Long-Term Follow-Up Study of Patients With Osteoarthritis of the Knee Treated With UBX0101 or Placebo

Inclusion Criteria: * Patients with knee OA who have completed a randomized placebo-controlled study of UBX0101. * Patients who are willing and able to consent to having blinded, long-term follow-up; consent via legally authorized representative is not accepted. Exclusion Criteria: * Patients with any condition that, in the opinion of the Investigator, would likely interfere with adhering to the study schedule of visits for 12 months. * Patients who are scheduled to undergo knee arthroplasty on either knee during the study. * Patients who anticipate arthroscopic surgery on either knee at any time during the study. * Patients who plan to receive treatment with an anti-nerve growth factor agent during the study. * Patients who plan to participate in another investigational study (including interventional studies of investigational drugs and investigational treatments \[e.g., braces, stem cells, and procedures\]) during the study.