They still have to license the IPIX compound. Just mentioning an IPIX compound in their patent as a possible combination with their compound does not give them the right to use said IPIX compound. Kevetrin is itself a patented compound and IPIX owns that patent.

"All I know is that I recall non-IPIX entities applying for patents which allow them to use a compound from IPIX in combo with their drug." - someconcerns