ARA-290 (Cibinetide): Small Fibre Neuropathy Research

Abstract still life: a fine network of glowing ink-green filaments like nerve fibres suspended in clear resin — **ARA-290.** Illustration, not a product photo.

Research compound. Not approved by FDA Philippines for human use unless stated. Nothing here is a dosing recommendation or medical advice.

What it is

ARA-290, generic name cibinetide, is an 11 amino acid peptide built from a region of erythropoietin (EPO), the hormone the kidneys release to stimulate red blood cell production. The team behind it, including Michael Brines and Anthony Cerami, had earlier shown that EPO has tissue-protective effects separate from its blood-forming effect. ARA-290 was engineered to isolate that protective signalling from the red-blood-cell effect, so it is described in the literature as a nonerythropoietic EPO derivative.

Its main clinical research focus is small fibre neuropathy, damage to the thinnest sensory nerve fibres, in two conditions where that damage is common: sarcoidosis and type 2 diabetes.

How it works

Classical EPO acts on a receptor pair (a homodimer of the EPO receptor) found mainly on the precursor cells that become red blood cells. Researchers identified a separate receptor complex, often called the innate repair receptor, made up of the EPO receptor paired with CD131, the beta common receptor subunit shared with several other cytokines. This second receptor complex is expressed on nerve, immune and other tissue cells rather than blood precursor cells, and activating it appears to trigger anti-inflammatory and tissue-protective signalling without stimulating erythropoiesis.

ARA-290 was designed to bind this innate repair receptor selectively. That selectivity is the reason it has been studied in neuropathy rather than as a substitute for EPO in anaemia: the safety concerns that limit EPO dosing, such as excessive red blood cell production and associated cardiovascular risk, are the effects ARA-290 is engineered to avoid.

What the research found

All of the published clinical work on ARA-290 is in small, phase 2-scale human trials. There is no phase 3 trial and no approval anywhere.

van Velzen and colleagues (2014) reviewed the early clinical development of ARA-290 in sarcoidosis-associated small fibre neuropathy, describing a favourable safety profile alongside reductions in neuropathy symptoms in the trials available at that point.
Brines and colleagues (2015) ran a phase 2 trial of ARA-290 in patients with type 2 diabetes who had painful neuropathy, reporting improvements in both metabolic control and neuropathic symptoms.
Culver and colleagues (2017) tested cibinetide in patients with sarcoidosis-associated small nerve fibre loss and neuropathic pain, using corneal confocal microscopy, a way of imaging nerve fibres in the cornea, to measure nerve fibre abundance before and after treatment, alongside pain outcomes.
Brines and colleagues (2018) followed up with an analysis of corneal nerve fibre size as a way to diagnose small fibre neuropathy and track response to treatment, comparing patients with diabetic and sarcoidosis-associated neuropathy.

The consistent thread across this body of work is the use of corneal confocal microscopy as an objective, imageable stand-in for nerve fibre health, since small fibre neuropathy is otherwise hard to quantify. The trials are small and industry-linked (Araim Pharmaceuticals, the company developing ARA-290, is connected to several of the listed authors), which is typical for early-phase peptide development but is a reason to wait for larger, independently replicated trials before treating the findings as settled.

Side effects reported in studies

The published trials describe ARA-290 as generally well tolerated in the populations studied, consistent with its design goal of avoiding EPO's erythropoiesis-related risks. This page does not state a specific adverse-event rate, since no verified source with that figure was opened while researching it. Anyone evaluating the compound should read the individual trial publications for their full safety tables rather than relying on a summary.

Status in the Philippines

No ARA-290 or cibinetide product is registered with FDA Philippines, and it has not been approved as a medicine by any regulator worldwide. It is not a controlled substance under RA 9165. It is a niche research compound locally, relevant mainly given the Philippines' high rate of type 2 diabetes and the neuropathy that can come with it, but nothing sold locally has gone through the clinical trials described above.

Storage

As an unapproved research peptide, ARA-290 should be handled like other lyophilised peptides: keep it refrigerated before and after reconstitution, away from heat and light, and avoid repeated freeze-thaw cycles. See the beginner guide for handling basics.

Common questions

What is ARA-290?

ARA-290, generic name cibinetide, is an 11 amino acid peptide engineered from a region of erythropoietin (EPO). It was designed to keep EPO's tissue-protective signalling while removing the ability to stimulate red blood cell production.

What is small fibre neuropathy?

It is damage to the thinnest nerve fibres in skin and other tissue, the ones that carry pain and temperature sensation. Standard nerve conduction tests, which check larger fibres, can look normal, so it is often assessed with a skin biopsy or corneal confocal microscopy instead. Sarcoidosis and diabetes are both established causes.

Does ARA-290 raise red blood cell counts like EPO does?

No, and that is the point of the design. It targets a different receptor combination than the one that drives erythropoiesis, so the published trials describe it as nonerythropoietic, meaning it should not raise hematocrit the way therapeutic EPO does.

Is ARA-290 an approved medicine?

No. It has been tested in phase 2 trials for sarcoidosis-associated and diabetes-associated small fibre neuropathy, but it is not approved by any medicines regulator and is not available as a prescribed drug.

Is ARA-290 legal in the Philippines?

It is not a scheduled controlled substance, but no ARA-290 or cibinetide product is registered with FDA Philippines. It is sold locally, where available, as a research compound rather than a medicine.