SEER-1 neurotrophic keratopathy
0.1% RGN-259 (Thymosin ß4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial.
Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. · International journal of molecular sciences
Study record
- Population
18 adults with stage 2 or 3 neurotrophic keratopathy: 10 assigned RGN-259 and eight placebo. All completed the study.
Read source · Full-text reportMethods — Subject demographics; Table 1- Formulation
0.1% RGN-259 (timbetasin acetate), an ophthalmic solution containing synthetic full-length thymosin beta 4, versus vehicle.
Read source · Full-text reportIntroduction; Materials and Methods- Route
Topical ophthalmic application.
Read source · Full-text reportIntroduction; Materials and Methods- Dose & frequency
0.1% ophthalmic solution five times daily; this establishes no human or KLOW regimen for systemic use or TB-500 fragments.
Read source · Full-text reportIntroduction — SEER-1 regimen- Study design
Multicenter randomized, placebo-controlled, double-masked phase 3 study (NCT02600429). Recruitment stopped early at 18 rather than the planned 46 participants.
Read source · Full-text reportMaterials and Methods — Study design; Subject demographics- Duration
Four weeks of treatment followed by two weeks of observation, with final assessment at day 43.
Read source · Full-text reportResults 2.1; Table 2; Materials and Methods- Reported findings
Primary day-29 complete healing: 6/10 versus 1/8; Fisher exact p=0.0656, not statistically significant. Day-43 secondary healing favored RGN-259 (5/10 versus 0/8; p=0.0359).
Read source · Full-text reportResults 2.1; Table 2; Statistical Analyses- Adverse events
At least one adverse event: 4/10 versus 3/8 participants. One serious event in the active arm was judged unrelated; one active-arm event was judged treatment-related. No withdrawals due to adverse events.
Read source · Full-text reportResults 2.4; Table 5- Monitoring
Visit-based adverse-event queries and ocular examinations included visual acuity, slit-lamp examination, corneal sensitivity, fundoscopy and intraocular pressure at specified visits through day 43.
Read source · Full-text reportMaterials and Methods — Safety outcome measures
What it supports
Exploratory human evidence of corneal healing with an ophthalmic full-length thymosin-beta-4 preparation.
What it does not establish
Primary endpoint not met; small, prematurely stopped study with baseline imbalances and multiple secondary analyses. Day-36 narrative says 6/10 healed, whereas Table 2 reports 4/10; this record does not resolve that discrepancy. An ad hoc chi-square analysis does not replace the primary Fisher test. Not evidence for injected TB-500 or KLOW.
Funding
ReGenTree funded the trial; several authors were employed by ReGenTree or its parent company. Sponsor employees participated in study design (Funding; Conflicts of Interest).
Literature search cutoff: 2026-09-08 · Not independently clinically reviewed
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