A Study Comparing BL-M05D1 With the Investigator's Choice of Treatment Regimen in Patients With Claudin (CLDN)18.2-Positive Advanced Gastric Cancer or Gastroesophageal Junction Adenocarcinoma (GC/GEJC) Who Have Received Prior First-Line Treatment

A Randomized Controlled Phase III Clinical Study Comparing BL-M05D1 for Injection With the Investigator's Choice of Treatment Regimen in Patients With Claudin (CLDN) 18.2-positive Advanced Gastric Cancer or Gastroesophageal Junction Adenocarcinoma (GC/GEJC) Who Have Received Prior First-line Treatment

This trial is a registrational Phase III, randomized, open-label, multicenter study to evaluate the efficacy and safety of BL-M05D1 in patients with Claudin (CLDN) 18.2-positive advanced gastric cancer or gastroesophageal junction adenocarcinoma (GC/GEJC) who have received prior first-line treatment.

Study Overview

• Status: Not yet recruiting
• Conditions: Gastric Cancer; Gastroesophageal Junction Adenocarcinoma
• Intervention / Treatment: Drug: BL-M05D1; Drug: Docetaxel; Drug: Paclitaxel; Drug: Irinotecan hydrochloride

Detailed Description

In this trial, the experimental group receives BL-M05D1, with each treatment cycle lasting 3 weeks. The control group receives investigator-selected treatment regimens: paclitaxel, docetaxel, or irinotecan.

• Study Type: Interventional
• Enrollment (Estimated): 438
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Sa Xiao, PHD; Phone Number: 15013238943; Email: xiaosa@baili-pharm.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China
      • Beijing Cancer Hospital
      • Contact: Lin Shen

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Voluntarily sign the informed consent form and comply with the protocol requirements;
2. No gender restrictions;
3. Age: ≥18 years and ≤75 years;
4. Expected survival time ≥3 months;
5. Pathologically confirmed locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma;
6. Patients who have failed prior first-line standard therapy must have evidence of radiographic clear progression;
7. Ability to provide archived or fresh tumor tissue;
8. Must have at least one measurable lesion as defined by RECIST v1.1;
9. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1;
10. Toxicity from prior anti-tumor therapy must have recovered to ≤ Grade 1 as defined by NCI-CTCAE v5.0;
11. No severe cardiac dysfunction, with left ventricular ejection fraction (LVEF) ≥50%;
12. Organ function levels must meet the requirements;
13. Coagulation function: International Normalized Ratio (INR) ≤1.5, and activated partial thromboplastin time (APTT) ≤1.5 × upper limit of normal (ULN);
14. Urine protein ≤2+ or <1000 mg/24h;
15. For premenopausal women of childbearing potential, a pregnancy test must be performed within 7 days before starting treatment, with serum pregnancy test negative, and must be non-lactating; all enrolled patients (regardless of male or female) must take adequate barrier contraceptive measures throughout the entire treatment period and for 6 months after treatment completion.

Exclusion Criteria:

