Genzyme Corp. has announced findings from a large, multi-centre, observational study that investigated the long-term durability of Carticel (autologous cultured chondrocytes) in patients who had pain and functional impairment from defects in the articular cartilage of their knee.
These findings revealed that almost 90 per cent of patients treated with Carticel who experienced improvement in knee function at an early follow-up, sustained their improvement for up to almost 10 years. The data were presented at this week's American Academy of Orthopaedic Surgeons' (AAOS) annual meeting in San Fransisco.
"We knew that autologous chondrocyte implantation (ACI) worked for select patients, but did it last?" said Allen Anderson, MD, (Nashville, TN) a leading orthopaedic surgeon in the field of sports medicine who presented the data at the medical meeting. "These data suggest that the ACI technique not only works, but when it works, the results will last for a long time. Similar results of long term durability had been previously reported by Lars Peterson, M.D., but this multi-centre experience suggests that sustainable results can be reproduced by others".
Seventy-two patients were enrolled from 35 different centres across the US. All patients enrolled had low functional scores (overall condition score of 3.4 points on the Modified Cincinnati Knee Rating System). Patients were young (age of 37 years) and had moderate to large lesions (lesion size of 4.3 cm2) on the femoral chondyles (Lateral Femoral Chondyle, Medial Femoral Chondyle and Trochlea) and most patients had undergone at least one previous treatment for their cartilage injury. At their early follow-up, 75 per cent of all patients' experienced significant improvement in their knee function (mean improvement of 4.3 in overall condition). Of those patients, 87 per cent sustained improvement at the later follow-up time point.
"Long-term durability of Carticel had not been evaluated in the United States and there was a critical need to determine if Carticel patients experienced sustained improvement," said Leanna M. Caron, vice president and general manager of Genzyme Biosurgery, the division that manufactures and commercializes Carticel. "This study demonstrates both the durability and value of Carticel and leads the field to conclude that a vast majority of this patient population maintained improvement years following their initial procedure".
"The data show that in this patient population marrow stimulation techniques like micro-fracture are not benign and can compromise a patient's ability to benefit from a subsequent treatment with ACI, effectively limiting their future treatment options," said Tom Minas, MD, an internationally renowned orthopaedic surgeon for his extensive work in the field of Cartilage Repair and principal investigator in this study.
"Orthopaedic surgeons should reconsider using marrow stimulation techniques as first-line treatment for patients with larger chondral lesions. These techniques should be reserved for patients with smaller defects, in younger patients, where a good result is more predictable."
Carticel was the first cell therapy to be approved by the FDA. First introduced in March of 1995, Carticel received accelerated approval from the FDA in August of 1997 after the FDA instituted specific cell therapy guidelines. Under accelerated approval, the FDA required Genzyme to conduct confirmatory post-marketing clinical studies. Genzyme successfully completed the confirmatory studies and, in June of 2007, the FDA deemed the commitment satisfied.
Carticel is for autologous use and is indicated for the repair of symptomatic cartilage defects of the femoral condyle (medial, lateral or trochlea), caused by acute or repetitive trauma, in patients who have had an inadequate response to a prior arthroscopic or other surgical repair procedure.