This prospective, multi-center, randomized, controlled clinical study compares Affinity® plus SOC to SOC alone in subjects with VLUs. Affinity® will be used along with standard of care on venous leg ulcers (VLUs) of greater than 4 weeks which have not adequately responded to conventional ulcer therapy.

Two hundred (200) subjects with a chronic VLU ranging in size from 2cm2 and 80 cm2 will be randomized 1:1 to either Affinity® and SOC or SOC alone following the 28 day screening period. Following screening and randomization, subjects shall be seen weekly for up to 24 weeks. For subjects that heal prior to week 24, a healing confirmation visit shall occur two weeks later to confirm maintenance of complete wound closure.

Subjects that are randomized into the SOC group whose VLU has not healed by week 12 may be crossed over to receive Affinity® and followed for an additional 12-14 weeks.

Inclusion Criteria:

1. Ulcers of venous origin, as clinically determined by clinical signs and symptoms (e.g. hyperpigmentation of the surrounding skin, history of swelling, varicosities, lipodermatosclerosis and/or dermatitis) or other assessments (e.g. venous reflux test).
2. Venous insufficiency ulcers, of at least 1-month duration, which have not adequately responded to conventional ulcer therapy
3. Venous insufficiency ulcers between 2 cm2 and 80 cm2
4. Partial- or full-thickness VLU, including ulcers with tissue damage that extends through the epidermis and into the upper epidermis (papillary dermis), or into the deep dermis (reticular dermis) but not through muscle, tendon, capsule, or into bone.
5. Subjects are between 18 and 85 years of age.
6. IRB approved Informed Consent Form is signed before screening and treatment.
7. Subject is expected to be available for 24 week follow-up
8. Females of child-bearing potential must be practicing an acceptable means of birth control as determined by the investigator.
9. Subjects with bilateral ulcers may be enrolled.

Exclusion Criteria:

1. Ankle Brachial Index (ABI) of <0.65
2. Venous insufficiency ulcers less than 2cm2 or greater than 80cm2
3. Vasculitis, severe rheumatoid arthritis, and other collagen vascular diseases
4. Clinically significant medical conditions which would impair wound healing, as determined by the investigator, including renal, hepatic, hematologic, neurologic or immune disease
5. Signs and symptoms of infection, cellulitis, osteomyelitis
6. Necrotic or avascular ulcer beds
7. Ulcer with exposed bone, tendon or fascia
8. Subjects receiving hemodialysis or have uncontrolled diabetes
9. Subjects who are currently receiving or have received at any time within one month prior to entry into the study, corticosteroids (>15 mg/day), immunosuppressive agents, radiation therapy, or chemotherapy. Anticipated use of the above agents will exclude subjects from entry into the study.
10. Subjects enrolled in other wound drug investigational studies within the past three months, or device studies within the past 30 days.
11. Subject is pregnant or breast feeding.