Venous leg ulcers are a common, costly and debilitating condition, with few effective treatments. Compression bandaging helps healing, but more than four out of every ten leg ulcers remain unhealed after three months. New treatments to help heal venous ulcers are urgently needed. Initial studies with a new drug product candidate called Nexagon® (developed by CoDa Therapeutics, Inc.) have shown improvements in healing when applied topically to a wound. Further research will be undertaken to assess the safety and activity of Nexagon® when applied to venous leg ulcers in humans, and to obtain further information on the most appropriate dose or doses to apply. A proposed randomised controlled trial aims to further evaluate Nexagon® by randomly allocating (e.g., by the toss of a coin) 90 people with venous leg ulcers to Nexagon® (one of two different doses) or a vehicle (substance containing no medication) to be applied to their ulcer three times over four weeks. Participants will be followed up for 12 weeks to evaluate ulcer healing.