A Research Study to Evaluate the Safety and Potential Efficacy of ON101 Cream for the Treatment of Venous Leg Ulcers.

Inclusion Criteria: 1. Has signed a written informed consent prior to the study procedure 2. Male or female aged at least 20 years old 3. Venous outflow/venous capacitance (VO/VC) compatible with venous insufficiency measured at screening visit or within 3 months prior to enrollment 4. Has adequate vascular perfusion of the affected limb, confirmed by Ankle-Brachial Index (ABI) ≥ 0.8 and ≤ 1.3 measured at screening visit or within 3 months prior to enrollment 5. The target ulcer have all of the following characteristics: 1. C6 or C6R per the Clinical-Etiology-Anatomic-Pathophysiologic (CEAP) Classification System; 2. Located between the knee and ankle (at or above the malleolus); 3. No active infection; 4. Post debridement ulcer area is ≥ 3 cm2 and ≤ 20 cm2 at the time of enrollment; 5. Has been presented for at least 6 weeks before enrollment; 6. A minimum of 2 cm margin between the qualified target ulcer and any other ulcers on the target limb (post debridement); 7. Involves a full thickness skin loss, but without exposure of tendon, muscle, or bone; 8. Must be nonhealing as defined as ≤ 30% reduction in ulcer area in response to standard of care (SoC) during the 2-week run-in period 6. Considered by the Investigator to be compliant/adhere to the compression device during the 2-week run-in period 7. If female of child-bearing potential, has a negative pregnancy test on urine at screening and must not be breastfeeding 8. Able and willing to attend the scheduled visits and comply with the study procedures. Exclusion Criteria: 1. Presence of necrosis, purulence, or sinus tracts that cannot be removed by debridement 2. With deep vein thrombosis within 4 weeks prior to enrollment 3. Has endovenous surgery planned or performed within 4 weeks prior to enrollment 4. Laboratory values at Screening of: 1. Liver function test (total bilirubin, aspartate aminotransferase \[AST\], or alanine aminotransferase \[ALT\]) \> 3x the upper limit of normal, or 2. Poor nutritional status defined as albumin \< 2.5 g/dL, or 3. Renal function test (serum creatinine) \> 2x the upper limit of normal, or 4. Glycosylated hemoglobin (HbA1c) ≥ 9 % 5. Presence of any clinically significant medical condition(s) in medical history during screening period that, in the opinion of the Investigator, could interfere with ulcer healing, including but not limited to the following: 1. Systemic infection not controlled by suitable antibiotic treatment 2. Active malignant disease. A subject, who has had a malignant disease in the past, was treated and is currently disease-free, maybe considered for study entry. 3. Acquired immune deficiency syndrome (AIDS) or HIV positive 6. Has received treatment with immunosuppressive or chemotherapeutic agents, radiotherapy, or systemic corticosteroids within 4 weeks prior to enrollment 7. Heavy smoker (≥ 20 cigarettes per day) 8. Use of any investigational drug or therapy within 4 weeks prior to enrollment 9. A psychiatric condition (e.g., suicidal ideation), current or chronic alcohol or drug abuse problem, determined from the subject's medical history, which in the opinion of the Investigator, may pose a threat to subject compliance 10. Judged by the Investigator to be not suitable for study participation