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Tb52.5

TB-500 Research

Mostly mechanism / observational

17 peer-reviewed studies

What the evidence says

Mostly mechanism / observational

Most TB-500 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.

Most evidence is from mixed-quality randomised trials published 1990–2022 with a typical study size of 18 participants.

Based on 17 studies · 5 RCTs · 701 total participants

Confidence

Moderate confidence

By outcome

Vision & eye health
Mostly mechanism / observational3 studies
Cardiac repair & heart
Too few graded studies2 studies
Hair & nails
Too few graded studies2 studies
Wound & ulcer healing
Too few graded studies1 study
Tumor biology & cancer risk
Too few graded studies1 study
Safety profile
Too few graded studies1 study

Steady research

2 studies in the last 5 years

199020062022

1RCT2010

Ruff D, Crockford D, Girardi G, Zhang Y · Ann N Y Acad Sci (2010)

2RCT2007

Guarnera G, DE Rosa A, Camerini R · Ann N Y Acad Sci (2007)

3RCT2010

Guarnera G, DeRosa A, Camerini R · Ann N Y Acad Sci (2010)

4Review2016

In plain English: Treatment with thymosin beta 4 (Tβ4) reduces infarct volume and preserves cardiac function in preclinical models of cardiac ischemic injury.

Pipes GT, Yang J. · Vitam Horm (2016)

Review of Tβ4 cardioprotection in preclinical models of cardiac ischemic injury
Reduces infarct size with additional antifibrotic and proangiogenic effects
Effects attributed to SRF-MRTF-G-actin signaling and pleiotropic pathway interactions

5Review2016

In plain English: Tβ4 also accelerated the rate of repair in phase 2 trials with patients having pressure ulcers, stasis ulcers, and epidermolysis bullosa wounds.

Kleinman HK, Sosne G. · Vitam Horm (2016)

Review of Tβ4 in dermal wound repair, with angiogenic and anti-inflammatory activity
Tβ4 accelerated healing across multiple preclinical models, including diabetic and aged animals and burns
Reports Phase 2 trials in pressure ulcers, stasis ulcers and epidermolysis bullosa where Tβ4 accelerated repair

6Review2003

In plain English: Only the effects of thymosin beta 4 on the actin cytoskeleton have an explanation based on identified molecular interactions.

Bubb MR. · Vitam Horm (2003)

Review of the molecular interactions of Tβ4, a ~5-kDa actin-monomer-sequestering protein
Notes Tβ4 also acts as an anti-inflammatory agent and inhibitor of bone-marrow stem-cell proliferation
Emphasizes that, apart from actin sequestration, most attributed functions lack a defined molecular mechanism

7Review2012

In plain English: Thymosin β4 binds to actin and promotes cell migration, including the mobilization, migration, and differentiation of stem/progenitor cells, which form new blood vessels and regenerate the tissue.

Goldstein AL, Hannappel E, Sosne G, Kleinman HK. · Expert Opin Biol Ther (2012)

Review of thymosin β-4 (Tβ4) as a naturally occurring repair/regeneration peptide released after injury
Tβ4 sequesters G-actin, promotes cell migration and angiogenesis, and reduces inflammation and scarring
Surveys proposed therapeutic uses in skin, eye, heart and brain — largely preclinical with early clinical work

8In Vitro1993

In plain English: The increase in F-actin is correlated with a corresponding decrease in the complex of G-actin with T beta 4.

Nachmias VT, Cassimeris L, Golla R, Safer D. · Eur J Cell Biol (1993)

Mechanistic study of the Tβ4–G-actin complex in thrombin-activated human platelets
Actin polymerization on platelet activation tracks loss of the Tβ4–G-actin complex
Supports the model of Tβ4 as a dynamic buffer of polymerizable actin

9In Vitro1990

In plain English: AcSDKP a new regulator of the hematopoietic system can be generated from thymosin beta 4 by a one-step enzymatic cleavage in vitro and in vivo.

Grillon C, Rieger K, Bakala J, Schott D, Morgat JL, Hannappel E, Voelter W, Lenfant M. · FEBS Lett (1990)

In-vitro / in-vivo demonstration that the regulatory tetrapeptide AcSDKP is generated from Tβ4 by enzymatic cleavage
Both Tβ4 and AcSDKP were detected in bone-marrow cells
Identifies a Tβ4-derived signaling product relevant to hematopoiesis and tissue regulation

10Animal2015

In plain English: Hair re-growth was faster in Tβ4-overexpressing mice, but slower in knockout mice.

