ARA-290What the studies show

Q: What kind of evidence exists for ARA-290 (cibinetide)?

Small human studies. Several small placebo-controlled human trials, each about four weeks long and company-sponsored, on top of animal injury models; no large or long trial and no approval anywhere.

An 11-amino-acid piece of erythropoietin, built to protect tissue without making red blood cells, tested in small trials for small-fiber nerve damage.

5 min read · Small human studies · Updated November 2026

In short

Name: ARA-290 (cibinetide)
Evidence: Small human studies
Bottom line: Several small placebo-controlled human trials, each about four weeks long and company-sponsored, on top of animal injury models; no large or long trial and no approval anywhere.

Before you read this

This guide explains what published studies found. That is all it is.

It is not medical advice and it is not instructions for using anything. Where a dose appears, we are reporting what a named study gave the people or animals in it — a fact about the study, not an instruction to you.

The compounds here are not approved by the FDA for use in people and are sold for laboratory research only. A study tells you what happened to the subjects in it; it does not tell you what would happen to you. Talk to a doctor first.

What it is

ARA-290, also called cibinetide, is a chain of 11 amino acids copied from one surface of erythropoietin (EPO), the hormone that tells bone marrow to make red blood cells. EPO was known to do something else as well: in injured tissue it damps inflammation and keeps cells alive, acting through a different receptor from the one that makes red cells. That second receptor is a pairing of the EPO receptor with a subunit called the beta common receptor, which the researchers who described it named the innate repair receptor ¹. In 2008 a group at Araim Pharmaceuticals showed that a short peptide copied from helix B of EPO — the part that faces that receptor — protected tissue in animal models of nerve, heart and kidney injury but did not change red cell counts ². In blood the peptide is gone within minutes, yet the effects in animals lasted for days, which the authors took to mean it switches something on rather than staying around ².

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Sarcoidosis and the thinnest nerves

The human work centres on sarcoidosis, an inflammatory disease that in many patients damages the thinnest nerve fibers, producing burning pain, numbness and strange temperature sensations that standard nerve tests miss. In 2012 a group at Leiden University Medical Center ran a small randomized, placebo-controlled pilot in sarcoidosis patients with these symptoms, giving ARA-290 by injection for four weeks; the treated group reported fewer symptoms on a neuropathy questionnaire, and the authors reported no safety concern ³.

A 2013 trial from the same centre added an objective measure. Patients received daily subcutaneous ARA-290 or placebo for 28 days, and the researchers counted the tiny nerve fibers in the cornea with a confocal microscope — a window onto small-fiber damage elsewhere in the body. Fiber density rose in the treated group and symptom scores improved ⁴. A larger 2017 trial across several sites randomized 64 sarcoidosis patients to placebo or one of three daily doses for 28 days, and again reported more corneal nerve fibers in treated patients than in those given placebo, along with less pain ⁵.

Diabetes

The one trial outside sarcoidosis is in type 2 diabetes. In a 2014 placebo-controlled study, 38 people with type 2 diabetes and small-fiber neuropathy received ARA-290 or placebo by daily injection for 28 days. The treated group reported fewer neuropathic symptoms, corneal nerve fiber density increased, and — unexpectedly — HbA1c and blood lipids improved over the four weeks ⁶. The authors raised the possibility that the peptide acts on metabolism as well as on nerves; that has not been tested further in people.

What it is, and what is not known

The most useful fact about ARA-290 is what it does not do. Erythropoietin itself raises red cell counts and with them the risk of clots, which limits its use for anything other than anemia; the peptide was engineered to keep the protective signal and lose that effect, and in the animal and human studies it did not change red cell counts ².

What is not known is a longer list. Every trial above lasted four weeks, so nothing is known about longer courses or about what happens after the injections stop. Every trial was supported by the company developing the peptide and had its inventors among the authors, which is normal for an early drug and a reason to wait for independent work. The total number of people treated in published trials is in the low hundreds. Cibinetide is not an approved medicine anywhere; it remains an investigational drug.

What these studies are, and aren't

Small human studies. Several small placebo-controlled human trials, each about four weeks long and company-sponsored, on top of animal injury models; no large or long trial and no approval anywhere.