Chicken Chemical Helps Arthritic Knees

Patients whose arthritic knees aren’t helped by painkillers are getting a new option: injections of a substance derived from chickens that may help cushion their joints.

The Food and Drug Administration approved two versions of hyaluronate, the first new option for osteoarthritis in 25 years.

Hyaluronate is found naturally in the fluid of people’s joints, helping to lubricate and cushion them. But in osteoarthritis, patients’ hyaluronate degrades.

Italy’s Fidia Corp. and New Jersey’s Biomatrix Inc. culled hyaluronate from chickens and modified it for humans. Clinical trials showed injections directly into the knee reduced pain for about six months.

“It does appear, over the short term, to relieve pain,” said Dr. Doyt Conn, senior vice president of the Arthritis Foundation.

Fidia’s Hyalgan began selling last month, and the five required injections cost about $500 - similar to six months of prescription painkillers, said Hyalgan’s distributor, Sanofi Corp.

The FDA approved Biomatrix’ three-injection Synvisc on Wednesday. It will be sold this fall by Wyeth-Ayerst Laboratories; a price was not announced.

Currently, patients try painkillers and weight loss. Occasional steroid injections help worsening pain, while knee replacements help severe patients.