A Phase I/II Study of FG-M108 Plus FG-B901 in Advanced CLDN18.2-Positive Solid Tumors

An Open-Label, Multicenter Phase I/II Clinical Trial to Evaluate the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of FG-M108 Injection in Combination With FG-B901 Injection in Patients With Unresectable Locally Advanced or Metastatic Solid Tumors

This open-label, multicenter Phase I/II trial evaluates the combination of FG-M108 and FG-B901 in patients with unresectable locally advanced or metastatic solid tumors that are positive for Claudin 18.2 and have progressed on, are intolerant to, or lack standard therapy. The Phase I dose-escalation part (using a BF-BOIN design) assesses safety, tolerability, and pharmacokinetics, and determines the recommended Phase II dose (RP2D) of FG-B901 when given with fixed-dose FG-M108. The Phase IIa expansion cohorts, grouped by tumor type, further evaluate safety and preliminary efficacy, with antitumor activity measured by RECIST 1.1 and iRECIST, while also exploring biomarker correlates. Key eligibility requires CLDN18.2 positivity (≥10% tumor cells with ≥1+ membrane staining by IHC), ECOG performance status 0-1, and measurable disease. Up to approximately 30 participants will be enrolled per cohort in Phase IIa. The study aims to provide initial evidence on the combination's safety, tolerability, PK, immunogenicity, and clinical activity in this hard-to-treat population.

Study Overview

• Status: Not yet recruiting
• Conditions: Solid Tumor Malignancies; Claudin 18.2
• Intervention / Treatment: Drug: FG-B901; Drug: FG-B901; Drug: FG-M108

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Zhaoyu Jin Yu; Phone Number: +8610-60709130; Email: pr@futuregenbiopharm.com

Study Locations

• China
  • Ha’erbin, China
    • Harbin Medical University Cancer Hospital
    • Contact: Yanqiao Zhang; Phone Number: +8610-86298278; Email: yanqiaozhanggcp@163.com
  • Shenyang, China
    • The First Hospital of China Medical University
    • Contact: Funan Liu; Phone Number: +8610-83282066; Email: lfn540@126.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Voluntarily sign the informed consent form, understand the study, are willing to comply with and have the ability to complete all trial procedures;
• Age 18-75 years (inclusive), any gender;
• Have histologically or cytologically confirmed locally advanced or metastatic solid tumors, and have failed standard therapy, or are intolerant to standard therapy, or for whom standard therapy is not available;
• CLDN18.2 positive (defined as ≥10% of tumor cells showing membrane staining ≥1+ by central laboratory IHC)
• ECOG 0-1
• Expected survival ≥3 months;
• Have at least one measurable tumor lesion according to RECIST 1.1 criteria;
• Adequate cardiac, bone marrow, liver, renal function;

Exclusion Criteria:

• Have received a live vaccine within 3 months prior to the first dose;
• Received radiotherapy within 4 weeks before the first dose
• Received Chinese herbal medicine with antitumor indications within 2 weeks before the first dose
• Previously received any therapy targeting CLDN18.2
• History of other malignancies within 3 years before the first dose
• Experienced Grade ≥3 immune-related adverse events (irAEs) from prior immunotherapy or discontinued immunotherapy due to irAEs, or have irAEs from prior immunotherapy that the investigator judges to still have clinical impact
• Toxicity from prior antitumor therapy has not recovered to NCI CTCAE v5.0 Grade 0-1
• History of severe allergic reactions, or hypersensitivity, or intolerance to any known component of the investigational products or other monoclonal antibodies
• Have brain or leptomeningeal metastases with symptoms
• Presence of clinically symptomatic body cavity effusions (pleural effusion, ascites, pericardial effusion, etc.) requiring local therapy or repeated drainage, or effusions that are poorly controlled per investigator judgment
• Uncontrolled or clinically significant cardiovascular and cerebrovascular diseases
• Clinically uncontrolled diseases such as diabetes, thyroid disorders (hormone replacement therapy does not affect enrollment), or other severe systemic diseases requiring systemic treatment
• Active or progressive infection requiring systemic treatment within 2 weeks before the first dose
• Known or suspected active autoimmune disease requiring systemic treatment
• Pregnant or breastfeeding female participants
• Known history of Hepatitis C or chronic active Hepatitis B

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dose Expansion Cohort; Once the effective dose has been determined, 1~2 expansion cohorts will be opened to evaluate the efficacy and safety of the selected dose.	Drug: FG-B901; Accelerated titration method, IV infusion Q3W; Adaptive BOIN design, IV infusion Q3W. (21-day cycles); Drug: FG-B901; 1~2 dose levels of FG-B901 will be tested according to an accelerated titration method followed by a adaptive BOIN design; Drug: FG-M108; 300 mg/m2, IV infusion Q3W (21-day cycles)
Experimental: Dose Escalation Cohort; Experimental : Monotherapy Dose Escalation Cohort Eight dose levels of FG-B901 combined with fixed-dosed FG-M108 will be tested according to an accelerated titration method followed by a adaptive BOIN design.	Drug: FG-B901; Accelerated titration method, IV infusion Q3W; Adaptive BOIN design, IV infusion Q3W. (21-day cycles); Drug: FG-B901; 1~2 dose levels of FG-B901 will be tested according to an accelerated titration method followed by a adaptive BOIN design; Drug: FG-M108; 300 mg/m2, IV infusion Q3W (21-day cycles)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective Response Rate (ORR)	ORR is defined as the proportion of participants who have a best overall response of Complete Response (CR) or Partial Response (PR) as assessed by investigator evaluation per RECIST 1.1.	Up to 24 months
Disease control rate (DCR)	DCR is defined as the proportion of participants who have a best overall response of Complete Response (CR), Partial Response (PR), or Stable Disease (SD) as assessed by investigator evaluation per RECIST 1.1.	Up to 24 months
Safety assessed by Adverse Events (AEs)	An AE is any adverse medical event that occurs during a clinical study, whether or not related with medicinal product, including signs, symptoms, abnormal laboratory test results and diseases. The incidence and severity of AEs during the clinical study are recorded and analyzed.	Up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival (OS)	OS is defined as the time from randomization to deathdue to any cause.	Up to 24 months
Progression Free Survival (PFS)	PFS is defined as the duration from randomization to the first imaging confirmation of progressive disease per RECIST 1.1 by investigator evaluation or death due to any cause (whichever occurs first).	Up to 24 months
Duration Of Response (DOR)	DOR is defined as the time from the date of the first response (CR/PR) until the date of progressive disease as assessed by investigator evaluation per RECIST 1.1 or death due to any cause (whichever occurs first).	Up to 24 months
Time to progression (TTP)	TTP	Up to 24 months
Maximum measured plasma concentration of FG-B901 and FG-M108	Cmax	Up to 24 months
Time to maximum plasma concentration of FG-B901 and FG-M108	Tmax	Up to 24 months
Half-life of FG-B901 and FG-M108	T1/2	Up to 24 months

Collaborators and Investigators

• Sponsor: FutureGen Biopharmaceutical (Beijing) Co., Ltd

Study record dates

Study Major Dates

• Study Start (Estimated): July 30, 2026
• Primary Completion (Estimated): August 31, 2028
• Study Completion (Estimated): February 28, 2029

Study Registration Dates

• First Submitted: July 10, 2026
• First Submitted That Met QC Criteria: July 10, 2026
• First Posted (Actual): July 15, 2026

Study Record Updates

• Last Update Posted (Actual): July 15, 2026
• Last Update Submitted That Met QC Criteria: July 10, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: FG-B901-02

Drug and device information, study documents

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