Some days the arthritis pain would get so bad that Sylvia Zebroski, 51, of Stamford, Conn., couldn't sleep. Aspirin worked for a while, but then she developed stabbing pains in her stomach. She switched to naproxen, which, like aspirin, is a so-called nonsteroidal anti-inflammatory drug, or NSAID. Same story. "I took myself off naproxen and went to my doctor in tears," she recalls. He put her on a new experimental drug, and this time, no arthritis pain--and no stomach pain. Says Zebroski: "It's made all the difference in the world."
The drug that changed Zebroski's life is just one of...