Pilot study of the safety and efficacy of angiogenic therapy in diabetic foot syndrome

BACKGROUND: The syndrome of diabetic foot remains the main cause of non-traumatic amputation of the lower extremity in the world. Even with the provision of comprehensive medical care in the conditions of a specialized center, 10-15% of patients do not succeed in healing the ulcerative defect due to the ischemic component. AIMS: The objective of this study is evaluation of safety and efficacy of pl-VEGF165 transfer in patients with neuroischemic type of diabetic foot syndrome. METHODS: The pilot study included 35 diabetic patients with neuroischemic foot ulcers (Wagner stage 1-2) who were not candidates for revascularization procedures (NCT02538705). The patients were closely monitored after repeated pl-VEGF165 intramuscular gene transfer (2,4 mg) at 1, 3, and 6 months after treatment. The primary efficacy endpoint was the surface area of the ulcers (sq.cm), the secondary endpoints were transcutaneous oxygen tension (Tcp02), ankle-brachial index (ABI), neuropathy disability score (NDS), neuropathy symptoms score (NSS), and Michigan neuropathy screening instrument (MNSI). Adverse events were monitored throughout the study. RESULTS: The use of pl-VEGF165 as part of complex treatment allowed to achieve wound healing in 65,7% of patients with chronic ulcerative defects, the safety of the target limb was 84%. Carrying out therapeutic angiogenesis as a part of the combined therapy ensured a reduction in the average area of the resistant to treatment defects from 3.6 [1.0; 7.05] cm2 to 0.0 [0.0;2.0] cm2 (p=0,001), which correlated with an increase in the TcPo2 index by 15% from 35 [29.5; 40.5] to 40.5 [36.0; 46.5] mm Hg (p= p=0,005) and in the ABI by 16% from 0.96 [0.82;1.08] to 1.11 [0.85; 1.24] (p=0,062). The decrease in the signs of diabetic neuropathy was determined - the scores of NSS scales and VAT decreased from 6,5 [5.75; 8.0) to 6.0 [5.25; 7.0] (p=0,004) and from 9.0 [8.0; 13.5] to 8.0 [7.0; 12.7] (p=0,001), respectively. No adverse effects associated with the use of pl-VEGF165 were recorded. CONCLUSIONS: Thus, preliminary results of the pilot study show that the use of pl-VEGF165 gene transfer in combination therapy allows for complete healing of neuroischemic diabetic foot ulcers in the majority of patients