Gilead Sciences and Galapagos reported Thursday that a Phase II study of filgotinib in adults with moderately-to-severely active ankylosing spondylitis met its primary efficacy endpoint. The companies are developing the experimental JAK1 inhibitor as part of a collaboration covering inflammatory diseases.
The TORTUGA trial randomised 116 patients with moderately-to-severely active ankylosing spondylitis to receive filgotinib or placebo once daily for 12 weeks. Results showed that patients treated with filgotinib achieved significantly greater improvements in AS Disease Activity Score (ASDAS), the main goal, at week 12, with a mean change from baseline of -1.5 versus -0.6 for those treated with placebo. Further, 76 percent of patients in the filgotinib arm also achieved an ASAS20 response compared 40 percent of those treated with placebo.
The companies noted that in the trial, adverse events were generally mild or moderate in severity and occurred in an equal proportion of patients in the filgotinib and placebo groups. Gilead and Galapagos added that one patient given filgotinib experienced a serious adverse event of pneumonia, which resolved after hospital-based antibiotic treatment. A further subject given the drug, who had an inherited risk for thrombosis, experienced a non-serious deep venous thrombosis after completing the course of treatment.
John McHutchison, head of R&D at Gilead, said "these data are encouraging, suggesting filgotinib has the potential to play an important role in addressing this medical need." The drugmakers indicated that detailed results from the study will be submitted for presentation at a future scientific conference.
Gilead and Galapagos are also investigating filgotinib in the ongoing FINCH Phase III programme in rheumatoid arthritis, the DIVERSITY late-stage trial in Crohn's disease and the Phase III SELECTION study in ulcerative colitis. Gilead gained rights to filgotinib under a deal  potentially worth more than $2 billion announced in 2015, shortly after AbbVie decided against  exercising its right to the compound in favour of developing its own experimental JAK1 inhibitor ABT-494.
For related analysis, see ViewPoints: AS data the entrée for filgotinib with key Phase III results imminent .