A study to assess safety, tolerability and clinical effects of single and repeat dose intra-articular administration of UBX0101 in patients with moderate to severe painful knee osteoarthritis (OA).

This is a randomized, double-blind, placebo-controlled study conducted as two parallel cohorts to assess the safety, tolerability, and clinical effects of single dose (SD) and repeat dose (RD) intra-articular (IA) administration of UBX0101 in patients with symptomatic knee osteoarthritis (OA).

Approximately 36 patients will be randomly assigned to either Cohort 1 (SD) or Cohort 2 (RD) (18 patients per treatment cohort) and further randomized in a 2:1 ratio to UBX0101 and placebo in each cohort.

The primary objective of the study is to evaluate the safety and tolerability of SD and RD IA administration of UBX0101 over 24 weeks.

Key Inclusion Criteria:

• Patients who are ambulatory with a diagnosis of OA of the knee and who have moderate to severe knee pain as measured on the 11-point (0-10) average daily pain NRS.
• Kellgren-Lawrence grade of 1-4 on a weight-bearing radiograph of target knee.
• Patients aged ≥ 40 and ≤ 85 years.
• Patients are permitted but not required to use an oral NSAID, serotonin, and norepinephrine reuptake inhibitors (SNRIs), tramadol, or acetaminophen, provided that they have been taking a stable dose and regimen of medication for at least 4 weeks prior to Screening.

Key Exclusion Criteria:

• Patients with any condition, including laboratory or imaging findings and findings in the medical history or in the pre-study assessments, that in the opinion of the Investigator or the Medical Monitor constitutes a risk or contraindication for participation in the study or that could interfere with the study objectives, conduct, or evaluation or prevent the patient from fully participating in all aspects of the study.
• Patients with a body mass index (BMI) ≥40 kg/m².
• Patients with fibromyalgia.
• Systemic autoimmune disease with musculoskeletal involvement or any history of a systemic inflammatory arthritis.
• Patients who have received IA treatment in the target knee with steroids or hyaluronic acid derivatives within the last 16 weeks prior to Screening, or with extended-release corticosteroid (e.g., Zilretta®) within the last 20 weeks.
• Patients who are using a topical NSAID or topical analgesics on the target knee.
• Patients who have used opioid analgesics (other than tramadol), marijuana or marijuana-derived products (e.g., cannabidiol), and topical capsaicin on the target knee within 8 weeks prior to Screening.
• Patients with a history of traumatic knee injury to the target knee, including, but not limited to, patients with meniscal root tear, within 2 years of study entry.
• Patients who have undergone diagnostic arthroscopy to the target knee in the previous 6 months.
• Patients who have undergone arthroscopic surgery (including microfracture and meniscectomy) on the target knee in the last 2 years prior to the Screening visit or are anticipated to have arthroscopic surgery on either knee at any time during the study period.
• Patients with a history of previous total or partial knee arthroplasty in the target knee.
• Patients with an effusion at the Screening visit, which, in the opinion of the Investigator following examination and discussions with the patient, requires drainage for symptom relief.
• Patients who have had regenerative joint procedures on any joint, including, but not limited to, platelet-rich plasma injections, stem cell transplantation, autologous chondrocyte transplantation, or mosaicplasty.
• Patients with secondary arthritis that involves the target knee or would confound assessments of knee OA.