Although it was assumed that Bernard Pomerance's play "The Elephant Man" was the basis for the David Lynch film, that it not the case. Of course, both the play and the film are based on the real life of John Merrick, so it is not surprising that the relationship between Merrick and his physician, Sir Frederick Treves, is not surprising.
The chief conceit of this play is introduced in Scene III, when the actor playing Merrick contorts himself to approximate projected slides of the real Merrick while Treves lectures on the Elephant Man's condition. As Pomerance points out in his introductory note, Merrick's face was sufficiently deformed that his speech was very difficult to understand. Consequently, "Any attempt to reproduce his appearance and his speech naturalistically--IF it were possible--would seem to me not only counterproductive, but, the more remarkably successful, the more distracting from the play."
Pomerance captures the plight of Merrick, rescued from being a freak attraction in traveling sideshows, he is educated and introduced to London society. But although Merrick is changed from an object of pity to a favorite of high society, he is denied the chance to lead a normal life. Pomerance uses the model Merrick made of the St. Philip's Church as a central metaphor for the Elephant Man's life at London Hospital. The play is episodic in nature, and we actually learn much more about the people in Merrick's life than we do about the man himself.
Pomerance's movie and theatrical play won all the major drama awards including the Tony, Obie, Drama Desk Award and New York Drama Critics Circle Award. If you are interested in either the Lynch film or the life of John Merrick, then this play is a worthy of your consideration as Treves's work "The Elephant Man and Other Reminiscences," which is reprinted in "The Elephant Man, A Study in Human Dignity" by Ashley Montagu.