Study of the Kinesin Oral Molecular Degrader BBI-940 in Subjects With Advanced or Metastatic Breast Cancer (KOMODO-1)

April 9, 2026 updated by: Boundless Bio, Inc.

An Open-Label, Multicenter, First-in-Human, Phase 1 Study of BBI-940 in Advanced or Metastatic Breast Cancer: Kinesin Oral Molecular Degrader for Oncology (KOMODO-1)

This is a first-in-human, open-label, Phase 1 study evaluating BBI-940, an investigational kinesin oral molecular degrader, administered as monotherapy or in combination with fulvestrant in adults with advanced or metastatic breast cancer.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The study consists of two parts: Part 1 (dose escalation) and Part 2 (dose expansion).

Part 1 is a dose-escalation phase designed to evaluate the safety and tolerability of BBI-940 and to determine the recommended dose for expansion (RDE). Participants may have estrogen receptor-positive, HER2-negative (ER+/HER2-) breast cancer or triple-negative breast cancer of the luminal androgen receptor subtype (TNBC-LAR).

Part 2 is a dose-expansion phase designed to further evaluate BBI-940 at the selected RDE in defined participant populations.

Part 2A evaluates BBI-940 in combination with fulvestrant, including multiple dose cohorts to evaluate the safety of the combination regimen and to determine the combination RDE in participants with ER+/HER2- breast cancer without an ESR1 mutation.

Part 2B evaluates BBI-940 monotherapy at the RDE in participants with ER+/HER2- breast cancer with FGFR1 amplification.

Part 2C evaluates BBI-940 monotherapy at the RDE in participants with TNBC-LAR.

Across all parts of the study, treatment is administered in repeated 28-day cycles, and participants undergo protocol-specified safety assessments.

Study Type

Interventional

Enrollment (Estimated)

96

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90025
        • Recruiting
        • The START Center for Cancer Research
    • New York
      • Lake Success, New York, United States, 11042
        • Recruiting
        • The START Center for Cancer Research
    • Texas
      • Austin, Texas, United States, 78758
        • Recruiting
        • NEXT Oncology
      • Dallas, Texas, United States, 75390
        • Recruiting
        • University of Texas Southwestern Medical Center
      • Houston, Texas, United States, 77054
        • Recruiting
        • NEXT Oncology
      • San Antonio, Texas, United States, 78229
        • Recruiting
        • NEXT Oncology
      • San Antonio, Texas, United States, 78229
        • Recruiting
        • The START Center for Cancer Care
    • Virginia
      • Fairfax, Virginia, United States, 22031
        • Recruiting
        • NEXT Oncology

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria

  • Adults with locally advanced or metastatic breast cancer, including estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) disease or triple-negative breast cancer with luminal androgen receptor subtype (TNBC-LAR; androgen receptor expression ≥10% by immunohistochemistry), as applicable by study part.
  • Prior treatment with standard therapies known to provide clinical benefit, appropriate for disease subtype and study part, including endocrine therapy with CDK4/6 inhibition for ER+/HER2- disease.
  • Measurable disease per RECIST v1.1, except for participants enrolled in Part 1A.
  • Molecular eligibility as applicable by study part, including absence of an ESR1 mutation (Part 2A) or presence of FGFR1 amplification (Part 2B), based on prior local testing.
  • Availability of archival or newly obtained formalin-fixed, paraffin-embedded (FFPE) tumor tissue suitable for protocol-specified biomarker analyses.
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
  • Adequate hematologic, hepatic, renal, and coagulation function per protocol-defined laboratory criteria.
  • Estimated life expectancy of at least 12 weeks.
  • Ability to swallow oral medication and provide written informed consent.