1. Prior anti-tumor treatment;
2. Positive HER2 expression in tumor tissue;
3. History of severe cardiovascular or cerebrovascular disease;
4. Prolonged QT interval, complete left bundle branch block, third-degree atrioventricular block, frequent and uncontrollable arrhythmias;
5. Unstable thrombotic events requiring therapeutic intervention within 6 months prior to screening;
6. Active autoimmune diseases and inflammatory diseases;
7. Diagnosis of another malignancy within 3 years prior to the first dose;
8. Hypertension poorly controlled by two antihypertensive medications;
9. History of interstitial lung disease (ILD) requiring hormone therapy, etc.;
10. Concurrent pulmonary disease resulting in clinically severe respiratory impairment;
11. Infection requiring clinical intervention within 2 weeks prior to randomization;
12. Patients with poorly controlled blood glucose levels;
13. Patients with active central nervous system metastases;
14. Patients with large serous cavity effusions, symptomatic serous cavity effusions, or poorly controlled serous cavity effusions;
15. Imaging findings indicating tumor invasion or encasement of major blood vessels such as those in the chest, neck, or pharynx;
16. History of allergic reactions to recombinant humanized antibodies or human-mouse chimeric antibodies, or allergy to any excipient of BL-M05D1;
17. Prior organ transplantation or allogeneic hematopoietic stem cell transplantation;
18. Positive for human immunodeficiency virus antibody, active tuberculosis, active hepatitis B virus infection, or active hepatitis C virus infection;
19. Active infection requiring systemic treatment;
20. Pregnant or breastfeeding women;
21. Esophageal or gastric varices requiring intervention within the past three months, etc.;
22. History of intestinal obstruction, inflammatory bowel disease, or extensive bowel resection, etc.;
23. Presence of other serious physical or laboratory abnormalities, or poor compliance, which may increase the risk of participating in the study, interfere with study results, or make the patient unsuitable for participation in the study as judged by the investigator.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BL-M05D1; Participants receive BL-M05D1 in the first cycle (3 weeks). Participants with clinical benefit could receive additional treatment for more cycles. The administration will be terminated because of disease progression or intolerable toxicity occurring or other reasons.	Drug: BL-M05D1; Administration by intravenous infusion for a cycle of 3 weeks.
Active Comparator: Paclitaxel or Docetaxel or Irinotecan hydrochloride; Participants receive Paclitaxel or Docetaxel or Irinotecan hydrochloride in the first cycle. Participants with clinical benefit could receive additional treatment for more cycles. The administration will be terminated because of disease progression or intolerable toxicity occurring or other reasons.	Drug: Docetaxel; Administration by intravenous infusion for a cycle of 3 weeks.; Drug: Paclitaxel; Administration by intravenous infusion for a cycle of 4 weeks.; Drug: Irinotecan hydrochloride; Administration by intravenous infusion for a cycle of 2 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall survival (OS)	Overall survival (OS) is defined as the time between the subject's randomization date and subject's death.	Up to approximately 24 months
Progression-free survival (PFS)	Progression-free survival (PFS) as assessed by BICR is defined as the time between the date subjects were randomized and the first observation of disease progression (based on BICR's image-based assessment) or death.	Up to approximately 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective Response Rate (ORR)	Objective response rate (ORR) is defined as the number of CR and PR in the treatment and control groups divided by the number of that group in the full analysis set (FAS).	Up to approximately 24 months
Disease Control Rate (DCR)	Disease Control Rate (DCR) : Percentage of all randomized subjects who rated the best overall response (BOR) as complete response (CR), partial response (PR), and disease stabilization (SD) according to RECIST 1.1 criteria.	Up to approximately 24 months
Duration of Response (DOR)	Duration of Response (DOR) : defined as the period from the date when tumor response is first recorded to the date when objective tumor progression is first recorded or the date of death.	Up to approximately 24 months
Treatment Emergent Adverse Event (TEAE)	TEAE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally emerging, or any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a pre-existing condition during the treatment of BL-M05D1. The type, frequency and severity of TEAE will be evaluated during the treatment of BL-M05D1.	Up to approximately 24 months
Anti-drug antibody (ADA)	Frequency of anti-BL-M05D1 antibody (ADA) will be investigated.	Up to approximately 24 months

Collaborators and Investigators

• Sponsor: Sichuan Baili Pharmaceutical Co., Ltd.
• Collaborators: Baili-Bio (Chengdu) Pharmaceutical Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2029

Study Registration Dates

• First Submitted: April 2, 2026
• First Submitted That Met QC Criteria: April 2, 2026
• First Posted (Actual): April 8, 2026

Study Record Updates

• Last Update Posted (Actual): April 8, 2026
• Last Update Submitted That Met QC Criteria: April 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Stomach Diseases; Stomach Neoplasms; Organic Chemicals; Heterocyclic Compounds; Hydrocarbons; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Camptothecin; Alkaloids; Taxoids; Cyclodecanes; Diterpenes; Docetaxel; Irinotecan; Paclitaxel
• Other Study ID Numbers: BL-M05D1-301

Drug and device information, study documents

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