Healing · Eye

TB-500 / thymosin beta-4

Peptilex evidence grade ABCDEUpdated 19 Oct 2026 How grades work

Type: Thymosin beta-4: natural 43-amino-acid protein; TB-500: synthetic fragment or version of it
Main use or focus: Injury recovery, muscle and tendon repair
Also known as: TB-500

Key results

Complete corneal healingNeurotrophic keratopathy · phase 3

Thymosin beta-4 eye drops

6 of 10

Placebo

1 of 8

Source: SEER-1 · Int J Mol Sci 2022 · 18 participants

2026

global SEER-2 results expected (late 2026)

Registered trialSEER-2

Where it stands

Thymosin beta-4 eye drops reached phase 3: in SEER-1 the cornea healed completely in 6 of 10 patients vs 1 of 8 on placebo; the global SEER-2 results are expected in late 2026. For TB-500 and injury recovery, the evidence comes from animal studies.

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Research at a glance

Publications by typePubMed, all years

All papers629

Human studies349

Animal studies only216

Randomized trials5

Meta-analyses & systematic reviews1

Source: PubMed and ClinicalTrials.gov via the Peptilex study database

Registered trials by phaseClinicalTrials.gov · name in study title

ongoing / startingcompleted / other

Phase 12

Phase 29

Phase 35

Source: PubMed and ClinicalTrials.gov via the Peptilex study database

Trial starts per yearClinicalTrials.gov · by start date (planned starts included)

12016

12018

12020

12022

2024

12026

Source: PubMed and ClinicalTrials.gov via the Peptilex study database

Registered trials

ClinicalTrials.gov · name in study title · ongoing first

Study	Phase	Status	Participants	Start
Assessment of the Safety and Efficacy of 0.1% RGN-259 Ophthalmic Solution for the Treatment of NK: SEER-2 NCT05555589ReGenTree, LLC	Phase 3	Recruiting	70	Apr 2023
Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye Syndrome: ARISE-3 NCT03937882ReGenTree, LLC	Phase 3	Completed	700	May 2019
Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye Syndrome : ARISE-2 NCT02974907ReGenTree, LLC	Phase 3	Completed	601	Nov 2016
Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye Syndrome: ARISE-1 NCT02597803ReGenTree, LLC	Phase 2/3	Completed	317	Sep 2015
Efficacy and Safety Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction NCT05984134Beijing Northland Biotech. Co., Ltd.	Phase 2	Completed	90	Jul 2022
Study of Thymosin Beta 4 in Patients With Pressure Ulcers NCT00382174RegeneRx Biopharmaceuticals, Inc.	Phase 2	Completed	72	May 2006
Study of Thymosin Beta 4 in Patients With Venous Stasis Ulcers NCT00832091RegeneRx Biopharmaceuticals, Inc.	Phase 2	Completed	72	Jul 2006
Safety and Efficacy of Thymosin Beta 4 Ophthalmic Solution in Patients With Dry Eye NCT01387347ReGenTree, LLC	Phase 2	Completed	72	Aug 2011
Safety and Efficacy Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction.Infarction NCT05485818Beijing Northland Biotech. Co., Ltd.	Phase 2	Completed	62	Nov 2020
Comparative Study of Thymosin Beta 4 Eye Drops vs. Vehicle in the Treatment of Severe Dry Eye NCT01393132Michigan Cornea Consultants, PC	Phase 2	Completed	9	Mar 2011

Show 5 moreShow fewer

Study	Phase	Status	Participants	Start
A Phase 1a Study of Thymosin Beta 4 in Healthy Volunteers NCT04555824Beijing Northland Biotech. Co., Ltd.	Phase 1	Completed	54	Jul 2017
A Phase 1b Study of Thymosin Beta 4 in Healthy Volunteers NCT04555850Beijing Northland Biotech. Co., Ltd.	Phase 1	Completed	30	Jul 2018
Assessment of the Safety and Efficacy Study of RGN-259 Ophthalmic Solutions for Neurotrophic Keratopathy : SEER-1 NCT02600429ReGenTree, LLC	Phase 3	Stopped early	18	Sep 2015
A Phase 2 Study on Effect of Thymosin Beta 4 on Wound Healing in Patients With Epidermolysis Bullosa NCT00311766RegeneRx Biopharmaceuticals, Inc.	Phase 2	Stopped early	30	Feb 2006
A Phase 2 Study of the Safety and Efficacy of Thymosin Beta 4 for Treating Corneal Wounds NCT00598871ReGenTree, LLC	Phase 2	Stopped early	12	Dec 2007

1 further registry entry from a sponsor we could not verify is not listed.

Showing 15 of 16 matching registered studies. See all on ClinicalTrials.gov.

Latest key papers

PubMed · newest first

2025
Medical and surgical interventions for neurotrophic keratopathy
Meta-analysisKruoch Z et al. · Cochrane Database of Systematic ReviewsPMID 41347649
2022
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
Human RCTPhase 3Sosne G et al. · International Journal of Molecular SciencesPMID 36613994
2015
Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial
Human RCTPhase 2Sosne G et al. · CorneaPMID 25826322
2010
The effect of thymosin treatment of venous ulcers
Human RCTPhase 2Guarnera G et al. · Annals of the New York Academy of SciencesPMID 20536470
2007
Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing
Human RCTGuarnera G et al. · Annals of the New York Academy of SciencesPMID 17495250

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DBPC-157 DKPV