Cibinetide

Overview

Cibinetide, previously developed as ARA-290, is a synthetic peptide modeled on the helix-B surface of erythropoietin. It was designed to investigate tissue-protective signaling without erythropoietin’s red-blood-cell-stimulating activity. Human research has focused mainly on small-fiber neuropathy associated with sarcoidosis or type 2 diabetes.

The evidence remains early and mixed. Short randomized trials reported signals in selected symptom or nerve-fiber measures, but other measures and dose arms did not separate from placebo. No phase 3 programme or approved treatment regimen was identified.

Identity and nomenclature

FDA, NIH NCATS and PubChem map ARA-290, ARA 290, pHBSP and PHBSP to cibinetide. PeptideGuide’s phrase “Cibinetide (Nerve Repair)” is not a chemical name; “Nerve Repair” is a promotional interpretation and was removed.

The parent compound must also be separated from cibinetide acetate, PubChem CID 163342019. The acetate record has formula C53H88N16O23 and molecular weight 1317.4 g/mol. Mixing the parent and salt would corrupt identity, mass and any formulation-specific evidence.

Proposed mechanism

Cibinetide reproduces an 11-residue surface region of erythropoietin rather than the full hormone. Cell and animal studies describe signaling through a proposed heteromeric complex of the erythropoietin receptor and the β-common receptor CD131. The literature often calls this the innate repair receptor.

Experimental models associate this pathway with modulation of inflammatory and cellular-stress responses without the erythropoietic effect expected from the classical erythropoietin-receptor homodimer. That mechanism is a preclinical pharmacology model. It does not prove that cibinetide regenerates nerves or improves clinical outcomes in patients.

Early human neuropathy studies

A randomized pilot enrolled 22 people with sarcoidosis and symptoms of small-fiber neuropathy. The cibinetide group improved more than placebo on the Small Fiber Neuropathy Screening List, but pain and fatigue measures improved similarly in both groups. The authors identified the small sample, heterogeneous neuropathy and incomplete objective confirmation as important limitations.

A later single-site sarcoidosis study reported improvements in symptoms and corneal nerve-fiber measurements after 28 days. Changes in skin intraepidermal nerve-fiber density were not statistically significant. These findings were hypothesis-generating, not confirmation of durable nerve regeneration.

In a phase 2 type-2-diabetes study, 49 participants were enrolled and 48 analyzed. PainDetect scores improved more with cibinetide, whereas NPSI improved in both groups and SFNSL changed significantly in neither. The corneal nerve-fiber finding came from a subgroup selected for low baseline density, limiting generalization.

Phase 2b result

NCT02039687 randomized 64 participants with sarcoidosis-associated small-fiber loss across three cibinetide arms and placebo. Change in corneal nerve-fiber area at 28 days was the primary surrogate endpoint.

Only the 4 mg study arm had a statistically significant placebo-corrected change in that endpoint. The 1 mg and 8 mg arms did not, so the result did not show a consistent dose-response relationship. Pain improved in all groups. In participants with moderate-to-severe pain, the highlighted placebo-corrected result in the 4 mg arm was not statistically significant (P=0.157).

The registry also reports no improvement over placebo in skin intraepidermal nerve-fiber density. The study therefore supports a narrow corneal surrogate signal at one tested exposure, not established analgesic efficacy or generalized nerve repair.

Development and regulatory status

NIH NCATS classifies cibinetide as investigational. A July 2026 ClinicalTrials.gov query identified four cibinetide/ARA-290 records: NCT02039687 and NCT02070783 were completed, NCT06626971 was terminated, and NCT01933529 had unknown status because it had not been verified since 2015. None was listed as active or recruiting.

NCT06626971 enrolled nine participants in diabetic macular oedema and was terminated because the study drug expired and no replacement was available; no results are posted. NCT01933529 and NCT02070783 also have no posted results.

EMA orphan designation EU/3/16/1721 concerns prevention of graft loss in pancreatic-islet transplantation. Orphan designation provides development incentives; it is not marketing authorization and does not establish efficacy or a clinical regimen.

Safety, pharmacokinetics and dosing boundary

The available human studies were small and short. They cannot establish long-term safety, uncommon harms, reproductive safety, interaction risk or safety across different neuropathy causes. In NCT02039687, the registry lists at least one serious treatment-emergent adverse event in three treated participants across the 1 mg and 8 mg groups. Those summary counts do not establish that cibinetide caused the events, but they contradict a blanket description of side effects as “minimal.”

Pharmacokinetic values are route-dependent. Healthy-volunteer data cited in the clinical literature describe a terminal plasma half-life of about 2 minutes after intravenous administration and about 20 minutes after subcutaneous administration. PeptideGuide’s separate 2–4 hour value was not supported by the reviewed human evidence.

Trial exposures document what investigators tested. They are not an approved regimen, a compounding instruction or a recommendation for self-use.

Evidence conclusion

Cibinetide has a well-resolved 11-amino-acid identity and a plausible erythropoietin-derived research mechanism. It also has more human investigation than many online “repair peptides.” That does not make the evidence conclusive: the trials were small and short, symptom outcomes were inconsistent, one phase 2b dose arm drove the primary surrogate signal, and no active late-stage programme was identified.

Claims of proven nerve regeneration, reliable pain relief, broad anti-inflammatory benefit, minimal risk or established dosing are not supported.