RecruitingA Multicenter, Open-Label, Single-Arm Extension Study to Evaluate the Safety and Efficacy of FURESTEM-OA-Kit Inj. in Knee Osteoarthritis Patients Who Received Placebo in the K0701 Phase 2a TrialA Multicenter, Open-Label, Single-Arm Extension Study to Evaluate the Safety and Efficacy of FURESTEM-OA-Kit Inj. in Knee Osteoarthritis Patients Who Received Placebo in the K0701 Phase 2a Trial