Cibinetide
In a 64-person phase 2b trial, 4 mg cibinetide increased corneal nerve-fiber area. A separate 48-person diabetes trial found improvements in HbA1c pattern and PainDetect scores. Pain did not separate from placebo in the phase 2b trial, the other doses missed, and no phase 3 program or approved product was found. Two supporting animal papers have been retracted.
Non-erythropoietic erythropoietin-derived peptide
- Eleven-amino-acid synthetic peptide
- Also called ARA-290 and pHBSP
- Designed from erythropoietin helix B
- About 130 people received it in published studies
What did the largest cibinetide trial find?
In 64 people with sarcoidosis-associated small nerve-fiber loss and neuropathic pain, 4 mg daily for 28 days increased placebo-corrected corneal nerve fiber area by 697 square micrometers, 95% CI 159 to 1,236, P = 0.012. The 1 mg and 8 mg groups did not separate from placebo.
The primary endpoint peaked at the middle dose: +109 at 1 mg, +697 at 4 mg, and +431 at 8 mg after placebo correction. Each arm contained only about 14 to 16 participants, so the non-monotonic result needs replication.
Phase 2b · middle-dose imaging signal
Randomized placebo-controlled phase 2b trial
Culver et al., Investigative Ophthalmology and Visual Science, 2017
In 64 randomized participants, placebo-corrected corneal nerve fiber area increased significantly only at 4 mg: +697 square micrometers (95% CI 159 to 1,236; P = 0.012). The 1 mg and 8 mg estimates crossed zero. Pain improved in all groups; the moderate-to-severe 4 mg subgroup result was P = 0.157.
- Daily subcutaneous treatment lasted 28 days.
- The positive primary endpoint was a surrogate imaging measure.
- Participants / model
- People with sarcoidosis-associated small nerve-fiber loss and neuropathic pain
- Treatment
- Cibinetide 1, 4, or 8 mg daily versus placebo
- Follow-up
- 28 days
- Study design
- Two-center randomized double-blind placebo-controlled phase 2b trial
- Funding
- Araim Pharmaceuticals-linked development program
Small arms, no conventional dose response, no significant pain-intensity effect, and no independent replication.
Read the original sourceNCT02039687 · outcomes and adverse events
Clinical trial registry results
ClinicalTrials.gov, NCT02039687
Posted results provide the four-arm corneal, pain, walk, participant-flow, and adverse-event tables. Treatment-emergent event counts were 14/16, 11/16, 12/14, and 12/16 for 1 mg, 4 mg, 8 mg, and placebo; serious-event counts were 2, 0, 1, and 0.
- The 8 mg serious event was listed as suicidal ideation.
- Registry analysis included 62 of 64 randomized participants.
- Participants / model
- Sarcoidosis-associated small-fiber neuropathy and pain
- Treatment
- Daily subcutaneous cibinetide 1, 4, or 8 mg or placebo
- Follow-up
- 28 days
- Study design
- Posted results for randomized phase 2b trial
- Funding
- Araim Pharmaceuticals
A treatment-emergent event is not automatically caused by the drug; arm sizes were very small.
Read the original sourceDid cibinetide reduce neuropathic pain?
Pain intensity improved in every phase 2b group, including placebo. In the moderate-to-severe subgroup, the 4 mg placebo-corrected pain result was P = 0.157, so it was not statistically significant.
The imaging endpoint does not establish less pain or better function. Six-minute walk distance moved in the active arms but did not show a reported significant between-group difference.
Phase 2b · middle-dose imaging signal
Randomized placebo-controlled phase 2b trial
Culver et al., Investigative Ophthalmology and Visual Science, 2017
In 64 randomized participants, placebo-corrected corneal nerve fiber area increased significantly only at 4 mg: +697 square micrometers (95% CI 159 to 1,236; P = 0.012). The 1 mg and 8 mg estimates crossed zero. Pain improved in all groups; the moderate-to-severe 4 mg subgroup result was P = 0.157.
- Daily subcutaneous treatment lasted 28 days.
- The positive primary endpoint was a surrogate imaging measure.
- Participants / model
- People with sarcoidosis-associated small nerve-fiber loss and neuropathic pain
- Treatment
- Cibinetide 1, 4, or 8 mg daily versus placebo
- Follow-up
- 28 days
- Study design
- Two-center randomized double-blind placebo-controlled phase 2b trial
- Funding
- Araim Pharmaceuticals-linked development program
Small arms, no conventional dose response, no significant pain-intensity effect, and no independent replication.
