In this Phase 2 study, Baseline (Day 0) confirmation of study eligibility will be completed the day before or day of study drug administration.~Study drug will be administered by intra-articular (IA) injection into the joint space of the index knee (knee selected for treatment).~Up to 270 participants will be randomly enrolled into 1 of 6 treatment sequences (45 participants/ group). Treatment Groups:~0.15 mg/mL XT-150 (1mL), 0.15 mg/mL XT-150 (1mL)~0.15 mg/mL XT-150 (1mL), 0.45 mg/mL XT-150 (1mL)~0.45 mg/mL XT-150 (1mL), 0.15 mg/mL XT-150 (1mL)~0.45 mg/mL XT-150 (1mL), 0.45 mg/mL XT-150 (1mL)~Placebo (1mL), 0.15 mg/mL XT-150 (1mL)~Placebo (1mL), 0.45 mg/mL XT-150 (1mL)~The study will be conducted in 2 stages, A and B. Participants will be randomized at Day 0 to a treatment regimen, one treatment assignment for Stage A and one treatment assignment for Stage B:~Stage A (Up to Day 180): Participants will receive placebo, 0.15 mg/mL XT-150 or 0.45 mg/mL XT-150 to the index knee at Day 0.~Stage B (Day 180 to Day 360): Participants will have the option to receive a pre-randomized dose (XT-150 0.15 mg/mL or 0.45 mg/mL) to the index knee anytime between Day 180 and Day 330.~Final assessments will be 12 months after the first IA dose.
This is a Phase 2 safety and efficacy study of XT-150 in adult participants experiencing moderate to severe pain due to osteoarthritis of the knee.