A Study of SKB571 in Participants With Gastrointestinal Tumors

A Phase II Clinical Study to Evaluate the Efficacy and Safety of SKB571 in Participants With Gastrointestinal Tumors

This is an open-label, multicenter, phase II study. The purpose of this study is to evaluate the safety, tolerability and preliminary anti-tumor activity of SKB571 in participants with gastrointestinal tumors.

Study Overview

• Status: Not yet recruiting
• Conditions: Gastrointestinal Tumors
• Intervention / Treatment: Drug: SKB571 for injection

Detailed Description

This is a multicenter, open-label, Phase II clinical study to evaluate the efficacy, safety, tolerability, PK characteristics, and immunogenicity of SKB571 in participants with gastrointestinal tumors. Approximately 120 subjects will be enrolled in this study, including 4 cohorts with approximately 20-30 participants enrolled in each cohort.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Xin Li, MD; Phone Number: 86-13311373861; Email: lixin@kelun.com

Study Locations

• China
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 404000
      • Chongqing University Three Gorges Hospital
  • Fujian
    • Fuzhou, Fujian, China, 350014
      • Fujian Cancer Hospital
    • Xiamen, Fujian, China, 361003
      • The First Affiliated Hospital of Xiamen University
  • Guangdong
    • Guangzhou, Guangdong, China, 510060
      • Sun Yat-Sen University Cancer Center
    • Guangzhou, Guangdong, China, 510655
      • The Sixth Affiliated Hospital, Sun Yat-sen University
  • Guangxi
    • Nanning, Guangxi, China, 530021
      • The People's Hospital of Guangxi Zhuang Autonomous Region
  • Hebei
    • Shijiazhuang, Hebei, China, 050011
      • The Fourth Hospital of Hebei Medical University
  • Heilongjiang
    • Harbin, Heilongjiang, China, 150081
      • Tumor Hospital of Harbin Medical University
  • Henan
    • Luoyang, Henan, China, 471003
      • The First Affiliated Hospital of Henan University of Science and Technology
    • Zhengzhou, Henan, China, 450052
      • the First Affiliated Hospital of Zhengzhou University
    • Zhengzhou, Henan, China, 450008
      • Henan Cancer Hospital
  • Hunan
    • Changsha, Hunan, China, 410013
      • Hunan Cancer Hospital
  • Jiangsu
    • Nanjing, Jiangsu, China, 210029
      • Jiangsu Province Hospital
    • Nanjing, Jiangsu, China, 210009
      • Jiangsu Cancer Hospital
  • Jiangxi
    • Nanchang, Jiangxi, China, 330006
      • The Second Affiliated Hospital of Nanchang University
    • Nanchang, Jiangxi, China, 3300029
      • Jiangxi Cancer Hospital
  • Jilin
    • Changchun, Jilin, China, 130021
      • The First Hospital of Jilin University
  • Liaoning
    • Shenyang, Liaoning, China, 110001
      • The First Hospital of China Medical University
  • Shaanxi
    • Xi'an, Shaanxi, China, 710004
      • The Second Affiliated Hospital of Xi'an Jiaotong University
  • Shandong
    • Jinan, Shandong, China, 250021
      • Shandong Provincial Hospital
    • Jinan, Shandong, China, 250117
      • Cancer Hospital of Shandong First Medical University
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200127
      • Renji Hospital, Shanghai Jiao Tong University School of Medicine
  • Shanxi
    • Taiyuan, Shanxi, China, 030013
      • Shanxi Provincial Cancer Hospital
  • Sichuan
    • Chengdu, Sichuan, China, 610041
      • Sichuan Cancer Hospital
  • Tianjin Municipality
    • Tianjin, Tianjin Municipality, China, 300060
      • Tianjin Medical University Cancer Institute & Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Male or female, age ≥ 18 years and ≤ 75 years at the time of signing the informed consent form (ICF).
2. Participants must have histologically or cytologically confirmed gastrointestinal tumors.
3. At least one measurable lesion as assessed by the investigator according to RECIST v1.1.
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
5. Life expectancy ≥ 12 weeks as assessed by the investigator.
6. Adequate organ and bone marrow function.
7. Male and female participants must agree to use highly effective methods of contraception during the study treatment period.
8. Participants must voluntarily join this study, sign the ICF, and be able to comply with the visits and related procedures specified in the protocol.

