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OncoMatch/Clinical Trials/NCT06923345

Modified Long-Course Radiotherapy Followed by Chemotherapy and PD-1 Inhibitor for MSS/pMMR High-risk Mid/Low LARC (MODIFI-RC-I)

Is NCT06923345 recruiting? Yes, currently enrolling (Jun 2026). This Phase 2 trial studies multiple treatments including Reduced CTV and Conventional CTV for rectal cancer.

Phase 2RecruitingSixth Affiliated Hospital, Sun Yat-sen UniversityNCT06923345Data as of Jun 2026Location: China

Treatment: Reduced CTV · Conventional CTVThe goal of this clinical trial is to evaluate whether a total neoadjuvant therapy (TNT) regimen combining long-course chemoradiotherapy, sequential chemotherapy, and PD-1 inhibitor can improve response rates, enhance tolerability, and improve prognosis in patients with locally advanced, microsatellite-stable (MSS) rectal cancer. The main questions it aims to answer are: Does this TNT approach improve complete response (CR) rates? How does selective reduction of clinical target volume (CTV) to S2/S3 level compare with conventional CTV irradiation in terms of efficacy and safety? Researchers will compare a selective CTV reduction group and a conventional CTV irradiation group to assess differences in treatment outcomes, including complete response, tumor regression grading (TRG), organ preservation, R0 resection rates, and long-term survival. Participants will: Receive long-course chemoradiotherapy with either conventional or reduced CTV irradiation. Undergo sequential chemotherapy. Receive PD-1 inhibitor treatment. Be monitored for safety, tumor regression, and long-term survival outcomes.

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Extracted eligibility criteria

Treatments studied

Other

Reduced CTVConventional CTV

Cancer type

Colorectal Cancer

Biomarker criteria

Required: MSH2 positive (by IHC) (positive)

Tumor biopsy immunohistochemistry indicating pMMR (MSH1, MSH2, MSH6, and PMS2 all positive)

Required: MSH6 positive (by IHC) (positive)

Tumor biopsy immunohistochemistry indicating pMMR (MSH1, MSH2, MSH6, and PMS2 all positive)

Required: PMS2 positive (by IHC) (positive)

Tumor biopsy immunohistochemistry indicating pMMR (MSH1, MSH2, MSH6, and PMS2 all positive)

Required: MSH1 positive (by IHC) (positive)

Tumor biopsy immunohistochemistry indicating pMMR (MSH1, MSH2, MSH6, and PMS2 all positive)

Disease stage

Required: Stage II, III

Performance status

ECOG 0–1(Restricted strenuous activity)

Demographics

Ages ≤ 75

Prior therapy

No prior treatment (treatment-naive required)
Max 0 prior lines

Cannot have received: systemic or local anti-tumor treatment

No prior systemic or local anti-tumor treatment for rectal cancer, including radiotherapy, chemotherapy, immunotherapy, biologics, or small-molecule targeted therapy.

Cannot have received: radical surgery

Prior systemic or local anti-tumor treatment for locally advanced rectal cancer, including radical surgery, chemotherapy, radiotherapy, immunotherapy (e.g., immune checkpoint inhibitors, immune cell therapy), biological agents, or targeted therapy.

Cannot have received: pelvic or abdominal radiotherapy

History of pelvic or abdominal radiotherapy.

Lab requirements

Blood counts

ANC ≥ 1.5 × 10⁹/L (1,500/mm³); Platelet count ≥ 100 × 10⁹/L (100,000/mm³); Hemoglobin ≥ 90 g/L

Kidney function

Estimated creatinine clearance (CrCl) ≥ 50 mL/min; Urine protein < 2+ or 24-hour urine protein quantification < 1.0 g

Liver function

Total bilirubin (TBil) ≤ 1.5 × ULN; AST and ALT ≤ 2.5 × ULN; Serum albumin (ALB) ≥ 28 g/L

Cardiac function

Left ventricular ejection fraction (LVEF) ≥ 50%

Adequate organ function: Hematology...Renal function...Liver function...Coagulation function...Cardiac function

Structured fields extracted by AI. May contain errors — verify against the official protocol.

Frequently asked questions

Is NCT06923345 currently recruiting?

Yes, this trial is currently recruiting patients.

Can patients have received prior systemic therapy?

No. This trial requires treatment-naive patients — prior systemic therapy is an exclusion criterion.

Does this trial require MSH2?

Yes, MSH2 positive (by IHC) is a required biomarker for enrollment.

Does this trial require MSH6?

Yes, MSH6 positive (by IHC) is a required biomarker for enrollment.

Does this trial require PMS2?

Yes, PMS2 positive (by IHC) is a required biomarker for enrollment.

What disease stage is eligible?

Stage II or III is required.

Is there an age limit?

Yes. Patients must be 75 years or younger.

Could you qualify for this trial?

Enter your biomarker results to see how this trial's eligibility criteria match your specific cancer profile.

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