van der Heijde D, et al. -

Researchers performed the TORTUGA trial to test the safety and effectiveness of filgotinib, an oral selective Janus kinase 1 (JAK1) inhibitor, for treating patients with active ankylosing spondylitis. For the treatment of these patients who have not responded to first-line pharmacological therapy with non-steroidal anti-inflammatory drugs (NSAIDs), filgotinib is efficacious and safe. Nasopharyngitis was the most common treatment-emergent adverse event, and no deaths were reported during the investigation.

Methods

• Researchers enlisted adult patients from 30 sites in seven countries (Belgium, Bulgaria, Czech Republic, Poland, Estonia, Spain, and Ukraine) in this completed, randomized, double-blind, placebo-controlled, phase 2 trial.
• Eligibility criteria included patients who had active ankylosing spondylitis and an inadequate response or intolerance to two or more NSAIDs.
• Patients were randomized (1:1) with an interactive web-based response system to either filgotinib 200 mg or placebo orally once daily for 12 weeks.
• By current use of conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) and previous receipt of anti-tumor necrosis factor therapy, randomization was stratified.
• To treatment assignment, the patients, study team, and study sponsor were masked.
• The change from baseline in ankylosing spondylitis disease activity score (ASDAS) at week 12 was the primary endpoint, which was evaluated in the full analysis set (ie, all randomized patients who received at least one dose of study drug).
• According to actual treatment received, safety was assessed.

Results

• Two hundred sixty-three patients were screened and 116 randomly assigned to filgotinib (n=58) or placebo (n=58) between March 7, 2017 and July 2, 2018.
• It was noted that 55 (95%) patients in the filgotinib group and 52 (90%) in the placebo group completed the study.
• Findings revealed that the mean ASDAS change from baseline to week 12 was −1.47 (SD 1.04) in the filgotinib group and −0.57 (0.82) in the placebo group, with a least squares mean difference between groups of −0.85 (95% CI −1.17 to −0.53; p < 0.0001).
• Researchers reported treatment-emergent adverse events in 18 patients in each group, the most common being nasopharyngitis (in two patients in the filgotinib group and in four patients in the placebo group).
• They observed that treatment-emergent adverse events prompted lasting treatment cessation in two patients (a case of grade 3 pneumonia in the filgotinib group and of high creatine kinase in the placebo group); no deaths were reported.