Exclusion Criteria:

1. Participants with other malignant tumors within 3 years before the first dose of study treatment.
2. History or current metastases to central nervous system.
3. Current uncontrolled concomitant diseases
4. Clinically severe lung damage due to complications of lung disorder
5. Participants with a history of interstitial lung disease (ILD)/non-infectious pneumonitis
6. A history of severe skin diseases
7. Unresolved toxicity from prior anti-tumor therapy
8. Serious infection within 4 weeks before the first dose of study treatment
9. Known active pulmonary tuberculosis.
10. Participants who have undergone major surgery or had severe trauma within 4 weeks before the first dose, or are expected to require major surgery during the study.
11. Known history of allogeneic organ transplant or allogeneic hematopoietic stem cell transplant.
12. Pregnant or breastfeeding women.
13. Other conditions deemed by the investigator as unsuitable for participation in this clinical trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Gastric Cancer/Gastroesophageal Junction Adenocarcinoma (GC/GEJ)	Drug: SKB571 for injection; Intravenous(IV) infusion(Q3W)
Experimental: Oesophageal Squamous Cell Carcinoma (ESCC)	Drug: SKB571 for injection; Intravenous(IV) infusion(Q3W)
Experimental: Colorectal Adenocarcinoma (CRC)	Drug: SKB571 for injection; Intravenous(IV) infusion(Q3W)
Experimental: Hepatocellular Carcinoma (HCC) or Bile Duct Cancer (BTC) or other types of gastrointestinal tumors	Drug: SKB571 for injection; Intravenous(IV) infusion(Q3W)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Objective response rate (ORR)	Up to approximately 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-free survival (PFS), duration of response (DOR), disease control rate (DCR), and overall survival (OS)		Up to approximately 24 months
Safety and tolerability	Incidence and severity of adverse events (AEs) and serious adverse events (SAEs) (based on CTCAE v6.0), clinically significant abnormal laboratory test results, etc.	Up to approximately 24 months
Maximum Plasma Concentration (Cmax) of SKB571-ADC	Blood Samples will be collected to determine the Cmax of SKB571-ADC in the plasma	Up to approximately 24 months
Immunogenicity	Blood Samples will be collected to measure Anti-drug antibody (ADA) against SKB571 in the serum	Up to approximately 24 months
Minimum Plasma Concentration(Cmin) of SKB571-ADC	Blood samples will be collected to determine the Cmin of SKB571-ADC in the plasma	Up to approximately 24 months
Maximum Plasma Concentration(Cmax) of SKB571-TAb	Blood samples will be collected to determine the Cmax of SKB571-TAb in the plasma	Up to approximately 24 months
Minimum Plasma Concentration(Cmin) of SKB571-TAb	Blood Samples will be collected to determine the Cmin of SKB571-TAb in the plasma	Up to approximately 24 months
Maximum Plasma Concentration (Cmax) of unconjugated KL610348	Blood Samples will be collected to determine the Cmax of unconjugated KL610348 in the plasma	Up to approximately 24 months
Minimum Plasma Concentration(Cmin) of unconjugated KL610348	Blood Samples will be collected to determine the Cmin of unconjugated KL610348 in the plasma	Up to approximately 24 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between biomarkers and efficacy	To evaluate the correlation between the expression levels of tumor-related genes in tumor tissues and efficacy	Up to approximately 24 months

Collaborators and Investigators

• Sponsor: Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): June 30, 2026
• Primary Completion (Estimated): August 31, 2027
• Study Completion (Estimated): June 30, 2028

Study Registration Dates

• First Submitted: April 14, 2026
• First Submitted That Met QC Criteria: April 26, 2026
• First Posted (Actual): May 4, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Gastrointestinal tumors
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Digestive System Diseases; Digestive System Neoplasms; Therapeutics; Drug Administration Routes; Drug Therapy; Injections
• Other Study ID Numbers: SKB571-II-04

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No