BLMP6 (Fibulin-4 Targeting Breast Cancer Peptide)

Overview

BLMP6 is a synthetic short peptide that binds the extracellular matrix protein fibulin-4 (FBLN4). It was identified by the Kolonin lab at McGovern Medical School at UTHealth Houston using in vivo phage display screening against metastatic breast cancer in xenograft mouse models, and reported in Molecular Therapy Oncology in April 2026 (DOI 10.1016/j.omton.2026.201207). Fibulin-4 is normally a structural component of elastic fibers in connective tissue. The team discovered that fibulin-4 expression is dramatically reorganized and upregulated in the tissue microenvironment of aggressive invasive breast cancers, while normal breast tissue and non-invasive tumors show minimal expression. This difference makes fibulin-4 a useful targeting marker. The team demonstrated two applications. As an imaging probe, BLMP6 conjugated to a fluorescent dye traveled directly to metastatic lesions in mice xenografted with triple-negative breast cancer. As a therapeutic, BLMP6 conjugated to monomethyl auristatin E (MMAE), an FDA-approved cytotoxic warhead used in several antibody-drug conjugates, suppressed metastasis to distant organs and improved survival. The discovery used a combination of phage display, biochemistry, AlphaFold-derived structural prediction, and human tissue array validation. BLMP6 is a research compound and is not approved for human use. No clinical trials have been initiated and no IND filing has been disclosed.

Mechanism of Action

BLMP6 binds fibulin-4, an extracellular matrix glycoprotein. Fibulin-4 normally helps assemble tropoelastin into mature elastic fibers in connective tissue. In aggressive invasive breast cancers, fibulin-4 is upregulated and structurally reorganized around the tumor margins, producing a microenvironment signature that distinguishes invasive disease from non-invasive disease and normal tissue. By binding fibulin-4 selectively in this altered conformation, BLMP6 acts as a homing agent that concentrates conjugated payloads (imaging dyes or cytotoxic drugs) at metastatic and pre-metastatic invasive lesions while sparing healthy tissue.

Potential Benefits

• Targets a feature of the tumor microenvironment rather than a tumor cell surface antigen, broadening applicability to cancers lacking clean receptor targets
• Functions both as an imaging probe and as a drug-delivery vehicle
• Triple-negative breast cancer applicability validated in preclinical mouse models
• Smaller and cheaper to manufacture than antibody-drug conjugates
• Better tumor tissue penetration than typical antibody-based therapies
• Defined synthetic chemistry

Research Dosage Notes

The following reflects doses used in published research studies. This is not medical advice.

Not applicable - research compound only. Mouse xenograft studies used specific doses reported in the primary publication.

Routes of Administration

Read our full Routes of Administration Guide for detailed comparison of all delivery methods.

Reconstitution

Amino Acid Sequence

Side Effects & Safety

• No human safety data established
• Potential off-target binding to fibulin-4 in non-cancer connective tissue conditions has not been fully characterized

Pharmacokinetics

Synergistic Compounds

The following compounds have been studied alongside BLMP6 (Fibulin-4 Targeting Breast Cancer Peptide) for potential complementary or synergistic effects:

Related Peptides

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References & Further Reading

• Fibulin-4 expressed in metastatic breast cancer is a target of peptide-based imaging probes and experimental therapeuticsDaquinag AC, Zhang S, An Z, Azhdarinia A, Ghosh S, Farmer S, Ramesh AK, AghaAmiri S, Hernandez Vargas S, Kolonin M. Molecular Therapy Oncology. 2026
• Preclinical efficacy of experimental peptide therapy suggests a new target for metastatic breast cancer treatmentsCatherine Marfin. Medical Xpress. 2026