Cibinetide Phase 2b Sarcoidosis Study: NCT02039687

NCT02039687 was a small randomized trial of ARA 290, later called cibinetide, in adults with sarcoidosis-associated small-nerve-fiber loss and neuropathic pain. At 28 days, the paper's primary corneal nerve fiber area comparison favored the middle of three studied active groups, but not the lower or higher group. The highlighted pain and walking comparisons were not statistically significant, and the later corneal comparisons were also inconclusive. A serious event of suicidal ideation was considered possibly related to the study article. This is a short, source-limited imaging result, not confirmation of durable nerve repair, pain relief, a complete safety profile, or another material's equivalence.[1–4]

Study at a glance

The group strengths and route identify what investigators studied. They are not preparation, administration or treatment instructions.

Design, population and masking

The study enrolled at Cleveland Clinic and Leiden University Medical Center. A unit independent of the sites generated block randomization; the EU results identify the contract research organization as generating the code. Matching assignments were implemented through the site pharmacies. The U.S. registry lists participants, care providers, investigators and outcome assessors as masked, while the paper describes a double-blind trial and masked image/tissue assessment.[1][2][4]

Eligibility included age 18–70, established sarcoidosis and clinically important distal pain. The paper required corneal or skin fiber measurements more than two standard deviations below a reference mean. It excluded several competing causes of neuropathy, while allowing well-controlled diabetes; five participants had diabetes. Pregnancy, breastfeeding, severe obesity and specified other conditions or recent treatments also limited eligibility. This was not a trial in every type of neuropathy or in people without painful symptoms.[1]

The public EU protocol-summary fields use a one-standard-deviation threshold and describe the primary endpoint as nerve fiber density, while the paper and posted results use nerve fiber area. These are not identical measurements or criteria. Without the full protocol versions and statistical analysis plan, this review cannot establish the chronology or reason for those differences.[1][4][5]

What the primary analysis measured

Corneal confocal microscopy provided images for quantifying corneal nerve fiber area, or CNFA. A masked analyst selected six to eight images per eye based on quality. The paper says CNFA at day 28 was the prespecified primary endpoint; that is the authors' report, not an independent verification of the original statistical plan.[1]

The modified intention-to-treat set required randomization, study exposure, a baseline CNFA value and at least one post-baseline CNFA assessment. The mixed-model repeated-measures analysis included treatment, visit and their interaction, baseline as a covariate, site as a random effect, and a Kenward–Roger degrees-of-freedom calculation. Table 2 says all post-baseline visits entered the model. This is not an analysis of all 64 randomized participants with complete observations.[1]

CNFA is a structural imaging measure, not itself pain relief, walking function or a validated clinical surrogate for disease modification. The paper explored its suitability as a surrogate; a correlation or representative image does not establish that changing CNFA reliably predicts a meaningful clinical benefit. The surrogate-endpoint guide explains that distinction.

Day-28 corneal nerve results

Only the middle-group interval excluded zero. The result is not a monotonic pattern of increasing effect across the studied groups, and it does not identify an optimal treatment regimen.[1]

The descriptive within-group changes were −64.3, +533.8 and +203.8 µm² in the three active groups and −170.0 µm² with placebo. These are not the model-adjusted group means: Table 2 gives 511.1 for the middle group and −186.30 for placebo, whose difference is the reported +697.4. Subtracting the raw changes produces a different number and should not replace the modeled contrast.[1][2]

The EU raw result table displays placebo change as +170.0, unlike the negative value in the paper and U.S. registry. Its comparison fields also label the same modeled estimates as “equivalence” and “t-test.” The paper identifies them as MMRM comparisons, with no equivalence margin. This summary uses the paper's stated analysis and flags those registry inconsistencies rather than silently resolving them.[1][2][4]

Multiplicity, power and missing information

The accessible paper does not describe a family-wise multiplicity adjustment across the three active-versus-placebo comparisons and numerous secondary, subgroup and correlation analyses. The complete original plan was not obtained. The displayed P values should therefore be read as nominal reports, not as an independently verified multiplicity-controlled hierarchy of confirmed benefits.[1]

