The Food and Drug Administration on Thursday approved the first generic substitute for Copaxone, a widely used drug for multiple sclerosis and the biggest-selling product for Teva Pharmaceutical Industries.

The approval of the generic, which was developed by the team of Sandoz and Momenta Pharmaceuticals — could bring some price competition to the market for multiple sclerosis drugs. Prices for those drugs have tripled in the last several years, to over $60,000 a year, even as more products have come to market.

“It’s the inverse of what you normally expect when there is competition,” said Dr. Dennis N. Bourdette, chairman of neurology at Oregon Health and Science University. “There’s no apparent reason for the skyrocketing prices of those drugs, aside from that we have no cost controls in this country.”

Dr. Bourdette welcomed the generic, but said its impact would depend on its price. Citing competitive reasons, Momenta and Sandoz declined to say when the generic version would go on sale and how much it would cost.