Following oral dosing, filgotinib is rapidly converted to its primary active metabolite, which has a similar Janus kinase 1 selectivity profile and contributes to the overall pharmacodynamic response.

Filgotinib has a low drug–drug interaction potential without clinically significant interactions with commonly coadministered medications, such as methotrexate or statins; cytochrome P450 3A4 substrates, including oral contraceptives; and acid-reducing agents, including proton pump inhibitors and histamine antagonists.

Intrinsic factors such as age, sex, race, mild renal impairment, and mild-to-moderate hepatic impairment have either no or minimal impact on the pharmacokinetics of filgotinib and its primary metabolite.