrent capecitabine and two cycles of sintilimab), followed by six cycles of the Capeox regimen in combination with sintilimab and Suvemcitug. Initially, 6 patients will be enrolled to receive 2 mg/kg of suvecitib for safety evaluation. After the third patient completes neoadjuvant therapy, if two or more patients develop Grade 4 acute radiation-induced rectal injury, the dose of suvecitib will be reduced to 1.5 mg/kg for re-evaluation. If two or more patients still develop Grade 4 acute radiation-induced rectal injury, the dose will be further reduced to 1 mg/kg for re-evaluation.If 1 or fewer patients develop Grade 4 acute radiation-induced rectal injury, the sample size for this cohort will be expanded to 18 patients.

Drug: Drug：sintilimab; Drug: Drug：Capecitabine; Drug: Drug：Suvemcitug; Radiation: Radiation: Neoadjuvant Radiotherapy

Interventions

Drug：sintilimab DRUG

During neo-CRT: 2 cycles of sintilimab, 200mg d1 q3w. After neo-CRT: 6 cycles of sintilimab, 200mg d1 q3w.

Treatment Arm

Drug：Capecitabine DRUG

During neo-CRT: capecitabine, 1000 mg/m², twice daily, days 1-14, every 3 weeks, 2 cycles. After neo-CRT: 6 cycles of capecitabine, 1000 mg/m², twice daily, days 1-14, every 3 weeks.

Treatment Arm

Drug：Suvemcitug DRUG

After neo-CRT: 6 cycles of suvecitib (anti-angiogenic agent), 2.0/1.5/1.0 mg/kg, Day 1, every 3 weeks.

Treatment Arm

Radiation: Neoadjuvant Radiotherapy RADIATION

IMRT DT: 50Gy/25Fx

Treatment Arm

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \) Aged 18-75 years;
• \) ECOG 0-1;
• \) Histologically confirmed rectal adenocarcinoma;
• \) Preoperative staging: cT3-4N0M0 or cT1-4N+M0;
• \) Distance from the tumour's inferior margin to the anus ≤ 12 cm;
• \) Tumour biopsy immunohistochemistry indicates pMMR, i.e. positive expression of all MSH1/MSH2/MSH6/PMS2, and molecular testing indicates MSS (microsatellite-stable).
• \) Liver function: Serum total bilirubin ≤ 1.5 × ULN (for subjects with Gilbert's syndrome, total bilirubin ≤ 3 × ULN is allowed)；aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × ULN；
• \) Renal function: serum creatinine ≤ 1.5 × ULN, or creatinine clearance \> 50 mL/min;
• \) Other: not pregnant or breastfeeding; no other malignant diseases within the past 5 years or concurrently (excluding basal cell carcinoma of the skin or cervical carcinoma in situ); no mental illness preventing the provision of informed consent; no concomitant serious diseases that would shorten survival;
• \) No previous surgery, chemotherapy or radiotherapy for rectal cancer;
• \) No previous immunotherapy;
• \) Previous endocrine therapy: no restrictions.

You may not qualify if:

• \) Failure to sign an informed consent form;
• \) Immunohistochemistry of tumor biopsy specimens indicating dMMR or microsatellite instability testing indicating MSI-H;
• \) Preoperative evidence of distant metastasis;
• \) History of severe bleeding tendency or coagulation disorders; patients who have previously or currently require long-term anticoagulant therapy (e.g., patients with atrial fibrillation who have a CHADS2 score of ≥2).
• \) History of myocarditis, cardiomyopathy, or malignant arrhythmias. History of unstable angina, congestive heart failure, or vascular disease (e.g., an aortic aneurysm requiring surgical repair or peripheral venous thrombosis) requiring hospitalization within 12 months prior to study treatment, or other cardiac conditions that may affect the safety evaluation of the study drug (e.g., poorly controlled arrhythmias, myocardial infarction, or ischemia) ;
• \) History of esophageal or fundic varices, severe ulcers, unhealed wounds, gastrointestinal perforation, abdominal fistula, gastrointestinal obstruction, intra-abdominal abscess, or acute gastrointestinal bleeding within 6 months prior to study treatment;
• \) History of any arterial thromboembolic event, venous thromboembolism of Grade 3 or higher according to NCI CTCAE Version 5.0, transient ischemic attack, cerebrovascular accident, hypertensive crisis, or hypertensive encephalopathy within 6 months prior to study treatment;
• )An acute exacerbation of chronic obstructive pulmonary disease (COPD) within 1 month prior to study treatment; current hypertension with a systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥100 mmHg despite treatment with oral antihypertensive medications; severe hypertension that is poorly controlled with medication;
• \) History of HIV infection or active chronic hepatitis B or C, or other active, clinically significant infections;
• \) Subjects with active pulmonary tuberculosis (TB) who are currently receiving antituberculosis therapy or who have received such therapy within 1 year prior to screening;
• \) Cachexia, organ dysfunction;
• \) History of pelvic or abdominal radiation therapy;
• \) Multiple primary colorectal cancers;
• \) Patients with seizures requiring treatment (e.g., with steroids or antiepileptic therapy);
• \) History of other malignancies within the past 5 years, excluding cured cervical carcinoma in situ or basal cell carcinoma of the skin;

Sponsors & Collaborators

• Sun Yat-sen University: lead

Study Sites (1)

Sun Yat-sen University Cancer Center

Guangzhou, Guangdong, 510060, China

Location

MeSH Terms

Conditions

Rectal Neoplasms

Interventions

Neoadjuvant Therapy

Condition Hierarchy (Ancestors)

Colorectal Neoplasms; Intestinal Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Diseases; Rectal Diseases

Intervention Hierarchy (Ancestors)

Combined Modality Therapy; Therapeutics

Central Study Contacts

Xiao weiwei

CONTACT

8613710390520; xiaoww@sysucc.org.cn

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chief Physician

Study Record Dates

• First Submitted: July 23, 2026
• First Posted: August 19, 2026
• Study Start: September 1, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): September 1, 2031
• Last Updated: August 19, 2026

Record last verified: 2026-08

Locations

CN (1)