Albert Innaurato, a playwright who enjoyed spectacular success for a time in the late 1970s, including having a play run on Broadway for more than four years, has died in Philadelphia. He was 70. His cousin Stephen Paesani said Mr. Innaurato was found dead in his bed on Tuesday, and had probably been dead for two days. The cause was not clear, Mr. Paesani said, but Mr. Innaurato had had heart problems recently.

Mr. Innaurato’s biggest hit, written while he was still in his 20s, was “Gemini,” a comic drama about a Harvard student who returns to his blue-collar Philadelphia neighborhood for his 21st birthday and has to confront, among other things, his sexual orientation. It opened on May 21, 1977, at the Little Theater on Broadway and ran for 1,819 performances.