An Open Label Extension Study to Assess the Safety of Long-Term Treatment With Ampion for Severe OA of the Knee

Patients enrolled in AP-003-C Main Study will be offered the option to roll-over to the open
label extension study at the final visit of the Main Study (Week 12).

Approximately 171 subjects with knee pain due to severe osteoarthritis of the knee (KL IV)
may enroll in the 40-week OLE study. The OLE Study allows for a 60-day screening window from
Week 12 of the Main Study for enrollment in the Extension study. Extension study visits will
include 9 visits: Week 12 in-office visit (Day 84± 60 days), a 24-hour post-injection
follow-up call, Week 24 in-office visit (Day 168 ± 7 days), a 24-hour, post-injection
follow-up call, Week 36 in-office visit (Day 252 ± 7 days), a 24-hour, post-injection
follow-up call, Week 48 in-office visit (Day 336 ± 7 days ), a 24-hour, post-injection
follow-up call, and a Week 52 final visit (Day 364 ± 7 days ).

Inclusion Criteria:

1. Subjects who completed the AP-003-C Main study and have not developed any exclusionary
criteria

2. Able to provide written informed consent to participate in the study

3. Willing and able to comply with all study requirements and instructions of the site
study staff

4. Male or female, 40 years to 85 years old (inclusive), as assessed in the AP-003-C Main
Study

5. Must be ambulatory, as assessed in the AP-003-C Main Study

6. Study knee must have a clinical diagnosis of OA and supported by radiological evidence
(Kellgren Lawrence Grade IV) as assessed in the AP-003-C Main Study.

7. Moderate to moderately-severe OA pain in the study knee (rating of at least 1.5 on the
WOMAC Index 3.1 5-point Likert Pain Subscale), as assessed in the AP-003-C Main Study

8. Moderate to moderately-severe OA function in the study knee (rating of at least 1.5 on
the WOMAC Index 3.1 5-point Likert Function Subscale), as assessed in the AP-003-C
Main Study

9. WOMAC A, 5-point Likert pain subscale <1.5 in the contralateral knee, as assessed in
the AP-003-C Main Study

10. Ability to discontinue NSAID ± 72 hours before/after injections (in-office visits).
Low-dose Aspirin (81 mg) is allowed during the study but must not be taken at least 24
hours prior to in-office visits.

11. No analgesia (including acetaminophen [paracetamol]) taken 24 hours prior to an
efficacy measure

Exclusion Criteria:

1. As a result of medical review and screening investigation, the Principal Investigator
considers the patient unfit for the study

2. Known clinically significant liver abnormality (e.g., cirrhosis, transplant, etc.)

3. A history of allergic reactions to human albumin (reaction to non-human albumin such
as egg albumin is not an exclusion criterion)

4. A history of allergic reactions to excipients in 5% human albumin (N-acetyltryptophan,
sodium caprylate)

5. Presence of tense effusions

6. Inflammatory or crystal arthropathies, acute fractures, history of aseptic necrosis or
joint replacement in the affected knee

7. Isolated patella femoral syndrome, also known as chondromalacia

8. Any other disease or condition interfering with the free use and evaluation of the
index knee for the duration of the trial (e.g. cancer, congenital defects, spine
osteoarthritis)

9. Major injury to the index knee within the last 12 months

10. Severe hip osteoarthritis ipsilateral to the index knee

11. Any pain that could interfere with the assessment of study knee pain (e.g. pain in any
other part of the lower extremities, pain radiating to the knee)

12. Any pharmacological or non-pharmacological treatment targeting OA started or changed 4
weeks prior to entry into the OLE study, or likely to be changed during the duration
of the OLE study

13. Pregnancy or planning to become pregnant during the study

14. Use of the following medications:

1. No IA injected pain medications in the study knee during the study. No Hyaluronic
Acid (HA) or steroid injections in the study knee at least 12 weeks prior to Day
84 of the Extension Study. HA and steroid injections in the contralateral knee
(non-study knee) are acceptable while on study except ± 14 days of an Ampion
injection in the study knee.

2. No analgesics containing opioids

3. NSAIDs are not permitted ± 72 hours before/after injections at in-office visits;
acetaminophen is available as a rescue medication during the study from the
provided supply

4. No topical treatment on the study knee during the study

5. No significant anticoagulant therapy (e.g. Heparin or Lovenox) during the study
(treatment such as Aspirin and Plavix are allowed)

6. No systemic treatments that may interfere with safety or efficacy assessments
during the study

7. No immunosuppressants

8. No use of corticosteroids

9. No human albumin treatment in the 3 months prior to the AP-003-C Main Study or
interim period prior to enrollment into the OLE study. No human albumin treatment
throughout the duration of the OLE study