Efficacy and Safety of XT-150 in Osteoarthritis of the Knee

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:

1. 0.15 mg/mL XT-150 (1mL), 0.15 mg/mL XT-150 (1mL) 2. 0.15 mg/mL XT-150 (1mL), 0.45 mg/mL XT-150 (1mL) 3. 0.45 mg/mL XT-150 (1mL), 0.15 mg/mL XT-150 (1mL) 4. 0.45 mg/mL XT-150 (1mL), 0.45 mg/mL XT-150 (1mL) 5. Placebo (1mL), 0.15 mg/mL XT-150 (1mL) 6. 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.