Cadonilimab for PD-1/PD-L1 Blockade-refractory, MSI-H/dMMR, Advanced Colorectal Cancer

Cadonilimab (Bispecific Anti-PD-1/CTLA-4 Antibody) for PD-1/PD-L1 Blockade-refractory, Microsatellite Instability-high (MSI-H) or Mismatch Repair-deficient (dMMR), Advanced Colorectal Cancer: a Single Group, Multicenter, Phase 2 Trial

KEYNOTE-177 is currently the only randomized controlled phase III clinical trial evaluating the efficacy and safety of pembrolizumab versus standard chemotherapy combined with targeted first-line therapy for dMMR/MSI-H metastatic colorectal cancer. The study was conducted at 192 centers in 23 countries and enrolled a total of 307 subjects. The results of the study showed that the median PFS of pembrolizumab was 16.5 months, which was double the 8.2 months in the chemotherapy group (HR 0.60; 95% CI: 0.45-0.80; P = 0.0002). In addition, the ORR was 45.1% in the pembrolizumab group and 33.1% in the chemotherapy group, and a higher percentage of patients achieving a complete remission (CR) with pembrolizumab than in the chemotherapy group (13.1% vs. 3.9%). The U.S. FDA approved pembrolizumab in June 2020 for the first-line treatment of MSI-H/dMMR metastatic colorectal cancer.

The results of the KEYNOTE-177 study showed that 29% of patients with dMMR/MSI-H metastatic colorectal cancer experienced direct disease progression (PD) after first-line pembrolizumab monotherapy. This may suggest that some dMMR/MSI-H patients have primary resistance to anti-PD-1 monotherapy. In the first-line treatment cohort of the CheckMate 142 study using nivolumab combined with ipilimumab, the proportion of patients with direct PD was 13%, suggesting that the combination of PD-1 inhibitors and anti-CTLA-4 mAb may have help overcome this primary resistance. In addition, in the second-line and above cohort of the CheckMate142 study, 12% of patients receiving nivolumab in combination with ipilimumab experienced PD directly, compared with 26% of patients receiving nivolumab alone.

A study published on 《The Lancet Oncolog》 on the efficacy and safety of ipilimumab monotherapy and ipilimumab combined with anti-PD-1 monoclonal antibody in patients with anti-PD-1 monoclonal antibody-resistant melanoma Retrospective study. The study included 355 patients with unresectable metastatic stage III or IV melanoma who received ipilimumab monotherapy after failure of anti-PD-(L)1 monoclonal antibody (n=162), or Ipilimumab combined with anti-PD-1 therapy (n=193). The ORR was 31% in the combination arm, significantly higher than the 13% in the ipilimumab monotherapy arm. In addition, the median OS and PFS of the combination therapy group were 20.4 months and 3.0 months, respectively, which were also significantly higher than those of the single-agent group of 8.8 months and 2.6 months.

The aim of this study was to evaluate the objective response rate (ORR) of Cadonilimab, a bispecific anti-PD-1/CTLA-4 antibody, for PD-1/PD-L1 blockade-refractory, microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR), advanced colorectal cancer.

Study Overview

• Status: Recruiting
• Conditions: Colorectal Cancer Stage IV; Mismatch Repair-deficient (dMMR); Microsatellite Instability-high (MSI-H)
• Intervention / Treatment: Drug: Cadonilimab

• Study Type: Interventional
• Enrollment (Estimated): 28
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Qin Zheng
• Study Contact Backup: Name: Yanhong Deng, M.D.; Phone Number: +86-13925106525; Email: 13925106525@163.com

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510655
      • Recruiting
      • The Sixth Affiliated Hospital of Sun Yat-sen University
      • Contact: Yanhong Deng, M.D.; Phone Number: 86-13925106525; Email: 13925106525@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Willing and able to provide written informed consent.
2. Histological or cytological documentation of adenocarcinoma of the colon or rectum.
3. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
4. Tumor tissues were identified as mismatch repair-deficient (dMMR) by immunohistochemistry (IHC) method or microsatellite instability-high (MSI-H) by polymerase chain reaction (PCR).
5. Subjects with stage IV colorectal cancer must have measurable or non measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria, version 1.1.
6. Previous treatment with an anti-PD-1 or PD-L1 monoclonal antibody for advanced or metastatic colorectal cancer has failed. Treatment failure was defined as: disease progression or unacceptable toxicity during treatment or within 6 months after the last treatment.
7. Adequate bone marrow, liver and renal function as assessed by the laboratory required by protocol.

Exclusion Criteria:

1. Previously received anti-cytotoxic T lymphocyte-associated antigen 4 (cytotoxic T-lymphocyte-associated Protein 4, CTLA-4) antibody.
2. Significant cardiovascular disease including unstable angina or myocardial infarction within 6 months before initiating study treatment.
3. Heart failure grade III/IV (NYHA-classification).
4. Unresolved toxicity higher than CTCAE v.5.0 Grade 1 attributed to any prior therapy/procedure.
5. Subjects with known allergy to the study drugs or to any of its excipients.
6. Current or recent (within 4 weeks prior to starting study treatment) treatment of another investigational drug or participation in another investigational study.
7. Breast- feeding or pregnant women.
8. Lack of effective contraception.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cadonilimab; Cadonilimab alone	Drug: Cadonilimab; Cadonilimab, 6 mg/kg every 2 weeks until disease progression, intolerable toxicity, or duration of treatment for 2 years

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
12-month Progression-free survival (PFS) rate	The PFS was defined as the time from enrollment until tumor progression or death from any cause, whichever occurred first. The 12-month PFS rate was defined as the proportion of patients without disease progression or death at the 12th month after initiation of the study. treatment.	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective response rate (ORR)	The percentage of subjects with total number of Complete Response (CR) + total number of Partial Response (PR).	2 years
Overall Survival (OS)	OS is defined as the time from date of randomization to death due to any cause. Subjects still alive at the time of analysis were censored at their last date of last contact.	5 years
Toxicity assessed using the The National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), version 5.0.	The grade of toxicity will be assessed using the NCI-CTCAE, version 5.0. Grade refers to the severity of the AE. The CTCAE displays Grades 1 (lowest level) through 5 (highest level) with unique clinical descriptions of severity.	2 years

Collaborators and Investigators

• Sponsor: Sun Yat-sen University

Study record dates

Study Major Dates

• Study Start (Actual): February 7, 2023
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: June 15, 2022
• First Submitted That Met QC Criteria: June 15, 2022
• First Posted (Actual): June 21, 2022

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 20, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Immunotherapy; PD-1; CTLA-4
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Intestinal Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Neoplasms; Rectal Diseases; Colonic Diseases; Colorectal Neoplasms; Diabetes Mellitus, Insulin-Dependent, 12; Turcot syndrome
• Other Study ID Numbers: CSWOG-C03

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No