Acanthamoeba keratitis (AK) is a rare, sight-threatening eye infection that affects the cornea. It can cause extreme pain and light sensitivity. If left untreated, it can lead to severe vision loss or even blindness. However, a new drug candidate has shown promising results in treating this condition.
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Understanding Acanthamoeba Keratitis
AK is a type of microbial keratitis, which refers to corneal infections caused by microorganisms. In this case, a cyst-forming microorganism called Acanthamoeba is the cause of AK. While relatively uncommon, affecting about one in 37,000 contact lens wearers per year in the UK, it is responsible for approximately half of the cases of sight loss in this group. Contact lens wearers are particularly at risk. However, reusable contact lens wearers face nearly four times the risk than those those wearing daily disposables.
To prevent AK, it is important for contact lens wearers to follow safe use advice, such as:
- using daily disposables if possible
- washing and drying hands before handling lenses
- maintaining good lens and lens case hygiene
- avoiding wearing lenses while bathing, swimming, or showering.
- avoiding wearing lenses overnight and replacing them after each use
The Need for Effective Treatment
Until now, the treatment options for AK have been limited, with variable outcomes and difficulties in accessing the recommended therapy. The current widely recommended treatment, low concentration polihexanide (PHMB 0.02%), is not a licensed drug, and its effectiveness has been inconsistent. Clinicians have faced challenges in accessing the treatment, and mistakes in formulation have led to poor results. Furthermore, the lack of a proven treatment protocol has resulted in variations in how the drug is used and in treatment outcomes.
The Breakthrough Drug Candidate
In a groundbreaking international clinical trial, a new drug candidate based on pioneering research by UCL and Moorfields Eye Hospital has shown remarkable efficacy in treating AK. The drug candidate, a high concentration of polihexanide (PHMB 0.08%), has been found to be highly effective when used with a novel and evidence-based treatment protocol.
The Phase 3 randomized controlled double-blind clinical trial followed a Phase 1 trial in healthy volunteers, which demonstrated the safety of the higher concentration of polihexanide. The trial compared the efficacy and safety of the high concentration monotherapy to a widely used dual therapy combining a lower dose of PHMB with propamidine.
The Clinical Trial Results
The clinical trial involved the analysis of 127 people being treated for AK at six hospitals across Europe. The researchers found both formulations to be highly effective when used with the detailed drug delivery protocol. The medical cure rate was an impressive 87%, meaning that 87% of participants were cured of AK without needing surgery, which is one of the highest cure rates ever reported for AK.
The treatment failure rate was 13.4%, with nearly half of those requiring therapeutic corneal transplant surgery. However, the overall transplant surgery rate of 6.3% is one of the lowest reported in any case series of AK. These results indicate that the new drug candidate has the potential to be a game-changer for AK treatment, addressing the currently unmet needs of patients and improving treatment outcomes.
The Advantages of the New Monotherapy
The new monotherapy has several advantages over the current dual therapy. Firstly, the simplicity of the treatment reduces the risk of errors in practice, ensuring consistent and effective treatment outcomes. Additionally, the new drug candidate offers a standardized treatment protocol, which clinicians can strictly follow to maximize its efficacy.
The Impact on AK Patients
The availability of an effective and standardized treatment for AK is a significant development for patients worldwide. AK causes severe pain and discomfort, and the length of the disease often results in poor visual outcomes and surgery. With the new candidate, the hope is improved treatment access, leading to more consistent and positive outcomes for patients.
Seeking Regulatory Approvals
SIFI pharmaceutical company is seeking regulatory approvals for the high concentration of polihexanide in Europe, the UK, and the US. The goal is to make polihexanide 0.08% (Akantior®) available as the first approved orphan medicinal product for the treatment of AK.
Patient Advocacy and Future Outlook
Patient advocates, such as Juliette Vila Sinclair Spence, Rare Disease Patient Advocate & Chairwoman of the Acanthamoeba Keratitis Eye Foundation, are optimistic about the potential of the new drug candidate. They see it as a significant step forward in providing standardized treatment for AK and bringing hope to patients who have faced the challenges of this rare disease.
Moving forward, continued research, regulatory approvals, and accessibility of the new drug candidate will play a vital role in improving the management and outcomes of AK. With the advancements in treatment, the future looks brighter for patients battling Acanthamoeba keratitis.
For more information on rare ophthalmology/eye diseases, visit https://checkrare.com/diseases/ophthalmology-eye-diseases/
