Patient case (clinical description): A 47-year-old woman comes to the office complaining of pain in the calf and knee when she bends down. The pain limits her activity. Her medical history is significant for osteoarthritis, for which she uses nonsteroidal anti-inflammatory drugs (NSAIDs) for the past two years. She is living with her husband and has 3 children. She doesn't smoke but drinks alcohol occasionally. Her vital signs are normal. On physical examination, there is a small effusion in the right knee. The effusion grew a little larger and she developed a tender swelling in the popliteal fossa and calf. Both the pain and swelling worsened as she bent and straightened her knee.

Patient's own account: I'm a 47-year-old woman, married with 3 kids. I don't smoke and I drink occasionally. I went to the doctor because of pain in my calf and knee when I was bending down. This has been limiting my daily activities. I have been diagnosed with osteoarthritis for which I have taken anti-inflammatory drugs for the past 2 years. The doctor saw a small fluid buildup in my right knee. This buildup became a bit bigger and I have a swollen calf. The pain is worse when I bend and straighten my knee.

Clinical trial: A Phase 3 Study to Evaluate the Efficacy and Safety of Resiniferatoxin for Pain Due to Osteoarthritis of the Knee

Eligibility criteria:
Key Inclusion Criteria:

          -  Male or female 35 to 85 years of age (inclusive).

          -  Diagnosis of moderate to severe pain in the index knee due to OA.

          -  Pain in the non-index knee is less than pain in the index knee.

          -  Body mass index ≤40 kg/m².

          -  Experienced treatment failure with at least 2 prior categories of therapies.

          -  Able to understand and complete study-related forms and communicate with the
             Investigator and/or site staff.

        Key Exclusion Criteria:

          -  Evidence or history of a serious coagulopathy or hemostasis problem, such as inherited
             bleeding disorders or thrombocytopenia.

          -  History of or current condition of poorly controlled hypertension, QTc prolongation,
             history of risk factors for Torsades de Pointes, or family history of long QT
             syndrome; or is using concomitant medications that prolong the QT interval.

          -  Received index knee injections with corticosteroids within 30 days, or hyaluronic acid
             within 3 months, or platelet-rich plasma within 6 months prior to the injection day.

          -  Pre-existing osteonecrosis, subchondral insufficiency fracture, severe bone on bone
             OA, or knee pain attributable to disease other than OA.

          -  Instability or misalignment in the index knee.

          -  Concurrent use of opioids or indications other than knee pain.

          -  History within the past 2 years of substance abuse, including alcohol.

          -  Allergy or hypersensitivity to chili peppers, capsaicin, resiniferatoxin,
             acetaminophen, tramadol, or radiographic contrast agents.

          -  Female participants who are pregnant, planning on becoming pregnant, or currently
             breastfeeding.

          -  Any medical condition or comorbidities that, in the Investigator's opinion, could
             adversely impact study participation or safety, conduct of the study, or interfere
             with pain assessments.

          -  Sensory peripheral neuropathy that is of moderate severity or higher.

          -  Arterial or venous thrombi (including stroke), myocardial infarction, hospital
             admission for unstable angina, cardiac angioplasty, or stenting within the past 12
             months.

          -  Known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome-related
             illness, acute or history of chronic hepatitis B or hepatitis C. Participants with
             these viral infections who are receiving or have received antiviral treatment and have
             a viral load that is undetectable are eligible.

          -  Concurrent medical or arthritic conditions that could interfere with the evaluation of
             the index knee joint including chondromalacia patellae, metabolic diseases,
             gout/pseudogout, hemochromatosis, acromegaly, fibromyalgia, rheumatoid arthritis, or
             other inflammatory arthropathies affecting the knee joint.

          -  Undergone arthroscopic surgery of the index knee within 6 months of the injection day,
             or open surgery to the index knee within 24 months of the injection day.

          -  Undergone replacement surgery of the index knee.

          -  Presence of surgical hardware or other foreign bodies in the index knee.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 35 Years old.
Subject must be at most 85 Years

Eligibility (NLI label): Entailment