Actively Recruiting
Neoadjuvant Chemoradiotherapy Combined With Tislelizumab With or Without Probio-M9 in pMMR/MSS Locally Advanced Middle and Low Rectal Cancer: A Single-Center, Prospective, Randomized Controlled Trial
Led by Seventh Medical Center of PLA General Hospital · Updated on 2026-03-10
50
Participants Needed
1
Research Sites
186 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating the safety and effectiveness of neoadjuvant chemoradiation combined with Tislelizumab, a PD-1 inhibitor, with or without the probiotic Probio-M9, in patients with locally advanced rectal adenocarcinoma that is pMMR/MSS and located within 10 cm from the anal verge. This study is a prospective, randomized controlled trial comparing two experimental groups and a control group receiving chemoradiation only. The goal is to compare various clinical outcomes among these groups to better understand treatment effects. Participants will receive long-course chemoradiotherapy with 50 Gy delivered in 25 fractions alongside concurrent Capecitabine. Following this, they will receive two cycles of CapeOX chemotherapy combined with Tislelizumab administered intravenously at 200 mg every 3 weeks. Participants are randomly assigned to receive either daily oral Probio-M9 at 2 grams or a matched placebo starting from the beginning of chemoradiotherapy until surgery. Surgery with total mesorectal excision (TME) follows the treatment phase. During the study, participants will undergo evaluations including stool sample collection to analyze gut microbiota changes at baseline, during treatment, and before surgery. Researchers will monitor pathological complete response (pCR) within 10 days post-surgery as the primary outcome. Secondary outcomes include overall survival and disease-free survival rates at 2, 3, and 5 years, as well as immune-related adverse events. The study is conducted at a single center with a planned follow-up extending up to 5 years after treatment initiation.
CONDITIONS
Brief Title
Neoadjuvant Chemoradiotherapy Plus Tislelizumab With or Without Probio-M9 in pMMR/MSS Locally Advanced Rectal Cancer
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Age 18 years or older
- ECOG performance status between 0 and 2
- Biopsy-confirmed rectal adenocarcinoma
- Tumor located within 10 cm of the anal verge
- No distant metastasis present
- Clinical stage II or III based on MRI, excluding T4b
- Measurable tumor lesion at least 10 mm in diameter on baseline imaging
- Willing and able to follow the study protocol
- Agree to provide blood and tissue samples for research
- No prior anti-tumor treatments such as radiotherapy, chemotherapy, immunotherapy, biological therapy, or herbal therapy
- No history of immune system disorders including lupus, rheumatoid arthritis, vasculitis, scleroderma, pemphigus, dermatomyositis, mixed connective tissue disease, autoimmune hemolytic anemia, thyroid autoimmune disease, ulcerative colitis, or HIV infection
- No major organ dysfunction (heart, lung, liver, kidney)
- No jaundice or gastrointestinal obstruction
- No acute or ongoing infections
- Adequate blood and biochemical function including neutrophils ≥ 1.5 × 10^9/L, hemoglobin ≥ 80 g/L, platelets ≥ 100 × 10^9/L, serum creatinine ≤ 1.5 × upper limit of normal, total bilirubin ≤ 1.5 × upper limit of normal, ALT and AST ≤ 2.5 × upper limit of normal
- No social or psychiatric conditions interfering with participation
- Women of childbearing potential must have a negative pregnancy test and agree to use effective contraception from study start until 60 days after last study drug dose
You will not qualify if you...
- History of multiple primary cancers or other malignant tumors besides rectal cancer
- Receipt of any anti-cancer treatment including surgery, chemotherapy, or radiotherapy within the last 5 years
- Recent major surgery
- Conditions impairing absorption of capecitabine such as swallowing difficulties, persistent nausea or vomiting, or chronic diarrhea
- Uncontrolled or severe other diseases
- Known allergies to study drugs
- Life expectancy of 5 years or less
- Planned or prior organ or bone marrow transplant
- Use of immunosuppressive therapy or systemic corticosteroids within 1 month before enrollment
- History of central nervous system disorders affecting consent or medication compliance
- Other conditions that could interfere with study results or cause early treatment stop such as alcoholism or drug abuse
- Pregnant or breastfeeding women, or women planning pregnancy during treatment
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Approximately 10 to 12 weeks (duration of chemoradiotherapy and chemotherapy until surgery)
Participants receive long-course chemoradiotherapy with concurrent Capecitabine, followed by two cycles of CapeOX chemotherapy combined with Tislelizumab. They are randomized to also receive either daily oral Probio-M9 or placebo from the start of chemoradiotherapy until the day before surgery.
Weekly visits during chemoradiotherapy and chemotherapy cycles
Duration - 1 day
Participants undergo surgical resection of the tumor following completion of neoadjuvant treatment.
1 visit (in-person) for surgery
Duration - Up to 5 years
Participants are monitored for outcomes including pathological response, survival rates, immune-related adverse events, and changes in gut microbiota. Stool samples are collected at baseline, during treatment, and prior to surgery.
Periodic visits for assessments and sample collection over several years
Trial Site Locations
Total: 1 location
1
Seventh Medical Center of Chinese PLA General Hospital
Beijing, Beijing Municipality, China, 100700
Actively Recruiting
Research Team
J
Junfeng Du, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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