Certepetide

What is Certepetide?

Certepetide (development codes CEND-1 and LSTA1) is a 9-amino-acid cyclic tumor-homing peptide developed by Lisata Therapeutics (formerly Caladrium Biosciences) and licensed from Erkki Ruoslahti's group at the Sanford Burnham Prebys Medical Discovery Institute. The peptide is a chemically optimized member of the iRGD (internalizing RGD) family — synthetic peptides Ruoslahti's group developed to exploit a tumor-penetration pathway distinct from classical receptor-mediated drug delivery. Certepetide's mechanism involves a two-step receptor engagement: it first binds αv-integrins (specifically αvβ3 and αvβ5) on tumor vasculature, where proteolytic cleavage by tumor-associated proteases releases a fragment with an exposed C-terminal RXXR/K motif that engages neuropilin-1 (NRP-1) on the same vascular endothelium and adjacent tumor stroma. The NRP-1 engagement activates the CendR (C-end Rule) tissue-penetration pathway — a transient and tumor-selective increase in vascular and stromal permeability that enables enhanced delivery of co-administered chemotherapy, antibodies, nanoparticles, or other therapeutics into tumor tissue that would otherwise be poorly accessible. The mechanism distinguishes certepetide from antibody-drug conjugates and other receptor-targeted delivery approaches because the tumor-penetration effect operates on bystander co-administered drugs without requiring direct conjugation. The foundational work establishing the iRGD/CendR mechanism includes Sugahara's 2009 Cancer Cell paper on tissue-penetrating delivery (PMID 19962669) and the 2010 Science paper showing that co-administration of iRGD enhances cancer drug efficacy in animal models (PMID 20378772). Lisata Therapeutics has advanced certepetide through clinical development since the late 2010s, with the first-in-human Phase 1b trial in metastatic pancreatic ductal adenocarcinoma (PDAC) reported by Dean and colleagues in Lancet Gastroenterology and Hepatology 2022 (PMID 35803294) — the trial combined certepetide with the standard PDAC chemotherapy backbone of gemcitabine + nab-paclitaxel and reported acceptable safety with encouraging efficacy signals in a difficult-to-treat malignancy. Subsequent population pharmacokinetic work (Winning 2025 Clinical Pharmacology in Drug Development, PMID 39789733) and pharmacokinetic characterization (Järveläinen 2023 International Journal of Molecular Sciences, PMID 36982773) have refined the dosing and exposure framework. The current development pipeline includes the BOLSTER Phase 3 PDAC trial (combination with gemcitabine + nab-paclitaxel as first-line metastatic PDAC therapy), the LSTA1-GBM-2A Phase 2a glioblastoma trial (combination with temozolomide; protocol published by Truusalu 2025 in BMJ Open, PMID 41248393), and additional combinations across solid tumor indications. Certepetide is investigational and not FDA-approved. The peptide represents a distinctive approach within oncology drug development — a non-cytotoxic delivery enhancer rather than a tumor-killing agent itself — and the clinical hypothesis is that it makes existing chemotherapy more effective in tumors that have been historically resistant to drug penetration (PDAC, glioblastoma, peritoneal carcinomatosis). Whether the BOLSTER Phase 3 trial and other late-stage programs will translate the encouraging Phase 1b/2 signals into FDA-approval-grade efficacy is the principal open question.

What Certepetide Is Investigated For

Certepetide is a clinical-trial-stage oncology investigational drug, not a consumer-research-channel peptide. The molecule is being developed by Lisata Therapeutics for combination with standard-of-care chemotherapy in pancreatic ductal adenocarcinoma (the BOLSTER Phase 3 trial in metastatic first-line PDAC, combined with gemcitabine + nab-paclitaxel) and in glioblastoma multiforme (the LSTA1-GBM-2A Phase 2a trial, combined with temozolomide). The clinical hypothesis is that certepetide's tumor-penetrating mechanism — αv-integrin binding plus neuropilin-1-mediated CendR pathway activation — enables enhanced chemotherapy delivery into tumor tissue that has been historically poorly accessible to systemic drug therapy. The foundational work from Erkki Ruoslahti's group at Sanford Burnham (Sugahara 2009 Cancer Cell, 2010 Science) established the iRGD/CendR mechanism in animal models, and the first-in-human Phase 1b PDAC trial (Dean 2022 Lancet Gastroenterol Hepatol) demonstrated translation feasibility in patients. The Phase 3 BOLSTER readout will determine whether certepetide reaches FDA approval. This is investigational oncology, not a peptide consumers self-administer. There is no clinical use outside Lisata-sponsored trials, no FDA approval, no validated dosing protocol for off-label use, and no consumer-research-channel positioning that makes practical sense. Patients with metastatic pancreatic cancer or glioblastoma should consult their oncology team about clinical-trial enrollment. The peptide is included in this directory because it represents a substantive advanced-stage oncology peptide drug development program with peer-reviewed translational data — distinct from research-channel peptide marketing and worth tracking as the Phase 3 readout approaches.