Read the original sourceNCT02039687 · outcomes and adverse events
Clinical trial registry results
ClinicalTrials.gov, NCT02039687
Posted results provide the four-arm corneal, pain, walk, participant-flow, and adverse-event tables. Treatment-emergent event counts were 14/16, 11/16, 12/14, and 12/16 for 1 mg, 4 mg, 8 mg, and placebo; serious-event counts were 2, 0, 1, and 0.
- The 8 mg serious event was listed as suicidal ideation.
- Registry analysis included 62 of 64 randomized participants.
- Participants / model
- Sarcoidosis-associated small-fiber neuropathy and pain
- Treatment
- Daily subcutaneous cibinetide 1, 4, or 8 mg or placebo
- Follow-up
- 28 days
- Study design
- Posted results for randomized phase 2b trial
- Funding
- Araim Pharmaceuticals
A treatment-emergent event is not automatically caused by the drug; arm sizes were very small.
Read the original sourceWhat did the developers' later image reanalysis change?
A post hoc reanalysis of the 4 mg and placebo images found no significant treatment difference in standard corneal nerve fiber density or length. Pixel-based nerve area and branch density did separate.
For nerve length, the net change was about 1.15 mm/mm², near the estimated minimum detectable change, but the adjusted comparison was not significant. The result supports a narrow image-area signal. It does not establish broad nerve regeneration.
Image reanalysis · density and length did not separate
Post hoc imaging analysis
Brines et al., Scientific Reports, 2018
In the 4 mg and placebo phase 2b image subset, standard nerve-fiber density and length did not show a significant treatment difference. Pixel-based nerve area and branch density did separate.
- Baseline n = 63; day-28 comparison used 16 placebo and 15 treated participants.
- The authors described small groups and post hoc analysis.
- Participants / model
- Phase 2b sarcoidosis imaging dataset
- Treatment
- Cibinetide 4 mg daily versus placebo
- Follow-up
- 28 days
- Study design
- Post hoc reanalysis of corneal confocal microscopy images
- Funding
- Developer-linked author group
Standard nerve-fiber density and length did not differ significantly; only the post hoc area and branch-density measures did.
Read the original sourceWhat happened in the type 2 diabetes study?
In 48 analyzed participants with type 2 diabetes and painful neuropathy, 4 mg daily for 28 days produced a between-group HbA1c pattern through day 56, P = 0.002. PainDetect improved by 3.3 points versus 1.1 with placebo, P = 0.037.
Complete serial HbA1c data were available for 42 people. Mean day-56 change was -0.21 percentage points with cibinetide and +0.21 with placebo. This isolated metabolic signal was not replicated in another trial.
Diabetes phase 2 · unreplicated HbA1c signal
Randomized placebo-controlled phase 2 trial
Brines et al., Molecular Medicine, 2015
Among 48 analyzed participants, daily 4 mg ARA-290 for 28 days produced a significant HbA1c pattern through day 56, P = 0.002. In 42 with serial measurements, day-56 mean change was -0.21 percentage points versus +0.21 with placebo. PainDetect improved 3.3 versus 1.1 points, P = 0.037.
- Four serious adverse events occurred in the active arm; investigators judged two possibly related.
- The metabolic result has not been independently replicated.
- Participants / model
- Adults with type 2 diabetes and painful neuropathic symptoms
- Treatment
- Subcutaneous ARA-290 4 mg daily versus placebo
- Follow-up
- 28 days treatment plus 28 days follow-up
- Study design
- Double-blind randomized placebo-controlled phase 2 trial
- Funding
- Investigator-initiated, developer-linked author group
Small study with multiple outcomes, incomplete serial HbA1c data, and no replication.
Read the original sourceWhat did the diabetic macular edema study show?
The open-label study recruited nine people and eight completed 12 weeks. Mean visual acuity worsened by 2.9 letters, central retinal thickness increased by 10 micrometers, retinal sensitivity fell by 0.53 dB, and tear production fell by 0.13 mm.
A patient-reported visual-function questionnaire improved by 2.7 points, but every listed objective mean endpoint failed to improve. With no control group and only eight completers, the study cannot establish benefit.
