ARA-290

ARA-290 (cibinetide) is an 11-amino-acid synthetic peptide that reproduces the helix-B surface of erythropoietin (EPO). Its central mechanism is selective agonism of the innate repair receptor (IRR), a heterodimeric complex of the erythropoietin receptor (EPOR) and the beta common receptor (CD131). The IRR is selectively expressed in stressed, injured, or inflamed tissue and is largely absent from healthy cells, providing a degree of tissue-targeted activity.

Unlike native EPO, which also binds the homodimeric EPOR to drive red blood cell production, ARA-290 engages only the IRR and does not activate hematopoiesis. IRR signaling initiates anti-apoptotic cascades, suppresses pro-inflammatory cytokine release, and promotes cell survival in damaged tissue.

ARA-290 additionally antagonizes the transient receptor potential vanilloid 1 (TRPV1) channel, contributing to direct analgesic effects independent of its immune-modulatory actions. In rat models of peripheral nerve injury, the compound dose-dependently suppressed spinal microglia activation in the L5 dorsal horn and surrounding lumbar segments, a mechanism linked to its sustained relief of mechanical and cold allodynia. Stable hemoglobin values across all published clinical trials confirm its hematopoietic neutrality, distinguishing it from native EPO, which carries thromboembolic risk at therapeutic doses.

Clinical evidence for ARA-290 derives primarily from Phase 2 trials in sarcoidosis-associated small fiber neuropathy (SFN) and, secondarily, in type 2 diabetes.

A randomized, double-blind, placebo-controlled pilot study (Heij et al., Molecular Medicine 2012; PMID 23168581; n=22) administered 2 mg intravenously three times weekly for four weeks. ARA-290 produced significantly greater improvement in Small Fiber Neuropathy Screening List scores versus placebo (change −11.5 versus −2.9; p<0.05) and in SF-36 pain and physical functioning subscales (p<0.01), with no safety concerns identified.

A subsequent blinded, placebo-controlled trial (Dahan et al., Molecular Medicine 2013; PMID 24136731; 28 days SC daily) demonstrated improved neuropathic symptoms, significantly increased corneal nerve fiber density, improved cutaneous temperature sensitivity, and better 6-minute walk test performance versus placebo.

A Phase 2b dose-ranging study in 64 sarcoidosis-SFN patients (Culver et al., Investigative Ophthalmology and Visual Science 2017; DOI 10.1167/iovs.16-21291) tested 1, 4, and 8 mg subcutaneously daily for 28 days. The 4 mg arm produced approximately a 23% increase in corneal nerve fiber area versus placebo and significant increases in regenerating GAP-43-positive skin fibers, meeting its pre-specified primary endpoint. Placebo-corrected pain reductions were also noted in patients with moderate-to-severe baseline pain.

A Phase 2 trial in type 2 diabetes (n=48; 4 mg SC daily for 28 days) showed improvements in HbA1c (p=0.002), neuropathic symptom scores by PainDetect (p=0.037), and corneal nerve fiber density in a nerve-impaired subgroup (p=0.02).

Rat peripheral nerve injury studies confirmed dose-dependent allodynia relief lasting up to 20 weeks, correlated with suppressed spinal microglia reactivity at 10 to 30 µg/kg (Swartjes et al., Molecular Pain 2014; PMID 24529189). ARA-290 holds FDA Orphan Drug and Fast Track designations for sarcoidosis-associated neuropathy (granted 2016) and EU Orphan Drug Designation. No Phase 3 trial has been completed; the developing company, Araim Pharmaceuticals, has since closed, and the compound holds no marketing approval in any jurisdiction.

Typical dosage: 2-4 mg (daily for cycles).

The 2012 pilot study administered 2 mg intravenously three times weekly for four weeks. Subsequent sarcoidosis and diabetes trials used 4 mg subcutaneously once daily for 28 days. A dose-ranging study formally tested 1, 4, and 8 mg SC daily; the 4 mg dose produced the strongest and most consistent efficacy signal, with no meaningful advantage observed at 8 mg. In animal studies, doses of 3 to 60 µg/kg produced anti-nociceptive effects dose-dependently.

ARA-290 is not approved for clinical use in any jurisdiction and is not available as a licensed pharmaceutical. Outside of formal trials it is sold by compounding pharmacies and research chemical suppliers. Community and off-label reports describe 1 to 4 mg administered subcutaneously daily or three to five times per week for four to eight weeks, largely mirroring the clinical trial protocol. No consensus exists on maintenance dosing, cycling intervals, or reconstitution standards for non-trial use. Human safety data do not extend beyond the 28 to 56-day trial windows in published literature.

This information is provided for educational reference only and does not constitute medical advice. ARA-290 is not FDA-approved; administration outside a supervised clinical setting involves uncharacterized risks.

No compound-specific stability data has been identified for this peptide. The general lyophilized-peptide handling framework applies — see Storage & handling for temperature, reconstitution diluent, and beyond-use dating principles.

No published clinical or preclinical studies have formally evaluated ARA-290 in combination with other compounds. All of the following reflects anecdotal community use only.

• BPC-157: Anecdotally combined on the rationale of complementary tissue repair mechanisms. BPC-157 is proposed to act via nitric oxide and growth hormone receptor pathways while ARA-290 targets the innate repair receptor. No safety or efficacy data exist for this combination.

• TB-500 (thymosin beta-4): Reported in community forums alongside ARA-290 for neuropathy recovery. The anecdotal rationale cites TB-500 promotion of cell migration and angiogenesis alongside ARA-290 neuro-immune repair. Strictly anecdotal.

• Low-dose naltrexone (LDN): Used by some practitioners managing autoimmune or inflammatory neuropathies for putative complementary immune modulation. LDN's own evidence base in small fiber neuropathy is limited to small observational studies. No data support combining it with ARA-290.

ARA-290 is not currently FDA-approved for any indication. It is generally classified as a research compound. Regulatory status varies by country.

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Reported side effects: Generally well-tolerated

Across all published Phase 2 clinical trials, no serious adverse events were attributed to ARA-290. Hematological parameters — hemoglobin, platelet count, and white blood cell count — showed no clinically significant changes, consistent with the compound's design to avoid hematopoietic receptor activation.

In the Phase 2b sarcoidosis trial, adverse event profiles were similar between active and placebo groups. In the type 2 diabetes trial, four serious adverse events occurred in the active arm; two were judged unrelated to the study drug and none were attributed to ARA-290 itself.

• Injection site reactions (erythema, local discomfort) were the most commonly noted local effects; all were mild and self-resolving. • Mild headache and transient nausea were reported at low frequency. • No cardiovascular or thromboembolic events were attributed to the drug in any published trial, consistent with its hematopoietic neutrality. • Theoretical caution is warranted in active malignancy: IRR anti-apoptotic signaling could hypothetically support tumor cell survival, though no human data address this risk. • Pregnancy and lactation: no clinical safety data; avoid on precautionary grounds. • Hypersensitivity to erythropoietin-derived peptide sequences is a theoretical contraindication. • Long-term human safety data beyond the 28 to 56-day trial windows are absent. • Research-grade peptide from unregulated commercial sources carries unknown purity and sterility risks.