ARA-290, also known as cibinetide, is an 11-amino-acid synthetic peptide engineered from the aqueous face of helix B of erythropoietin (EPO). It was designed to activate the innate repair receptor (IRR) — a heteromeric complex of the EPO receptor and the beta-common receptor (CD131) — while lacking the erythropoietic activity mediated by the classical EPO receptor homodimer. This article summarizes the structural origin, proposed mechanism, and published preclinical and clinical literature for ARA-290, along with storage and handling guidance for the compound as a laboratory reference standard. All information is provided strictly for in-vitro and laboratory research use only. Last reviewed: July 2026.
What Is ARA-290?
ARA-290 (CAS 1208243-50-8) is a short linear peptide corresponding to a discontinuous set of residues on the solvent-exposed surface of EPO's helix B. In the foundational work by Brines and colleagues, published in Proceedings of the National Academy of Sciences in 2008, investigators mapped EPO's tissue-protective activity to helix B (residues 58–82) and then further reduced it to an 11-residue "helix B surface peptide" (HBSP). The N-terminal glutamine can spontaneously cyclize to pyroglutamate, producing the pyroglutamate form (pHBSP) that corresponds to ARA-290 as it is generally supplied. Because the peptide reproduces only a surface patch rather than the receptor-binding sites of EPO, it does not bind the EPO receptor homodimer and, in that 2008 work, was reported to be non-erythropoietic both in vitro and in vivo.
The compound is also referred to in the literature as cibinetide, the international nonproprietary name used in its clinical-stage program. It was developed by researchers associated with Warren Pharmaceuticals and later Araim Pharmaceuticals.
Mechanism of Action: The Innate Repair Receptor
EPO has two functionally separable roles. Its hormonal role — driving red blood cell production — is signaled through a homodimer of the EPO receptor (EPOR)₂. Its paracrine/autocrine tissue-protective role is signaled through a distinct heterocomplex of EPOR and CD131, the beta-common receptor shared with the GM-CSF, IL-3, and IL-5 receptors. This heterocomplex is what Brines and Cerami termed the innate repair receptor.
A central observation in the literature is that the IRR is not constitutively active in healthy tissue. It is upregulated locally in response to injury, hypoxia, or inflammatory signaling, which means IRR agonists are described as acting in a context-dependent manner — engaging tissue that is already in a damage-response state. A 2016 review in PAIN Reports by Dahan, Brines, Niesters, Cerami, and van Velzen describes the IRR as a receptor that simultaneously activates anti-inflammatory and tissue-repair pathways, with temporal and spatial separation from erythropoietic signaling.
Receptor selectivity: why the distinction matters experimentally
The practical consequence for research design is that ARA-290 provides a way to interrogate CD131-dependent tissue-protective signaling without the confounding hematologic and hemodynamic effects that accompany recombinant EPO in animal models. Swartjes and colleagues used this directly: in a 2011 Anesthesiology study, ARA-290 produced long-term relief of allodynia in rats, and that effect was absent in beta-common receptor knockout mice — genetic evidence that the response is CD131-dependent rather than EPOR-homodimer-mediated.
Published Research Overview
ARA-290 has an unusually broad published record for a compound of this class, spanning cell culture, rodent models, and small controlled human trials.
Preclinical findings
- Foundational tissue-protection work (PNAS, 2008). Helix B peptide protected motoneurons against kainic-acid excitotoxicity in vitro and reduced infarct volume in a rodent stroke model; the 11-amino-acid surface peptide showed benefit in ischemic stroke and renal ischemia–reperfusion models, accelerated cutaneous wound closure, and improved novel-object-recognition performance in rats. Neither peptide was erythropoietic in the assays reported.
- Neuropathic pain and microglia (Anesthesiology, 2011). ARA-290 produced long-lasting relief of allodynia in rats, dependent on the beta-common receptor, with the authors attributing the effect to anti-inflammatory activity possibly within the central nervous system.
- Metabolic models. In type 2 diabetic Goto-Kakizaki rats, ARA-290 administered daily for up to four weeks was reported in Molecular Medicine to lower plasma glucose at weeks 3 and 4, reduce hemoglobin A1c by roughly 20%, and increase glucose-stimulated insulin secretion in isolated islets.
- Neuroinflammation and behavior (Frontiers in Pharmacology, 2022). In a chronic-stress mouse model, ARA-290 was reported to attenuate depression-like behavior alongside reductions in inflammatory markers.
- Recent in-vitro work (Toxicology Research, 2025). In PC12 cells exposed to cadmium, ARA-290 pretreatment was associated with improved viability on MTT assay, reduced DNA damage on comet assay, lower reactive oxygen species and malondialdehyde, higher glutathione, total antioxidant capacity and superoxide dismutase activity, fewer TUNEL-positive cells, and reduced TNF-α, IL-1β, and IL-6 — a useful contemporary reference point for laboratories using ARA-290 as an IRR-agonist tool compound in oxidative-stress and cytotoxicity assays.
