Leg and foot ulcers due to venous disease or diabetes are chronic wounds that can take 6 or more months to heal. Growth factors have been used to try and improve this healing, however, many such studies have failed, and that is thought to be due enzymes in the wound that degrade the growth factors and prevent them from working. This is a proof of concept study that will evaluate the treatment of chronic leg ulcers with topically applied growth factors that are combined with a therapy to prevent their inactivation in the wound.

Inclusion Criteria:

• Men and women aged ≥18 years
• Ulcer size 1-64 cm²
• Ulcer extends through both the epidermis and dermis, with no exposed tendon or bone
• Ulcer duration >3 months
• Ulcer located between and including the knee and ankle
• For venous leg ulcers - Venous refilling time <25s on photoplethysmography or abnormal venous insufficiency Duplex scan
• For diabetic foot ulcers - confirmed type 1 or type 2 diabetes mellitus with a haemoglobin A1C < 12%
• Wounds have not been treated with Promogran in the previous 4 weeks
• Patients able to give informed consent

Exclusion Criteria:

• Ankle-brachial index <0.8
• Ulcer with local or systemic signs of infection
• Patients who have been previously treated with Becaplermin gel
• Receiving corticosteroids or immune suppressants
• History of autoimmune disease
• Uncontrolled diabetes (baseline haemoglobin A1C > 12%)
• Severe rheumatoid arthritis
• Uncontrolled congestive heart failure
• Malnutrition (albumin <2.5g/dL)
• Unable to adhere to the protocol
• Known sensitivities to the wound dressings used in the trial
• A history of any previous malignancy
• pregnant or lactating women