This is a Phase 2a, multi-center, randomized, double-blind, placebo-controlled, dose escalation study to evaluate the safety and tolerability of twice daily (BID) topically administered concentrations of Nu-3 gel in subjects with Type 1 and 2 diabetic non-healing target chronic diabetic foot ulcer (cDFU). The study will be conducted in 4 phases: Screening, SOC Run-In, Treatment, and a Safety Follow-up.~Subjects will have the study explained to them and will be provided the study specific informed consent form (ICF). For eligible subjects, the screening evaluations will be performed after the subject provides a written informed consent. For subjects enrolled in the study, activities will consist of two visits prior to randomization: screening visit, and a run-in visit; this will be followed by six scheduled visits (total = 8 visits). Screening will commence 14 days (± 2 days) prior to baseline visit.~During the screening period, a target cDFU will be established and characterized using information obtained from the subject's medical history. At the end of the screening and the beginning of the run-in SOC periods, subjects will have their selected target lesion assessed again. Those subjects whose target ulcers are shown to have ≥ 30% decrease in area will be considered as responders and will be discontinued from the study.~Non-responder subjects will enter the active treatment period and will be randomized in a 3:1 ratio into one of these dose cohorts in a dose escalating manner:~Cohort 1: 5% Nu-3 gel + SOC (n = 12) or placebo gel + SOC (n = 4)~Cohort 2: 10% Nu-3 gel + SOC (n = 12) or placebo gel + SOC (n = 4)~Study drug will be applied BID to the target cDFU for 28 days (± 2 days).~The decision to dose-escalate to the next higher concentration will be based on the recommendation of the Data Monitoring Committee (DMC) that will review all of the safety data from the previous subject cohort concurrent with the safety follow-up period. This decision will be based on pre-defined Dose Limiting Toxicity criteria (DLT), which will be detailed in the DMC charter. The maximum tolerated dose (MTD) will be considered as the dose level below that for which a DLT was observed. If the criteria for a DLT occurs in the initial dosing cohort then the study will be halted.~All randomized subjects will continue to receive SOC throughout the study per Appendix 4.~After completing the active treatment period, subjects will return after 2 weeks for a follow-up safety evaluation.
A PHASE 2a, MULTI-CENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED DOSE ESCALATING STUDY TO EVALUATE THE SAFETY AND TOLERABILITY OF TOPICALLY APPLIED BISPHOSPHOCIN NU-3 GEL TO CLINICALLY NONINFECTED CHRONIC DIABETIC FOOT ULCERS (cDFU)