This is in the My Sister Eileen wiki:
In 1953, Joseph A. Fields and Jerome Chodorov adapted their 1940 play for Wonderful Town, with lyrics by Betty Comden and Adolph Green and music by Leonard Bernstein. Its success on Broadway prompted Harry Cohn, head of Columbia Pictures, which had released the 1942 screen adaptation of the play, to seek the film rights to the musical. When they proved to be too costly, he decided to hire Jule Styne and Leo Robin to write a different score. Because the film couldn't bear any resemblance to Wonderful Town, a studio attorney was assigned to make sure there were no similarities between the two. Even the musical numbers had to be positioned at different places in the storyline.