ARA-290 is a synthetic linear 11-residue peptide, pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser, carrying an N-terminal pyroglutamate. Its sequence was designed from the aqueous-facing surface of helix B of erythropoietin (EPO), and it appears in the literature as pyroglutamate helix B surface peptide (pHBSP) and under the nonproprietary name cibinetide.

The peptide has been characterized as a selective ligand of the heteroreceptor formed by the EPO receptor and the β-common receptor subunit (CD131). In the originating studies, helix B–derived peptides did not engage the classical EPO receptor homodimer and lacked erythropoietic activity, distinguishing them pharmacologically from the parent cytokine. Downstream work has examined CD131 externalization and stress-response signaling in cultured cells exposed to the peptide.

ARA-290 is cited in basic research on cytokine receptor pharmacology, EPOR/CD131 heteroreceptor signaling, cellular stress-response pathways in mesenchymal-derived and endothelial cell cultures, and structure–activity studies of EPO-derived peptides. With two free glutamate side chains and a free C-terminal carboxylate, the peptide carries a net negative charge at neutral pH.

Research use only. This material is sold for in-vitro laboratory research and development purposes exclusively. It is not a drug, food, or dietary supplement, has not been evaluated by the FDA, and must not be used in humans or animals.