From New York Times

David H. Koch, an industrialist who amassed a multibillion-dollar fortune with his brother Charles and then joined him in pouring their riches into a powerful right-wing libertarian movement that helped reshape American politics, died on Friday at his home in Southampton, N.Y. He was 79.

Charles G. Koch announced the death in a statement, which noted that David Koch had been treated for prostate cancer in the past. “Twenty-seven years ago,” the statement said, “David was diagnosed with advanced prostate cancer and given a grim prognosis of a few years to live. David liked to say that a combination of brilliant doctors, state of the art medications and his own stubbornness kept the cancer at bay.”