Importantly, the sample-size calculation targeted a within-group eight-point improvement in the secondary Small Fiber Neuropathy Screening List, with 16 participants per group and 90% stated power. It was not a demonstrated 90%-power calculation for the primary between-group CNFA comparison. Possible limited power does not turn an inconclusive pain or walking comparison into evidence of benefit.[1]

The main article describes the analysis-set exclusions and repeated-measures model, but does not provide a complete independently auditable missing-data strategy or modern estimand specification. Its diabetes-exclusion sensitivity result is described as unchanged with data not shown. This review has not reconstructed participant data or verified every model assumption. See trial estimands and missing data and confidence intervals and P values.

Follow-up does not establish durability

The paper says CNFA trended back toward baseline after treatment stopped. In Table 2's later assessment, the middle-group contrast was +161.38 µm², 95% CI −412.6 to +735.4, P=0.576; the lower- and higher-group P values were 0.953 and 0.840. None of these later comparisons excluded no difference.[1]

The table title calls this assessment day 58, while its row says day 56. The registries' broader 12-week follow-up description is a separate timing statement. This source ambiguity is retained; the short-term imaging signal is not described as persistent or as verified throughout the full follow-up period.

Symptoms, function and other structural measures

Conventional intraepidermal nerve fiber density did not show a between-group treatment effect. A different measure, GAP-43-positive regenerating-fiber length, favored the middle group, reported P=0.035. It used a novel measurement introduced by an author and was one of several secondary analyses.[1]

Six-minute walking distance increased by 17.7 metres in the middle group and 1.2 metres with placebo, but the between-group comparison was not statistically significant, P=0.11. Within that active group, change in CNFA correlated with change in walking distance, Spearman rho 0.645, P=0.009. Correlation does not demonstrate that treatment improved walking through nerve repair.[1]

Patient-reported outcomes improved in placebo as well as active groups. Table 3's many within-group P values test change from baseline, not randomized superiority. In 44 participants with baseline Brief Pain Inventory average pain at least five, the highlighted middle-group placebo-corrected estimate was −1.01 points, 95% CI −2.42 to +0.41, P=0.157. The lower- and higher-group pain comparisons were also inconclusive. The paper's favorable wording about clinical importance should not replace these between-group uncertainties.[1]

No group showed a statistically significant change from baseline in the fatigue scale. Other questionnaires had varying available-data counts, and some quality-of-life results were described without displayed data. These analyses do not establish relief of every symptom or improvement in everyday function.[1][4] See negative and inconclusive results.

Adverse events and the possibly related serious event

The serious event in the highest studied group was suicidal ideation, considered possibly related by investigators. The paper reports syncope, headache and enteritis among serious events in two lower-group participants, assessed as unrelated. The registry lists additional serious-event terms; multiple events can occur in the same person, so event terms must not be counted as additional participants.[1][2][4]

Common reported events included injection-site pain, diarrhea, fatigue, headache and nausea. The paper and EU record report no deaths. Both registries specify 28 days of treatment plus 84 days of safety follow-up, or reporting through 16 weeks; that window should not be shortened to the 28-day efficacy endpoint.[1][2][4]

Table 4's grouped “related” category includes possible, probable, definite and missing relationship entries. It is not a count of proven drug-caused events. Investigator relatedness judgments, small groups and a brief trial cannot establish freedom from uncommon, delayed or psychiatric harms. See adverse events and tolerability.

Enrollment, analysis and completion counts

The flow diagram shows 74 screened and 64 randomized, 16 per group. It then distinguishes clinical completion from analysis exclusions. One middle-group participant withdrew without primary-endpoint follow-up. Two nominal highest-group assignments could not be verified because of pharmacy-record discrepancies.[1][4]

The U.S. flow classifies the two unverifiable assignments among noncompletions; the paper and EU flow separately show 15 clinical completions in that arm and the two analysis exclusions. Do not subtract those exclusions again from the paper's completion row or collapse completion, analysis and safety into one population.[1][2][4]

The posted raw primary result retains 16 middle-group participants, whereas the paper's modeled analysis has 15. Available questionnaire counts also vary by instrument. The sources do not provide a participant-level reconciliation of every observation and classification. The primary estimate remains a reported model result, not a reason to hide that uncertainty.

