Genzyme Corporation (CAMBRIDGE, Massachusetts) announced that the US FDA has approved new labeling for Carticel^R (autologous cultured chondrocytes) based on the company's completing a final FDA postapproval commitment study. The labeling incorporates safety and efficacy data from the Study of the Treatment of Articular Repair (STAR), a postmarketing nonrandomized, open-label trial of Carticel in patients with cartilage defects.

Investigators enrolled patients in 29 clinical centers in this prospective 4-year study, which achieved all its endpoints. The data from the study will be presented at the American Orthopaedic Society for Sports Medicine (AOSSM) Meeting on July 15, 2007, in Calgary, Canada.

Carticel is a novel cell therapy derived from in vitro expansion of chondrocytes harvested from the patient's normal, femoral articular cartilage. The implant has been used in more than 10,000 knees over the course of a decade. Biopsies from a lesser-weight bearing area are the source of chondrocytes, which are isolated, expanded through cell culture to approximately 12 million chondrocytes, and implanted into articular cartilage defects beneath an autologous periosteal flap.

Carticel 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 (eg, debridement, microfracture, drilling/abrasion arthroplasty, or osteochondral allograft/autograft). Carticel should be used only in conjunction with debridement, placement of a periosteal flap, and rehabilitation. It is not indicated for the treatment of cartilage damage associated with generalized osteoarthritis. The independent contributions of the autologous cultured chondrocytes and other components of the therapy to treatment outcome are unknown. Patients receive 200 to 300 mg biopsy of healthy cartilage taken from their knee in an arthroscopic procedure. Genzyme's cell culture laboratory technicians use proprietary methods to expand a patient's own cartilage cells. The cells are then delivered to the hospital, where the surgeon implants them into the patient's knee defect in a surgical procedure.

A subsequent surgical procedure, primarily arthroscopy, following Carticel implantation is common. The STAR study showed that most common reactions (>5% of patients) included arthrofibrosis/joint adhesions, graft overgrowth, chondromalacia or chondrosis, cartilage injury, graft complication, meniscal lesion, graft delamination, and osteoarthritis. Because residual quantities of gentamicin may be present in the Carticel implant, it should not be used in patients with a known history of hypersensitivity to gentamicin, other aminoglycosides, or materials of bovine origin. In addition, Carticel should not be used in patients who have previously had cancer in the bones, cartilage, fat, or muscle of the treated limb. Use in patients over age 65 or in joints other than the knee has not yet been assessed.

Carticel was introduced in March of 1995 and was the first cell therapy to be approved by the FDA. The implant received accelerated approval from the FDA in August of 1997 after the agency instituted specific cell therapy guidelines. Under accelerated approval, Genzyme was required by the FDA to conduct confirmatory postmarketing studies.

—A. Techman

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