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Oncology & Specialized

iRGD

Tumor-penetrating peptide that opens a transport route into solid tumors so co-given chemotherapy reaches deeper — investigational, oncology-only.

InvestigationalEvidence level 3 of 5: Limited human dataAlso: Certepetide, LSTA1, CEND-1, Internalizing RGD peptide, CRGDKGPDC

Overview

iRGD is a small cyclic peptide that acts as a molecular key to solid tumors. It first docks onto αv integrins, which are abundant on tumor blood vessels. Tumor enzymes then cut it, exposing a hidden motif that binds neuropilin-1 and switches on a transport pathway through the vessel wall and deep into tumor tissue. Drugs given at the same time — chemotherapy, antibodies or imaging agents — ride along without being chemically attached. In animal models this markedly increased drug penetration. In people, it is being tested as certepetide alongside standard chemotherapy for pancreatic cancer, with encouraging but not yet definitive results. It has no standalone anticancer effect and belongs only in clinical trials under an oncologist.

Classification
Cyclic 9-amino-acid tumor-penetrating peptide (CRGDKGPDC, disulfide-bonded)
Route
Intravenous (clinical trials only)
Half-life
Short (minutes to ~2 hours, IV)

Mechanism of action

Primary targetαv integrins, then neuropilin-1 (NRP-1) on tumor vasculature
  1. Integrin homingRGD motif binds αvβ3/αvβ5 integrins on tumor endothelium.
  2. Proteolytic cleavageTumor proteases cut iRGD, exposing the CendR motif (CRGDK).
  3. Neuropilin-1 bindingCendR motif engages NRP-1 on vessel and tumor cells.
  4. Bulk transport activationTriggers a transcytosis-like pathway through tumor tissue.
  5. Co-drug penetrationCo-administered drugs travel deeper into the tumor mass.
Downstream effects
  • Greater intratumoral drug delivery
  • Potential chemo-response enhancement
  • Possible metastasis reduction (preclinical)

Researched for

  • Metastatic pancreatic ductal adenocarcinoma
  • Locally advanced pancreatic cancer
  • Glioma and osteosarcoma (orphan designations)
  • Tumor imaging and drug delivery

Research notes

  • Sugahara et al. (Science, 2010): co-administered iRGD increased tumor penetration and efficacy of multiple drugs in mouse models.
  • Dean et al. (Lancet Gastroenterol Hepatol, 2022): Phase 1 with gemcitabine/nab-paclitaxel showed acceptable safety and response signals in metastatic pancreatic cancer.
  • ASCEND randomized Phase 2 (2025): median PFS unchanged (5.5 vs 5.5 months); OS 12.4 vs 9.7 months, not statistically significant.
  • Phase 1b/2a iLSTA (2025, with durvalumab) reported high preliminary response rates; final data pending.

Reported side effects

  • Toxicity largely reflects the co-administered chemotherapy
  • Infusion reactions possible
  • No standalone side-effect profile established

Contraindications & cautions

  • Use outside a clinical trial or oncology protocol
  • Pregnancy
  • Known hypersensitivity to the peptide

Lab monitoring

  • Per oncology protocol and co-administered agent
  • Staging imaging and tumor markers per standard of care

Dosing and pricing for iRGD

Dosing references and compound pricing are available to established patients in the secure portal after a medical evaluation.

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