Table 1 Inclusion criteria for patients in the open-label study of APS on patients with OA

Male or female ≥40 years

Willingness and ability to comply with the study procedures and visit schedules and ability to follow verbal and written instructions

A standing radiograph of the knee showing a Kellgren grade of 2 or 3 (within 6 months prior to screening or at screening)

Frequency of knee pain on most days (>15 days) over the last month

Diagnosis of unilateral knee OA according to the American College of Rheumatology (ACR) criteria (clinical and radiological categories) based on an x-ray performed within 6 months prior to screening

Body mass index (BMI) ≤40 kg/m²

On the WOMAC LK 3.1 questionnaire, the mean total score of the 5 pain subscale items together must be ≥ 2.0 at screening and at baseline (Day 1 pre-injection)

Failed at least 1 prior conservative OA therapy (physiotherapy and/or simple analgesics)

Signed an IEC-approved ICF

Willingness to abstain from the use of topical pain therapies (e.g., NSAIDs, capsaicin, lidocaine patches, heat patches), intra-articular corticosteroids, and viscosupplementation during the study

Willingness to abstain from systemic pain medications, except for rescue medication (acetaminophen, maximum daily dose ≤ 4 g); also, to abstain from rescue medication for at least 48 h prior to post-screening study visits