Another possible approach is to integrate a stemmer into the full text index. This would just be a modified tokenizer. That would automatically change the search into a search of word stems. This might be suitable for your application. You could also break each token into any recognizable stems when it is indexed. For example, biomedical could be broken into bio- and medic-.
Note that you can do exact Unicode prefix searches of non-inlined, non-blob literals or URIs using the TERM2ID index.
Note that you can do exact prefix searches of inline RDF Values using the OSP(C) index.
I have captured some of this documentation at .
I am going to close this ticket out as "won't fix." You can use the mechanisms described here to implement a stem search or prefix search. That should provide low-latency prefix or stem prefix search suitable for your application.
If you want to add some documentation onto this ticket about the FullTextIndex.Options or a recipe to configure the FullTextIndex for your application, I am happy to post that to the wiki page for the free text search.