ARA-290

ARA-290 (cibinetide) is an 11–amino-acid peptide engineered from erythropoietin (EPO) to keep EPO’s tissue-protective, anti-inflammatory activity while removing its blood-cell–stimulating effect. Developed by Araim Pharmaceuticals from the work of Anthony Cerami, ARA-290 reproduces a single surface of the EPO molecule and signals through a separate receptor — which is why researchers have studied it for nerve repair and inflammation without the clot-related risks that come with raising red-cell mass.

What is ARA-290?

ARA-290, also known as cibinetide, Helix B Surface Peptide (HBSP) or pyroglutamate HBSP (pHBSP), is a short linear peptide of eleven amino acids. Its sequence corresponds to the aqueous-facing surface of helix B of erythropoietin — the part of the EPO molecule that does not contact the classic erythropoietic receptor. Because it copies only this “tissue-protective” face, ARA-290 retains EPO’s repair signalling but is non-erythropoietic: it does not meaningfully raise red blood cell counts. The N-terminal residue is a cyclised glutamine (pyroglutamate), which is reflected in the pHBSP name. It is classed as a tissue-protective, anti-inflammatory research peptide.

How ARA-290 is studied to work

The central idea behind ARA-290 is receptor selectivity. Erythropoietin can act on two different receptor assemblies, and ARA-290 was designed to engage only one of them.

• It binds the innate repair receptor (IRR) — a heterocomplex of the EPO receptor (EPOR) and the beta-common receptor (CD131).
• This receptor is expressed mainly on injured or inflamed tissue, not on red-cell precursors.
• It does not activate the homodimeric (EPOR)₂ receptor that drives erythropoiesis — hence no rise in hematocrit.
• Downstream signalling reported in the literature includes JAK2/STAT3 and PI3K/Akt, plus anti-apoptotic Bcl-2–family pathways.
• The net studied effects are anti-inflammatory, anti-apoptotic, reduced vascular permeability and pro-repair.

Reported effects and benefits in the research literature

Across preclinical and early clinical work, ARA-290 has been studied mainly as a tissue-protective and nerve-repair agent. Reported areas of interest include:

• Neuropathic pain and small-fibre neuropathy — the most-studied application.
• Sarcoidosis-associated small-fibre neuropathy — reduced pain alongside objective signs of nerve-fibre regeneration.
• Type 2 diabetic neuropathy — improved neuropathic symptom scores and some metabolic measures.
• Diabetic macular edema — listed as an investigational indication on an anti-permeability rationale.
• Wound healing and general anti-inflammatory tissue protection — largely preclinical and mechanistic.

What this does not mean: these are early-phase findings in specific patient groups, often with small numbers. None of them establish ARA-290 as a proven treatment, and nothing here is guidance for personal use. Reported regulatory designations are investigational status, not marketing approval.

What the human evidence shows

Human data for ARA-290 come from small, early-phase trials. A 2012 randomized pilot in sarcoidosis patients with small-fibre neuropathy (Heij and colleagues, Molecular Medicine, n = 22) found intravenous ARA-290 was well tolerated and improved neuropathic-symptom scores. A larger Phase 2b study (NCT02039687) used corneal confocal microscopy as an objective endpoint and reported a significant increase in corneal nerve-fibre abundance (on the order of 23% at the 4 mg dose), more regenerating intra-epidermal nerve fibres, and clinically meaningful pain reduction in patients with moderate-to-severe pain. A separate Phase 2 trial in type 2 diabetes (Brines and colleagues, 2015) reported improved PainDetect neuropathic-symptom scores plus modest improvements in HbA1c and lipid profile.

Despite these encouraging signals, ARA-290 / cibinetide is not approved by the FDA or any major regulator for any indication. It remains investigational. Orphan-drug and fast-track designations have been reported in company communications, but a designation is an early regulatory step, not evidence of efficacy or an approval.

Handling, storage and reconstitution (research context)

ARA-290 is supplied as a lyophilized (freeze-dried) powder for laboratory use. General peptide-handling principles apply:

• Lyophilized powder: kept frozen and protected from light and moisture for long-term storage.
• Reconstituted solution: refrigerated and used over a short period; minimize freeze–thaw cycles.
• Reconstitution with bacteriostatic water sets the concentration (mg/mL) — use the reconstitution calculator to work out concentration and draw volume, and see why syringe “units” are not a dose for the measurement math.

Cautions and considerations

• ARA-290 is a research compound, not an approved medicine.
• Its regulatory status is investigational; reported designations are not approvals.
• Purity and identity matter — a certificate of analysis (COA) documents what is actually in a vial.
• This page is informational only and not medical advice; it is intended for an audience of 21+.

Frequently asked questions

Is ARA-290 the same as EPO?

No. ARA-290 copies only one tissue-protective surface of the erythropoietin molecule. It shares EPO’s repair signalling but not its ability to stimulate red blood cell production.

Does ARA-290 raise red blood cell counts?

In the published research it is described as non-erythropoietic, because it does not activate the homodimeric EPO receptor that drives erythropoiesis. This is the main reason it was developed.

Is ARA-290 FDA-approved?

No. ARA-290 / cibinetide is investigational and has not been approved for any indication. Any reported orphan-drug or fast-track status is an early regulatory step, not an approval.

What is the innate repair receptor?

It is a receptor assembly combining the EPO receptor with the beta-common receptor (CD131). It appears on stressed or injured tissue and is the target through which ARA-290 is thought to act.

Related compounds and further reading

• BPC-157 — another widely discussed tissue-repair research peptide.
• TB-500 (Thymosin β4) — studied in healing and recovery contexts.
• GHK-Cu — a copper peptide studied for skin and tissue repair.
• How to reconstitute peptides and sterile technique — core handling guides.
• Browse the full peptide library and all guides.

For informational use only. Not medical advice; consult a qualified healthcare professional. 21+.