Exonate’s lead ophthalmology candidate EXN407 meets endpoints in Phase Ib/IIa trial for diabetic macular oedema


EXN407 has the potential to be the first topical treatment for diabetic retinopathy and diabetic macular oedema

A physician puts drops into a patient's eye. Image credit: ©Jack Tamrong – stock.adobe.com

In a news release, Exonate noted that EXN407 has the potential to be the first topical treatment for DR and DME. Image credit: ©Jack Tamrong – stock.adobe.com

The mRNA therapy company Exonate, based in Cambridge, United Kingdom, announced its lead ophthalmology candidate EXN407 achieved pre-specified endpoints in a Phase Ib/IIa study. It also met all the safety and pharmacokinetic parameters. The trial was carried out in collaboration with Janssen. The company's primary focus is therapies for diabetic complications including diabetic retinopathy (DR) and diabetic macular oedema (DME).1

These results show promising biological activity and the company notes that EXN407 has the potential to be the first topical treatment for DR/DME. The use of topical drops would significantly reduce the treatment burden for patients and ophthalmologists.

EXN407 is described as a small molecule inhibitor of splice factor kinase SRPK1. Patients in the Phase Ib/IIa trial were treated twice a day for 3 months, with either EXN407 or a placebo.1 The study met all endpoints well and achieved encouraging results, including:

  • No clinically meaningful changes or trends in any safety parameters
  • No tolerability issues reported
  • Only mild adverse events reported
  • No adverse events leading to treatment or study discontinuation
  • Highlighted signals of biological activity (macular thickness reduction and decrease in retinal vascular leakage)1

In the company’s press release, Dr Catherine Beech, CEO of Exonate, said, “The results from the EXN407 trial are very encouraging, with the data validating the hypothesis that modulating VEGF splicing can lead to clinical benefits. We are excited to progress to the Phase II trial next year and welcome enquiries by potential partners for the program.”

Exonate will progress EXN407 to a Phase II clinical study in 2024 to fully demonstrate efficacy in patients with severe DME.


1. Exonate announces successful completion of Phase Ib/IIa trial in diabetic macular oedema. Exonate Ltd. November 28,2023. Accessed December 11, 2023. https://www.exonate.com/updates/exonate-announces-successful-completion-phase-ibii/
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