Gao X, Liang H, Hou F, Zhang Z, Nuo M, Guo X, Liu D. · PLoS One (2015)

Transgenic mouse study: epidermal Tβ4 overexpression accelerated hair regrowth; global knockout slowed it
Tβ4 upregulated VEGF and modulated P38/ERK/AKT signaling, linking it to angiogenesis-driven follicle growth
An animal model demonstrating the cell-migration / angiogenesis process attributed to Tβ4

11Observationaln=657 · large study2017

In plain English: Plasma TB4 is elevated in women with HFpEF and has prognostic information.

Drum CL, Tan WKY, Chan SP, Pakkiri LS, Chong JPC, Liew OW, Ng TP, Ling LH, Sim D, Leong KTG, Yeo PSD, Ong HY, Jaufeerally F, Wong RCC, Chai P, Low AF, Lund M, Devlin G, Troughton R, Cameron VA, Lam CSP, Richards AM. · J Am Heart Assoc (2017)

Human biomarker study measuring circulating TB4 by mass spectrometry in HFpEF (n=219), HFrEF (n=219) and controls (n=219)
Plasma TB4 elevated specifically in women with HFpEF, carrying prognostic information
Studies endogenous, circulating TB4 — not administered TB-500 — as a biomarker

12RCTn=18 · very small study2022

In plain English: Complete healing occurred after 4 weeks in 6 of the 10 RGN-259-treated subjects and in 1 of the 8 placebo-treated subjects (p = 0.0656), indicating a strong efficacy trend.

Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. · Int J Mol Sci (2022)

Randomized, placebo-controlled, double-masked Phase 3 trial of 0.1% RGN-259 (pharmaceutical thymosin β-4) eye drops for persistent epithelial defects in Stage 2-3 neurotrophic keratopathy
Complete healing at 4 weeks in 6/10 treated vs 1/8 placebo (p = 0.0656, trend); significant healing by day 43 (p = 0.0359) with no recurrence in the treated group
Treated subjects had significant improvements in ocular discomfort, foreign-body sensation and dryness; no significant adverse effects

13Review2018

In plain English: Phase 3 clinical trials using Tβ4 to treat dry eye and neurotrophic keratopathy are currently ongoing.

Sosne G. · Expert Opin Biol Ther (2018)

Narrative review of Tβ4 in ocular surface repair, from basic discovery to clinical translation
Phase 3 trials of Tβ4 (RGN-259) for dry eye and neurotrophic keratopathy were underway
Frames the strongest human-trial evidence for any Tβ4 indication — ophthalmic, not musculoskeletal

14Animal2015

In plain English: Hair re-growth was faster in Tβ4-overexpressing mice, but slower in knockout mice.

Gao X, Liang H, Hou F, Zhang Z, Nuo M, Guo X, Liu D. · PLoS One (2015)

Transgenic mouse study: epidermal Tβ4 overexpression accelerated hair regrowth; global knockout slowed it
Tβ4 upregulated VEGF and modulated P38/ERK/AKT signaling, linking it to angiogenesis-driven follicle growth
An animal model demonstrating the cell-migration / angiogenesis process attributed to Tβ4

15RCTn=9 · very small study2015

In plain English: At day 56, the RGN-259-treated group (12 eyes) had 35.1% reduction of ocular discomfort compared with vehicle control (6 eyes) (P = 0.0141), and 59.1% reduction of total corneal fluorescein staining compared with vehicle control (P = 0.0108).

Sosne G, Dunn SP, Kim C. · Cornea (2015)

Small multicenter, randomized, double-masked, placebo-controlled Phase 2 trial of 0.1% RGN-259 (thymosin β-4) eye drops in 9 patients with severe dry eye
Significant reductions in ocular discomfort (OSDI) and corneal fluorescein staining vs vehicle at multiple time points, persisting 28 days post-treatment
Again topical OCULAR pharmaceutical Tβ4, not injectable TB-500 — does not establish efficacy for the marketed musculoskeletal use

16In Vitro2007

In plain English: TB4 induces tumor metastasis and paclitaxel resistance, which is the most significant obstacle to successful therapy in tumors.

Moon EY, Song JH, Yang KH. · Oncol Res (2007)

Cell-model study: TB4 peptide treatment / overexpression increased tumor-cell survival and reduced paclitaxel-induced caspase-3 activation
Silencing TB4 (siRNA) reduced viability and increased caspase-3 activity
Links TB4 to tumor metastasis and chemoresistance in HeLa and gastric tumor cell lines

17Observationaln=17 · very small study2021

In plain English: The use of peptides BPC157 and thymosin-beta-4 (TB4) has not been studied in the treatment of knee pain.

Lee E, Padgett B. · Altern Ther Health Med (2021)

Retrospective single-clinic chart review of intra-articular BPC-157, alone or combined with TB4, for knee pain (17 patients, 16 reached)
Uncontrolled, retrospective design with self-reported pain ratings — very low evidence quality
Authors explicitly state the peptides had not previously been studied for knee pain

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