Key Exclusion Criteria

  • Prior exposure to an inhibitor or degrader of Kinesin.
  • Known hypersensitivity to study intervention(s) or excipients.
  • Receipt of recent anticancer therapy within protocol-defined washout periods.
  • Other active malignancy likely to interfere with study assessment.
  • Baseline QTcF >470 msec or congenital long QT syndrome.
  • Clinically significant pulmonary embolism within 6 weeks prior to first dose.
  • Major surgery within 4 weeks or minor surgery within 2 weeks prior to first dose.
  • Active infection requiring systemic therapy within 2 weeks prior to first dose.
  • Pregnant or breastfeeding, or planning conception or gamete donation during the study or required post-treatment period.
  • Prior solid organ transplant or allogeneic stem cell transplant with protocol-defined exceptions.
  • Failure to recover to CTCAE Grade ≤1 (or baseline) from prior anticancer therapy, with protocol-specified exceptions.
  • Any serious or uncontrolled medical, laboratory, or psychiatric condition that could compromise safety or study integrity.
  • Other exclusion criteria as specified in the study protocol.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Parts 1A, 1B. BBI-940 Monotherapy Escalation
Participants receive BBI-940 given alone in multiple sequential dose escalation cohorts. BBI-940 is given orally in repeated 28-day cycles.
Drug: BBI-940
Oral small molecule degrader targeting Kinesin.
Experimental: Part 2A. BBI-940 in Combination with Fulvestrant (ER+/HER2- Breast Cancer without an ESR1 Mutation)
Participants receive BBI-940 in combination with fulvestrant. BBI-940 is given orally in repeated 28-day cycles at one of multiple potential dose levels.
Drug: BBI-940
Oral small molecule degrader targeting Kinesin.
Drug: Fulvestrant
Selective estrogen receptor degrader administered intramuscularly.
Experimental: Part 2B. BBI-940 Monotherapy Expansion (ER+/HER2- Breast Cancer with FGFR1 Amplification)
Participants receive BBI-940 given alone at the recommended dose for expansion (RDE). BBI-940 is given orally in repeated 28-day cycles.
Drug: BBI-940
Oral small molecule degrader targeting Kinesin.
Experimental: Part 2C. BBI-940 Monotherapy Expansion (TNBC-LAR)
Participants receive BBI-940 given alone at the recommended dose for expansion (RDE). BBI-940 is given orally in repeated 28-day cycles.
Drug: BBI-940
Oral small molecule degrader targeting Kinesin.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rate of dose limiting toxicities (DLTs) in each BBI-940 monotherapy dose escalation cohort.
Time Frame: First 28 days of study treatment (through end of Cycle 1).
DLTs will be assessed during the first 28 days of study treatment (Cycle 1) to establish the maximum tolerated dose (MTD) and the recommended dose for expansion (RDE) of BBI-940 as monotherapy.
First 28 days of study treatment (through end of Cycle 1).
Incidence of treatment emergent adverse events (TEAEs) in each dose group and overall as assessed by CTCAE version 5.0.
Time Frame: First dose of study treatment through 30 days after the last dose of study treatment.
Incidence of treatment emergent adverse events (TEAEs) will be assessed by maximum severity and maximum causality.
First dose of study treatment through 30 days after the last dose of study treatment.
Incidence of study treatment discontinuation and/or interruption by dose group and overall.
Time Frame: First dose of study treatment through 30 days after the last dose of study treatment.
The incidence of study treatment discontinuation and/or interruption will be assessed.
First dose of study treatment through 30 days after the last dose of study treatment.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Objective response rate (ORR) per RECIST Version 1.1 by dose group and overall.
Time Frame: From first dose of study treatment until disease progression per RECIST 1.1, death, withdrawal, loss to follow-up, or study completion; tumor assessments every 8 weeks (±7 days); assessed up to approximately 3 years.
Objective response rate (ORR) will be summarized by dose group and overall, based on the number of participants achieving a best response of partial response or complete response.
From first dose of study treatment until disease progression per RECIST 1.1, death, withdrawal, loss to follow-up, or study completion; tumor assessments every 8 weeks (±7 days); assessed up to approximately 3 years.
Time of maximum plasma concentration (Tmax) of BBI-940.
Time Frame: From 0 hours through up to 24 hours after BBI-940 dosing.
Time of maximum plasma concentration (Tmax) of BBI-940 will be determined.
From 0 hours through up to 24 hours after BBI-940 dosing.
Maximum observed plasma concentration (Cmax) of BBI-940.
Time Frame: From 0 hours through up to 24 hours after BBI-940 dosing.
Maximum observed plasma concentration (Cmax) of BBI-940 will be determined.
From 0 hours through up to 24 hours after BBI-940 dosing.
Minimum observed plasma concentration (Ctrough) of BBI-940.
Time Frame: From 0 hours through up to 24 hours after BBI-940 dosing.
Minimum observed plasma concentration (Ctrough) of BBI-940 will be determined.
From 0 hours through up to 24 hours after BBI-940 dosing.
Area under the plasma concentration-time curve (AUC) of BBI-940.
Time Frame: From 0 hours through up to 24 hours after BBI-940 dosing.
Area under the plasma concentration-time curve (AUC) of BBI-940 will be determined.
From 0 hours through up to 24 hours after BBI-940 dosing.
Progression Free Survival (PFS) per RECIST Version 1.1 by dose group and overall.
Time Frame: From first dose of study treatment until first documented disease progression per RECIST 1.1 or death from any cause, whichever occurs first; tumor assessments every 8 weeks (±7 days); assessed up to approximately 3 years.
Progression-free survival is defined as the time from first dose of study treatment to the first documented disease progression per RECIST Version 1.1 or death from any cause, whichever occurs first.
From first dose of study treatment until first documented disease progression per RECIST 1.1 or death from any cause, whichever occurs first; tumor assessments every 8 weeks (±7 days); assessed up to approximately 3 years.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Boundless Bio, Inc.

Investigators

  • Study Director: Robert C. Doebele, MD, PhD, Boundless Bio, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 25, 2026

Primary Completion (Estimated)

February 28, 2029

Study Completion (Estimated)

May 31, 2029

Study Registration Dates

First Submitted

January 22, 2026

First Submitted That Met QC Criteria

February 10, 2026

First Posted (Actual)

February 12, 2026

Study Record Updates

Last Update Posted (Actual)

April 13, 2026

Last Update Submitted That Met QC Criteria

April 9, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • BBI-940-101

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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