Filgotinib

Breast Feeding; Lactation; Milk, Human; Enzyme Inhibitors; Protein Kinase Inhibitors; Signal Transduction Inhibitors; Janus Kinase Inhibitors; JAK Inhibitors

EMA approved medicines: Human medicine

Warning

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory.

L - Antineoplastic and immunomodulating agents

QL - Antineoplastic and immunomodulating agents

In addition to targeted Janus kinase (JAK) 1 inhibition, filgotinib targets pro-inflammatory cytokine signalling by inhibiting IL-6 induced STAT1 phosphorylation. Serum C-reactive protein levels are also reduced in response to filgotinib administration.

There are four Janus kinase (JAK) enzymes including JAK1, JAK2, JAK3, and tyrosine kinase 2. JAK1 mediates inflammatory cytokine signaling, while JAK2 and JAK3 are important components of hematologic and immune functions. Filgotinib selectively inhibits JAK1 and is for example nearly 30-fold more selective for JAK1 compared to JAK2. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway is implicated in several inflammatory pathologies and has been found to be continuously active in patients who have RA. Sustained activation of this pathway contributes to aberrant processes which lead to disease progression including elevated levels of matrix metalloproteinases (MMPs) and reduced cell apoptosis in RA affected synovial tissues. Filgotinib acts on the JAK-STAT pathway by selectively inhibiting JAK1 phosphorylation and preventing STAT activation, which ultimately results in reduced proinflammatory cytokine signaling.

Carboxylesterase enzymes are involved in the metabolism of filgotinib. The carboxylesterase 2 (CES2) isoform is chiefly responsible for metabolizing filgotinib to its major metabolite, GS-829845. Although carboxylesterase 1 (CES1) plays a less prominent role in the biotransformation of filgotinib, in vitro studies have demonstrated that CES1 will partially compensate in the event of CES2 saturation. GS-829845 is thus far the only major circulating metabolite to have been identified.