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Evaluating BBO-10203 for advanced solid tumors

A Phase 1a/1b Open-Label Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Efficacy of BBO-10203 in Subjects With Advanced Solid Tumors (The BREAKER-101 Study)

PHASE1 · TheRas, Inc., d/b/a BBOT (BridgeBio Oncology Therapeutics) · NCT06625775

This study is testing a new treatment called BBO-10203, alone and with another drug, to see if it can help people with advanced solid tumors, including certain types of breast cancer.

Quick facts

PhasePHASE1
Study typeInterventional
Enrollment392 (estimated)
Ages18 Years and up
SexAll
SponsorTheRas, Inc., d/b/a BBOT (BridgeBio Oncology Therapeutics) (industry)
Drugs / interventionsTrastuzumab, Bevacizumab
Locations36 sites (Duarte, California and 35 other locations)
Trial IDNCT06625775 on ClinicalTrials.gov

What this trial studies

This open-label, multi-center Phase 1a/1b study aims to assess the safety, tolerability, and pharmacokinetics of BBO-10203, a PI3Kα:RAS breaker, both as a standalone treatment and in combination with trastuzumab for patients with advanced solid tumors. The trial includes a dose escalation phase followed by an expansion phase to gather more data on its preliminary antitumor activity. Patients with specific types of advanced breast cancer and other solid tumors will be enrolled based on defined eligibility criteria.

Who should consider this trial

Good fit: Ideal candidates include adults with locally advanced unresectable or metastatic HER2-positive advanced breast cancer or other specified KRAS mutant solid tumors who have progressed on standard treatments.

Not a fit: Patients who have not received prior anti-HER2 therapy or those with HER2-positive advanced breast cancer who have had more than one prior line of treatment may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with advanced solid tumors, particularly those with HER2-positive breast cancer.

How similar studies have performed: Other studies have shown promise with similar approaches targeting HER2-positive tumors, indicating potential for success in this novel treatment strategy.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Locally advanced and unresectable or metastatic HER2-positive advanced breast cancer (aBC), HR-positive/HER2-negative advanced breast cancer, KRAS mutant advanced colorectal cancer (aCRC), or KRAS mutant advanced non-small cell lung cancer (aNSCLC)
* Measurable disease by RECIST v1.1 (except for HR-positive HER2-negative aBC where evaluable bone-only disease is permitted)
* Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1
* Adequate LVEF assessed by ECHO or MUGA (BBO-10203 + Trastuzumab cohorts only)
* Stable brain metastases
* Patients with HER2-positive aBC: Must have had at least 2 prior lines of anti-HER2-directed therapy. Only 1 prior line is acceptable where there is no other regionally available standard of care (SoC)
* Monotherapy Cohort patients with HR-positive, HER2-negative aBC, KRAS mutant aCRC or aNSCLC: Must have progression on, or disease recurrence after at least one line of SOC treatment or in the opinion of the investigator, would be unlikely to tolerate or derive clinically meaningful benefit from SoC therapy
* BBO-10203 + Fulvestrant combination cohort patients with HR-positive, HER2-negative aBC: confirmed PIK3CA mutation, must have been treated with a CDK4/6i
* BBO-10203 + Fulvestrant + ribociclib combination cohort patients with HR-positive, HER2-negative aBC: confirmed PIK3CA mutation, no prior systemic therapy in the aBC setting permitted
* BBO-10203 + FOLFOX + Bevacizumab combination cohort patients with KRAS mutant aCRC: One prior line of irinotecan-containing therapy for locally advanced or metastatic CRC is allowed but not required

Exclusion Criteria:

* Patients with KRAS mutant aCRC who have KRAS G12R mutation, BRAFV600E mutation, HER2amp, or dMMR/MSI-H tumors
* Patients with KRAS mutant aNSCLC who have KRAS G12R mutation, or tumors with other targetable driver mutations (eg, EGFR, anaplastic lymphoma kinase, ROS1/BRAF/RET/MET/EGFR exon20 insertion/NTRK/HER2)
* Patients with untreated and/or non-stable brain metastases

Other inclusion/exclusion criteria are specified in the protocol

Where this trial is running

Duarte, California and 35 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Solid Tumor, Adult, Metastatic Breast Cancer, Advanced Breast Cancer, HER2 Mutation-Related Tumors, HER2-positive Metastatic Breast Cancer, KRAS Mutant Metastatic Colorectal Cancer, Metastatic Lung Cancer, Metastatic Colorectal Cancer

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.