Macular edema · objective endpoints did not improve
Open-label phase 2 study
Lois et al., Journal of Clinical Medicine, 2020
Nine people were enrolled and eight completed 12 weeks of 4 mg daily. Mean visual acuity, retinal thickness, retinal sensitivity, and tear production did not improve; the patient-reported visual-function composite rose 2.7 points.
- No serious adverse events or anti-cibinetide antibodies were reported among completers.
- Participants / model
- Treatment-naive patients with diabetic macular edema and central retinal thickness over 400 micrometers
- Treatment
- Subcutaneous cibinetide 4 mg daily
- Follow-up
- 12 weeks
- Study design
- Single-center open-label single-arm phase 2 study
The study had eight completers and no control arm, so it cannot isolate benefit or estimate uncommon harms.
Read the original sourceWhat does the erythropoietin-derived design establish?
Cibinetide copies 11 residues from the exposed face of erythropoietin helix B and was designed to engage a proposed tissue-repair receptor complex without activating the classical receptor pathway that raises red-cell mass. This separation is supported mainly by preclinical models.
The names pHBSP, ARA-290, and cibinetide refer to the same core peptide in different parts of the literature. A mechanistic design does not prove pain relief, nerve regeneration, or metabolic benefit in people.
Phase 2b · middle-dose imaging signal
Randomized placebo-controlled phase 2b trial
Culver et al., Investigative Ophthalmology and Visual Science, 2017
In 64 randomized participants, placebo-corrected corneal nerve fiber area increased significantly only at 4 mg: +697 square micrometers (95% CI 159 to 1,236; P = 0.012). The 1 mg and 8 mg estimates crossed zero. Pain improved in all groups; the moderate-to-severe 4 mg subgroup result was P = 0.157.
- Daily subcutaneous treatment lasted 28 days.
- The positive primary endpoint was a surrogate imaging measure.
- Participants / model
- People with sarcoidosis-associated small nerve-fiber loss and neuropathic pain
- Treatment
- Cibinetide 1, 4, or 8 mg daily versus placebo
- Follow-up
- 28 days
- Study design
- Two-center randomized double-blind placebo-controlled phase 2b trial
- Funding
- Araim Pharmaceuticals-linked development program
Small arms, no conventional dose response, no significant pain-intensity effect, and no independent replication.
Read the original sourceDiabetes phase 2 · unreplicated HbA1c signal
Randomized placebo-controlled phase 2 trial
Brines et al., Molecular Medicine, 2015
Among 48 analyzed participants, daily 4 mg ARA-290 for 28 days produced a significant HbA1c pattern through day 56, P = 0.002. In 42 with serial measurements, day-56 mean change was -0.21 percentage points versus +0.21 with placebo. PainDetect improved 3.3 versus 1.1 points, P = 0.037.
- Four serious adverse events occurred in the active arm; investigators judged two possibly related.
- The metabolic result has not been independently replicated.
- Participants / model
- Adults with type 2 diabetes and painful neuropathic symptoms
- Treatment
- Subcutaneous ARA-290 4 mg daily versus placebo
- Follow-up
- 28 days treatment plus 28 days follow-up
- Study design
- Double-blind randomized placebo-controlled phase 2 trial
- Funding
- Investigator-initiated, developer-linked author group
Small study with multiple outcomes, incomplete serial HbA1c data, and no replication.
Read the original sourceHow much human safety evidence exists?
The largest trial was only 28 days. At least one treatment-emergent event occurred in 14 of 16 people at 1 mg, 11 of 16 at 4 mg, 12 of 14 at 8 mg, and 12 of 16 on placebo. Serious treatment-emergent events numbered two, zero, one, and zero in those groups.
The 8 mg serious event was recorded as suicidal ideation. These counts do not establish causation or a dose pattern, and the exposed population cannot characterize uncommon or long-term harms.
In the diabetes trial, four serious events occurred in the active arm; investigators judged two possibly related. One participant's borderline renal impairment worsened after a furosemide dose increase and study drug was stopped. Another had severe cellulitis followed by a fatal myocardial infarction judged unrelated.
NCT02039687 · outcomes and adverse events
Clinical trial registry results
ClinicalTrials.gov, NCT02039687
Posted results provide the four-arm corneal, pain, walk, participant-flow, and adverse-event tables. Treatment-emergent event counts were 14/16, 11/16, 12/14, and 12/16 for 1 mg, 4 mg, 8 mg, and placebo; serious-event counts were 2, 0, 1, and 0.
