Safety and Efficacy of an Amniotic Suspension Allograft Injection Over 12 Months in a Single-Blinded, Randomized Controlled Trial for Symptomatic Osteoarthritis of the Knee.

Abstract Purpose The purpose of this study is to determine the efficacy of amniotic suspension allograft (ASA) compared to hyaluronic acid (HA) and saline at up to 12 months of follow-up through the use of patient-reported outcomes, immunoglobulin levels, and anti-HLA levels. Methods Within this multicenter study, 200 patients were randomized 1:1:1 to a single intra-articular injection of saline, HA, or ASA. Patient-reported outcomes (PROs), including Knee Injury and Osteoarthritis Outcome Score (KOOS) and Visual Analog Score (VAS), were collected at multiple time points (baseline, 1 week, 6 weeks, 3 months, 6 months) out to 12 months to assess improvements in pain and function. Radiographs at baseline and 12 months were taken to determine radiographic changes, while blood was collected at baseline, 6 weeks, and 6 months to determine changes in immunoglobulins and anti-HLA levels. Statistical analyses were performed using Last Observation Carried Forward (LOCF) and Mixed Effects Model for Repeated Measures (MMRM). Results Treatment with ASA resulted in significant improvements in KOOS and VAS scores that were maintained through 12 months (p 0.05). The number and type of adverse events (AEs) reported for ASA was comparable to the HA injection group, while no treatment-emergent AEs were reported for the saline group. Conclusion This randomized controlled trial of ASA versus HA and saline for the treatment of symptomatic knee OA demonstrated clinically meaningful improved outcomes with ASA over the controls out to 12 months post-injection. No concerning immunological or adverse reactions to the ASA injection was identified with regards to severe adverse events, immunoglobulin or anti-HLA levels.