In 1979 J. Michael McIntosh was working in the laboratory of university biologist Baldomero Olivera when he isolated and characterized a painkiller in the venom of a cone snail.

McIntosh discovered that a component or factor in the venom affected the nervous system. He purified it and determined its chemical structure. Later, University of Utah biologist Doju Yoshikami and Olivera did research on the factor, dubbed omega-MVIIA, with George Miljanich, who worked at the University of Southern California and later moved to Neurex Corp., where he explored the factor's therapeutic potential.

Neurex was then bought by Ireland's Elan, which got Food and Drug Administration approval Tuesday to sell Prialt, as it is called, for chronic, intractable pain suffered by people with cancer, AIDS, injury, failed back surgery or certain nervous system disorders.

The drug should be available in the United States in late January 2005.