FDA Approves First Autologous Cellularized Scaffold for Repair of Knee Cartilage Defects

Product consists of autologous cells on bioresorbable collagen membrane

The FDA has approved Maci (autologous cultured chondrocytes on porcine collagen membrane, Vericel Corporation) for the repair of symptomatic, full-thickness cartilage defects of the knee in adults. Maci is the first FDA-approved product that applies the process of tissue engineering to grow cells on scaffolds using healthy cartilage tissue from the patient’s own knee.

Knee problems are common and occur in people of all ages. Cartilage defects in the knee can result from an injury or from straining the knee beyond its normal motion. Defects can also be caused by overuse, muscle weakness, and general wear and tear.

Maci consists of a patient’s own (autologous) cells, which are expanded and placed onto a bioresorbable, porcine-derived collagen membrane. This membrane is then implanted over the area where the defective or damaged tissue was removed. The procedure should be performed by a surgeon specifically trained in the use of Maci.

Each Maci implant consists of a small cellular sheet containing 500,000 to 1,000,000 cells per cm2 (approximately 0.16 square inches). The amount of Maci administered depends on the size of the cartilage defect, and the membrane is trimmed to ensure that the damaged area is completely covered. Multiple implants may be used if there is more than one defect.

Maci’s safety and efficacy were assessed in a two-year clinical trial designed to demonstrate reduced pain and improved function in comparison with microfracture, an alternative surgical procedure for cartilage repair. The trial included 144 patients (72 in each treatment group). Most of the patients who completed the trial also participated in a three-year follow-up study. The efficacy data supported a long-term clinical benefit from the use of the Maci implant in patients with cartilage defects.

The most common adverse events reported by patients who received Maci included joint pain, common cold-like symptoms, headache, and back pain.

Source: FDA; December 13, 2016.