Neoadjuvant Chemoradiotherapy Followed by Chemotherapy With or Without Tislelizumab for Resectable Ultra-low Rectal Cancer: The RELIEVE-02 Study

NCT07132463 | Not Yet Recruiting Phase 3

• 1 other identifier: RELIEVE-02
• Study Type: interventional
• Target: 154
• Locations: 0 countries
• Sites: N/A

Brief Summary

This open-label, multicenter, randomized controlled trial involved 154 patients with pathologically confirmed, previously untreated, resectable MSI-L or MSS/pMMR ultra-low rectal adenocarcinoma. Patients were randomly assigned (1:1) to two groups to receive concurrent chemoradiotherapy followed by 4-6 cycles of chemotherapy ± tislelizumab. After treatment, patients who achieved complete clinical response (cCR), including those who reached pCR after local excision, or near cCR with pCR after local excision, were recommended to continue with 4-2 cycles of chemotherapy ± tislelizumab, followed by a watch-and-wait approach. Patients evaluated as incomplete responders were recommended for total mesorectal excision (TME) surgery. The primary endpoint is the anus preservation rate, while secondary endpoints include CR rate, 1-year/2-year/3-year organ preservation rates, 1-year/2-year/3-year EFS rates, and 1-year/2-year/3-year OS rates, etc.

Conditions

Rectal Cancer

Keywords

Ultra-low Rectal Cancer; Tislelizumab; Neoadjuvant Chemoradiotherapy; Anus Preservation; PD-1

Outcome Measures

Primary Outcomes (1)

• Anus preservation rate

  Defined as the anus preservation rate in the efficacy-evaluable analysis set of patients, as assessed by the investigators.

  From first dose of radiotherapy up to approximately 24/32±4 weeks.

Secondary Outcomes (5)

• Complete Response rate (CR Rate)

  From first dose of radiotherapy up to approximately 24/32±4 weeks.

• 1/2/3-Year Organ-Preservation Rate

  From first dose of radiotherapy up to approximately 36 months.

• 1/2/3-Year EFS Rate

  From first dose of radiotherapy up to approximately 36 months.

• 1/2/3-Year OS Rate

  From first dose of radiotherapy up to approximately 36 months.

• Percentage of Participants With Adverse Events

  From first dose of radiotherapy up to approximately 36 months.

Study Arms (2)

Concurrent Chemoradiotherapy Followed by Chemotherapy Plus Immunotherapy Group

EXPERIMENTAL

Long-course chemoradiotherapy followed by 4 cycles of CAPOX and Tislelizumab. (Note: Patients evaluated as ncCR after completion, if refusing local excision, may receive an additional 2 cycles of CAPOX and Tislelizumab before re-evaluation.)

Radiation: Long-course chemoradiotherapy; Drug: Tislelizumab combined with the CAPOX regimen

Concurrent Chemoradiotherapy Followed by Chemotherapy Group

ACTIVE COMPARATOR

Long-course chemoradiotherapy followed by 4 cycles of CAPOX. (Note: Patients evaluated as ncCR after completion, if refusing local excision, may receive an additional 2 cycles of CAPOX before re-evaluation.)

Radiation: Long-course chemoradiotherapy; Drug: CAPOX regimen

Interventions

Long-course chemoradiotherapy RADIATION

45-50.4 Gy in 25-28 fractions to the pelvis on Days 1-5 each week. Capecitabine at a dose of 825 mg/m², taken orally twice daily (bid), 5 days per week during radiotherapy.

Concurrent Chemoradiotherapy Followed by Chemotherapy Group; Concurrent Chemoradiotherapy Followed by Chemotherapy Plus Immunotherapy Group

Tislelizumab combined with the CAPOX regimen DRUG

Tislelizumab 200 mg IV on Day 1 of each 21-day cycle. Capecitabine: 1000 mg/m² orally twice daily (bid) on Days 1-14 of each 21-day cycle. Oxaliplatin: 130 mg/m² IV on Day 1 of each 21-day cycle.

Concurrent Chemoradiotherapy Followed by Chemotherapy Plus Immunotherapy Group

CAPOX regimen DRUG

Capecitabine: 1000 mg/m² orally twice daily (bid) on Days 1-14 of each 21-day cycle. Oxaliplatin: 130 mg/m² IV on Day 1 of each 21-day cycle.

Concurrent Chemoradiotherapy Followed by Chemotherapy Group

Eligibility Criteria

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

You may qualify if:

• Able to provide written informed consent, understand, and comply with the requirements and evaluation schedule.
• Age ≥18 and ≤75 years old.
• Histologically confirmed rectal adenocarcinoma.
• Immunohistochemistry confirmed pMMR (positive for MLH1, MSH2, MSH6, and PMS2), or PCR/NGS confirmed MSI-L or MSS.
• Tumor distal margin confirmed to be ≤ 3 cm from the anal verge by colonoscopy, digital rectal examination, or MRI.
• Clinical stage cT1-3N1M0 or cT3N0M0 (the 8th UICC/AJCC; T and N evaluated by MRI).
• Resectable primary tumor assessed by the Investigator.
• No prior anti-tumor treatment for rectal cancer.
• Eastern Cooperative Oncology Group (ECOG) performance status score ≤ 1.
• Adequate organ function.
• Female subjects with the ability to become pregnant must have a serum pregnancy test with a negative result within 72 hours before the first dose and be willing to use highly effective contraceptive methods during the trial and for 120 days after the last dose. Male subjects whose partners are women of childbearing potential should be surgically sterilized or agree to use a highly effective method of contraception during the trial and for 120 days after the last dose.

You may not qualify if:

• Histologically confirmed poorly differentiated/undifferentiated adenocarcinoma, mucinous adenocarcinoma, or signet ring cell carcinoma.
• Previously received treatment for rectal cancer or have evidence of distant metastasis.
• Presence of the following high-risk factors assessed by MRI: MRF+, EMVI+, cN2, positive lateral lymph nodes, T3d.
• Presence of or at high risk for obstruction, perforation, or bleeding.
• Unsuitability for long-course radiotherapy.
• Inability to tolerate surgery.
• ≥ 2 colorectal cancer lesions at the same time.
• Contraindications for MRI examination.
• Other malignant tumors in the past or currently present.
• Active autoimmune disease requiring systemic therapy within the past 2 years.
• HIV infection.
• Untreated chronic hepatitis B or chronic hepatitis B virus (HBV) carriers (HBV DNA \> 500 IU/mL) or active HCV carriers with detectable HCV RNA.
• Hypersensitivity to any ingredient of tislelizumab, capecitabine, and oxaliplatin, or to any component of their containers.
• Other conditions judged by the researcher as not meeting the enrollment requirements.

Sponsors & Collaborators

• Fudan University: lead

MeSH Terms

Conditions

Rectal Neoplasms

Interventions

XELOX

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

Central Study Contacts

Jianmin Xu, MD

CONTACT

86-21-64041990; xujmin@aliyun.com

Wentao Tang, MD

CONTACT

tangwt1988@163.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chief Physician

Study Record Dates

• First Submitted: August 12, 2025
• First Posted: August 20, 2025
• Study Start: August 1, 2025
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2030
• Last Updated: August 20, 2025

Record last verified: 2025-08