Study to Evaluate Intra-articular Resiniferatoxin to Treat Moderate to Severe Pain From Knee Osteoarthritis

Inclusion Criteria: * BMI \< 50 kg/m * Have moderate-to-severe pain in the index knee due to osteoarthritis (OA) as assessed by the investigator, based on American College of Rheumatology criteria * Have had OA pain duration in the index knee ≥ 6 months prior to Screening * Reports worst daily average pain with walking of ≥ 4 on the 0 to 10 NRS for pain intensity during the week prior to Screening * Have a knee x-ray or MRI scan with KL grade ≥ 2 in the index knee based upon radiographic images obtained within 3 months prior to Screening (image must be available for review) * Have had treatment failure with at least two prior analgesic agents (at least one NSAID) defined as discontinuation due to side effects or inadequate response to treatment * Willing to abstain from other IA injections or knee surgery for at least 6 months after study treatment unless elects early discontinuation from the study * Able to comply with the study procedures and give informed consent * If on any analgesic medications, have been taking a stable dose for at least one month prior to screening with no increase in dose leading up to study treatment. Note that if the subject is on "as needed" or PRN analgesic medications, these may be continued during the study * Willing to follow contraception guidelines Exclusion Criteria: * Have a history of a hemorrhagic event that is CTCAEv5 Grade 2 or higher within the 6 months prior to screening * Have evidence of or history of a serious coagulopathy or he…