Short-Course RT Plus CAPOX and Tislelizumab vs Long-Course CRT Plus Tislelizumab for Locally Advanced Rectal Cancer

Prospective, Randomized, Phase II Trial of Modified Short-Course Radiotherapy Plus CAPOX and Tislelizumab Versus Long-Course Chemoradiotherapy Plus Tislelizumab for Locally Advanced Rectal Cancer

To explore the complete response (CR) rate of modified short-course radiotherapy plus CAPOX and Tislelizumab versus Long-course Chemoradiotherapy plus Tislelizumab for locally advanced rectal cancer.

Study Overview

• Status: Not yet recruiting
• Conditions: Locally Advanced Rectal Cancer
• Intervention / Treatment: Radiation: Modified Short-course radiotherapy; Drug: Oxaliplatin; Drug: Capecitabine; Drug: Tislelizumab; Drug: Capecitabine; Drug: Tislelizumab; Radiation: Long-course radiotherapy

Detailed Description

In the exploration of treatments for locally advanced rectal cancer (LARC), the novel model combining short-course radiotherapy with CAPOX chemotherapy and PD-1 inhibitor (tislelizumab) is demonstrating promising potential. By comparing the efficacy and safety of modified short-course radiotherapy versus traditional long-course radiotherapy within this combination regimen, this study aims to identify the optimal radiotherapy strategy to maximize tumor regression and improve the complete response rate, thereby offering a more promising treatment option for rectal cancer patients seeking organ preservation.

• Study Type: Interventional
• Enrollment (Estimated): 130
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Jinluan Li, MD; Phone Number: +86 15159628678; Email: lijinluan@fjmu.edu.cn
• Study Contact Backup: Name: Chunkang Yang, MD; Phone Number: +86 13509333116; Email: chunk330@163.com

Study Locations

• China
  • Fujian
    • Fuzhou, Fujian, China, 350014
      • Fujian Cancer Hospital
      • Principal Investigator: Chunkang Yang, MD
      • Contact: Jinluan Li, MD; Phone Number: +86-15959628678; Email: lijinluan@fjmuedu.cn
      • Contact: Chunkang Yang, MD; Phone Number: +86-13509333116; Email: chunk330@163.com
      • Principal Investigator: Jinluan Li, MD,PhD
    • Longyan, Fujian, China, 364000
      • The Second Hospital of Longyan
      • Contact: Ping Lin; Phone Number: +86-139 5909 4969; Email: stone3166@126.com
      • Sub-Investigator: Jihuang Wang
      • Sub-Investigator: Hongsheng He
    • Quanzhou, Fujian, China, 362200
      • Jinjiang Municipal Hospital
      • Contact: Yixiang Zhuang, MD; Phone Number: +86 18876539839

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18-75 years, any gender.
• Pathologically confirmed rectal adenocarcinoma.
• Baseline MR stage T3-4/N+.
• Distance from anal verge ≤12cm.
• No distant metastasis.
• Karnofsky Performance Status ≥70.
• Adequate organ function, no contraindications to surgery, radiotherapy, or immunotherapy.
• Microsatellite/mismatch repair status MSS/pMMR.
• No prior chemotherapy or any other anti-tumor treatment before inclusion.
• No prior immunotherapy.
• Ability to comply with the study protocol during the study period.
• Signed written informed consent.

Exclusion Criteria:

• Pregnant or lactating women.
• Pathological diagnosis of signet ring cell carcinoma.
• History of other malignancies within the past 5 years, except cured skin cancer and cervical carcinoma in situ.
• Uncontrolled epilepsy, central nervous system disorders, or history of psychiatric disorders that, in the opinion of the investigator, may interfere with signing the informed consent form or affect patient compliance with oral medication.
• Clinically significant (i.e., active) cardiac disease, such as symptomatic coronary artery disease, New York Heart Association (NYHA) Class II or greater congestive heart failure, or significant arrhythmias requiring drug intervention (see Appendix 12), or history of myocardial infarction within the past 12 months.
• Organ transplant recipients requiring immunosuppressive therapy and long-term steroid users.
• Patients with autoimmune diseases.
• Severe uncontrolled recurrent infections or other severe uncontrolled comorbidities.

