The primary objective of these case series is to evaluate the safety and tolerability of the KLOX BioPhotonic System as adjunctive therapy to Standard Of Care (SOC) in patients with venous leg ulcers.

Inclusion Criteria:

• Male or female 18 years of age and older;
• The subject or legal guardian must have signed an informed consent form;
• Female of child bearing potential must have a negative pregnancy test result at Baseline and both male and female patients must be willing to adhere to a medically-accepted birth control method during the course of the study;
• Willingness to return for all study visits;
• Proven venous leg ulcer, clinically defined and confirmed by duplex, refilling time or venous hypertension;
• Open venous leg ulcer present for more than 4 weeks prior to study entry (Screening/Visit 1);
• Ulcer area between 5 and 100 cm2 inclusive, with a maximum depth of 1 cm. The maximum diameter of the wound must not exceed 10 cm;
• Wound area has not changed by more than +/- 30% between Screening visit and Week 1/Visit 1 (before treatment).
• Adequate arterial blood perfusion (ABI (ankle brachial index) between 0.7 and 1.3, inclusive).

Exclusion Criteria:

• Venous leg ulcer present for more than 12 months;
• The ulcer to be treated is planned for operative debridement;
• The ulcer has significant necrotic tissue (e.g., more than 20% of the ulcer area);
• Major uncontrolled medical disorder(s) such as serious cardiovascular, renal, liver or pulmonary disease, lupus, palliative care or sickle cell anemia;
• Severe or significant hypoalbuminemia (albuminemia < 30 g/L, and/or pre-albumin < 5 mg/dL), or hypoproteinemia (proteinemia < 55g/L);
• Patient with moderate to severe anemia (Hb < 90g/L);
• Patient currently treated for an active malignant disease;
• Patient with history of malignancy within the wound;
• Patient with history of radiation therapy to the wound region;
• Patient with prior diagnosis of active malignant disease who is less than 1 year disease-free;
• Patient with a known osteomyelitis or active cellulitis;
• Patients that are immunosuppressed or on high dose chronic steroid use;
• Patients on systemic corticosteroids (a completion of corticosteroid course at least 30 days prior to study enrolment is required);
• Patient with active or systemic infection (note that the patient is however eligible for re-screening after the systemic infection has subsided);
• Successful revascularization surgery of the leg with the ulcer to be treated less than 8 weeks prior to Screening;
• Patients with severely uncontrolled diabetes mellitus (defined as A1C > 12%);
• Raynaud disease or other severe peripheral microvascular disease;
• Dermatologic comorbid disease (e.g., cutis laxa or collagen vascular disease);
• Active bleeding;
• Pregnancy, or breast feeding;
• Patients with bleeding diathesis;
• Patients on Warfarin or IV Heparin;
• The subject has any physical or psychiatric condition that in the Investigator's opinion would warrant exclusion from the study or prevent the subject from completing the study (e.g., severe morbid obesity, recent hip fracture, suspected non-compliance, etc.);
• Patients with ulcers from burns (from exposure to high heat), pressure ulcers or diabetic foot ulcers;
• Concurrent disease or drugs known to induce severe photosensitivity of the skin, such as porphyria;
• Patient has received biological-based therapy in any wound within 3 months of Screening;
• Concurrent participation in another clinical trial that involves an investigational drug or device that wound interfere with this study;
• Previous participation in other interventional wound healing clinical investigation within the 60 days prior to Screening visit.