HLB Therapeutics' ReGenTree Misses Primary Endpoint in European SEER-3 Phase 3 Trial of RGN-259 Thymosin Beta-4 Eye Drop for Neurotrophic Keratitis — Placebo Response Carries Control Arm
HLB Therapeutics (KOSDAQ: 115450) announced in late May 2026 that its US subsidiary ReGenTree failed to meet the primary endpoint in the European Phase 3 SEER-3 trial of RGN-259, a thymosin beta-4-based eye drop designed to rival Dompé's Oxervate (cenegermin) — the only FDA-approved prescription drop for neurotrophic keratitis. The trial did not show a statistically significant difference in complete corneal healing at 4 weeks compared to placebo, with a company spokesperson telling Korea Biomedical Review that 'a stronger-than-expected placebo effect in the control arm led to a puzzling outcome.' RGN-259 is licensed from RegeneRx and is also in Phase 3 development for dry eye syndrome (ARISE-3). HLB Therapeutics CEO Ahn Gi-hong said the company will analyze the SEER-3 results and focus resources on the ongoing US Phase 3 SEER-2 trial, with topline H2 2026.