RESUMEN
Janus kinases (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway is involved in pathophysiologic cascade of a notable number of rheumatic diseases. The development of JAK inhibitors has expanded treatment choices in rheumatoid arthritis (RA) with a sustained class-effect efficacy. Filgotinib is a novel selective inhibitor of JAK1 isoform licensed for use in RA and ulcerative colitis. In this review we aim to present an analysis of filgotinib's efficacy and drug-specific safety warnings. Patients with RA with or without concomitant conventional synthetic Disease-Modifying Antirheumatic Drugs (csDMARDs) (naïve or experienced) and those who have failed biologic Disease-Modifying Antirheumatic Drugs (bDMARDs) were examined in randomised clinical trials. Filgotinib was also tested against placebo, methotrexate, or adalimumab. Long-term extension trials provide insights for up to four years of continuous filgotinib administration. Beneficial effects are depicted in both disease activity parameters and quality of life indexes in moderate or severe RA with a longitudinal efficacy. In head-to-head comparison with adalimumab, filgotinib 200 mg was non-inferior. Adverse effects alerts are marked by the elevated risk of infectious adverse effects with the exception of herpes zoster infection, which has a low incidence.
RESUMEN
Rheumatoid arthritis (RA) is a systemic inflammatory disease treated with conventional and biologic disease-modifying drugs. Methotrexate is the anchor drug for the treatment of RA and is also frequently used for various autoimmune diseases. Adverse events are common and generally easy to manage, involving mainly the gastrointestinal tract and the liver function. However, neurotoxicity is very uncommon in adults with rheumatic diseases. B cell depletion with rituximab is another therapy approach particularly in patients with refractory RA. Whistle leukoencephalopathy - namely progressive multifocal leukoencephalopathy-is an infrequent but well-described side effect of rituximab. In contrast, central nervous system toxicity due to methotrexate is extremely rare especially in RA individuals under oral or subcutaneous low dose on weekly basis. We present a challenging case of a RA patient on treatment with methotrexate and rituximab presenting with leukoencephalopathy. The patient was diagnosed with methotrexate-induced leukoencephalopathy which reversed after treatment discontinuation. We comment on the symptoms and diagnostic workout and we review the available literature on this issue based on recommendations for narrative reviews.