ARA-290

ARA-290, also known as cibinetide, is a synthetic 11-amino acid peptide derived from the helix B surface of erythropoietin (EPO). It was designed to selectively engage the innate repair receptor (IRR), a heterodimer of the EPO receptor and the beta common receptor (CD131), without activating the classical homodimeric EPO receptor responsible for erythropoiesis. Developed by Araim Pharmaceuticals, ARA-290 represents an effort to separate the tissue-protective signaling of EPO from its hematopoietic effects. The peptide has been investigated in multiple clinical studies for neuropathic conditions and has advanced through Phase 2 clinical trials. ARA-290 does not stimulate red blood cell production and is not erythropoietic at any studied concentration, making it distinct from EPO and its analogs.

ARA-290 has been investigated for its selective activation of the innate repair receptor (IRR), a heterodimeric complex composed of the EPO receptor and beta common receptor (CD131). Researchers observed that upon binding the IRR, ARA-290 initiates signaling through JAK2 and downstream pathways including STAT3 and NF-κB modulation, distinct from the STAT5-dominant signaling of classical EPO receptor activation. Studies suggest that this selective engagement is associated with anti-apoptotic signaling in stressed or damaged tissues without triggering erythropoietic responses. In preclinical models of peripheral neuropathy, researchers observed that ARA-290 administration was associated with changes in small nerve fiber density and inflammatory cytokine profiles. The peptide has also been investigated for its effects on macrophage polarization, with studies suggesting it may promote a shift from pro-inflammatory to reparative phenotypes in tissue injury models.

Small Fiber Neuropathy

Brines et al. (2014) investigated ARA-290 in patients with sarcoidosis-associated small fiber neuropathy. Researchers observed improvements in corneal nerve fiber density and patient-reported outcome measures following a 28-day treatment period, providing early clinical evidence for the peptide’s activity at the innate repair receptor [1].

Innate Repair Receptor Characterization

Brines et al. (2008) described the discovery and characterization of the tissue-protective EPO receptor (now called the innate repair receptor) and demonstrated that engineered EPO derivatives lacking erythropoietic activity retained cytoprotective signaling, laying the foundation for ARA-290 development [2].

Metabolic Parameters

Dahan et al. (2013) investigated ARA-290 in a clinical study examining safety, pharmacokinetics, and metabolic parameters in subjects with type 2 diabetes. Researchers reported the peptide was well-tolerated and observed changes in glycemic variability markers during the treatment period [3].