History & Discovery

The certepetide story begins with Erkki Ruoslahti's group at the Sanford Burnham Prebys Medical Discovery Institute (formerly the Burnham Institute) in La Jolla, California. Ruoslahti is a foundational figure in integrin biology — his 1980s work characterizing the RGD motif as the cell-attachment recognition sequence in fibronectin established a substantial portion of modern integrin pharmacology. In the late 2000s, Ruoslahti's lab applied phage-display screening of tumor-vasculature binding peptides to identify iRGD (internalizing RGD), a cyclic peptide that not only bound αv-integrins on tumor vasculature but also engaged neuropilin-1 after proteolytic cleavage — activating a tissue-penetration pathway that the group named the C-end Rule (CendR). The foundational publications came in rapid succession. The Sugahara 2009 Cancer Cell paper (PMID 19962669) introduced the iRGD/CendR mechanism with proof-of-concept tissue-penetration data. The Sugahara 2010 Science paper (PMID 20378772) extended the work to demonstrate that simple co-administration of iRGD with cancer drugs (without direct conjugation) enhances drug efficacy in animal tumor models — the translational concept that would eventually drive certepetide's clinical positioning as a delivery enhancer rather than a conjugated drug-targeting agent. The Alberici 2013 Cancer Research paper (PMID 23151901) on de novo design of tumor-penetrating peptides extended the mechanistic understanding. Lisata Therapeutics (formerly Caladrium Biosciences) licensed the certepetide development rights from Sanford Burnham and advanced the molecule through clinical development. The first-in-human Phase 1b trial in metastatic pancreatic ductal adenocarcinoma was reported by Dean and colleagues in Lancet Gastroenterology and Hepatology 2022 (PMID 35803294), combining certepetide (then called CEND-1) with the standard PDAC chemotherapy backbone of gemcitabine + nab-paclitaxel. The trial demonstrated translation feasibility with acceptable safety and encouraging efficacy signals, supporting advancement to the Phase 3 BOLSTER trial in metastatic first-line PDAC. The 2021 Hurtado de Mendoza Nature Communications paper (PMID 33750829) established β5 integrin upregulation in PDAC vasculature as a mechanistic rationale for PDAC as a particularly suitable indication. The 2023 Järveläinen IJMS paper (PMID 36982773) characterized the pharmacokinetics, disposition, and duration of CendR pathway activation. The 2025 Winning Clin Pharmacol Drug Dev paper (PMID 39789733) refined population pharmacokinetic modeling in metastatic PDAC patients. The LSTA1-GBM-2A Phase 2a glioblastoma protocol (Truusalu 2025 BMJ Open, PMID 41248393) extended the development program to a second high-unmet-need indication. The peptide received the International Nonproprietary Name 'certepetide' as part of the regulatory development process, alongside the development codes CEND-1 and LSTA1. The INN assignment reflects the advanced regulatory and clinical-trial infrastructure of the program. As of 2026, certepetide sits in Phase 3 PDAC development and Phase 2a glioblastoma development, with the BOLSTER Phase 3 readout as the principal regulatory inflection point. Whether certepetide reaches FDA approval will depend on whether the encouraging Phase 1b/2 signals translate to clinically meaningful overall-survival benefit in the Phase 3 trial.

How It Works

Certepetide is a tiny 9-amino-acid peptide developed by Lisata Therapeutics that acts like a key for tumors. When you give it alongside chemotherapy, it binds to the blood vessels feeding tumors, gets cut by tumor-associated enzymes, and then briefly opens up the tumor's normally-tight defenses so the chemotherapy drugs can actually reach the cancer cells. It doesn't kill cancer itself — it just makes the chemo drugs you're already getting much more effective. The lead use is for pancreatic cancer (which is famously hard to treat partly because chemo can't reach the tumor), where it's currently in Phase 3 trials combined with the standard chemotherapy regimen. There's also a Phase 2 trial in glioblastoma. It's not FDA-approved yet — the Phase 3 readout will determine whether it gets approved.

