As a child/teen I read The Neverending Story as well as several other books by the same author. I know that the former was adapted into a film (possibly two films), and I presume that the novel was also translated into English.
Still, native English readers I have spoken with don't seem familiar with Michael Ende beyond this one book - or rather the film of the book. Were they never translated, or are the translations out of print? It seems highly unusual to translate only one novel by an author.