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Oncology · Investigational

Vantictumab

No lawful US pathway

Tell me if this changesRead the free 2026 Peptide Safety Checklist →
Written by Peptide Association Editorial TeamLast reviewed Editorial policy

01 · Overview

Vantictumab (OMP-18R5) is a fully human monoclonal antibody, not a peptide, that inhibits Wnt pathway signaling by binding Frizzled receptors 1, 2, 5, 7, and 8 (PMID 31338636). It binds a conserved epitope in the Frizzled extracellular domain and blocks canonical Wnt signaling induced by multiple Wnt ligands (PMID 22753465).

The therapeutic rationale is based on dysregulated Wnt signaling in solid tumors such as breast and pancreatic cancer. In mouse xenograft studies of human tumors, it reduced tumor growth and tumor-initiating cell frequency and acted synergistically with chemotherapy (PMID 22753465).

02 · Research summary & key findings

In a phase 1b study with nab-paclitaxel and gemcitabine in untreated metastatic pancreatic cancer, fragility fractures attributed to vantictumab occurred at the higher dose, and the study was terminated because of bone-related safety concerns (PMID 31338636). In a phase 1b study with paclitaxel in HER2-negative breast cancer, the overall response rate was 31.3%, but 6 patients had fractures, limiting further development (PMID 32803633). Clinical development has not advanced beyond phase 1.

03 · Regulatory status

Vantictumab is in the investigational stage. While preclinical and early-phase data exist, it has not received regulatory approval for clinical use in the United States.

No lawful pathway today

Vantictumab is not FDA-approved and does not currently have a lawful prescription or compounding pathway in the United States, so we do not sell it and will not book a consultation for it. That can change: in 2026 FDA began reviewing several peptides for compounding.

See the 13 FDA-approved compounds in Oncology

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04 · Administration routes

  • Intravenous

References

  1. [1]Wnt pathway inhibition via the targeting of Frizzled receptors results in decreased growth and tumorigenicity of human tumors Proc Natl Acad Sci U S A, 2012. PMID 22753465
  2. [2]A phase 1b dose escalation study of Wnt pathway inhibitor vantictumab in combination with nab-paclitaxel and gemcitabine in patients with previously untreated metastatic pancreatic cancer Invest New Drugs, 2020. PMID 31338636
  3. [3]Phase Ib clinical trial of the anti-frizzled antibody vantictumab (OMP-18R5) plus paclitaxel in patients with locally advanced or metastatic HER2-negative breast cancer Breast Cancer Res Treat, 2020. PMID 32803633

Primary literature

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Disclaimer: This information is provided for educational and research purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide therapy. The Peptide Association does not endorse or recommend any specific treatment protocol. See our editorial policy for how this content is produced and reviewed. Clinicians: join the network.