Study on Safety, Tolerability and Prelimenary Efficacy of LNA043 in Patients Undergoing Autologous Chondrocyte Implantation

Inclusion Criteria: * Written informed consent must be obtained before any assessment is performed * Patient is ≥18 and≤ 50 years old at time of screening * Patient has a body mass index (BMI) \<30 kg/m2 at screening * Patient has a localized articular cartilage defect of the knee and is scheduled for an ACI procedure * Able to communicate well with the investigator, to understand and comply with the requirements of the study. Exclusion Criteria: * Patient has radiologically apparent degenerative joint disease in the target knee as determined by Kellgren and Lawrence grade ≥2 based on X-ray evaluation performed within 6 months from screening * Patient has unstable knee joint or insufficiently reconstructed ligaments, based on medical history and physical examination by the investigator. * Patient scheduled for a concomitant articular surgical procedure (e.g., anterior cruciate ligament reconstruction) other than debridement or partial meniscectomy * Patient has malalignment (valgus- or varus-deformity) in the target knee ≥ 5° based on based on X-ray evaluation performed within 6 months from screening.at screeningmedical history. In suspected cases, the mechanical axis must be established radiographically through complete leg imaging during standing and in postero-anterior projection. * Patient has a known autoimmune disease, inflammatory arthropathy (including but not limited to rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, CPPD, gout), active acute or chronic infection of the joint, recent Lyme disease to the knee, systemic cartilage disorder, or a known systemic connective tissue disease. * Patient has had surgical treatment of the target knee using autologous osteochondral transplantation/mosaicplasty within 12 months prior to screening (Note: prior diagnostic arthroscopy with debridement and lavage, meniscal surgery, microfracture, anterior cruciate ligament reconstruction, and extra-articular surgery e.g., high-tibial osteotomy are acceptable). * Patient is unable to undergo magnetic resonance imaging (MRI) or presents absolute contraindications to MRI (e.g., metallic implants, metallic foreign bodies, pacemaker, defibrillator). * Patient taking medications prohibited by the protocol: corticosteroids by any route (except topical) from 4 weeks prior to screening; nonsteroidal anti-inflammatories or aspirin (greater than 100 mg per day) within 2 weeks prior to screening; paracetamol greater than 3000 mg per day within 2 weeks prior to screening; glucosamine or chondroitin sulfate within 2 weeks prior to screening; any local treatment i.a. into the knee within 3 months from screening. * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they are using highly effective methods of contraception during dosing and for 15 days after stopping of investigational drug. * Regular smokers (use of tobacco/nicotine products in the previous 3 months \> 5 cigarettes/day). Urine cotinine levels will be measured during screening for all subjects. Regular smokers will be defined as any subject who reports tobacco use of \> 5 cigarettes/day and/or who has a urine cotinine ≥ 500 ng/mL.