- The 8 mg serious event was listed as suicidal ideation.
- Registry analysis included 62 of 64 randomized participants.
- Participants / model
- Sarcoidosis-associated small-fiber neuropathy and pain
- Treatment
- Daily subcutaneous cibinetide 1, 4, or 8 mg or placebo
- Follow-up
- 28 days
- Study design
- Posted results for randomized phase 2b trial
- Funding
- Araim Pharmaceuticals
A treatment-emergent event is not automatically caused by the drug; arm sizes were very small.
Read the original sourceDiabetes phase 2 · unreplicated HbA1c signal
Randomized placebo-controlled phase 2 trial
Brines et al., Molecular Medicine, 2015
Among 48 analyzed participants, daily 4 mg ARA-290 for 28 days produced a significant HbA1c pattern through day 56, P = 0.002. In 42 with serial measurements, day-56 mean change was -0.21 percentage points versus +0.21 with placebo. PainDetect improved 3.3 versus 1.1 points, P = 0.037.
- Four serious adverse events occurred in the active arm; investigators judged two possibly related.
- The metabolic result has not been independently replicated.
- Participants / model
- Adults with type 2 diabetes and painful neuropathic symptoms
- Treatment
- Subcutaneous ARA-290 4 mg daily versus placebo
- Follow-up
- 28 days treatment plus 28 days follow-up
- Study design
- Double-blind randomized placebo-controlled phase 2 trial
- Funding
- Investigator-initiated, developer-linked author group
Small study with multiple outcomes, incomplete serial HbA1c data, and no replication.
Read the original sourceMacular edema · objective endpoints did not improve
Open-label phase 2 study
Lois et al., Journal of Clinical Medicine, 2020
Nine people were enrolled and eight completed 12 weeks of 4 mg daily. Mean visual acuity, retinal thickness, retinal sensitivity, and tear production did not improve; the patient-reported visual-function composite rose 2.7 points.
- No serious adverse events or anti-cibinetide antibodies were reported among completers.
- Participants / model
- Treatment-naive patients with diabetic macular edema and central retinal thickness over 400 micrometers
- Treatment
- Subcutaneous cibinetide 4 mg daily
- Follow-up
- 12 weeks
- Study design
- Single-center open-label single-arm phase 2 study
The study had eight completers and no control arm, so it cannot isolate benefit or estimate uncommon harms.
Read the original sourceWhich preclinical claims should no longer be used?
A 2012 rat acute-kidney-injury paper was retracted in February 2026, and a 2014 mouse insulin-resistance paper was retracted in April 2024. Neither should support efficacy or mechanism claims.
Kidney paper · retracted February 2026
Retraction notice
Molecular Medicine, 2026
The journal retracted the 2012 rat kidney-injury paper after image-integrity concerns and publisher review of whether selected blot bands represented the observed experimental results.
- Participants / model
- Retracted rat study publication record
- Treatment
- pHBSP or ARA-290 preclinical claim
- Follow-up
- Retraction published February 26, 2026
- Study design
- Publisher retraction notice
The retracted kidney paper does not support cibinetide claims.
Read the original sourceMetabolic mouse paper · retracted April 2024
Retraction notice
British Journal of Pharmacology, 2024
The 2014 mouse diet-induced insulin-resistance paper is marked retracted, with the retraction published in April 2024. The notice does not state a reason.
- Participants / model
- Retracted mouse study publication record
- Treatment
- pHBSP preclinical metabolic claim
- Follow-up
- Retraction published April 2024
- Study design
- Publisher retraction notice
The retracted mouse paper does not support the human HbA1c finding.
Read the original sourceIs cibinetide approved, and did it reach phase 3?
U.S. FDA and ClinicalTrials.gov records listed no approved cibinetide or ARA-290 product and no phase 3 trial. An EU orphan designation for sarcoidosis exists, but orphan designation is a development incentive rather than marketing authorization.
The last published clinical study was the tiny open-label macular-edema trial. Completed or orphan-designated status cannot supply a prescribing label, routine dose, contraindications, interaction rules, or missed-dose guidance.
