Phase II Study of the Effects of rhPDGF-BB Injection on Lateral Epicondylitis

Inclusion Criteria:

1. Subject has signed the Institutional Review Board (IRB) approved Informed Consent Form specific to this study prior to enrollment
2. Subject has a clinical diagnosis of lateral epicondylitis
3. Subject's symptoms can be reproduced with resisted supination or wrist dorsiflexion

4. Subject's symptoms have persisted for at least 3 months despite conservative treatment that includes one or combinations of:

   1. Physical therapy
   2. Splinting
   3. Nonsteroidal antiinflammatory drug (NSAID)
   4. Corticosteroid injection
5. Subject is independent, ambulatory, and can comply with all post-injection evaluations and visits
6. Subject is 21-80 years of age and considered to be skeletally mature

Exclusion Criteria:

1. Subject has undergone previous corticosteroid injection therapy to the effected elbow in less than three months prior to enrollment
2. Subject has received previous Platelet Rich Plasma (PRP) injection to the affected elbow
3. Subject is deemed to require a corticosteroid injection into the affected elbow during the course of the study
4. Subject uses chronic medications known to affect the skeleton (e.g. glucocorticoid usage >10mg/day)
5. Subject has undergone surgical intervention to the affected elbow for the treatment of lateral epicondylitis

6. Subject has a positive medical history of any of the following:

   1. medial epicondylitis
   2. radial tunnel syndrome
   3. carpal tunnel syndrome
   4. septic or gouty arthritis
   5. cervical radiculopathy
   6. trauma to the affected elbow within the past 6 weeks
   7. neuromuscular or musculoskeletal deficiency, which limits the ability to perform functional measurement (e.g. grip strength test)
7. Subject currently has an acute infection at the injection site
8. Subject has tested positive or been treated for a malignancy in the past or is suspected of having a malignancy or are currently undergoing radio- or chemotherapy treatment for a malignancy anywhere in the body, whether adjacent to or distant from the proposed rhPDGF-BB Injection treatment site
9. Subject is physically or mentally compromised (e.g. currently being treated for a psychiatric disorder, senile dementia, Alzheimer's disease, etc.) to the extent that the Investigator judges the subject to be unable or unlikely to remain compliant
10. Subject has an allergy to yeast-derived products
11. Subject has received an investigational therapy or approved therapy for investigational use within 30 days of injection procedure or during the follow-up phase of this study
12. Subject is a prisoner, or is known or suspected to be transient
13. Subject's condition represents a worker's compensation case
14. Subject is currently involved in a health-related litigation procedure
15. Subject has documented evidence of a history (e.g. liver testing) of drug/alcohol abuse within the 12 months prior to screening for study entry
16. Subject is pregnant, or able to become pregnant but not practicing a medically-accepted form of birth control, and/or intending to become pregnant during this study period