There doesn't seem to be an exact equivalent in the English-speaking world, other than the calque. To quote from Wikipedia: "Literary science (German: Literaturwissenschaft) is an umbrella term, used in many European countries, for all kinds of scientific study pertinent to literature. The main branches of literary science are history of literature, literary criticism, and literary theory."
The addition of 'wetenschap' (Wissenschaft in German) to a word to denote a subject studied does not connotate 'science' in the modern sense, but merely what in some cases might be translated with 'ology' (muziekwetenschap = musicology). There is also the distinction between literatuurwetenschap (literary studies) and taalwetenschap (linguistics). Just as the Bologna reform has engendered a flurry of ridiculous degrees, so do many exaggerate what might be considered a science, for instance 'mixology', the 'art' of mixing drinks.