Certepetide is a 9-amino-acid cyclic peptide (sequence cyclic-CRGDKGPDC, derived from the original iRGD scaffold) developed through chemical optimization of Erkki Ruoslahti's iRGD (internalizing RGD) platform at the Sanford Burnham Prebys Medical Discovery Institute. The mechanism involves a two-step receptor engagement that activates the C-end Rule (CendR) tissue-penetration pathway — a tumor-selective transient permeability increase that enables enhanced co-administered drug delivery. Step 1 — αv-integrin binding: Certepetide's RGD motif binds αv-integrins (specifically αvβ3 and αvβ5) on tumor vasculature endothelium. αv-integrins are upregulated on tumor blood vessels relative to normal vasculature, providing initial tumor-selective targeting. The integrin binding alone does not produce the tumor-penetration effect — it positions the peptide for the second step. Step 2 — Proteolytic cleavage and neuropilin-1 engagement: Tumor-associated proteases (predominantly furin-family proteases at the tumor vasculature) cleave certepetide between specific residues to expose a C-terminal RXXR/K motif. This exposed C-terminal motif then engages neuropilin-1 (NRP-1) on the same tumor vascular endothelium and adjacent tumor stroma. The NRP-1 engagement activates the CendR pathway — a vesicular transcytosis mechanism that produces transient and tumor-selective increases in vascular and stromal permeability. The CendR effect is paracrine in nature: once activated, it enhances penetration of bystander molecules (small-molecule chemotherapy drugs, antibodies, nanoparticles, oligonucleotides) into the tumor tissue without requiring direct conjugation. The Sugahara 2009 Cancer Cell paper (PMID 19962669) demonstrated the principle of tissue-penetrating delivery via iRGD-class peptides, and the 2010 Science paper (PMID 20378772) extended the work to show that simple co-administration of iRGD with cancer drugs (without conjugation) enhances drug efficacy in animal tumor models. The mechanism distinguishes certepetide from antibody-drug conjugates (which deliver payloads via direct conjugation to tumor-cell-targeting antibodies) and from receptor-targeted delivery approaches (which require conjugation of the targeting moiety to the therapeutic). Clinical pharmacokinetic characterization includes the Järveläinen 2023 IJMS paper (PMID 36982773) on PK, disposition, and duration of action, and the Winning 2025 Clinical Pharmacology in Drug Development paper (PMID 39789733) on population PK in metastatic PDAC patients. Certepetide is administered intravenously as a short infusion shortly before each chemotherapy dose, allowing the CendR pathway activation to coincide with peak chemotherapy plasma concentrations. The transient nature of the permeability increase is part of the safety profile — chronic permeability increase would have implications for off-target tissue exposure that are mitigated by the brief duration of the CendR effect. The Hurtado de Mendoza 2021 Nature Communications paper (PMID 33750829) extended the mechanism to β5-integrin-rich pancreas cancer and established the mechanistic case for PDAC as a particularly suitable indication. The β5 integrin upregulation in PDAC vasculature, combined with the dense desmoplastic stroma that has historically limited PDAC chemotherapy efficacy, makes the tumor-penetration mechanism a well-matched therapeutic strategy.

Evidence Snapshot

Research Gaps & Open Questions

What the current literature has not yet settled about Certepetide:

• 01Whether the BOLSTER Phase 3 PDAC trial will demonstrate clinically meaningful overall-survival benefit with certepetide + chemotherapy versus chemotherapy alone — the principal regulatory inflection point.
• 02Whether the tumor-penetration mechanism translates from PDAC to glioblastoma (LSTA1-GBM-2A) and to other solid tumors with similar drug-penetration barriers.
• 03Whether certepetide can be combined with ADCs, immune-checkpoint inhibitors, or other novel oncology drug classes to produce additive tumor-penetration benefit.
• 04The optimal dosing schedule relative to chemotherapy administration — whether the brief CendR activation window can be optimized for different chemotherapy backbone pharmacokinetics.
• 05The mechanism's tumor-selectivity in advanced metastatic disease — whether the αv-integrin and neuropilin-1 expression profiles that drive PDAC tumor selectivity hold up across different tumor histologies.
• 06Long-term safety of repeated certepetide administration over multiple chemotherapy cycles, beyond the durations characterized in the Phase 1b and Phase 2 trials.

Forms & Administration

Certepetide is administered as a short intravenous infusion shortly before each chemotherapy dose, allowing the transient tumor-penetration enhancement to coincide with peak chemotherapy plasma concentrations. In the BOLSTER Phase 3 PDAC trial, certepetide is co-administered with gemcitabine + nab-paclitaxel on the standard PDAC chemotherapy schedule. In the LSTA1-GBM-2A Phase 2a glioblastoma trial, certepetide is combined with temozolomide. The peptide is supplied as a sterile infusion preparation through Lisata Therapeutics for trial use only. There is no FDA-approved formulation, no compounding-pharmacy or telehealth availability, and no validated off-trial dosing.

Common Questions

Who Certepetide Is NOT For

Drug & Supplement Interactions

Documented drug-interaction data for certepetide come from the trial-stage development context. The intended interaction is with co-administered chemotherapy — certepetide is designed to enhance the tumor delivery of gemcitabine, nab-paclitaxel, temozolomide, and other chemotherapy backbone agents. The combination toxicity profile reflects the underlying chemotherapy plus minor additive contributions from the peptide, with the dominant adverse events attributable to the chemotherapy rather than the peptide. Interaction with concurrent supportive-care medications (anti-emetics, growth-factor support, transfusion support, etc.) follows the standard chemotherapy combination management. Patients enrolling in certepetide trials should disclose all concurrent medications to the trial team.

Safety Profile

Legal Status

Regulatory status changes over time. Verify current local rules with a qualified professional.

Myths & Misconceptions