Rectal Cancer PatientsPhase 2NeoCSR-OmicsNCT07898865
NeoCSR-Omics Trial: CAPOX + Serplulimab Before vs. After Short-course RT in LARC
A Phase 2 study testing radiotherapy, CAPOX (oxaliplatin/capecitabine) and Serplulimab in people with Rectal Cancer Patients and Locally Advanced Rectal Cancer (LARC), run by Chongqing University Cancer Hospital at 1 site in China.
Trial summary
This is a prospective, randomized, multicenter phase II trial evaluating neoadjuvant CAPOX chemotherapy combined with the PD-1 inhibitor serplulimab administered either before or after short-course radiotherapy (SCRT) in patients with locally advanced rectal cancer. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Rectal Cancer Patients, Locally Advanced Rectal Cancer (LARC)
- What is being tested?
- radiotherapy, CAPOX (oxaliplatin/capecitabine) and Serplulimab
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteChina
- Study dates
- 16 Oct 2025to 1 Oct 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18-70 years, any sex.
- Clinical stage II/III rectal adenocarcinoma (cT3-T4N0 or cT2-T4N+, M0) according to AJCC 8th edition.
- Tumor located ≤10 cm from anal verge (confirmed by colonoscopy or digital rectal exam).
- Histologically confirmed rectal adenocarcinoma.
- ECOG performance status 0-1.
- Adequate organ function:
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- Hemoglobin ≥90 g/L; WBC ≥3.5×10⁹/L; ANC ≥1.5×10⁹/L; Platelets ≥100×10⁹/L.
- Serum creatinine, BUN ≤1.0×ULN.
- ALT, AST, ALP ≤1.5×ULN; Total bilirubin ≤1.5×ULN.
- Negative urine protein; normal coagulation.
- No known allergy to fluoropyrimidines or platinum.
- No prior surgery (except diverting colostomy), chemotherapy, or radiotherapy for primary rectal cancer.
- No prior pelvic radiotherapy.
- Signed written informed consent.
Who cannot join
- Prior treatment with PD-1/PD-L1 or CTLA-4 inhibitors, or other investigational immunotherapies.
- Active autoimmune disease (e.g., Crohn's disease, ulcerative colitis, rheumatoid arthritis, scleroderma, SLE, vasculitis).
- Symptomatic interstitial lung disease or active pneumonia.
- GI conditions increasing risk of perforation (e.g., active diverticulitis, abscess, obstruction).
- History of other malignancies, except cured non-melanoma skin cancer or in situ cervical cancer.
- Active infections, uncontrolled heart failure, recent myocardial infarction (<6 months), unstable angina, or severe arrhythmia.
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- Other uncontrolled disease or condition that may interfere with study participation.
- Pregnancy or lactation.
- Known immunodeficiency (e.g., HIV) or history of organ/allo-HSCT transplantation.
- Active HBV (HBV DNA ≥2000 IU/mL), HCV infection, or active tuberculosis.
- Receipt of cancer vaccines or live vaccines within 4 weeks prior to enrollment (seasonal inactivated influenza vaccines allowed).
- Concurrent use of other investigational agents, long-term corticosteroids, or immunosuppressants.
- Psychiatric disorders, substance abuse, or social conditions limiting compliance.
- Known allergy or contraindication to study drugs.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Chongqing University Cancer Hospital
Chongqing, Chongqing Municipality
Qishuai Guo
About this study
Official title: Neoadjuvant Chemotherapy Plus Serplulimab Before Versus After Short-Course Radiotherapy in Locally Advanced Rectal Cancer : A Multicenter, Randomized Phase II Study With Integrated Multi-omics Profiling (NeoCSR-Omics Trial)
This is a prospective, randomized, multicenter phase II trial evaluating neoadjuvant CAPOX chemotherapy combined with the PD-1 inhibitor serplulimab administered either before or after short-course radiotherapy (SCRT) in patients with locally advanced rectal cancer. The primary endpoint is the complete response (CR) rate, defined as pathological complete response (pCR) plus clinical complete response (cCR). Secondary endpoints include safety, perioperative outcomes, survival, recurrence patterns, and integrated multi-omics analyses of paired tumor samples. The study aims to determine the optimal sequencing strategy and identify immune microenvironmental biomarkers predictive of response.