• Subjects with baseline hematological and biochemical parameters not meeting the following criteria: hemoglobin ≥90g/L; absolute neutrophil count (ANC) .≥1.5×10^9/L; platelets ≥100×10^9/L; ALT, AST ≤2.5 times the upper limit of normal; ALP

  ≤2.5 times the upper limit of normal; serum total bilirubin <1.5 times the upper limit of normal; serum creatinine <1 times the upper limit of normal; serum albumin ≥30g/L.

• Known deficiency of dihydropyrimidine dehydrogenase (DPD).
• Allergy to any investigational drug components.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Modified Short-course radiotherapy Combined with CAPOX plus Tislelizumab; Modified Short-course radiotherapy (GTV-P: 30 Gy/5f , CTV-P: 22.5 Gy/5 f),followed by Oxaliplatin ,Capecitabine and Tislelizumab q3w *4 cycles.Efficacy and surgery were assessed after the end of treatment.	Radiation: Modified Short-course radiotherapy; Rectal lesion + metastatic lymph nodes, GTV 30Gy/5Fx. Pelvic lymphatic drainage area, CTV 22.5Gy/5Fx.; Drug: Oxaliplatin; 130 mg/m²,d1, q3w ,4 cycles; Drug: Capecitabine; 1000 mg/m, d1-14,bid,q3w, 4 cycles; Drug: Tislelizumab; 200mg,d1,q3w,4 cycles; Drug: Capecitabine; 825 mg/m² ,BID ,on radiation days; Drug: Tislelizumab; 200mg,d1,q3w,3 cycles
Active Comparator: Long-course radiotherapy Combined with Capecitabine and Tislelizumab; Long-course radiotherapy (50.4 Gy/25 f) with concurrent Capecitabine (on radiation days) and Tislelizumab (q3w, 3cycles).Efficacy and surgery were assessed after the end of treatment.	Drug: Capecitabine; 1000 mg/m, d1-14,bid,q3w, 4 cycles; Drug: Tislelizumab; 200mg,d1,q3w,4 cycles; Drug: Capecitabine; 825 mg/m² ,BID ,on radiation days; Drug: Tislelizumab; 200mg,d1,q3w,3 cycles; Radiation: Long-course radiotherapy; Rectal lesion + metastatic lymph nodes+pelvic lymphatic drainage area,50.4 Gy/25 f

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complete Response (CR) Rate	Including pCR and CCR.	t 3 months after completion of neoadjuvant therapy and up to 12 months after enrollment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Organ Preservation Rate	Sphincter-saving rate in enrolled patients	1 year.
Surgical Complications	Incidence and severity of postoperative complications.	Within 30 days post-surgery
the Quality of Life	EORTC Core Quality of Life questionnaire (QLQ-C30)#range from 0-100, with comprehensive assessment indicators, including positive and negative indicators.	Baseline, before surgery, and up to 12 months after surgery
Grade ≥3 Adverse Event Rate	Incidence of grade 3 or higher adverse events graded according to CTCAE v4.0.	From start of treatment to 30 days after last dose, up to approximately 6 months
3y-DFS	Proportion of patients without disease recurrence or death from any cause at 3 years.	From enrollment to 36 month
3y-LRFS	Proportion of patients without local recurrence at 3 years.	From enrollment to 36 month
3y-OS	Proportion of patients alive at 3 years.	From enrollment to 36 month

Collaborators and Investigators

• Sponsor: Fujian Cancer Hospital
• Investigators: Principal Investigator: Jiunluan Li, MD, Fujian Cancer Hospital; Principal Investigator: Chunkang Yang, MD, Fujian Cancer Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): August 10, 2026
• Primary Completion (Estimated): August 10, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: March 6, 2026
• First Submitted That Met QC Criteria: March 10, 2026
• First Posted (Actual): March 13, 2026

Study Record Updates

• Last Update Posted (Actual): March 13, 2026
• Last Update Submitted That Met QC Criteria: March 10, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: CAPOX; PD-1 monoclonal antibody; Modified Short-course radiotherapy (mSCRT); Long-course radiotherapy (LCRT)
• Additional Relevant MeSH Terms: Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Nucleic Acids, Nucleotides, and Nucleosides; Coordination Complexes; Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Nucleosides; Uracil; Pyrimidinones; Deoxyribonucleosides; Fluorouracil; Capecitabine; Oxaliplatin; tislelizumab
• Other Study ID Numbers: CATIMOR-2

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No