ARA-290: Scientific Profile

Publicado el 12 de julio de 2026 · Actualizado el 28 de agosto de 2026

ARA-290 (Cibinetide; HBSP), CAS 1208243-50-8, is a linear peptide of 11 amino acids derived from the B helix of erythropoietin, designed for research use. It acts on the so-called innate repair receptor (EPOR/common beta-receptor heteromer, CD131) to modulate inflammation and tissue protection responses without stimulating erythropoiesis. The subject of preclinical studies and early-phase clinical trials in small-fiber neuropathy.

ARA-290, also known as cibinetide or Helix B Surface Peptide (HBSP), is a linear synthetic peptide of eleven amino acids (CAS 1208243-50-8; molecular formula C51H84N16O21; molecular weight approximately 1257.3 g/mol) used as a tool in biomedical research. Its design derives directly from the structural study of erythropoietin (EPO): the sequence reproduces the aqueous face of the B helix of the EPO molecule, a region that does not participate in binding to the classical erythropoietic receptor but that was experimentally associated with the cytoprotective properties of the hormone. The work of researchers in the field of tissue EPO, in particular Michael Brines and Anthony Cerami, led to the observation that the hematopoietic activity and the tissue-protective activity of EPO can be molecularly separated, which motivated the development of short peptides and non-erythropoietic derivatives such as ARA-290. The peptide sequence corresponds to pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser, with the N-terminal residue cyclized to pyroglutamate; this cyclization explains the loss of one water molecule relative to the linear chain and is consistent with the reported molecular formula.

From a class standpoint, ARA-290 is grouped among the repair or cytoprotective peptides. Its distinctive feature, and the reason for its interest in research, is that it lacks erythropoietic activity: it does not appreciably raise the hematocrit nor stimulate the production of erythrocytes in the models studied, unlike full EPO. This makes it a useful probe for experimentally separating the tissue-repair pathway from the hematopoietic pathway of EPO.

The proposed mechanism of action centers on the so-called innate repair receptor (IRR). Unlike the classical homodimeric erythropoietin receptor (EPOR/EPOR), which mediates erythropoiesis, the IRR is described as a heteromeric complex formed by an EPO receptor subunit associated with the beta-common receptor (βcR or CD131), the same subunit shared by cytokine receptors such as GM-CSF, IL-3, and IL-5. ARA-290 binds preferentially to this heteromer, which is expressed or induced in tissues subjected to metabolic, hypoxic, or inflammatory stress. Activation of the IRR has been linked in experimental models to the modulation of intracellular survival signaling cascades (including pathways associated with JAK2, PI3K/Akt, and the regulation of proinflammatory transcription factors), to a reduction in inflammatory signaling, attenuation of apoptosis, and promotion of local repair processes. Taken together, the preclinical literature describes ARA-290 as an agent that seeks to redirect the tissue response from a proinflammatory state toward one of resolution and repair, without the hematological effects of EPO.

The documented applications of ARA-290 fall mainly into two areas. On the preclinical level, it has been explored in animal and in vitro models of ischemia-reperfusion injury, renal damage, peripheral nerve injury, metabolic inflammation, and protection of pancreatic beta cells, among others. On the early-phase clinical level, ARA-290 has been evaluated in controlled trials in humans, notably in the context of small-fiber neuropathy associated with sarcoidosis and in populations with neuropathy of metabolic origin, with research groups in the Netherlands (the Leiden environment) among those that have conducted these studies. The outcomes explored included measures of neuropathic pain, intraepidermal nerve fiber density, and functional markers. It is important to emphasize, for a research reader, that these studies correspond to early stages of development: ARA-290 is not an approved drug nor does it have an authorized therapeutic indication, and the results, although promising in some outcomes, come from trials of limited size that require independent replication.

As for the level of evidence, ARA-290 stands out from many experimental peptides in having human data from randomized, placebo-controlled trials, in addition to a reasonably broad body of preclinical work. Nevertheless, the evidence remains investigational in nature: development has been concentrated in a relatively small number of groups and sponsors, the sample size of the clinical studies is modest, and there is no regulatory approval supporting an established clinical use. Therefore, any interpretation of its activity must be kept within the framework of preclinical and exploratory clinical research.

For laboratory work, ARA-290 is usually handled as a lyophilized powder that is reconstituted in an appropriate aqueous vehicle. Like any peptide, it is sensitive to degradation from repeated freeze-thaw cycles, and it is advisable to handle aliquots to minimize manipulation of the reconstituted material. Analytical characterization of the batch (identity by mass spectrometry, purity by HPLC) is recommended before its experimental use, given that the reproducibility of results depends on the integrity of the sequence and the absence of contaminants. In summary, ARA-290 constitutes a molecularly well-defined research tool for the study of the tissue repair pathway mediated by the innate repair receptor, with the methodological advantage of dissociating that signaling from the erythropoietic effects of EPO, and with a level of evidence that, while higher than that of many analogous peptides, remains in the investigational domain.