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    Immune Modulation
    15 min read

    ARA-290: Complete Research Guide to Innate Repair Receptor Agonist

    An evidence-based review of ARA-290 (cibinetide), an erythropoietin-derived peptide that activates the innate repair receptor for tissue protection and neuropathic pain relief without hematopoietic effects.

    Neuroprotection
    Immune Modulation
    Tissue Repair
    Medically reviewed byICL Medical TeamLast reviewed 23 May 2026Medical disclaimer

    Overview

    ARA-290 (cibinetide) is a synthetic 11-amino acid peptide derived from the helix B surface of erythropoietin (EPO). Unlike full-length EPO, which binds the classical homodimeric EPO receptor to stimulate red blood cell production, ARA-290 selectively activates the innate repair receptor (IRR), a heteromeric complex of EPO receptor and β-common receptor (CD131). This selectivity provides tissue-protective and anti-inflammatory effects without the dangerous hematopoietic side effects of EPO.

    The concept of separating EPO's tissue-protective functions from its blood cell-stimulating effects was pioneered by researchers at Yale and Warren Alpert Medical School of Brown University. Studies demonstrated that specific structural motifs on EPO's surface mediated cytoprotection independently of erythropoiesis, leading to the development of ARA-290 as a minimally functional peptide that retained tissue-protective activity.

    ARA-290 has completed multiple Phase 2 clinical trials for conditions including sarcoidosis-related small fiber neuropathy, diabetic neuropathy, and neuropathic corneal pain. Results have been promising, with significant improvements in nerve fiber density and pain reduction observed in controlled settings, making it one of the most clinically advanced tissue-protective peptides.

    Araim Pharmaceuticals, the compound's developer, has pursued regulatory approval for several indications. The peptide's clean safety profile and demonstrated clinical efficacy position it as a potentially important therapeutic for conditions where neuroinflammation and small fiber damage drive pathology.

    Quick facts

    Mechanism
    Innate repair receptor agonist providing tissue protection without erythropoiesis
    Primary use
    Neuroprotection & Pain Relief
    Evidence
    high
    FDA
    Not approved
    Route
    Subcutaneous injection or topical application
    Typical results
    Clinical trials show reduced neuropathic pain scores and improved corneal nerve fiber density within 4–12 weeks

    Chemical information

    Molecular mass
    1257.32 g/mol
    Chemical formula
    C₅₁H₈₄N₁₆O₂₁

    ARA-290 (C₅₁H₈₄N₁₆O₂₁) is a immune modulation compound with a molecular weight of 1257.32 g/mol. Its structural characteristics underpin its biological activity in immune system modulation.

    How ARA-290 works

    ARA-290 binds the innate repair receptor (IRR), a heterodimer of EPO receptor and β-common receptor (CD131), triggering JAK2-STAT5 signaling in tissue-resident macrophages and Schwann cells. This activates anti-inflammatory and pro-reparative gene programs, shifting macrophage polarization from M1 (pro-inflammatory) to M2 (reparative) phenotype and promoting Schwann cell-mediated nerve fiber regeneration.

    The IRR-mediated signaling cascade activates multiple downstream pathways including PI3K/Akt (cell survival), NF-κB suppression (anti-inflammatory), and VEGF upregulation (neurovascular repair). In Schwann cells, ARA-290 promotes myelination and axonal regrowth, explaining its ability to restore small fiber nerve density in neuropathic conditions. The peptide's action on resident macrophages shifts cytokine profiles from TNF-α/IL-1β dominance to IL-10/TGF-β, creating a permissive environment for tissue repair.

    Critically, ARA-290 does not activate the homodimeric EPO receptor responsible for erythropoiesis. This selectivity eliminates the risk of polycythemia (excessive red blood cell production), thrombosis, and hypertension that limit the use of full-length EPO as a tissue-protective agent. The peptide's 11-amino acid length also avoids immunogenicity concerns associated with larger protein therapeutics.

    In corneal nerve models, ARA-290 has been shown to promote corneal nerve fiber regeneration through direct effects on trigeminal sensory neurons and corneal keratocytes. The peptide reduces neuroinflammatory mediator release while simultaneously stimulating nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) expression in target tissues.

