ARA-290 Doses Used in Published Studies: What Researchers Reported

ARA-290, also called cibinetide, is a short peptide engineered from a region of the erythropoietin molecule that does not stimulate red blood cell production. It has been examined in a small number of human trials and in a broader set of animal models and cell-culture experiments. Each of those publications states the amount administered, the route and the duration, because that information describes the experimental conditions under which a result was obtained. Those conditions are not a plan for anyone. This page is for educational purposes only and is not medical advice; consult a licensed physician about any question concerning a medical condition or treatment.

Why no dosage chart appears on this page

A chart implies that numbers from different papers are comparable and can be averaged into a single figure. In the ARA-290 literature they are not. Human trials reported fixed amounts per injection given subcutaneously to adults with a specific diagnosis, as in the randomized, double-blind pilot study conducted in sarcoidosis patients with symptoms of small fiber neuropathy (PMID 23168581). Rodent studies expressed amounts per kilogram of body weight and delivered them systemically, as in the rat neuropathic pain work that reported long-term relief coupled with suppression of the spinal microglia response (PMID 24529189). Cell-culture experiments used molar concentrations in a dish, as in the study that reported attenuation of doxorubicin-induced genotoxicity and oxidative stress in vitro (PMID 32335150). Three different unit systems, three different biological contexts — no arithmetic converts one into another.

Human studies: route and course as described by researchers

Sarcoidosis-associated small fiber neuropathy

The earliest randomized human data came from a double-blind pilot study in sarcoidosis patients with symptoms of small fiber neuropathy, in which researchers administered the peptide subcutaneously as a fixed milligram-scale amount per injection against placebo and reported on safety alongside symptom outcomes (PMID 23168581). A second report in the same population described improvement in patient-reported symptoms together with an increase in corneal nerve fiber density following a multi-week subcutaneous course (PMID 24136731). The exact quantity per injection, the injection schedule and the number of treatment days are stated in those source papers; they were chosen by the investigators for a defined trial population under clinical supervision, with prespecified assessments of nerve fiber and symptom endpoints.

A 2014 review in an investigational-drugs journal summarised the rationale and the early clinical experience with ARA 290 for small fiber neuropathy in sarcoidosis and framed the peptide as an investigational candidate rather than an established therapy (PMID 24555851). Review articles of that kind describe what trials did; they do not convert trial conditions into general dosing advice.

Type 2 diabetes with neuropathic symptoms

A later clinical report examined the peptide in patients with type 2 diabetes, where researchers used subcutaneous administration over a multi-week course and reported changes in metabolic control alongside neuropathic symptom measures (PMID 25387363). As with the sarcoidosis work, the amount used was a fixed per-injection quantity rather than a weight-based calculation, and the study population was selected by diagnosis, laboratory criteria and consent — not by general interest in the compound.

Across these human reports the sample sizes were small and the follow-up periods short. The pilot study was explicitly labelled as such by its authors (PMID 23168581), and the diabetes study was likewise an early-phase investigation of both metabolic and neuropathic endpoints (PMID 25387363). Early-phase amounts are chosen to test feasibility and signal, not to define an optimum.

Animal studies: species, route and dosing periods

Neuropathic pain models

In rats, systemic administration of ARA 290 was reported to produce long-term relief of neuropathic pain, and the same study reported suppression of the spinal microglia response as a candidate mechanism (PMID 24529189). The dosing in that report was expressed per kilogram of body weight, as is conventional in rodent pharmacology, and relief was described as outlasting the treatment window rather than tracking it minute by minute (PMID 24529189). A separate 2016 study reported that ARA 290 relieved pathophysiological pain in animal models and identified the TRPV1 channel as a target, framing the effect as an interaction between immune signalling and nociception (PMID 26774587).

Inflammation, immune and tissue-repair models

In experimental colitis, researchers reported that cibinetide dampened innate immune cell functions and ameliorated the course of the disease model (PMID 29026145). In mice with genetic diabetes, activation of the EPOR-β common receptor complex by cibinetide was reported to ameliorate impaired wound healing (PMID 29223734). In a transplantation model, a nonhematopoietic erythropoietin analogue was reported to inhibit macrophage activation and prevent damage to transplanted islets (PMID 26683514). A neurodegeneration study reported that early monocyte modulation by the non-erythropoietic peptide ARA 290 decelerated the progression of Alzheimer's-disease-like pathology in a mouse model (PMID 34343617).

These reports differed not only in the amount administered but in nearly every other design feature: species and strain, the disease model used to create the phenotype, whether dosing began before or after the insult, how long dosing continued, and which tissue or behaviour was measured at the end. A figure that produced a result in a colitis model (PMID 29026145) carries no information about a wound-healing model in diabetic mice (PMID 29223734), even though both examined the same peptide.

Laboratory concentrations and imaging tracers are a different category again

Some ARA-290 work never involved a living organism receiving a therapeutic amount. One study exposed cultured cells to the peptide and reported attenuation of doxorubicin-induced genotoxicity and oxidative stress, using concentrations in the culture medium rather than doses in a body (PMID 32335150). A radiochemistry study synthesised a technetium-99m-labelled DOTA conjugate of ARA-290 and evaluated it as a potential SPECT tracer for targeting cardiac ischemic regions, where the injected quantity was a tracer amount defined by radioactivity, not a pharmacological dose (PMID 35317117). Concentrations in a dish and radiotracer activities are sometimes mistaken for dosing information; they describe entirely separate experimental purposes.

