ARA-290: 10 mg ($35)

Overview

ARA-290, also called cibinetide, is a synthetic peptide that selectively activates the innate repair receptor, producing tissue-protective and anti-inflammatory signaling without stimulating red blood cell production. Research has centered on regeneration of small nerve fibers in skin and cornea, inflammatory signaling, and symptoms including numbness, loss of feeling, stinging sensations, and chronic pain. It is derived from a specific surface region of erythropoietin, designed to separate one of that hormone's activities from another.

In plain terms

Erythropoietin, or EPO, is best known as the hormone that stimulates red blood cell production. Less widely known is that EPO also acts on nerve and other tissue through a completely different receptor, in a role associated with tissue protection rather than blood cell formation. The problem for researchers wanting to study that second role is that giving EPO also triggers the first, which changes blood composition and confounds the experiment.

ARA-290 is the attempt to solve that. Researchers identified the specific face of the EPO molecule responsible for engaging the tissue-protective receptor and built a short peptide reproducing just that surface. The resulting molecule is unable to activate the classical EPO receptor at all. It is a deliberate piece of molecular engineering — one function of a hormone isolated from another — and that design logic is much of why it appears in the research literature.

Technical description

ARA-290 (cibinetide) is an 11-amino-acid linear peptide corresponding to the aqueous face of helix B of erythropoietin, a region not involved in binding the homodimeric EPO receptor.

It is a selective agonist at the innate repair receptor (IRR), a heterocomplex of the EPO receptor β-subunit with the β-common receptor (CD131) shared with GM-CSF, IL-3, and IL-5 signaling. Because it does not engage the classical homodimeric EPOR, it lacks erythropoietic activity, permitting investigation of tissue-protective signaling independent of hematopoietic effects. Reported preclinical activity includes modulation of inflammatory signaling and effects in small-fiber neuropathy models. Plasma half-life is short, consistent with an unmodified linear peptide.

Regulatory status

ARA-290 has been investigated in clinical trials under regulatory oversight and holds orphan drug designation for certain indications, but is not an FDA-approved product and holds no marketing authorization. It is not a dietary supplement. Material supplied for laboratory research is not manufactured, tested, or released under pharmaceutical standards.