Exploring PD-1 therapy duration for rectal cancer treatment

Exploring the Treatment Duration of PD-1 Neoadjuvant Therapy in Stage II-III dMMR Rectal Cancer: a Prospective，Multicentre, Single-arm Study

This study is testing how long PD-1 therapy should be given to people with stage II-III rectal cancer to see if it helps them have the best chance of a complete response before surgery.

Quick facts

• Study type: Observational
• Enrollment: 100 (estimated)
• Ages: 18 Years to 80 Years
• Sex: All
• Sponsor: Xijing Hospital (Academic / other)
• Drugs / interventions: chemotherapy, immunotherapy
• Locations: 1 site (Xi'an, Shaanxi)
• Trial ID: NCT06613165 on ClinicalTrials.gov

What this trial studies

This study investigates the optimal duration of PD-1 monotherapy in patients with stage II-III dMMR rectal cancer to achieve the best pathological complete response (pCR). Participants will receive preoperative treatment with PD-1 antibodies, with evaluations conducted every two cycles to assess clinical response. If a clinical complete response (cCR) is observed, surgical intervention will follow. The study will compare pCR rates, adverse reactions, and three-year event-free survival across varying treatment cycles.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 to 80 with confirmed dMMR/MSI-H rectal adenocarcinoma at clinical stages II-III who have not received prior systemic therapies.

Not a fit: Patients with prior systemic therapies or those with severe organ dysfunction may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to more effective treatment protocols for patients with dMMR rectal cancer, improving their chances of complete response and survival.

How similar studies have performed: While the approach of using PD-1 therapy in this context is promising, the specific exploration of treatment duration in this patient population is relatively novel.

Eligibility criteria

Inclusion Criteria:

* 1.Age: 18 to 80 years old, male or female;
* 2.Patients with histologically or cytologically confirmed dMMR/MSI-H rectal adenocarcinoma, clinical stage II-III;
* 3.No prior systemic therapy, including chemotherapy, radiotherapy, immunotherapy, or targeted therapy;
* 4.ECOG Performance Status (PS) score of 0-1;
* 5.Estimated life expectancy of ≥ 3 months;
* 6.Normal function of major organs, with no severe abnormalities in blood, heart, lung, liver, kidney, bone marrow, or immunodeficiency. Laboratory tests must meet the following criteria: Hemoglobin (Hb) ≥ 90 g/L; White blood cell count (WBC) ≥ 3.0 × 10\^9/L; Neutrophil count (NEUT) ≥ 1.5 × 10\^9/L; Platelet count (PLT) ≥ 90 × 10\^9/L; Liver function (Aspartate Aminotransferase AST or Alanine Aminotransferase ALT) ≤ 2.5 times the upper limit of normal (ULN); Renal function (serum creatinine sCr) ≤ 1.5 times ULN; Total bilirubin (TBIL) ≤ 1.5 times ULN; Urine protein and occult blood \< 2+; Fecal occult blood \< 2+;
* 7.Subjects must voluntarily participate in this study, sign the informed consent form, demonstrate good compliance, and cooperate with follow-up visits;
* 8.The investigator believes that the patient can benefit from the treatment. Physical status score PS ≤ 2;
* 9.Patients and their families must understand and be willing to participate in this study, providing written informed consent.

Exclusion Criteria:

* 1.Patients with a confirmed allergy to the investigational drug and/or its excipients;
* 2.Subjects who have received or are currently receiving additional chemotherapy, radiotherapy, targeted therapy, or immunotherapy;
* 3.Patients with any active autoimmune disease or a history of autoimmune disease;
* 4.Patients with Lynch syndrome;
* 5.Patients with poorly controlled cardiac symptoms or diseases, such as New York Heart Association (NYHA) Class II or higher heart failure, unstable angina pectoris, or myocardial infarction within the past year;
* 6.Pregnant or lactating women;
* 7.Patients with acute infections requiring antibiotic treatment;
* 8.Patients with positive hepatitis B or hepatitis C antibodies;
* 9.Patients with positive HIV antibodies;
* 10.Patients with other diseases that the investigating physician considers may affect prognosis and survival;
* 11.Any other conditions deemed inappropriate for participation in this study by the investigating physician.

Where this trial is running

Xi'an, Shaanxi

• Xijing hospital — Xi'an, Shaanxi, China (Recruiting)

Study contacts

• Study coordinator: Jipeng Li, Doctor

Conditions Immune-related Adverse Event; Neoadjuvant Therapy; dMMR Colorectal Cancer; Colorectal Cancer; deficient Mismatch Repair; locally advanced; immune checkpoint