Read the detailed description
Colorectal cancer is one of the most common malignancies worldwide, with rectal cancer accounting for over 700,000 new cases annually. In China, colorectal cancer ranks second in incidence and fourth in cancer-related mortality. More than half of newly diagnosed patients present with locally advanced rectal cancer (LARC), requiring multimodality therapy. Neoadjuvant approaches have improved local control and compliance compared with adjuvant strategies, but conventional fluoropyrimidine-based chemoradiotherapy achieves limited pathological complete response (pCR) rates of ~15% and distant metastasis rates remain high. Total neoadjuvant therapy (TNT), which delivers systemic chemotherapy before surgery, has become the new standard of care, supported by phase III trials such as RAPIDO, PRODIGE-23, and STELLAR, which demonstrated improved pCR and survival. However, the optimal sequencing of chemotherapy and radiotherapy-induction versus consolidation-remains uncertain, with each approach offering distinct advantages. Immunotherapy targeting the PD-1/PD-L1 axis has transformed cancer treatment and shows dramatic efficacy in mismatch repair-deficient (dMMR)/MSI-H colorectal cancer, but the vast majority of rectal cancers are mismatch repair-proficient (pMMR)/microsatellite stable (MSS), where single-agent immunotherapy is ineffective. Preclinical and translational studies suggest radiotherapy enhances antitumor immunity by promoting antigen release, immunogenic cell death, and T cell infiltration. Several phase II/III studies have shown promising efficacy of combining SCRT, chemotherapy, and PD-1 inhibitors, with complete response (CR) rates exceeding 40%. Building on these findings, this randomized phase II trial (NeoCSR-Omics) will compare induction immunochemotherapy followed by SCRT versus SCRT followed by consolidation immunochemotherapy in LARC patients. The primary endpoint is CR rate, defined as pCR plus cCR. Secondary endpoints include safety, perioperative outcomes, survival, recurrence, and quality of life. Fresh and surgical tumor samples will undergo single-cell RNA sequencing and TCR/BCR sequencing to explore how treatment sequencing reshapes the tumor microenvironment and to identify biomarkers predictive of response. This study aims to determine the optimal sequence of immunochemotherapy and radiotherapy and provide mechanistic insights to guide precision treatment in locally advanced rectal cancer.
- Being tested
- radiotherapy, CAPOX (oxaliplatin/capecitabine), Serplulimab
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
radiotherapyRadiation
- Short-course pelvic radiotherapy
- IMRT/VMAT/TOMO, 25 Gy in 5 fractions (5 Gy per fraction)
CAPOX (oxaliplatin/capecitabine)Drug
- Capecitabine: 1000 mg/m² orally BID, D1-14, every 3 weeks
- Oxaliplatin: 130 mg/m² IV, D1, every 3 weeks
SerplulimabDrug
Serplulimab (HLX10): 300 mg IV, D1, every 3 weeks
| Study group | Role | What they receive |
|---|---|---|
| Arm A - Consolidation Arm (SCRT → CAPOX + Serplulimab) | Experimental | * Short-course radiotherapy (25 Gy in 5 fractions over 1 week)
* Followed after 1-2 weeks by 3 cycles CAPOX chemotherapy plus serplulimab. Receives: Radiation: radiotherapy; Drug: CAPOX (oxaliplatin/capecitabine); Drug: Serplulimab |
| Arm B - Induction Arm (CAPOX + Serplulimab → SCRT) | Experimental | * Three cycles of CAPOX chemotherapy plus serplulimab
* Followed after 1-2 weeks by short-course radiotherapy (25 Gy in 5 fractions over 1 week). Receives: Radiation: radiotherapy; Drug: CAPOX (oxaliplatin/capecitabine); Drug: Serplulimab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Complete Response (CR)
CR is defined as the proportion of patients achieving either pathological complete response (pCR, no residual viable tumor in the resected specimen) after radical surgery or clinical complete response (cCR, absence of residual tumor confirmed by endoscopy, digital rectal examination, and pelvic MRI in patients managed with organ preservation).
Measured: one year
Secondary outcomes (8)
Treatment-related adverse events
Measured: three months
Incidence of surgical complications
Measured: 30 days
Changes in immune microenvironment
Immune profiling of tumor and stromal compartments using histopathology and multi-omics analyses to assess differences between treatment arms and correlation with efficacy.
