Polihexanide (PHMB) Eye Drops in Patients Affected by Acanthamoeba Keratitis

Inclusion Criteria

• willing to give informed consent
• man or woman of any race and ≥12 years of age
• able to understand and willing to comply with study procedures, restrictions and requirements
• Clinical findings consistent with Acanthamoeba keratitis
• Confocal microscopy findings consistent with Acanthamoeba keratitis
• The following previous treatments for Acanthamoeba keratitis are eligible: antibiotics, antiviral and antifungal drugs, antiinflammatory drugs
• Females of childbearing potential will be included if they are either sexually inactive or using one highly effective contraceptive
• Females of childbearing potential agree to remain sexually inactive or to keep the same birth control method for at least 28 days following the last study drug dose
• A female of non-childbearing potential must have undergone one sterilization procedures at least 6 months prior to the first study drug dose
• A non-vasectomized male subject agrees to use a condom with spermicide or abstain from sexual intercourse during the study until 90 days beyond the last dose of study drug and the female partner agrees to comply with inclusion 7 or 8. For a vasectomized male who has had his vasectomy 6 months or more prior to study start, it is required that they use a condom during sexual intercourse. A male who has been vasectomized less than 6 months prior to study start must follow the same restrictions as a non-vasectomized male.
• If male, they must agree not to donate sperm from the first study drug dose until 90 days after dosing

Exclusion Criteria

• Subject with documented history and/or clinical signs of concomitant presence of an ocular infection caused by viruses (herpes simplex virus [HSV]) or fungi.
• Subject treated with drugs having effects on Acanthamoeba cysts prior to study entry, including biguanides (PHMB, chlorhexidine) and diamidines (propamidine, hexamidine).
• Subjects requiring systemic immunosuppression for Acanthamoeba associated scleritis.
• Subjects requiring urgent surgical intervention for advanced Acanthamoeba keratitis in either eye (e.g., for advanced corneal thinning/melting etc.).
• Subject with known or suspected allergy to biguanides, diamidines or intolerance to any other ingredient of the investigational treatments.
• Subject affected by immunodeficiency diseases or taking systemic immunosuppressive therapy.
• Subject with a major systemic disease or other illness that would, in the opinion of the investigator, compromise subject's safety or interfere with the collection or interpretation of study results.
• If female, pregnancy, planned pregnancy, or breast-feeding
• Subject is participating in another interventional clinical study with an experimental or unapproved/unlicensed therapy or has participated in another interventional clinical study within 4 weeks prior to this study.