ARA 290/Cibinetide Type 2 Diabetes Trial: NTR3858

NTR3858 was a short, investigator-initiated, double-blind, placebo-controlled proof-of-concept study of ARA 290, later called cibinetide, in people with type 2 diabetes and painful neuropathic symptoms. Forty-nine people enrolled; one active-group participant stopped after worsening borderline renal insufficiency and was excluded, leaving 48 analyzed. HbA1c and PainDetect showed between-group patterns favoring active exposure, but other symptom instruments, quantitative sensory tests, walking distance, and full-cohort corneal nerve-fiber density did not show a consistent benefit. Four serious adverse events occurred in the active arm, and named authors held commercial roles and equity. This mixed record cannot support a blanket claim of nerve repair, broad symptom efficacy, or equivalence to another material.[1][2][3][4]

Study at a glance

The historical amount, route, frequency, and duration identify the experiment. They are not preparation, dosing, injection, administration, self-use, or treatment guidance.[1]

Exact identity and trial scope

The paper describes the test article as ARA 290, a linear 11-amino-acid peptide with reported molecular mass 1,257, produced by Bachem and prepared in study vials. The protocol observed participants during 28 days of exposure and for another 28 days. Those facts bound the evidence to the named clinical material and experiment.[1]

They do not establish the composition of another item called ARA 290 or cibinetide. A name, amino-acid sequence, catalog entry, supplier claim, or visual similarity cannot by itself establish identity, purity, sterility, stability, bioavailability, exposure, or equivalence to the material used here.[1]

The study enrolled people with type 2 diabetes and painful neuropathic symptoms, many using background medication. Baseline glycemic control was generally good, leaving limited room for large HbA1c change. The small proof-of-concept design was suited to finding signals, not establishing durable diabetes control, neuropathy reversal, complication prevention, or uncommon safety.[1]

Participant flow and endpoint-specific denominators

Investigators screened 61 people and enrolled 49. One active-group participant stopped on day 15 after worsening borderline renal insufficiency and was excluded from the analysis. The remaining analyzed population was 48, 24 active and 24 placebo.[1]

Complete serial HbA1c measurements were available for 42 participants, 21 per group. One placebo participant lacked a baseline PainDetect score and was excluded from that instrument’s analysis. Corneal-density subgroup counts were smaller still. “Enrolled,” “analyzed,” “complete HbA1c,” and “questionnaire evaluable” therefore are not interchangeable. Excluding a participant after a safety-related discontinuation may also make estimates less conservative than an analysis retaining everyone enrolled.[1]

The paper calls the trial double-blind and placebo-controlled but does not provide enough public methodological detail to invent an allocation sequence or concealment procedure. This page reports what the source establishes and does not add unsupported randomization mechanics.[1]

Prespecified endpoints and exploratory hierarchy

Prespecified endpoints included adverse events and laboratory safety; HbA1c change at days 28 and 56; and four questionnaires: the Small Fiber Neuropathy Screening List (SFNSL), PainDetect, Neuropathic Pain Symptom Inventory (NPSI), and RAND-36. Secondary assessments included quantitative sensory testing, corneal nerve-fiber density, and six-minute walk distance at day 28.[1]

The analysis of participants whose baseline corneal nerve-fiber density was more than one standard deviation below normal was post hoc. A subgroup defined after looking at the data can suggest a future hypothesis, but it cannot replace the nonsignificant full-cohort result. The paper reports many endpoints and does not describe a clear multiplicity-control plan, increasing the chance of isolated nominal p values.[1]

HbA1c result in the 42-person subset

Among the 42 participants with complete serial values, active-group mean HbA1c change was −0.16 percentage points (SE .07) at day 28 and −0.21 (.09) at day 56. Placebo changes were −0.01 (.07) and +0.21 (.08). Repeated-measures analysis reported p=.002 for the group pattern over time.[1]

This is a short-term laboratory result in 21 people per group, not evidence that complications were prevented or long-term glycemic control was achieved. Because seven of 49 enrolled participants were absent from this complete-data analysis, the result also depends on who had serial measurements and the model applied.[1]

The cholesterol-to-HDL ratio and triglyceride analyses reported nominal p=.039 and .043, while HDL itself was p=.066. Triglyceride samples were not fasting. These secondary laboratory signals should not be promoted to established lipid benefit, particularly given multiple comparisons and short follow-up.[1]

PainDetect signal and symptom instruments that differed

PainDetect scores improved by 3.3 points with active exposure and 1.1 with placebo at day 28, and by 4.2 versus 0.74 at day 56. Repeated-measures analysis was p=.037 in the text; the figure displays .03. The precise presentation difference should remain visible rather than being silently harmonized.[1]

The other instruments did not tell the same story. Both groups improved by about 20% on NPSI at day 28, and neither remained significantly changed from baseline at day 56. SFNSL did not change significantly. RAND-36 physical-role and vitality domains improved within the active group at nominal p=.05 and .02, but a within-group p value is not a direct active-versus-placebo effect.[1]

The mixed pattern matters. PainDetect, NPSI, SFNSL, and quality-of-life domains measure overlapping but nonidentical constructs. One between-group questionnaire signal amid null or transient results cannot be summarized as consistent neuropathic-pain relief.[1]