Measured: Baseline, after neoadjuvant therapy, and at surgery (up to 6 months)
Radical resection (R0)
Measured: one year
Overall survival rate
Measured: three year
Disease-free survival rate
Measured: three year
Locoregional recurrence rate
Measured: three year
Distance metastasis rate
Measured: three year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Oct 2026
- Study start16 Oct 2025
- Primary completion1 Oct 2027 (estimated)
- Study completion1 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Rectal Cancer PatientsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chongqing University Cancer Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Qishuai GUO, Chongqing University Cancer Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07898865
- Sponsor's protocol ID
- NeoCSR-Omics
- Acronym
- NeoCSR-Omics
- Status last verified
- Oct 2026
- First submitted
- 21 Oct 2026
- Last updated
- 27 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The investigators do not plan to share individual participant data.
Study at a glance
From the registry record, last updated by the sponsor on 27 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Neoadjuvant Chemotherapy Plus Serplulimab Before Versus After Short-Course Radiotherapy in Locally Advanced Rectal Cancer : A Multicenter, Randomized Phase II Study With Integrated Multi-omics Profiling (NeoCSR-Omics Trial)
- ClinicalTrials.gov ID
- NCT07898865
- Acronym / sponsor ID
- NeoCSR-Omics / NeoCSR-Omics
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Chongqing University Cancer HospitalUniversity, hospital or other
- Study start
- 16 Oct 2025 (actual)
- Primary completion
- 1 Oct 2027 (estimated)
- Study completion
- 1 Oct 2028 (estimated)
- First posted
- 27 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a prospective, randomized, multicenter phase II trial evaluating neoadjuvant CAPOX chemotherapy combined with the PD-1 inhibitor serplulimab administered either before or after short-course radiotherapy (SCRT) in patients with locally advanced rectal cancer. The primary endpoint is the complete response (CR) rate, defined as pathological complete response (pCR) plus clinical complete response (cCR). Secondary endpoints include safety, perioperative outcomes, survival, recurrence patterns, and integrated multi-omics analyses of paired tumor samples. The study aims to determine the optimal sequencing strategy and identify immune microenvironmental biomarkers predictive of response.
Detailed description
Colorectal cancer is one of the most common malignancies worldwide, with rectal cancer accounting for over 700,000 new cases annually. In China, colorectal cancer ranks second in incidence and fourth in cancer-related mortality. More than half of newly diagnosed patients present with locally advanced rectal cancer (LARC), requiring multimodality therapy. Neoadjuvant approaches have improved local control and compliance compared with adjuvant strategies, but conventional fluoropyrimidine-based chemoradiotherapy achieves limited pathological complete response (pCR) rates of ~15% and distant metastasis rates remain high. Total neoadjuvant therapy (TNT), which delivers systemic chemotherapy before surgery, has become the new standard of care, supported by phase III trials such as RAPIDO, PRODIGE-23, and STELLAR, which demonstrated improved pCR and survival. However, the optimal sequencing of chemotherapy and radiotherapy-induction versus consolidation-remains uncertain, with each approach offering distinct advantages. Immunotherapy targeting the PD-1/PD-L1 axis has transformed cancer treatment and shows dramatic efficacy in mismatch repair-deficient (dMMR)/MSI-H colorectal cancer, but the vast majority of rectal cancers are mismatch repair-proficient (pMMR)/microsatellite stable (MSS), where single-agent immunotherapy is ineffective. Preclinical and translational studies suggest radiotherapy enhances antitumor immunity by promoting antigen release, immunogenic cell death, and T cell infiltration. Several phase II/III studies have shown promising efficacy of combining SCRT, chemotherapy, and PD-1 inhibitors, with complete response (CR) rates exceeding 40%. Building on these findings, this randomized phase II trial (NeoCSR-Omics) will compare induction immunochemotherapy followed by SCRT versus SCRT followed by consolidation immunochemotherapy in LARC patients. The primary endpoint is CR rate, defined as pCR plus cCR. Secondary endpoints include safety, perioperative outcomes, survival, recurrence, and quality of life. Fresh and surgical tumor samples will undergo single-cell RNA sequencing and TCR/BCR sequencing to explore how treatment sequencing reshapes the tumor microenvironment and to identify biomarkers predictive of response. This study aims to determine the optimal sequence of immunochemotherapy and radiotherapy and provide mechanistic insights to guide precision treatment in locally advanced rectal cancer.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Arm A - Consolidation Arm (SCRT → CAPOX + Serplulimab) | Experimental | Radiation: radiotherapy, Drug: CAPOX (oxaliplatin/capecitabine), Drug: Serplulimab* Short-course radiotherapy (25 Gy in 5 fractions over 1 week) * Followed after 1-2 weeks by 3 cycles CAPOX chemotherapy plus serplulimab. |
| Arm B - Induction Arm (CAPOX + Serplulimab → SCRT) | Experimental | Radiation: radiotherapy, Drug: CAPOX (oxaliplatin/capecitabine), Drug: Serplulimab* Three cycles of CAPOX chemotherapy plus serplulimab * Followed after 1-2 weeks by short-course radiotherapy (25 Gy in 5 fractions over 1 week). |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (14 listed)
- Age 18-70 years, any sex.
