NCT06895577

Neoadjuvant Chemoradiotherapy Plus Sintilimab for MSS, Locally Advanced Rectal Cancer-

Neoadjuvant Chemoradiotherapy Plus Sintilimab for MSS, Locally Advanced Rectal Cancer: A Single-Center, Open-Label, Single-Arm, Phase 2 Trial

• Status: Withdrawn
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 0 (actual)
• Sponsor: Sun Yat-sen University · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

This research investigates the efficacy and safety of combining Sintilimab, a PD-1 inhibitor, with neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced microsatellite-stable (MSS) rectal cancer. Given the limitations of current treatment strategies in achieving optimal clinical outcomes, this prospective, single-center, phase II clinical trial aims to improve pathological complete response (pCR) rates and overall survival (OS). The primary endpoint is pCR, with secondary endpoints including disease-free survival (DFS) and the incidence of treatment-related adverse events. This study seeks to provide insights into a novel treatment paradigm for MSS locally advanced rectal cancer, potentially offering improved therapeutic options for this patient population.

Detailed description

Locally advanced rectal cancer (LARC) presents a complex treatment challenge, often requiring a multimodal approach to achieve optimal cure rates and improve survival. Currently, the combination of short-course radiotherapy (SCRT) and neoadjuvant chemotherapy has become a critical treatment strategy for LARC patients. Compared to conventional long-course radiotherapy (LCRT), SCRT is associated with a shorter treatment duration, typically lasting only five days, which facilitates rapid tumor shrinkage and minimizes surgical delays. This expedited treatment approach not only reduces the risk of postponing surgery but also improves the management of patients by minimizing fatigue and treatment-related side effects associated with longer regimens. Despite the promising outcomes associated with SCRT and neoadjuvant chemotherapy, a significant proportion of patients still do not achieve satisfactory clinical responses to standard treatment regimens. In recent years, the emergence of immune checkpoint inhibitors has revolutionized cancer treatment. In particular, PD-1 inhibitors such as Sintilimab have demonstrated significant antitumor activity across various solid tumors, notably in microsatellite instability-high (MSI-H) cancers. However, the potential benefits of these agents in microsatellite-stable (MSS) rectal cancer remain insufficiently explored. This study aims to investigate the effects of combining Sintilimab with neoadjuvant chemotherapy and SCRT in a single-center, phase II trial for MSS locally advanced rectal cancer. By evaluating treatment responses and survival outcomes, we hope to provide a novel therapeutic option that enhances clinical efficacy for patients with LARC.

Conditions

• Rectal Cancer

Interventions

Type	Name	Description
DRUG	neoadjuvant SCRT followed by Sintilimab plus CAPOX	SCRT (a total of 25 Gy in 5 days) followed by sintilimab (3mg/kg intravenous drip on day 1; every 3-week cycle for two cycles) combined with CAPOX (oxaliplatin 130 mg/m2 intravenous infusion over 2 h on day 1, capecitabine 1000 mg/m2 orally twice daily from day 1-14, in every 3-week cycle for two cycles) 1 week later.

Timeline

• Start date: 2025-06-20
• Primary completion: 2025-12-31
• Completion: 2025-12-31
• First posted: 2025-03-26
• Last updated: 2025-05-21

Locations

1 site across 1 country: China