Sensory, walking, and corneal outcomes

Quantitative sensory testing showed no significant treatment change in either group. Six-minute walk distance increased 3.5% in the active group (p=.09) and 1.1% with placebo; neither comparison established a functional benefit.[1]

In the full cohort, corneal nerve-fiber density changed by +1.1 (SE 1.1) with active exposure and +0.1 (SE 1.2) with placebo, a nonsignificant result. In the post hoc low-baseline-density subgroup, 18 active participants increased by 2.6 (SE 1.0; within-group p=.02), while 19 placebo participants increased by .7 (SE 1.3) nonsignificantly. The subgroup is exploratory, the p value is within active participants, and the page does not call it confirmed nerve regeneration.[1]

Adverse events and four serious events

Reported adverse-event episode counts were similar overall: 54 mild, 9 moderate, and 1 severe episode with active exposure, versus 61 mild and 5 moderate with placebo. Investigators classified 25 active episodes as possibly and 39 as unlikely related, versus 40 and 26 under placebo. Episode counts are not participant counts, and this small study cannot compare rare-harm rates reliably.[1]

Four serious adverse events occurred in the active arm. The safety paragraph says two were judged unlikely related and the remaining two possibly related, then gives narratives whose wording is not perfectly simple. This page preserves the source rather than issuing a new causality verdict.[1]

One participant with borderline renal insufficiency had a furosemide increase after week 2 and a creatinine rise from 119 to 159 µmol/L. The safety committee stopped ARA 290; furosemide continued at the increased amount, and renal function did not improve over six weeks of follow-up. The participant was excluded from analysis. Another participant, a 70-year-old man, was hospitalized with severe cellulitis two weeks after the final exposure and later died after myocardial infarction; the safety committee judged the infarction unrelated. The event count, timing, committee assessments, and analysis exclusion all belong in the record.[1]

Funding, conflicts, and the registry identity warning

Support came from the Dutch government’s NIRM program, Swedish Research Council, ALF, and Swedish Diabetes Association. Michael Brines, Ann N. Dunne, and Anthony Cerami were officers of Araim Pharmaceuticals and owned stock or options. “Investigator-initiated” describes study initiation; it does not mean that no author had a commercial interest.[1]

The paper identifies NTR3858. It must not be relabeled NCT01933529. The latter is a separate Stockholm phase 2 study in prediabetes and drug-naive type 2 diabetes, planned for 24 participants, with oral-glucose-tolerance and insulin-secretion outcomes. Its live page now shows unknown status, last verified September 2015, and no results posted.[1][4][5] That comparison is included only to prevent conflation; it supplies no result for NTR3858.

Statistical significance, effect, uncertainty, and importance

• Statistical significance: HbA1c and PainDetect showed reported between-group patterns; many other symptom, sensory, functional, and corneal outcomes did not.
• Effect size: the HbA1c contrast was small and short term; PainDetect changes were a few score points.
• Uncertainty: the study was small, denominator-specific, multiple-outcome, and excluded one active participant after a renal event.
• Clinical importance: no durable neuropathy reversal, diabetes-complication prevention, sustained function, or long-term safety was established.

Important limitations

The exposure and follow-up periods were each 28 days. Only 48 participants were analyzed, only 42 had complete serial HbA1c, and other endpoints used different counts. Baseline diabetes was generally well controlled, background pain medication varied, multiple outcomes were tested without a clear multiplicity plan, and the corneal subgroup was post hoc. The study cannot resolve rare harms, durability, or clinical complications.[1]

What this study does not prove

NTR3858 does not prove consistent pain relief, nerve regeneration, durable glycemic control, improved walking, prevention of diabetes complications, or long-term safety. It does not convert the post hoc corneal subgroup into a confirmatory result or erase the four serious events and renal exclusion. It also does not authenticate another ARA 290/cibinetide material, and NCT01933529 is not this published trial.[1][5]

Frequently asked questions

How many people were studied?

Sixty-one were screened and 49 enrolled. One active participant stopped and was excluded, leaving 48 analyzed; only 42 had complete serial HbA1c data.[1]

What were the prespecified endpoint groups?

They included safety/laboratories, HbA1c, SFNSL, PainDetect, NPSI, and RAND-36. Sensory, walking, and corneal measures were secondary.[1]

Did every pain measure favor ARA 290?

No. PainDetect showed a between-group pattern, while NPSI improved transiently in both groups and SFNSL did not change significantly.[1]

Did the study prove corneal nerve regeneration?

No. Full-cohort density change was nonsignificant; the low-baseline-density signal came from a post hoc subgroup and was not confirmatory.[1]

What happened in the renal case?

Creatinine worsened after a furosemide increase; the committee stopped ARA 290, renal function did not improve during follow-up, and the participant was excluded.[1]

Is NCT01933529 the registration for this paper?

No. The paper names NTR3858. NCT01933529 is a different, stale-status study with another population and endpoint set.[1][5]

Does “investigator-initiated” mean no commercial conflict?

No. Three named authors were Araim Pharmaceuticals officers and owned stock or options, despite the investigator-initiated design.[1]

Primary and official sources

1. Primary full text, PMCID PMC4365069
2. PubMed: PMID 25387363
3. Publisher version: DOI 10.2119/molmed.2014.00215
4. OMON migrated registry record: NL-OMON21147 / old NTR3858
5. Separate comparison record only: NCT01933529