    • IRR activation: Selectively binds EPO receptor/CD131 heterodimer for tissue protection without erythropoiesis
    • Macrophage polarization: Shifts M1 to M2 phenotype, promoting anti-inflammatory cytokine profiles
    • Nerve regeneration: Stimulates Schwann cell myelination and small fiber nerve regrowth
    • NF-κB suppression: Reduces inflammatory signaling cascades in damaged tissues
    • Neurotrophic support: Upregulates NGF and BDNF expression in neural tissues

    Pharmacokinetics

    ParameterValueSignificance
    Molecular Weight1257.32 g/molPeptide size suitable for subcutaneous absorption
    Half-life~2 minutes (plasma)Rapid clearance; effects mediated by sustained receptor signaling
    Bioavailability~90% (subcutaneous)Excellent SC absorption despite short plasma half-life
    Duration of Effect24–48 hoursBiological effects persist well beyond plasma elimination

    Dosing & administration

    ARA-290 dosing varies by indication and individual factors. No FDA-approved dosing exists for this compound; protocols in the literature derive from limited clinical or preclinical data and practitioner experience.

    Any use should be conducted under qualified medical supervision with appropriate monitoring of safety markers.

    Important: These dosing ranges are not FDA-approved. Any use should be under qualified medical supervision.

    Calculate dose & reconstitution

    Side effects & safety

    Safety data for ARA-290 is primarily derived from preclinical studies and limited human data. Long-term effects in humans remain incompletely characterized.

    Common

    • Clinically demonstrated reduction in neuropathic pain scores
    • Restoration of corneal nerve fiber density in neuropathic conditions
    • Anti-inflammatory effects without immunosuppression
    • No hematopoietic side effects (no red blood cell overproduction)
    • Favorable safety profile demonstrated across multiple clinical trials
    • Potential disease-modifying effects in small fiber neuropathy

    Serious / potential risks

    • Injection site reactions (mild, transient)
    • Mild headache reported in some clinical trial participants
    • Fatigue in small percentage of subjects
    • Generally well-tolerated with no serious adverse events in trials
    • Long-term safety data still accumulating

    Drug interactions

    MedicationInteractionRecommendation
    Erythropoietin (EPO)Potential receptor competitionAvoid concurrent use; EPO may compete at the IRR while adding hematopoietic risk
    NSAIDsComplementary analgesiaCan be combined for pain management; different mechanisms of action
    Gabapentin/PregabalinAdditive neuropathic pain reliefCombination may allow reduced gabapentinoid dosing
    ImmunosuppressantsTheoretical concernARA-290's immune-modulating effects may alter immunosuppressant requirements

    Storage & handling

    Lyophilized (powder)

    • Store at -20°C to 4°C (freezer or refrigerator)
    • Protect from light and moisture
    • Stable for 12–24 months when stored properly
    • Keep in original sealed container until reconstitution

    Reconstituted solution

    • Refrigerate at 2–8°C after reconstitution
    • Use bacteriostatic water for multi-dose reconstitution
    • Typical stability: 14–28 days refrigerated
    • Do not freeze reconstituted solution

    Cost & availability

    SourceCostNotes
    Research suppliersVaries widelyQuality and purity vary significantly between sources
    Compounding pharmaciesPrescription requiredHigher quality assurance and purity testing

    The bottom line

    ARA-290 is a immune modulation compound with research interest in neuroprotection, immune modulation, tissue repair. While preclinical evidence is encouraging, it remains investigational and is not FDA-approved. Any use should be under qualified medical supervision.

    Best for

    • Researchers studying immune system modulation
    • Individuals interested in neuroprotection under medical guidance

    Not for

    • Self-administration without medical supervision
    • Pregnant or breastfeeding individuals
    • Individuals with contraindicated conditions

    Related compounds

    Frequently asked questions

    References

    1. [1] Brines M, Dunne AN, van Bruggen N, et al.. ARA 290, a nonerythropoietic peptide engineered from erythropoietin, improves metabolic control and neuropathic symptoms in patients with type 2 diabetes. Mol Med (2014). doi: 10.2119/molmed.2014.00215 PMID: 25517970
    2. [2] Dahan A, Dunne A, Swartjes M, et al.. ARA 290 improves symptoms in patients with sarcoidosis-associated small fiber neuropathy. Mol Med (2013). doi: 10.2119/molmed.2013.00056 PMID: 23979710
    3. [3] Heij L, Niesters M, Swartjes M, et al.. Safety and efficacy of ARA 290 in sarcoidosis patients with symptoms of small fiber neuropathy. Mol Med (2012). doi: 10.2119/molmed.2012.00332 PMID: 23019073
    4. [4] Brines M, Cerami A.. The receptor that tames the innate immune response. Mol Med (2012). doi: 10.2119/molmed.2011.00414 PMID: 22207354