A First-in-Human Study Using BDC-4182 as a Single Agent in Advanced Gastric and Gastroesophageal Cancer

A Phase 1/2, First-in-Human, Dose Escalation and Expansion Study of BDC-4182 as a Single Agent in Patients With Advanced Gastric and Gastroesophageal Cancer

A first-in-human study using BDC-4182 as a single agent in gastric and gastroesophageal cancers

Study Overview

• Status: Recruiting
• Conditions: Gastroesophageal Adenocarcinoma; Gastric Cancer Adenocarcinoma Metastatic
• Intervention / Treatment: Drug: BDC-4182

Detailed Description

This is a dose escalation study designed to evaluate the safety and tolerability of BDC-4182 to establish the recommended Phase 2 dose (RP2D). Participants will be enrolled in each dose cohort until the maximum tolerated dose (MTD) is reached. Additional participants may be enrolled into backfill cohorts at dose levels that have been cleared to collect additional safety and tolerability data. Additional participants may be enrolled at the determined RP2D in an expansion portion of the study.

• Study Type: Interventional
• Enrollment (Estimated): 122
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Bolt Biotherapeutics; Phone Number: +1 650 434 8640; Email: clinicaltrials@boltbio.com

Study Locations

• Australia
  • New South Wales
    • Darlinghurst, New South Wales, Australia
      • Recruiting
      • AUS Site 2
      • Contact: Site 8002
    • Westmead, New South Wales, Australia
      • Recruiting
      • AUS Site 5
      • Contact: Site 8005
  • Queensland
    • Birtinya, Queensland, Australia
      • Recruiting
      • AUS Site 1
      • Contact: Site 8001
  • Victoria
    • Clayton, Victoria, Australia
      • Recruiting
      • AUS Site 4
      • Contact: Site 8004
    • Heidelberg, Victoria, Australia
      • Recruiting
      • AUS Site 3
      • Contact: Site 8003
• South Korea
  • Seongnam-si, South Korea
    • Recruiting
    • SK Site 2003
    • Contact: Site 2003
  • Seoul, South Korea
    • Recruiting
    • SK Site 2001
    • Contact: Site 2001
  • Seoul, South Korea
    • Recruiting
    • SK Site 2002
    • Contact: Site 2002
  • Seoul, South Korea
    • Recruiting
    • SK Site 2004
    • Contact: Site 2004
  • Seoul, South Korea
    • Recruiting
    • SK Site 2005
    • Contact: Site 2005
• Taiwan
  • Kaohsiung City, Taiwan
    • Recruiting
    • TWN Site 9004
    • Contact: Site 9004
  • Kaohsiung City, Taiwan
    • Recruiting
    • TWN Site 9005
    • Contact: Site 9005
  • Taichung, Taiwan
    • Recruiting
    • TWN Site 9001
    • Contact: Site 9001
  • Taipei, Taiwan
    • Recruiting
    • TWN Site 9003
    • Contact: Site 9003
  • Taipei, Taiwan
    • Recruiting
    • TWN Site 9006
    • Contact: Site 9006
  • Taoyuan District, Taiwan
    • Recruiting
    • TWN Site 9002
    • Contact: Site 9002

Participation Criteria

Eligibility Criteria

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

Description

Key Inclusion Criteria:

• Has disease that is measurable by Response Evaluation Criteria in Solid Tumors (RECIST) v.1.1.
• Subjects must have histologically/cytologically confirmed gastric or gastroesophageal cancer that is metastatic (Stage 4) or unresectable (Stage 3).
• Subjects must have received at least 1-2 prior lines of locally available standard therapies or must be intolerant of standard therapies.
• For subjects in escalation: If prior Claudin 18 IHC expression is known, the subject must have some degree of Claudin 18 expression as defined as Positive or have expression ≥ 1% of tumor cells IHC ≥ 2+. Consult with Medical Monitor as needed.
• Adequate organ function
• Agree to have a biopsy prior to enrollment, at acceptable risk in the judgement of the Investigator. If a biopsy is not safely accessible or clinically feasible, an adequate archival tumor sample must be submitted.

Key Exclusion Criteria:

• Known central nervous system (CNS) metastases except for disease that is asymptomatic, clinically stable, and has not required steroids for at least 14 days before starting study treatment.
• Cardiac disease, pulmonary disease, or hepatic disease
• Active infection
• History of inflammatory eye disease
• Residual toxicity from a previous treatment
• Any investigational agent or standard anti-cancer therapies within 28 days before starting study treatment or within 5 estimated elimination half-lives, whichever is shorter.

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 Escalation; Escalating doses followed by backfill of selected doses	Drug: BDC-4182; Immune stimulating antibody conjugate (ISAC), consisting of an anti-claudin 18.2 monoclonal antibody conjugated to a TLR 7/8 dual agonist
Experimental: Dose Expansion; Expansion at determined RP2D	Drug: BDC-4182; Immune stimulating antibody conjugate (ISAC), consisting of an anti-claudin 18.2 monoclonal antibody conjugated to a TLR 7/8 dual agonist

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence and nature of AEs considered by the Investigator or Sponsor to be clinically relevant, attributable to study treatment, and meeting dose-limiting toxicity (DLT) criteria	Escalation period	Up to 21 days
Incidence of adverse events (AEs) and serious adverse events (SAEs) graded according to CTCAE v5.0	Escalation period	approximately 2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective response rate (ORR) according to RECIST v. 1.1	Escalation and expansion periods	approximately 4 years
Duration of Response (DOR)	Escalation and expansion periods	approximately 4 years
Disease control rate (DCR)	Escalation and expansion periods	approximately 4 years
Progression-free survival (PFS)	Escalation and expansion periods	approximately 4 years
Best Overall Response (BOR)	Escalation and expansion periods	approximately 4 years
Overall survival (OS)	Escalation and expansion periods	approximately 4 years
PK (Cmax) of BDC-4182	Escalation and expansion periods	approximately 4 years
PK (Cmin) of BDC-4182	Escalation and expansion periods	approximately 4 years
PK (AUC0-tau) of BDC-4182	Escalation and expansion periods	approximately 4 years
PK (AUC0-inf) of BDC-4182	Escalation and expansion periods	approximately 4 years
PK (CL) of BDC-4182	Escalation and expansion periods	approximately 4 years
PK (Vc or Vss) of BDC-4182	Escalation and expansion periods	approximately 4 years
PK (Terminal half-life) of BDC-4182	Escalation and expansion periods	approximately 4 years

Collaborators and Investigators

• Sponsor: Bolt Biotherapeutics, Inc.
• Investigators: Study Director: Bolt Clinical Development, Bolt Biotherapeutics

Study record dates

Study Major Dates

• Study Start (Actual): May 26, 2025
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2029

Study Registration Dates

• First Submitted: April 4, 2025
• First Submitted That Met QC Criteria: April 4, 2025
• First Posted (Actual): April 10, 2025

Study Record Updates

• Last Update Posted (Actual): January 27, 2026
• Last Update Submitted That Met QC Criteria: January 23, 2026
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Gastric Cancer; Gastroesophageal Cancer
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Stomach Diseases; Stomach Neoplasms
• Other Study ID Numbers: BBI-4182-101

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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