Leo Sternbach, who developed a revolutionary new class of tranquilizers that included Valium, one of the first blockbuster “lifestyle” drugs, died at his home in North Carolina. He was 97.

Sternbach, an award-winning chemist who helped the Swiss drug conglomerate Roche Group build its U.S. headquarters in Nutley, N.J., died late Wednesday, Sept. 28, in Chapel Hill, N.C., after a short illness. His wife, sons and other relatives were at his side, according to the company.

An Austrian native who fled the Nazis during World War II, Sternbach said he loved chemistry from his youth. He led development of more than a dozen important drugs during a six-decade career.

Valium was the country’s most prescribed drug from 1969 to 1982. Nicknamed “Mother’s Little Helper” after the Rolling Stones song, it was three times more potent than its predecessor, Librium, another member of the class of tranquilizers invented by Sternbach.

Sternbach was born in 1908 in Abbazia, part of the Austrian Empire that today is Croatia, and earned a doctoral degree in organic chemistry at the University of Krakow in Poland. He began working at Roche’s Basel headquarters in 1940 and in June 1941 fled to the United States with his new bride and the rest of Roche’s Jewish scientists.

Besides his wife and son Daniel, Sternbach is survived by his other son, Michael, and five grandchildren.