Accelerate Your Breast Cancer
Drug Development

Explore CDX Models

Explore Orthotopic Models

Crown Bioscience offers reproducible, cost-effective in vivo systems for early-stage drug evaluation, with well-characterized breast cancer cell lines representing diverse molecular backgrounds.

A broad panel of clinically relevant breast cancer CDX models covering major molecular subtypes and therapy resistance profiles is available. HER2-positive disease is represented by models such as subcutaneous BT474 and JIMT-1, as well as BT474-Luc bioluminescent models enabling intracranial, intratibial, and systemic metastasis studies. 

Triple-negative breast cancer is extensively covered, including documented responses for some models to paclitaxel, docetaxel, carboplatin, irinotecan, and erlotinib. Hormone receptor–positive disease is represented by estrogen-dependent Luminal A and B models, including endocrine therapy–resistant and ESR1-mutated variants, with sensitivity data for tamoxifen, fulvestrant, palbociclib, and combination regimens. 

Many models have been evaluated in standard-of-care and targeted therapy studies, providing detailed growth kinetics, drug response, and tolerability data, making this collection a robust translational platform for preclinical evaluation of novel agents, resistance mechanisms, and subtype-specific therapeutic strategies.

Applications:

• Rapid in vivo screening and candidate prioritization
• Pharmacokinetic/pharmacodynamic (PK/PD) studies
• Resistance mechanism modeling

Explore Syngeneic Models

For immuno-oncology research, our syngeneic breast cancer models are derived from mouse tumors with intact immune systems, enabling evaluation of immune checkpoint inhibitors, cancer vaccines, and T cell engagers.

The most clinically relevant syngeneic breast cancer models include 4T1, EMT6, and JC, all established in immunocompetent mice. The 4T1 model is an aggressive triple-negative murine mammary carcinoma with spontaneous metastases to lung, liver, brain, bone, and lymph nodes. Given its characteristics, this model is ideal for evaluating the effect of compounds on metastatic spread. 

The EMT6 model, a moderately immunogenic mammary carcinoma, grows more slowly and is suitable for testing immunotherapies, co-stimulatory agents, and combination regimens with chemotherapies, reflecting partial responses and resistance patterns seen in patients. 

The JC model is less aggressive and allows for extended treatment windows, making it useful for studying chemotherapy and immunotherapy in a slower-growing tumor context. Luciferase-expressing variants, such as 4T1-Luc, enable non-invasive bioluminescent imaging to monitor tumor growth and metastasis, providing valuable tools for preclinical evaluation of novel therapies in a physiologically relevant immune environment.

Finally, chimeric models have also been developed, such as EMT6-hHER2, which is a HER2-positive variant of EMT6 generated by stable expression of human HER2. Implanted orthotopically, it maintains a similar immune cell composition to the parental line. The model shows strong responsiveness to immunotherapies and dose-dependent tumor suppression with the HER2-targeted antibody–drug conjugate trastuzumab deruxtecan (DS-8201). This makes it particularly valuable for evaluating HER2-targeted therapies, antibody–drug conjugates, and immune checkpoint inhibitors in an immunocompetent setting.

Applications:

• Supports testing of immunotherapies in an intact murine immune system
• Reproducible and fast with predictable tumor growth
•  Cost-efficient

Explore Mice Models

For immunotherapy research in human-relevant immune contexts, we offer humanized PDX and CDX models reconstituted with human immune cells.

For breast cancer, several patient-derived xenograft (PDX) models have been established in CD34+ humanized mice, representing triple-negative breast cancer with invasive ductal carcinoma histology. These models originate from pretreated patients and maintain the molecular and histopathological features of the original tumors. In addition, human breast cancer cell lines have been successfully engrafted in CD34+ humanized mice. These cell line-derived xenograft models offer reproducible and genetically well-characterized platforms for large-scale screening.

Humanized breast cancer models are particularly valuable for preclinical testing of different molecules, such as antibodies targeting immune populations, antibody–drug conjugates, and combination regimens in a physiologically relevant immune context, This enables the study of tumor–immune interactions, biomarker discovery, and patient stratification strategies. Their predictive value is enhanced by the ability to capture donor-to-donor immune variability, mirroring clinical heterogeneity in treatment response.

Applications:

• Evaluation of human-specific immuno-oncology agents
• Immune cell trafficking and activation studies
• Combination therapy optimization

https://www.crownbio.com/model-systems/in-vitro/organoids

https://www.crownbio.com/organoidxplore

Through our exclusive license with Hubrecht Organoid Technology (HUB), Crown Bioscience offers the only commercial breast cancer organoid services with matched PDX–PD(X)Os pairs for seamless in vitro to in vivo translation.

The organoid panel includes a diverse range of clinically relevant breast cancer models capturing key subtypes and treatment histories. Notably, several triple-negative breast cancer models originate from the same patient across multiple disease stages, all pretreated with chemotherapy, targeted agents, and antibody–drug conjugates (ADCs) (such as sacituzumab govitecan) making them highly valuable for studying drug resistance and ADC efficacy. 

Additional TNBC models include brain metastasis–derived and metaplastic carcinoma, enabling research into rare and aggressive disease forms, as well as several models which progressed after immune checkpoint inhibitor therapy. HER2-positive and HER2-low invasive ductal carcinoma models provide platforms for evaluating HER2-targeted and HER2-low therapeutic approaches. Luminal B models with extensive endocrine therapy exposure, including an ESR1 Y537S mutation conferring oestrogen independence, are ideal for investigating hormone resistance mechanisms.

Together, these organoids offer a translationally rich resource for preclinical testing of novel therapies across breast cancer subtypes, treatment resistance contexts, and metastatic settings.

Applications:

• High-throughput drug screening (OrganoidXplore)
• Combination therapy testing
• Biomarker-driven patient stratification

Efficacy testing, resistance mechanism studies, biomarker validation, PK/PD, immuno-oncology evaluation, and combination therapies.

Exclusive HUB-licensed breast cancer organoids, many paired with PDX, capture disease progression, treatment resistance, and rare subtypes like metaplastic carcinoma. These models can be used in high-throughput drug screenings (OrganoidXplore).

Syngeneic models (4T1, EMT6, JC), chimeric EMT6-hHER2, and CD34+ humanized PDX/CDX breast cancer models.

Work with our scientific team to match model subtype, resistance profile, and biomarker landscape to your program’s mechanism and objectives.