Efficacy of Amniotic Suspension Allograft in Patients With Osteoarthritis of the Knee

This is a prospective, multicenter, randomized, double-blind, placebo-controlled Phase 3 study of ASA in patients with OA of the knee. Initially, 474 subjects are planned for inclusion in this study using a group sequential design with two interim analyses and a final analysis. Sample size re-estimation is planned at the second interim analysis. Based on conditional power, the maximum sample size may be increased to up to 700 patients. Patients will be randomly assigned in a 1:1 ratio to receive a single intra-articular (IA) injection of 2 mL of ASA (plus 2 mL of normal saline) or 4 mL of normal saline. Patients will be screened after informed consent is obtained. Eligible patients will be randomized to receive a single IA injection on Day 1. They will have serial assessments of knee pain, function, and symptoms scores, as well as safety assessments for up to 52 weeks after administration of the study drug. The planned sequence and maximum duration of the study periods will be as follows: * Screening: 2 weeks * Treatment: 1 day * Follow-up: 52 weeks The maximum treatment duration for each patient is 1 day. The maximum study duration for each patient is 54 weeks. Efficacy will be assessed via Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) responder rates. Safety will be assessed via monitoring of adverse events (AEs), safety laboratory testing, vital signs, physical examination, and concomitant medication use. An independent data monitoring committee (DMC) with a defined charter will review study data and make preliminary decisions relative to interim analyses. The assessments that are used in this study are standard, and are generally recognized as reliable, accurate, and relevant. No pediatric patients will be included as OA of the knee is an age-related disorder and rarely occurs in patients under the age of 18 years. The sponsor plans to submit a waiver for studies in all pediatric age subgroups.