Regulatory and registry records · no approval or phase 3
Regulatory and registry record set
FDA approval resources and trial registries
The cited records contain no FDA-approved cibinetide or ARA-290 product and no phase 3 trial under the exact names and codes. The registry record remains a small phase 1 and phase 2 development history.
- Participants / model
- United States approval records and human trial registries
- Treatment
- Cibinetide, ARA-290, ARA 290, ARA290, and pHBSP
- Study design
- Alias-based regulatory and registry coverage
Older registry records report differing statuses.
Read the original sourceEMA orphan record · designation only
Regulatory designation record
European Medicines Agency, EU/3/13/1191
The European Commission granted orphan designation for the cibinetide chemical sequence in sarcoidosis in October 2013. The record is a designation, not a marketing authorization.
- Participants / model
- Sarcoidosis development indication
- Treatment
- Cibinetide chemical sequence
- Follow-up
- Designation granted October 7, 2013
- Study design
- EU orphan designation record
Orphan status provides development incentives and does not establish efficacy, safety, or authorization to market.
Read the original sourceMacular edema · objective endpoints did not improve
Open-label phase 2 study
Lois et al., Journal of Clinical Medicine, 2020
Nine people were enrolled and eight completed 12 weeks of 4 mg daily. Mean visual acuity, retinal thickness, retinal sensitivity, and tear production did not improve; the patient-reported visual-function composite rose 2.7 points.
- No serious adverse events or anti-cibinetide antibodies were reported among completers.
- Participants / model
- Treatment-naive patients with diabetic macular edema and central retinal thickness over 400 micrometers
- Treatment
- Subcutaneous cibinetide 4 mg daily
- Follow-up
- 12 weeks
- Study design
- Single-center open-label single-arm phase 2 study
The study had eight completers and no control arm, so it cannot isolate benefit or estimate uncommon harms.
Read the original sourceStudies and sources
Phase 2b · middle-dose imaging signal
Randomized placebo-controlled phase 2b trial
Culver et al., Investigative Ophthalmology and Visual Science, 2017
In 64 randomized participants, placebo-corrected corneal nerve fiber area increased significantly only at 4 mg: +697 square micrometers (95% CI 159 to 1,236; P = 0.012). The 1 mg and 8 mg estimates crossed zero. Pain improved in all groups; the moderate-to-severe 4 mg subgroup result was P = 0.157.
- Daily subcutaneous treatment lasted 28 days.
- The positive primary endpoint was a surrogate imaging measure.
- Participants / model
- People with sarcoidosis-associated small nerve-fiber loss and neuropathic pain
- Treatment
- Cibinetide 1, 4, or 8 mg daily versus placebo
- Follow-up
- 28 days
- Study design
- Two-center randomized double-blind placebo-controlled phase 2b trial
- Funding
- Araim Pharmaceuticals-linked development program
Small arms, no conventional dose response, no significant pain-intensity effect, and no independent replication.
Read the original sourceNCT02039687 · outcomes and adverse events
Clinical trial registry results
ClinicalTrials.gov, NCT02039687
Posted results provide the four-arm corneal, pain, walk, participant-flow, and adverse-event tables. Treatment-emergent event counts were 14/16, 11/16, 12/14, and 12/16 for 1 mg, 4 mg, 8 mg, and placebo; serious-event counts were 2, 0, 1, and 0.
- The 8 mg serious event was listed as suicidal ideation.
- Registry analysis included 62 of 64 randomized participants.
- Participants / model
- Sarcoidosis-associated small-fiber neuropathy and pain
- Treatment
- Daily subcutaneous cibinetide 1, 4, or 8 mg or placebo
- Follow-up
- 28 days
- Study design
- Posted results for randomized phase 2b trial
- Funding
- Araim Pharmaceuticals
A treatment-emergent event is not automatically caused by the drug; arm sizes were very small.
Read the original sourceImage reanalysis · density and length did not separate
Post hoc imaging analysis
Brines et al., Scientific Reports, 2018
In the 4 mg and placebo phase 2b image subset, standard nerve-fiber density and length did not show a significant treatment difference. Pixel-based nerve area and branch density did separate.
- Baseline n = 63; day-28 comparison used 16 placebo and 15 treated participants.
- The authors described small groups and post hoc analysis.
