This research is being done to compare the efficacy of HP802-247 plus compression therapy against Vehicle plus compression therapy in achieving complete wound closure over the 16-week treatment period. Vehicle looks the same as HP802-247 but contains no cells. Target wound status is evaluated at each study visit (closed, open, reopened). At wound closure or completion of treatment all subject will enter an observational safety followed up period which ends at one year after initial exposure to test article.