Trefoil Therapeutics Announces Positive Data from Phase 2 Study TTHX1114 Showing Corneal Regeneration and Vision Recovery Following Descemet Stripping Only (DSO) Surgery

TTHX1114 has the potential to be the first pharmacological treatment for corneal endothelial dystrophies

CHICAGO, September 29, 2022–(BUSINESS WIRE)–Trefoil Therapeutics, a clinical-stage biotechnology company focused on restoring sight in people with corneal diseases, today announced positive Phase 2 results for TTHX1114 in patients with endothelial corneal dystrophy of Fuchs (FECD). TTHX1114, a patented variant of fibroblast growth factor 1 (FGF1), is administered as an intracameral injection into the anterior chamber of the eye. Most corneal transplants are done because of FECD.

Presented at the 2022 World Cornea Congress, data from the Phase 2 STORM trial investigated whether treatment with the investigational agent TTHX1114 resulted in faster recovery of vision in patients undergoing a Descemet Stripping Only (DSO) procedure ). DSO is an alternative to corneal transplantation that does not require donor tissue and thus eliminates the risk of graft rejection and the need for postoperative immunosuppression. Additionally, DSO is more accessible to the millions of people living with corneal diseases around the world.

Results from the Phase 2 STORM trial showed several positive efficacy outcomes for TTHX1114 as an adjunct to DSO and a favorable safety profile, including:

  • Recovery of 20/40 vision in an average time of 4.2 weeks after DSO and a single intracameral injection of TTHX1114

  • A significant dose-dependent effect of TTHX1114 on central corneal thickness (CCT) recovery, with median CCT recovered better than baseline at day 84

  • TTHX1114 and the intracameral injection procedure were well tolerated, and no serious adverse events were reported

“Data from the STORM trial show endothelial cell restoration and patient-reported visual recovery that indicate endothelial cells regenerate, migrate and help accelerate healing after DSO and a single injection of TTHX1114,” said Francis W. Price, Jr., MD, founder and chairman of Price Vision Group and the Cornea Research Foundation of America, and principal investigator of the trial. “For the millions of people with corneal endothelial disease, this has the potential to be a first-line pharmacological treatment option.”

Corneal endothelial disease/dystrophy (CED) occurs when the finite number of endothelial cells in the eye decline and stop functioning, resulting in swelling of the cornea. In FECD, this is compounded by the formation of collagen deposits inside the cornea which cause progressive and potentially debilitating vision loss. In any given year in the United States, an estimated 180,000 people are at risk of losing their sight due to Fuchs dystrophy, 78,000 of whom will need corneal transplants within two years.I

However, approximately 30,000 corneal transplants are performed in the United States each year, leaving tens of thousands of people without viable options to cope with their progressive vision loss.ii

“Corneal transplantation is not an ideal option for many people with corneal endothelial disease for a number of reasons, including the limited global supply of donors, cultural nuances, the complexity of the procedure and the time to vision recovery,” said David Eveleth, Ph.D., co-founder, president and CEO of Trefoil Therapeutics. “TTHX1114 offers the potential to restore vision by regenerating the cornea’s own endothelial cells. We will further evaluate this data to determine the next steps in our clinical and regulatory process.

About TTHX1114
TTHX1114 is an experimental variant of the naturally occurring molecule Fibroblast Growth Factor-1 (FGF1), which stimulates cell proliferation and migration while protecting cells from stress and injury. Trefoil’s clinical program for TTHX1114 in patients with FECD and other corneal endothelial dystrophies (CED) aims to regenerate corneal endothelial cells lost due to disease and thereby improve vision. FECD is a progressive disease that is the leading cause of corneal transplants in the United States. Although transplant surgery with human donor corneas can be effective in restoring vision, post-surgical recovery can be difficult and most patients require long-term immunosuppressive therapy to minimize the risk of transplant rejection. TTHX1114 is being studied for the treatment of corneal endothelial dystrophies by intracameral injection into the eyes.

About Trefoil Therapeutics
San Diego-based Trefoil Therapeutics is a clinical-stage biotechnology company focused on leveraging its FGF1 protein technology platform to develop first-in-class pharmacological treatments for serious corneal endothelial disease and epithelial disorders. . Trefoil’s lead product candidate is TTHX1114, an investigational form of naturally occurring FGF1 designed to stimulate corneal cell protection, proliferation and migration, thereby reversing vision loss. The technology behind Trefoil’s platform was developed by co-founders Michael Blaber, Ph.D., and David Eveleth, Ph.D., and is licensed from Florida State University. Trefoil investors include Bios Partners, Hatteras Venture Partners, Access Biotechnology, Solasta Ventures, InFocus Capital Partners, Correlation Ventures and ExSight Ventures. Learn more about

Safe Harbor Statement
The clinical research discussed in this press release is preliminary and the outcome of these studies may not be predictive of the outcome of subsequent clinical trials. Results of future clinical trials may not demonstrate sufficient safety and efficacy to obtain regulatory approval related to the clinical research results discussed in this press release.


I David C. Musch; Leslie M. Niziol; Joshua D. Stein; Roheena M. Kamyar; Alain Sucre. Prevalence of Corneal Dystrophies in the United States: Estimates from Claims Data, Clinical and Epidemiological Research, Volume 52, Number 9, 2011
ii 2021 Eye Bank Statistical Report. Eye Bank Association of America. (2022). Extract of

See the source version on


Media Contacts
Shay Smith
[email protected]

Comments are closed.