- Clinical stage II/III rectal adenocarcinoma (cT3-T4N0 or cT2-T4N+, M0) according to AJCC 8th edition.
- Tumor located ≤10 cm from anal verge (confirmed by colonoscopy or digital rectal exam).
- Histologically confirmed rectal adenocarcinoma.
- ECOG performance status 0-1.
Key exclusion criteria (14 listed)
- Prior treatment with PD-1/PD-L1 or CTLA-4 inhibitors, or other investigational immunotherapies.
- Active autoimmune disease (e.g., Crohn's disease, ulcerative colitis, rheumatoid arthritis, scleroderma, SLE, vasculitis).
- Symptomatic interstitial lung disease or active pneumonia.
- GI conditions increasing risk of perforation (e.g., active diverticulitis, abscess, obstruction).
- History of other malignancies, except cured non-melanoma skin cancer or in situ cervical cancer.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| radiotherapy1. Short-course pelvic radiotherapy 2. IMRT/VMAT/TOMO, 25 Gy in 5 fractions (5 Gy per fraction) | Radiation | Arm A - Consolidation Arm (SCRT → CAPOX + Serplulimab), Arm B - Induction Arm (CAPOX + Serplulimab → SCRT) |
| CAPOX (oxaliplatin/capecitabine)* Capecitabine: 1000 mg/m² orally BID, D1-14, every 3 weeks * Oxaliplatin: 130 mg/m² IV, D1, every 3 weeks | Drug | Arm A - Consolidation Arm (SCRT → CAPOX + Serplulimab), Arm B - Induction Arm (CAPOX + Serplulimab → SCRT) |
| SerplulimabSerplulimab (HLX10): 300 mg IV, D1, every 3 weeks | Drug | Arm A - Consolidation Arm (SCRT → CAPOX + Serplulimab), Arm B - Induction Arm (CAPOX + Serplulimab → SCRT) |
Primary outcome
Complete Response (CR)
Time frame: one year
CR is defined as the proportion of patients achieving either pathological complete response (pCR, no residual viable tumor in the resected specimen) after radical surgery or clinical complete response (cCR, absence of residual tumor confirmed by endoscopy, digital rectal examination, and pelvic MRI in patients managed with organ preservation).
8 secondary outcomes
Treatment-related adverse events
Time frame: three months
Incidence of surgical complications
Time frame: 30 days
Changes in immune microenvironment
Time frame: Baseline, after neoadjuvant therapy, and at surgery (up to 6 months)
Radical resection (R0)
Time frame: one year
Overall survival rate
Time frame: three year
Disease-free survival rate
Time frame: three year
Locoregional recurrence rate
Time frame: three year
Distance metastasis rate
Time frame: three year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Oct 2026.
- Individual participant dataSharing planned: No. The investigators do not plan to share individual participant data.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing radiotherapy, CAPOX (oxaliplatin/capecitabine) and Serplulimab in people with Rectal Cancer Patients and Locally Advanced Rectal Cancer (LARC), run by Chongqing University Cancer Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Qishuai Guo (+86-1399602842, cqzlyygqs@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Complete Response (CR) (time frame: one year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Oct 2026.