Health UK (Commonwealth Union) – A drug candidate, developed by pharmaceutical company SIFI S.p.A. as a result of groundbreaking research conducted by the University College London (UCL) and Moorfields Eye Hospital, has demonstrated remarkable effectiveness in treating a rare and vision-threatening eye infection in a recent international clinical trial.
The study’s results, published in the journal Ophthalmology, highlight the efficacy and safety of the first drug candidate designed to treat Acanthamoeba keratitis (AK), implementing an innovative and evidence-based treatment approach.
AK represents a form of microbial keratitis, which is a corneal infection leading to inflammation of the cornea, the eye’s transparent protective outer layer. AK can inflict severe pain and heightened sensitivity to light.
Researchers of the study pointed out that while AK is relatively rare, affecting approximately one in 37,000 contact lens wearers annually in the UK, it is responsible for roughly half of the cases of vision loss within this demographic. Contact lens wearers face an elevated risk of contracting the disease. Recent research by the UCL and Moorfields team has revealed that individuals using reusable contact lenses are almost four times more likely to develop AK compared to those who opt for daily disposables. Moreover, wearing lenses during showering or overnight also escalates the risk by more than threefold.
The subject of investigation in this clinical trial is a low-concentration solution of polihexanide (PHMB 0.02%), which was initially compounded and employed in the 1990s for treating AK. This development was pioneered by a team co-led by the lead author of the current study, Professor John Dart. Although it is widely recommended as an AK treatment, PHMB 0.02% is not a licensed drug, and its treatment outcomes have exhibited variability.
Professor John Dart from the UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust emphasized the importance of preventing Acanthamoeba keratitis among contact lens users through safe practices. These include opting for daily disposables when feasible, maintaining diligent hand hygiene before handling lenses, ensuring proper lens and lens case cleanliness, refraining from using lenses during activities such as bathing, swimming, or showering unless eye protection is worn, discarding lenses after use, avoiding overnight wear, and not using them daily. These practices can significantly reduce the risk of this potentially devastating eye condition.
“Unfortunately, when the disease does develop the course is prolonged and, in the recent past, one third of patients have had poor visual outcomes with one quarter requiring surgery at some stage.
“PHMB 0.02% is an effective and widely recommended unlicensed therapy, but many clinicians have trouble accessing it, mistakes in formulation can sometimes lead to poor results, and the lack of a proven treatment protocol has resulted in wide variations in how the drug is used and in treatment outcomes. We hope that our new robust findings with polihexanide 0.08% will be a game changer for AK treatment, by improving access and the consistency of treatment, addressing currently unmet patient needs.”
The Phase 3 double-blind randomized controlled clinical trial followed a Phase 1 study in healthy volunteers, which established the safety of a significantly higher concentration (0.08%) of polihexanide. This Phase 3 trial adhered to guidance provided by the European Medicines Agency and sought to compare the effectiveness and safety of a high concentration of polihexanide (0.08%) as a standalone treatment against a widely employed dual therapy, which combines a lower dose of PHMB (0.02%) with propamidine. All phases of the trials were sponsored and financially supported by the Italian pharmaceutical company SIFI, with additional co-funding from the European Commission.
The study encompassed the examination of 127 individuals undergoing treatment for Acanthamoeba keratitis at six hospitals situated across Europe, including locations in England, Italy, and Poland.
The research outcomes revealed that both treatment formulations proved highly effective when administered in accordance with the specified drug delivery protocol.
