By Frances Bishopp

Genzyme Tissue Repair has received an approvable letter from the FDA for its biologics license application (BLA) for Carticel, its cartilage cell culturing service. Final acceptance will follow once the company clarifies certain details pertaining to manufacturing and labeling and formally agrees to two post-marketing studies.

The Carticel treatment system (autologous cultured chondrocytes) grows a patient's own cartilage cells for use in treating damaged knee cartilage.

Carticel, launched by Genzyme Tissue Repair in 1995, is being reviewed under the FDA's accelerated approval policy, Cheryl Greenhouse, senior public relations associate with Genzyme Tissue Repair, told BioWorld Today. Genzyme Tissue Repair is a division of Genzyme Corp., of Cambridge, Mass., but has its own tracking stock.

In 1995, the FDA had no regulations governing the area of autologous cell therapy, she explained. That year, the FDA determined Carticel and similar products would be regulated and, after an initial safety review, permitted Genzyme to market the product as an unregulated device while the agency developed guidelines.

Genzyme filed its BLA for Carticel in March 1996. In March 1997, an FDA advisory panel determined by a vote of 11 to 0 that the procedure using Carticel provided a clinical benefit to patients with damage to the articular cartilage in the knee. (See BioWorld Today, March 7, 1997, p 1.)

The panel, however, refused to attribute that benefit to the actual cells that Genzyme's Tissue Repair division produces, maintaining there was not enough data to properly ascertain the role the implanted cells played. The panel recommended the company undertake post-marketing studies to determine what role if any the cells play in relieving the symptoms of cartilage damage.

In February 1997, the FDA issued its policy on autologous tissue and cell therapies. Carticel is the first product reviewed under the new policy, Greenhouse said. (See BioWorld Today, March 4, 1997, p.1.)

In its approvable letter, the FDA found Carticel to be safe and effective. The unresolved issues were described as minor by Greenhouse, who said, "We do not expect any difficulty in complying."

Genzyme will conduct two post-approval studies: a five-year evaluation which will compare Carticel to other treatment options and a smaller-scale study in which patients will undergo the autologous chondrocyte implantation surgical procedure and will be randomly assigned to receive either Carticel or placebo.

At a price of $10,000 per procedure, Carticel, in the first quarter of 1997, had sales of $1.12 million. Genzyme Tissue Repair, in the first quarter of 1997, had revenues of approximately $1.9 million and, as of March 31, 1997, had approximately $19 million in cash.

Genzyme Tissue Repair's stock (NASDAQ:GENZL) closed Friday at $11.25, down $0.687. *