ARA-290

ARA-290 (international nonproprietary name: cibinetide) is a synthetic 11-amino acid peptide derived from the tissue-protective domain of erythropoietin (EPO). It was deliberately engineered to preserve EPO's non-hematopoietic, tissue-protective signaling while completely eliminating erythropoietic activity. The N-terminal pyroglutamate (pGlu) modification confers enzymatic stability and contributes to receptor specificity.

The compound has been most extensively studied for sarcoidosis-associated small fiber neuropathy (SFN), with two published randomized controlled trials in humans. It is investigational only — not approved by the FDA or EMA for any indication — and is available exclusively through clinical trials.

ARA-290 is a selective agonist of the innate repair receptor (IRR), a heteromeric complex composed of the erythropoietin receptor (EPOR) and the beta-common receptor (betacR, also known as CD131). The IRR is the mechanistic basis for EPO's tissue-protective signaling, distinct from the homodimeric EPOR complex that drives red blood cell production. Critically, the IRR is selectively upregulated in injured, hypoxic, or inflamed tissues and is largely absent in healthy cells, providing the therapeutic selectivity that distinguishes ARA-290 from full-length EPO.

Upon binding to the IRR, ARA-290 activates anti-apoptotic signaling cascades (including PI3K/AKT and JAK2/STAT pathways), suppresses local pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6), and inhibits the microglial activation that perpetuates neuroinflammatory pain states. In animal models of neuropathic pain, these mechanisms produce sustained reversal of allodynia and hyperalgesia. The compound does not engage the homodimeric EPOR and therefore does not stimulate erythropoiesis, platelet aggregation, or thromboembolic events — risks that limit the use of full-length EPO in non-anemic patients.