Trial of BDC-1001 +/- Pertuzumab in Subjects With HER2-Positive Metastatic Breast Cancer

NCT05954143 | Terminated Phase 2 Results FDA Drug

• 1 other identifier: BBI-20231001
• Study Type: interventional
• Target: 11
• Locations: 2 countries
• Sites: 4

Brief Summary

This is an open-label, Phase 2 study to evaluate preliminary anti-tumor activity, safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of BDC-1001 administered as a single agent and in combination with pertuzumab in subjects with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer (MBC) previously treated with trastuzumab deruxtecan (Enhertu®).

Conditions

Metastatic Breast Cancer; HER2-positive Breast Cancer

Outcome Measures

Primary Outcomes (1)

• Objective Response Rate (ORR) Per RECIST v1.1 as Assessed by Investigator

  Objective Response Rate (ORR) was defined as the proportion of participants with best overall response of confirmed Complete Response (CR) or Partial Response (PR) as determined by the treating Investigator using RECIST v1.1 criteria.

  Up to approximately 1 year

Secondary Outcomes (7)

• Duration of Response (DOR) Per RECIST v1.1 as Assessed by Investigator

  Up to approximately 1 year

• Disease Control Rate (DCR) Per RECIST v1.1 as Assessed by Investigator

  Up to approximately 1 year

• Progression-Free Survival (PFS) Per RECIST 1.1 as Assessed by Investigator

  Up to approximately 1 year

• Overall Survival (OS)

  Up to approximately 1 year

• Number of Participants With at Least 1 Treatment Emergent Adverse Event (TEAE)

  Continuously from first dose of study treatment through end of treatment and Safety Follow-Up. Up to approximately 1 year

Study Arms (2)

BDC-1001 Single Agent

EXPERIMENTAL

BDC-1001 administered intravenously (IV) every 2 weeks

Drug: BDC-1001

BDC-1001 in Combination With Pertuzumab

EXPERIMENTAL

BDC-1001 administered intravenously (IV) every 2 weeks, in combination with pertuzumab administered intravenously (IV) as a fixed non-weight-based dose of 840-mg IV loading dose and then 420-mg IV maintenance dose every 3 weeks.

Drug: BDC-1001; Drug: Pertuzumab

Interventions

BDC-1001 DRUG

BDC-1001 is an immune-stimulating antibody conjugate (ISAC) designed to be delivered systemically (intravenously) and act locally by targeting HER2-expressing tumors and related metastatic disease for destruction by the innate and adaptive immune systems. BDC-1001 consists of an investigational biosimilar of the humanized monoclonal antibody (mAb) trastuzumab that is chemically conjugated to a toll-like receptor (TLR)7/8 agonist (payload) with an intervening non-cleavable, cell membrane impermeable linker.

BDC-1001 Single Agent; BDC-1001 in Combination With Pertuzumab

Pertuzumab DRUG

Pertuzumab is a monoclonal antibody that targets HER2 and prevents dimerization of HER2 with other members of the HER family (HER1, HER3, and HER4), thereby blocking ligand-activated downstream signaling.

Also known as: Perjeta®

BDC-1001 in Combination With Pertuzumab

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Histologically confirmed adenocarcinoma of the breast that is HER2+ (IHC 3+ or gene amplification by ISH or NGS).
• Have received 2 or more prior lines of anti-HER2-directed therapies, at least 1 in the metastatic setting and including trastuzumab deruxtecan.
• Measurable disease as determined by RECIST v.1.1.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Have life expectancy of greater than 12 weeks per the Investigator.
• All subjects must agree to have a biopsy prior to enrollment. If, in the judgment of the Investigator, a biopsy is not safely accessible or clinically feasible an archival tumor tissue sample must be submitted in lieu of a freshly collected specimen.

You may not qualify if:

• History of severe hypersensitivity to any ingredient of BDC-1001 or pertuzumab.
• Previous treatment with a small molecule TLR7/8 agonist or TLR7/8 agonist that has been conjugated to tumor-targeting antibody such as ISACs within 12 months before starting study treatment.
• Impaired cardiac function or history of clinically significant cardiac disease.
• Human Immunodeficiency virus (HIV) infection, active hepatitis B infection, or hepatitis C infection.
• Central nervous system metastases with the exception of disease that is asymptomatic, clinically stable, and has not required steroids for at least 28 days before starting study treatment.

Sponsors & Collaborators

• Bolt Biotherapeutics, Inc.: lead
• Hoffmann-La Roche: collaborator

Study Sites (4)

City of Hope

Irvine, California, 92618, United States

Location

Memorial Sloan Kettering Cancer Center

New York, New York, 10065, United States

Location

Virginia Cancer Specialists

Arlington, Virginia, 22205, United States

Location

Hospital Universitario 12 de Octubre

Madrid, 28041, Spain

Location

MeSH Terms

Conditions

Breast Neoplasms

Interventions

pertuzumab

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Results Point of Contact

• Title: Director of Clinical Development Operations
• Organization: Bolt Biotherapeutics, Inc.

clinicaltrials@boltbio.com

1-650-434-8640

Study Officials

• Bolt Clinical Development

  Bolt Biotherapeutics

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 23, 2023
• First Posted: July 20, 2023
• Study Start: November 30, 2023
• Primary Completion: September 20, 2024
• Study Completion: September 25, 2024
• Last Updated: November 20, 2025
• Results First Posted: November 20, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1); US (3)