Study of Resiniferatoxin for Knee Pain in Moderate to Severe Osteoarthritis

This study is to evaluate the safety of resiniferatoxin administered intra-articularly to
subjects with moderate to severe knee pain due to osteoarthritis (OA). It is also to assess
the preliminary efficacy of resiniferatoxin to relieve knee pain when walking.

Inclusion criteria:

1. Age: 35 years to 85 years

2. Diagnosis of moderate to severe pain due to OA: Moderate to severe osteoarthritis,
based on American College of Rheumatology (ACR) criteria

3. BMI < 40 kg/m2

4. Pain in the target knee has been treated with the following standard of care oral
agents: at least one NSAID, at least one opioid containing agent.

5. Prior failure in at least two prior analgesic agents, at least one NSAID and at least
one opioid containing agent

6. Willing to abstain from other intra-articular treatments of the knee or any knee
surgery while on study

7. Ability to comply with the study and give informed consent

8. If on an opioid medication, stable dose for at least 4 weeks prior to injection with
no increase in dose leading up to study injection

9. If on NSAIDs, be on a stable analgesic regimen for at least 4 weeks prior to injection

10. If on pain regimens other than opioid medication or NSAIDs, be on a stable regimen for
at least 30 days

11. Is in good general health and is considered to have a physical status that is American
Society of Anesthesiologists (ASA) category ≤ 3

12. Able to comply with study procedures, including the recording of daily questionnaires

Exclusion Criteria:

1. Has evidence or history of a coagulopathy or hemostasis problem at Screening or
Baseline (Day 1)

2. Treatment knee injections with corticosteroids within 30 days or hyaluronic acid
within 3 months prior to the procedure

3. If on opioid analgesics, an upper limit of 60 mg/day of oral morphine sulfate, 40
mg/day of oxycodone, 60 mg/day of hydrocodone, or 600 mg/day of tramadol, or
equivalent

4. Any of the following lab abnormalities within one week of the treatment day:

- Platelet count <100,000 cells/mm3

- Total neutrophil count <1500 cells/mm3

- Serum creatinine ≥ 1.5 x ULN

- Alanine aminotransferase (ALT) > 3.0 x ULN

- Aspartate aminotransferase (AST) > 3.0 x ULN

- Alkaline phosphatase > 2.0 ULN

- Bilirubin > 1.5 x ULN

- Temperature ≥ 100.4°F or other evidence of an infection

5. Secondary OA due to trauma in the target knee

6. Instability or misalignment in the target knee

7. Concurrent use of opioids for indications other than knee pain

8. History of substance abuse

9. Has an allergy or hypersensitivity to chili peppers, capsaicin, resiniferatoxin or
radiographic contrast agents

10. Female subjects who are pregnant at Screening or are planning on becoming pregnant, or
are currently breastfeeding

11. Subjects with any medical condition or comorbidities that could adversely impact study
participation or safety, conduct of the study, or interfere with pain assessments

12. Subjects who have participated in a clinical study of an investigational drug within 4
half-lives of Screening or are scheduled to receive and investigational agent while
participating in this study

13. Sensory peripheral neuropathy that is CTCAE Grade 2 or higher at Screening

14. Arterial or venous thrombi, myocardial infarction, admission for unstable angina,
cardiac angioplasty, or stenting within 3 months prior to Screening

15. Evidence or history of any hemorrhage or bleeding event that is higher than CTCAE
Grade 1 within 4 weeks prior to injection.

16. Known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome-related
illness, acute or history of chronic hepatitis B or C. Positive tests for HIV-1 or -2
antibodies, hepatitis B surface antigen, or hepatitis C antibodies.

17. Concurrent medical or arthritic conditions that could interfere with evaluation of the
index knee joint including fibromyalgia, rheumatoid arthritis, or other inflammatory
arthropathies affecting the knee joint

18. Subjects with significant pain in other joints may be excluded at the discretion of
the investigator

19. Subject has undergone arthroscopic or open surgery to the knee within 6 months of the
planned injection day

20. Subject has undergone replacement surgery of the treatment knee

21. The presence of surgical hardware or other foreign bodies in the treatment knee