A commentary discusses the potential position of this therapeutic class in the armamentarium, should phase 3 clinical trials confirm the efficacy of filgotinib in Crohn's disease. It notes oral administration makes this an attractive option for many patients over intravenous or injectable routes, and also small molecules might not experience the loss of response due to immunogenicity that is associated with use of biologicals. In terms of current knowledge gaps, it adds that it is not known whether using filgotinib in combination with a conventional immunomodulator would yield greater benefits as concomitant therapy was not permitted in the trial. Also, as has been noted with vedolizumab, the rates of response and incremental benefit are lower in anti-TNF exposed patients compared with those naive to biologicals, thus there is a possibility that these new treatment options with distinct mechanisms of action might not be sufficient to meet the needs of the growing proportion of patients refractory to anti-TNF therapies. It adds that in patients naive to biologicals, the absence of comparative effectiveness trials makes it a continuing challenge in making an informed decision about selecting a therapeutic class for initial trial.