Sponsor involvement and access limits

Araim Pharmaceuticals is the registered sponsor; the EU protocol summary lists Araim as providing monetary or material support. The paper reports partial Dutch government support through the Netherlands Institute for Regenerative Medicine, grant FES0908, and author relationships involving Araim research support, consulting, employment and patents.[1][2][5]

Michael Brines, identified as the masked corneal-image analyst, is also an author with Araim employment and patent disclosures. Masking to treatment and independence from the sponsor are different questions. The paper does not provide a comprehensive sponsor noninvolvement statement covering design, data analysis, interpretation and writing, so none is invented here.[1]

This review read the complete nine-page primary paper supplied through the official EU registry, the U.S. registry results, EU results and protocol-summary fields, and relevant current FDA records. The separate journal supplement, full original protocol/SAP and participant-level data were not obtained. A registry protocol summary is not the full protocol; the paper's statement of prespecification does not supply the missing original plan. Fresh PubMed checks returned no linked correction relationships, which is not a guarantee that every possible notice was located.[1–5]

Regulatory and material boundaries

The FDA 503A nomination-category document retrieved for this review is updated May 14, 2026. It lists “Cibinetide (ARA-290)” in Category 3, substances nominated without adequate support. This is a compounding-nomination classification, not a finished-drug approval or a determination that a particular commercial material matches the clinical test article.[6]

FDA's substance record assigns cibinetide UNII 9W5677JKDA and maps ARA 290 synonyms, while explicitly warning that a UNII does not imply regulatory review or approval.[7] This study record makes no affirmative claim of an FDA-approved cibinetide product based on a registry listing, identifier or absent search result. Use the trial and FDA status guide for the distinction.

NCT02039687 does not authenticate a separately sourced powder or vial. A shared name, research-use label or analytical document cannot establish matching sequence, formulation, manufacture, stability, exposure or clinical equivalence. The approved-drug versus research-material guide explains why study and product identities must remain separate.

Frequently asked questions

What was the reported primary endpoint?

The paper and posted results use change in corneal nerve fiber area from baseline to day 28. The EU protocol-summary field instead says density; this review has not independently resolved that chronology.

Did all three active groups show a difference from placebo?

No. Only the middle-group day-28 interval excluded zero. The comparisons are presented with their nominal P values and incomplete plan-access limits.

Did the study prove pain relief or better walking?

No. The highlighted placebo-corrected pain comparison had P=0.157, and the walking comparison had P=0.11. These are inconclusive comparisons, not proof of equal effects either.

Did the corneal signal persist?

Durability was not established. All later CNFA comparisons were inconclusive, and the paper describes movement back toward baseline.

Why are 64, 62, 61 and 60 all reported?

They refer to different randomization, safety, analysis and completion sets. Two unverifiable assignments and a voluntary withdrawal are handled differently across the source tables.

Were serious or possibly related events reported?

Yes. Three active-group participants had serious treatment-emergent events, including suicidal ideation in the highest studied group assessed as possibly related.

Does a trial record or FDA substance identifier validate a catalog material?

No. Neither establishes finished-product approval, clinical benefit, lot identity, quality or equivalence.

Primary and official sources

1. Primary article: DOI 10.1167/iovs.16-21291; complete paper supplied through the official EU registry
2. ClinicalTrials.gov: NCT02039687 study record and results
3. PubMed: PMID 28475703
4. EU Clinical Trials Register: EudraCT 2013-003016-45 results
5. EU public protocol-summary record: APCP-112
6. FDA 503A nomination categories, updated May 14, 2026
7. FDA substance record: cibinetide, UNII 9W5677JKDA

Review and corrections

Sources checked September 2, 2026 (America/Edmonton) / September 3, 2026 (UTC). Serum Research is responsible for this editorial summary. No independent clinical, statistical, scientific, analytical or regulatory review is claimed. This is not medical advice, treatment guidance, or a material-quality or equivalence conclusion.

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