- Participants / model
- Phase 2b sarcoidosis imaging dataset
- Treatment
- Cibinetide 4 mg daily versus placebo
- Follow-up
- 28 days
- Study design
- Post hoc reanalysis of corneal confocal microscopy images
- Funding
- Developer-linked author group
Standard nerve-fiber density and length did not differ significantly; only the post hoc area and branch-density measures did.
Read the original sourceDiabetes phase 2 · unreplicated HbA1c signal
Randomized placebo-controlled phase 2 trial
Brines et al., Molecular Medicine, 2015
Among 48 analyzed participants, daily 4 mg ARA-290 for 28 days produced a significant HbA1c pattern through day 56, P = 0.002. In 42 with serial measurements, day-56 mean change was -0.21 percentage points versus +0.21 with placebo. PainDetect improved 3.3 versus 1.1 points, P = 0.037.
- Four serious adverse events occurred in the active arm; investigators judged two possibly related.
- The metabolic result has not been independently replicated.
- Participants / model
- Adults with type 2 diabetes and painful neuropathic symptoms
- Treatment
- Subcutaneous ARA-290 4 mg daily versus placebo
- Follow-up
- 28 days treatment plus 28 days follow-up
- Study design
- Double-blind randomized placebo-controlled phase 2 trial
- Funding
- Investigator-initiated, developer-linked author group
Small study with multiple outcomes, incomplete serial HbA1c data, and no replication.
Read the original sourceMacular edema · objective endpoints did not improve
Open-label phase 2 study
Lois et al., Journal of Clinical Medicine, 2020
Nine people were enrolled and eight completed 12 weeks of 4 mg daily. Mean visual acuity, retinal thickness, retinal sensitivity, and tear production did not improve; the patient-reported visual-function composite rose 2.7 points.
- No serious adverse events or anti-cibinetide antibodies were reported among completers.
- Participants / model
- Treatment-naive patients with diabetic macular edema and central retinal thickness over 400 micrometers
- Treatment
- Subcutaneous cibinetide 4 mg daily
- Follow-up
- 12 weeks
- Study design
- Single-center open-label single-arm phase 2 study
The study had eight completers and no control arm, so it cannot isolate benefit or estimate uncommon harms.
Read the original sourceKidney paper · retracted February 2026
Retraction notice
Molecular Medicine, 2026
The journal retracted the 2012 rat kidney-injury paper after image-integrity concerns and publisher review of whether selected blot bands represented the observed experimental results.
- Participants / model
- Retracted rat study publication record
- Treatment
- pHBSP or ARA-290 preclinical claim
- Follow-up
- Retraction published February 26, 2026
- Study design
- Publisher retraction notice
The retracted kidney paper does not support cibinetide claims.
Read the original sourceMetabolic mouse paper · retracted April 2024
Retraction notice
British Journal of Pharmacology, 2024
The 2014 mouse diet-induced insulin-resistance paper is marked retracted, with the retraction published in April 2024. The notice does not state a reason.
- Participants / model
- Retracted mouse study publication record
- Treatment
- pHBSP preclinical metabolic claim
- Follow-up
- Retraction published April 2024
- Study design
- Publisher retraction notice
The retracted mouse paper does not support the human HbA1c finding.
Read the original sourceEMA orphan record · designation only
Regulatory designation record
European Medicines Agency, EU/3/13/1191
The European Commission granted orphan designation for the cibinetide chemical sequence in sarcoidosis in October 2013. The record is a designation, not a marketing authorization.
- Participants / model
- Sarcoidosis development indication
- Treatment
- Cibinetide chemical sequence
- Follow-up
- Designation granted October 7, 2013
- Study design
- EU orphan designation record
Orphan status provides development incentives and does not establish efficacy, safety, or authorization to market.
Read the original sourceRegulatory and registry records · no approval or phase 3
Regulatory and registry record set
FDA approval resources and trial registries
The cited records contain no FDA-approved cibinetide or ARA-290 product and no phase 3 trial under the exact names and codes. The registry record remains a small phase 1 and phase 2 development history.
- Participants / model
- United States approval records and human trial registries
- Treatment
- Cibinetide, ARA-290, ARA 290, ARA290, and pHBSP
- Study design
- Alias-based regulatory and registry coverage
Older registry records report differing statuses.
Read the original sourceWhy is Cibinetide in D tier?
D reflects early developer-linked trials with positive corneal-imaging, HbA1c, and PainDetect signals, but no consistent dose response, independent replication, or phase 3 program.