It is hypothesized that application at 4-week intervals of the human umbilical cord tissue TTAX01 to the surface of a well debrided, nonhealing venous leg ulcer (VLU) will result in a high proportion of wounds showing complete healing within 12 weeks of initiating therapy. This open label pilot study provides a framework for a larger, controlled study. The purposes for conducting this study are to evaluate the functionality of the protocol and to obtain an estimate of product safety and efficacy when applied according to the protocol instructions, and measured according to the stated endpoints.

Inclusion Criteria:

• Provide informed consent.
• Age ≥ 18 years and of either sex.
• Willing to comply with protocol instructions, including allowing all study assessments.
• Have a venous leg ulcer (VLU) between the knee and ankle (at or above the malleolus), with a surface area in the range of ≥ 2.0 cm2 and ≤ 18.0 cm2 confirmed using the wound imaging and measurement device.
• Venous insufficiency confirmed by duplex Doppler ultrasound examination for valvular or venous incompetence.
• Arterial supply adequacy confirmed by any one of the following: Great toe pressure ≥ 50 mm/Hg; Systolic blood pressure Ankle Brachial Index (ABI) in the range ≥ to 0.8 to ≤ 1.1; TcPO2 ≥ to 40 mmHg from the foot
• Target ulcer involves a full thickness skin loss, but WITHOUT exposure of tendon, muscle, or bone
• Target ulcer duration ≥ 6 weeks but ≤ 104 weeks
• For diabetic subjects an HbA1C < 12.0% per the local lab report

Exclusion Criteria:

• Therapy with another investigational agent within thirty (30) days of Screening, or during the study.
• A target ulcer of non-venous etiologies (e.g., sickle cell anemia, necrobiosis lipoidica diabeticorum, pyoderma gangrenosum, vasculopathic or vasculitic).
• Deep Vein Thrombosis (DVT) that is acute, defined as the first 10 days from onset of symptoms, or any DVT for which compression bandaging is considered by the Investigator to be contraindicated.
• Clinical evidence of ulcer bed infection as described in the Study Guide.
• Documented history of osteomyelitis at the target wound location within 6 months preceding the Screening Visit.
• Refusal of or inability to tolerate compression therapy.
• The subject is pregnant
• The subject is a nursing mother
• The subject is a woman of child-bearing potential who is unwilling to avoid pregnancy or use an appropriate form of birth control (adequate birth control methods are defined as: topical, oral, implantable, or injectable contraceptives; spermicide in conjunction with a barrier such as a condom or diaphragm; IUD; or surgical sterilization of partner).
• Therapy of the target ulcer with other birth tissue products, autologous skin graft, Apligraf®, or Dermagraft® within 30 days preceding the Screening Visit.
• Therapy of the target ulcer with topical growth factors within 1 week preceding the Screening Visit.
• Current therapy with systemic antibiotics.
• Current systemic therapy with cytotoxic drugs.
• Current therapy with chronic (> 10 days) oral corticosteroids.
• Current therapy with TNF alpha inhibitors other than Trental® (pentoxifylline).
• History of cancer in the preceding 5 years (other than carcinoma in situ of the cervix or adequately treated non-melanoma skin cancers).
• The subject has had previous use of NEOX® CORD 1K®, CLARIX® CORD 1K®, or TTAX01 applied to the index ulcer
• The subject has an allergy to Amphotericin B or glycerol
• The subject has an allergy to primary or secondary dressing materials used in this trial
• Per Investigator's discretion the subject is not appropriate for inclusion in the trial, e.g., undergoing surgical treatments or the subject currently has sepsis, i.e., life-threatening organ dysfunction caused by a dysregulated host response to infection