Inclusion Criteria:

• Male or female patients aged 18 years and older at screening.
• Patients with at least one defined VLU suitable for treatment that is no smaller than 2 cm^2 but no larger than 50cm^2 and is confirmed as venous in origin by clinical assessments, by Ankle Brachial Pressure Index (ABPI) ≥ 0.8 and/or toe systolic BP pressure > 90mm Hg.
• Presence of slough within the reference ulcer suitable for debridement therapy.
• Confirmed, clinically diagnosed VLU (ulceration of the lower limb, 30 days or more, with no other mechanistic explanation) which has been present for ≤ 2 years, defined by patient reporting or clinical records.
• Patients with more than one VLU on the target leg can be included, provided other ulcers are at least 1 cm away from the reference ulcer identified for treatment. Selection of the reference ulcer will be at the investigator’s discretion, provided it meets all other inclusion/exclusion criteria.
• Good general state of physical and mental health as assessed by the Investigator:
  • Stable chronic treated conditions such as diabetes or raised blood pressure are permissible, provided under good control, and on stable doses of medication where appropriate, with no admission for any acute hospital-based treatments in the last 3 months;
  • Laboratory parameters and vital signs at screening must be within the normal age-adjusted and comorbidity-adjusted ranges (one retest permitted if results are outside of range and re-performed within the 14-day screening period).
• Willing and able to attend and comply with study visits and study related activities.
• Provide a signed and dated written informed consent form.

Exclusion Criteria:

• HbA1c > 8.5% at screening.
• Significant hepatic impairment as defined by screening LFTs of AST and ALT > 3 times upper limit of normal (1 retest allowed).
• Significant cerebrovascular disease including myocardial infarction, unstable angina, history of stroke, transient ischaemic attacks or cerebral haemorrhage less than 6 months prior to screening.
• Uncontrolled screening hypertension defined as SBP > 160 mmHg, DBP > 90mmHg.
• Temperature of the patient is ≥ 38.0°C.
• Uncontrolled screening anaemia defined as haemoglobin < 10 g/dL in women, < 12g/dL in men.
• A clinical history of bleeding disorder including haemophilia, purpura, or thrombocytopenia.
• Current or history of use of anti-thrombotic therapy less than 7 days prior to screening. Low dose single antiplatelet agents (aspirin, ticlopidine, clopidogrel, prasugrel, ticagrelor) are permitted.
• Stage 4 or 5 chronic kidney disease, defined as eGFR of ≤ 30 mL/min.
• Reference ulcer has active infection or florid oedema at screening determined by the investigator using clinical criteria.
• Oral or IV antibiotics for any indication within 72 hours of screening.
• Reference ulcer has exposed tendons, ligaments, muscle, or bone.
• Reference ulcer with high levels of exudate, which in the opinion of the investigator, would render the proposed trial management protocol unsuitable.
• Active osteomyelitis, cellulitis or gangrene in either leg.
• Patients with amputation above a trans metatarsal amputation (TMA) in the target leg.
• Currently active malignancy or history of any malignancy in the target leg within 5 years prior to screening (other than successfully treated non-metastatic cutaneous squamous cell or basal cell carcinoma).
• Currently receiving or has received radiation, immunosuppression or chemotherapy within 3 months of screening.
• Planned vascular surgery, angioplasty, or thrombolysis procedures within the study period, or 4 weeks before screening.
• Prior skin graft, negative pressure therapy, ultrasound therapy, systemic or cutaneously applied growth factor, other enzymatic debriding agents (e.g., Collagenase, Nexobrid) or live maggot therapy applied to the reference ulcer within 2 weeks before screening.
• Currently enrolled or has been enrolled in the last 30 days in another investigational device or drug study.
• Known allergy or hypersensitivity to any component of the investigational product, medication or surgical dressings to be used in the study.
• Patients who, in the opinion of the study Investigator, have significant ongoing psychiatric disorders (including depression with psychosis, bipolar disease and schizophrenia), which may interfere with the study procedures, assessments and/or visits.
• Patients lacking capacity to provide informed consent.
• Pregnant or breastfeeding women.
• Women of child-bearing potential (WoCBP)* who are unwilling to practice highly effective contraception** or undergo pregnancy tests at screening, during the study if necessary, and on the last study visit.
• * Pregnancy testing and contraception are not required for women not of child-bearing potential, including postmenopausal women or those with documented hysterectomy or bilateral oophorectomy. Postmenopausal women must be amenorrhoeic for at least 12 months in order not to be considered of child-bearing potential. Postmenopausal status will be confirmed by measurement of FSH.
• ** Highly effective contraceptive measures include stable use of combined (oestrogen and progestogen containing) hormonal contraception (oral, intravaginal, transdermal) or progestogen-only hormonal contraception (oral, injectable, implantable) associated with inhibition of ovulation initiated 2 or more menstrual cycles prior to screening; intrauterine device (IUD); intrauterine hormone-releasing system (IUS); bilateral tubal ligation; vasectomised partner; and sexual abstinence***.
• *** Sexual abstinence is considered a highly effective method only if defined as refraining from heterosexual intercourse during the entire period of risk associated with the study treatments. The reliability of sexual abstinence needs to be evaluated in relation to the duration of the clinical trial and the preferred and usual lifestyle of the patient.

Eligibility last updated 12/14/21. Questions regarding updates should be directed to the study team contact.