Some leg ulcers do not seem to respond that well to the standard treatments that we currently use. One reason for this may be that there are high levels of bacteria in the ulcer which may be slowing down the rate of healing. Because we need to be careful about when we use antibiotics, this study will look at another way of killing bacteria in the ulcer. This new method involves putting a special gel on the ulcer and then shining a particular type of light (visible red light) onto the ulcer for a short period of time.

In the first part of the study, a single treatment with the gel and light will be investigated. The second part of the study will compare whether or not using the treatment once a week for 12 weeks is better than placebo.

Across the UK 57 people with chronic leg ulcers will be asked to take part in this study (9 in part 1 and 48 in part 2). Up to 10 sites will be involved including Cardiff University and hospitals in Bradford, Harrogate, Dundee, Hull, Plymouth and the Wirral.

The research is funded by Photopharmica Ltd.

Inclusion Criteria:

• Subjects will be males or females of non-childbearing status over 18 years of age.
• Subjects will have a chronic leg ulcer with an ABPI ≥ 0.6 (measured at screening).
• Subjects will have an ulcer that has been present for at least 3 months and not more than 3 years.
• Subjects will have an ulcer with an area of 2 - 100cm2 and a maximum linear dimension of 10cm.
• Subjects will have an ulcer with a total bacterial load of ≥ 104 CFU / cm2, determined within 2 weeks before the first treatment.
• Subjects will have voluntarily signed and dated a subject Informed Consent Form (ICF).
• Subjects will be, in the opinion of the Investigator, able to understand the study, co-operate with the study procedures and be willing to return to the clinic for all the required follow-up visits.
• Subjects should be of appropriate health to participate in the study, as determined by the Investigator. This will be determined by a medical history, physical examination, 12-lead ECG and clinical laboratory evaluations.

Exclusion Criteria:

• Subjects under the age of 18 years of age.
• Subjects who have taken topical or systemic antibiotics during the 2 weeks prior to screening.
• Subjects who have used any anti-microbial dressing or topical antiseptic / antimicrobial or received maggot therapy during the 2 weeks prior to screening.
• Subjects who have evidence of connective tissue disorders e.g. vasculitis or rheumatoid arthritis under active treatment.
• Subjects who have any clinically significant medical condition that would impair wound healing as determined by the investigator, including uncontrolled diabetes as determined by HbA1C (>12%) or immune disease.
• Subjects who are known to abuse alcohol or drugs currently, or to have psychological disorders that could affect follow-up care or treatment outcomes.
• Subjects who have received short course corticosteroids within 30 days prior to treatment.
• Subjects who have participated in a clinical trial of any investigational drug within 4 months prior to treatment.
• Subjects who have participated in a clinical trial of any investigational device, for example dressings, within 1 month prior to treatment.
• Subjects who have previously been treated with IMP in this trial.
• Subjects who have or are suspected of having malignancy, or who have received treatment for any active malignancy, apart from non-melanomatic skin cancer, within 3 months prior to treatment.
• Subjects with evidence of exposed bone, tendon or facia visible around the target wound.
• Subjects with photosensitivity disorders.
• Subjects with systemic infection, whether or not related to their ulcer.
• Subjects with clinically relevant (assessed by PI) active wound infection undergoing treatment.