ARA-290 (Cibinetide): The EPO Helix B Peptide That Skips Red Cells

ARA-290, USAN cibinetide, is an 11-amino-acid peptide modeled on the aqueous face of helix B of erythropoietin (EPO). Brines and Cerami built it to turn on a tissue-protective receptor and leave the hematopoietic EPO receptor alone. It is not recombinant EPO, the published trials did not raise red-cell mass, and there is no FDA-approved cibinetide product.

TL;DR

• ARA-290 is a synthetic 11-mer, not a linear scrap of the EPO protein. It copies the water-facing surface of helix B (residues 58 to 82), then adds an N-terminal pyroglutamate for stability (PNAS 2008).
• The target is a heterodimer, not the marrow EPO receptor. Tissue protection is assigned to EPO receptor (EPOR) paired with the beta-common subunit CD131 (PNAS 2004; Mol Med 2012).
• A 22-person sarcoidosis pilot used 2 mg intravenous ARA-290 three times a week for four weeks. The Small Fiber Neuropathy Screening List score fell more than placebo at week 4 (Heij et al., 2012).
• The 64-person phase 2b met its corneal-nerve primary endpoint at 4 mg subcutaneous daily. Placebo-corrected corneal nerve fiber area rose 697 µm² (about 23% from baseline, P = 0.012) (Culver et al., 2017).
• Orphan designation is not an approval. Araim reported U.S. and EU orphan status for sarcoidosis. No phase 3 program finished, and a catalog vial is not that clinical lot.

Educational only. Not medical advice, not a neuropathy protocol, and not a reason to treat research vials as EPO.

What is ARA-290, chemically?

It is a designed surface mimic, not a digested hormone fragment. Helix B of EPO sits on the outside of the folded protein. Brines, Cerami, and colleagues synthesized an 11-residue peptide that presents that aqueous face (PNAS 2008).

They pyroglutamylated the N-terminus so aminopeptidases cannot nibble it as fast. Catalogs also list pHBSP, pyroglutamate helix B surface peptide. The USAN is cibinetide.

Those names point at one scaffold. They do not mean every research acetate is Araim’s clinical material.

Solid-phase synthesis can make an 11-mer. That chemistry is covered in how peptides are made. See Peptides 101 for where this sits among healing and metabolic classes.

A powder still has to be reconstituted if a lab works with it. That is a chemistry step in the reconstitution guide and the calculator, not a dosing chart.

How does it skip erythropoiesis?

Classic EPO drives red cells through an EPOR homodimer in marrow. Tissue-protective signaling was assigned to a different complex: EPOR plus the beta-common receptor CD131 (Brines et al., PNAS 2004).

Carbamylated EPO still protected tissue in that 2004 model and did not stimulate erythropoiesis. Protection dropped when CD131 was missing.

The 2012 review named that heterodimer the innate repair receptor. Brines and Cerami argued it tames innate inflammation after injury without the hematocrit cost of recombinant EPO (Mol Med 2012).

ARA-290 is the short peptide they advanced as an agonist of that pathway. Forums shorten this to “EPO without blood.” The papers say something narrower: a helix-B mimetic aimed at a heterodimer, with no approved indication.

Immune-modulating thymic work lives in thymosin alpha-1. Gut-stable recovery peptides start with BPC-157.

What did the sarcoidosis trials actually show?

Leiden and Cleveland Clinic ran the human work that forums quote. Both studies were short, small, and industry-linked.

The 2012 pilot is the first randomized human signal. It is also n = 22, intravenous, and four weeks. That is a hypothesis generator, not a standard of care.

The 2017 phase 2b is the better imaging paper. The 4 mg arm moved corneal nerve area and regenerating skin fibers. Pain moved more in people who started with moderate to severe pain.

The 1 mg and 8 mg arms did not beat placebo on the primary endpoint. More milligrams was not automatically more nerve. No phase 3 followed those readouts into an approval.

Did it help diabetic neuropathy?

A type 2 diabetes study used 4 mg subcutaneous ARA-290 daily for 28 days, with follow-up to day 56. Neuropathic symptoms on the PainDetect questionnaire improved in the ARA-290 group (Brines et al., Mol Med 2014).

HbA1c and lipids also moved in a favorable direction across that window. The authors reported no identified safety issues.

That is still a small, early, sponsor-linked trial. It is not a cardiovascular outcomes program. It is not proof that a research vial will lower A1c.

If the question is which peptides forums discuss for tissue repair, start with BPC-157 and TB-500. Those are different molecules, different receptors, and a different evidence grade.

Is a catalog vial the same as cibinetide?

No. The published trials used Araim’s clinical peptide, given IV or subcutaneous under a protocol, with imaging and labs. Research listings sell a sequence-matched 11-mer if the COA is honest.

Orphan designation and Fast Track are development incentives, not marketing approval. Araim announced both for sarcoidosis-related use in 2017 and never brought a finished NDA across the line (PR Newswire, 2017).

A licensed EPO product has a label, a hematocrit warning, and a manufacturing file. A research 11-mer has a COA if the vendor published one.

Start with how to read a COA, then compare listings on the price index and clinics in the provider directory. People who teach peptide pharmacology rather than forum stacks are on the experts page.

Bottom line ARA-290 is a real 11-mer built from EPO helix B to hit a CD131-containing repair receptor without driving red cells. Small phase 2 neuropathy studies are interesting. They are not an approved nerve drug, and a catalog vial is not that clinical product.

Educational only. Not medical advice.