Why published study amounts do not become recommendations

1. Units are not interchangeable. Fixed subcutaneous amounts in human trials (PMID 23168581), per-kilogram systemic dosing in rodents (PMID 24529189) and molar concentrations in vitro (PMID 32335150) answer different questions and cannot be pooled.
2. Species differences are not a scaling factor. Receptor distribution, immune-cell behaviour, clearance and disease modelling all differ; a mouse model of Alzheimer's-like pathology (PMID 34343617) is not a miniature version of human disease.
3. Route and formulation matter. The human studies used subcutaneous injection of a defined investigational preparation under clinical oversight (PMID 25387363), and results obtained that way do not transfer to other routes or preparations.
4. Populations were narrow. Participants were selected by diagnosis and trial criteria, such as sarcoidosis with symptoms of small fiber neuropathy (PMID 24136731), so outcomes describe those groups rather than people in general.
5. Endpoints were prespecified and measured with instruments. Corneal nerve fiber density and validated symptom questionnaires were assessed by researchers in a controlled setting (PMID 24136731); nothing comparable exists outside a study.
6. Regulatory status. ARA-290 / cibinetide has been described in the literature as an investigational, engineered peptide (PMID 24555851); there is no approved product on which a general dosing standard could rest, and peptide material sold for laboratory use is labelled research-use-only.

Tolerability and adverse events: What Studies Report

The randomized, double-blind pilot study in sarcoidosis patients was designed around safety as well as efficacy, and researchers reported that the peptide was tolerated at the amount and schedule tested in that small population (PMID 23168581). The subsequent report in the same indication described symptom and corneal nerve fiber outcomes over its treatment period without identifying a safety signal that halted the investigation (PMID 24136731), and the 2014 review characterised the peptide as engineered to avoid the erythropoietic activity associated with erythropoietin itself (PMID 24555851). Short, small trials of this type can detect common, near-term events; they are not large enough or long enough to characterise uncommon or delayed harms, and the type 2 diabetes study was likewise an early-phase investigation with a limited follow-up window (PMID 25387363).

What the published literature does not establish

The available reports do not define an optimal amount, an optimal schedule, or a duration beyond the treatment windows the investigators chose. No published study in this set compared a range of amounts in humans over long periods, and no study reported outcomes in healthy volunteers taking the peptide for general purposes; the human work was conducted in defined patient groups with small fiber neuropathy or type 2 diabetes (PMID 23168581, PMID 25387363). Mechanistic findings — TRPV1 involvement in pain models (PMID 26774587), macrophage and monocyte modulation (PMID 26683514, PMID 34343617) and EPOR-β common receptor signalling in tissue repair (PMID 29223734) — describe biology in models, not clinical outcomes in people.

For readers comparing sources, the most useful habit is to check which species was studied, which route was used, how long dosing continued, and what was measured, then to read the number in that context rather than in isolation. That is how the study reported it, and that is the only context in which it means anything.

References

• Safety and efficacy of ARA 290 in sarcoidosis patients with symptoms of small fiber neuropathy: a randomized, double-blind pilot study (Molecular Medicine, 2012)
• ARA 290 improves symptoms in patients with sarcoidosis-associated small nerve fiber loss and increases corneal nerve fiber density (Molecular Medicine, 2013)
• ARA 290 for treatment of small fiber neuropathy in sarcoidosis (Expert Opinion on Investigational Drugs, 2014)
• ARA 290, a nonerythropoietic peptide engineered from erythropoietin, improves metabolic control and neuropathic symptoms in patients with type 2 diabetes (Molecular Medicine, 2015)
• ARA 290, a peptide derived from the tertiary structure of erythropoietin, produces long-term relief of neuropathic pain coupled with suppression of the spinal microglia response (Molecular Pain, 2014)
• ARA 290 relieves pathophysiological pain by targeting TRPV1 channel: Integration between immune system and nociception (Peptides, 2016)
• A Nonhematopoietic Erythropoietin Analogue, ARA 290, Inhibits Macrophage Activation and Prevents Damage to Transplanted Islets (Transplantation, 2016)
• Cibinetide dampens innate immune cell functions thus ameliorating the course of experimental colitis (Scientific Reports, 2017)
• Activation of the EPOR-β common receptor complex by cibinetide ameliorates impaired wound healing in mice with genetic diabetes (BBA Molecular Basis of Disease, 2018)
• Early monocyte modulation by the non-erythropoietic peptide ARA 290 decelerates AD-like pathology progression (Brain, Behavior, and Immunity, 2022)
• An engineered non-erythropoietic erythropoietin-derived peptide, ARA290, attenuates doxorubicin induced genotoxicity and oxidative stress (Toxicology in Vitro, 2020)
• Synthesis and evaluation of 99mTc-DOTA-ARA-290 as potential SPECT tracer for targeting cardiac ischemic region (Iranian Journal of Basic Medical Sciences, 2021)