I
Trying to add to your list with your criteria ---and starting with more familiar names:
Arthur Miller - Everybody Wins (1990) / The Misfits (1961)
Tennessee Williams - Baby Doll (1956) / The Loss of a Teardrop Diamond (2008)
John Steinbeck - Viva Zapata! (1952)
Sylvester Stallone - Rocky (1976)
Neil Simon - The Goodbye Girl (1977) / The Out of Towners (1970) / Murder by Death (1976) / The Cheap Detective (1978) / The Marrying Man (1991) / The Slugger's Wife (1985) / Max Dugan Returns (1983)--
I think he wrote these all directly for the screen.Waldo Salt - The Flame and the Arrow (1950)
Edward Anhalt - Hour of the Gun (1967) / The Gentleman from Nowhere (1948)
Stanley Shapiro - The Seniors (1978) / Carbon Copy (1981)
David Mamet - The Edge (1997) / Hoffa (1992)
Colin Welland - Chariots of Fire (1981) / Twice in a Lifetime (1985)
(I will try to find more and add by editing here)