Study to Assess Epidural Resiniferatoxin for the Treatment of Intractable Pain Associated With Advanced Cancer

Inclusion Criteria: * Histologically or cytologically confirmed advanced cancer * Targeted pain area of involvement that is at or below the lower thoracic or chest level down to lower extremities, attributed to the cancer * If pain is present in other areas, able to differentiate pain in the target area is the primary source of pain * Intractable pain that has not responded to standard therapies * Be opioid tolerant, defined as an average daily opioid consumption \> 30 mg oral morphine equivalent dose during the screening and which has been stable for the month prior to screening * Have a Karnofsky Performance Scale score ≥ 50 at Screening * In the Investigator's opinion, a reasonable expectation that the subject will be able to complete the study * Able to comply with the study procedures and give informed consent * Willing to follow contraception guidelines Exclusion Criteria: * Be undergoing or have plans to undergo changes to current cancer treatment from D-7 through M3 * Had an implantation of intrathecal pump or spinal cord stimulator less than 6 weeks prior to D1 or planning to undergo such a placement during the study prior to M3 * Have leptomeningeal metastases in the lumbar area * Unless approachable via the caudal route, have the level of intended epidural injection within site of prior lumbar spine surgical procedures that could disrupt the epidural space or otherwise impair ability of the injection to reach nerves * Has evidence of a non-correctable coagulopathy or hemostasis problem including a low platelet count, prothrombin time, abnormal PT or PTT, or on anticoagulant or antiplatelet therapies before and during investigational product (IP) administration * Have evidence or history of bleeding disorder or disseminated intravascular coagulation, any recent hemorrhage or bleeding event within 4 weeks prior to D1 * Have abnormal neutrophil or serum creatinine * Is febrile or has other evidence of infection within 24 hours of D1 * Has recently been diagnosed as COVID-19 positive or evidence of active infection. The subject may participate if full recovery has occurred with a negative RT-PCR test (any EUA cleared test) at least 1 week prior to D1 * Has an allergy or hypersensitivity to TRPV1 agonists, bupivacaine, radiographic contrast agents, fentanyl, hydromorphone, or morphine * Pregnant at Screening or planning on becoming pregnant or currently breastfeeding * Has an intrathecal shunt, increased intracranial pressure or evidence of brain pathology as determined by symptoms, history, physical examination, and/or magnetic resonance imaging (MRI) * Is unable or distinguish the target pain from any additional loci of pain at screening * Non-study related minor surgical procedure ≤ 2 days or major surgical procedure ≤ 7 days prior to screening and must be sufficiently recovered and stable prior to D1 * Has not recovered from toxicities from previous cancer treatment, including chemotherapy, hormone therapy, immunotherapy, radiotherapy or bisphosphonates. Participants are not eligible if they have received such therapy within the month prior to D1 * Non-study related minor surgical procedure ≤ 5 days or major surgical procedure ≤ 21 days prior to enrollment. In all cases, subjects must be sufficiently recovered and stable prior to IP administration on D1 * Arterial thrombi, myocardial infarction, admission for unstable angina, within 3 months prior to screening * Clinically significant electrocardiogram abnormalities * Have any medical condition that could adversely impact subject's participation or safety or interfere with pain assessments * Participation in another investigational trial during the study