Controlled human trials
Two published trials are most frequently cited. A randomized, double-blind, placebo-controlled exploratory trial in Molecular Medicine (2012) enrolled 22 patients with sarcoidosis and symptoms of small fiber neuropathy, assigning them to intravenous ARA-290 (2 mg, three times weekly; n = 12) or placebo (n = 10) for four weeks. The ARA-290 group showed a significantly greater improvement in Small Fiber Neuropathy Screening List score at week 4 (Δ −11.5 ± 3.04 versus Δ −2.9 ± 3.34, standard error of the mean; p < 0.05), with significant within-group changes in the pain and physical-functioning dimensions of the SF-36. No safety concerns were raised on clinical or laboratory assessment. Notably, Brief Pain Inventory and Fatigue Assessment Scale scores improved in both arms without separation from placebo — an important limitation given the 22-patient sample.
A separate phase 2 trial reported in Molecular Medicine (2015) evaluated 28 days of daily subcutaneous self-administered ARA-290 (4 mg) versus placebo in patients with type 2 diabetes, with follow-up to day 56; the report described improvements in hemoglobin A1c and lipid measures and in neuropathic symptom scores over the observation period. A 2017 study in Investigative Ophthalmology & Visual Science by Culver and colleagues used corneal confocal microscopy in sarcoidosis-associated small nerve fiber loss and reported that cibinetide increased corneal nerve fiber area relative to placebo in the 4 mg group, with changes correlating with GAP-43-positive regenerating intraepidermal fibers.
These trials are described here as published scientific context only. They involved defined patient populations under medical supervision and do not describe, endorse, or imply any use of the research compound supplied on this page.
Development status as of 2026
As a freshness marker for readers tracking the field: as of mid-2026, cibinetide has not received marketing approval from the FDA or EMA for any indication. The published clinical record ends at phase 2, and no phase 3 results have appeared in the peer-reviewed literature. ARA-290 therefore remains an investigational, unapproved compound whose evidence base is strongest in preclinical and mechanistic work. Laboratories citing it should treat the human data as exploratory and underpowered.
Common Research Applications
In laboratory settings ARA-290 is used chiefly as a selective probe of IRR/CD131-dependent signaling. Reported application areas include:
- Dissecting CD131-dependent versus EPOR-homodimer-dependent effects, typically alongside beta-common receptor knockout or knockdown controls
- In-vitro neuroprotection and cytotoxicity assays (viability, ROS, apoptosis endpoints)
- Models of inflammatory signaling and cytokine expression
- Tissue-injury and wound-repair model systems
Storage & Handling
Dynamite Research Peptides supplies ARA-290 as a lyophilized powder. Store the sealed vial at −20 °C or below, protected from light and moisture. Reconstitute immediately before use with a sterile solvent as indicated on the Certificate of Analysis (COA), keep reconstituted material refrigerated, and avoid repeated freeze–thaw cycles, which degrade peptide integrity. Handle with appropriate personal protective equipment in a ventilated laboratory setting. Short peptides with an N-terminal pyroglutamate are generally stable when dry, but solution stability should be verified for each experimental buffer.
Conclusion
ARA-290 (cibinetide) is a well-characterized tool compound for studying the innate repair receptor — the EPOR/CD131 heterocomplex through which erythropoietin exerts tissue-protective rather than erythropoietic effects. Its value in research is its receptor selectivity: it allows CD131-dependent pathways to be probed without the hematologic confounds of EPO itself. Our ARA-290 is high-purity, third-party tested, and ships with a COA so experimental results stay reliable and reproducible.
Frequently Asked Questions
What is ARA-290?
ARA-290, also called cibinetide, is an 11-amino-acid peptide derived from the aqueous surface of helix B of erythropoietin. It was engineered to engage the innate repair receptor (EPO receptor plus CD131) without activating the erythropoietic EPO receptor homodimer.
How does ARA-290 differ from erythropoietin?
EPO signals through two different receptor arrangements: a homodimer that drives red blood cell production and an EPOR/CD131 heterocomplex associated with tissue protection. ARA-290 reproduces only a surface region of EPO and was reported as non-erythropoietic in the 2008 PNAS characterization, so it engages the latter pathway selectively in the models studied.
What is the innate repair receptor?
It is the heteromeric EPO receptor / beta-common receptor (CD131) complex described by Brines and Cerami. It is upregulated locally in injured or inflamed tissue rather than being constitutively active, which is why IRR agonists are characterized in the literature as context-dependent.
Is ARA-290 an approved drug?
No. As of 2026 cibinetide has not been approved for any indication in the United States or Europe, and its published clinical development did not progress past phase 2 trials.
What is the purity level of Dynamite Research Peptides' ARA-290?
Our ARA-290 is typically 99%+ pure, verified by HPLC analysis. Detailed purity data is provided on the Certificate of Analysis (COA) included with each product.
What research applications is ARA-290 suitable for?
It is used in studies of innate repair receptor signaling, CD131-dependent pathways, in-vitro neuroprotection and oxidative stress, inflammatory cytokine expression, and tissue-repair model systems.
All products are for research use only — not for human or animal consumption, and not for diagnostic or therapeutic use.