Phase 3 Study of Filgotinib for Rheumatoid Arthritis Meets Primary, Secondary Endpoints

Walid Abi-Saab, MD

Results from the FINCH 2 study of filgotinib in adults with moderately-to-severely active rheumatoid arthritis and prior inadequate response/intolerance to biologic agents show that both doses met the primary and key secondary endpoints.

Patients who received filgotinib, a selective JAK1 inhibitor, were more likely to have achieved an American College of Rheumatology 20% response (ACR20) at week 12 (57.5% for filgotinib 100mg, P <.001; 66.0% for filgotinib 200mg, P <.001) compared to patients receiving placebo (31.1%).

The data was announced by Gilead Sciences, Inc. and Galapagos NV, which have collaborated in the development and commercialization of filgotinib.

"Gilead is committed to the development of new therapies that offer meaningful benefit for people living with rheumatoid arthritis and other serious inflammatory diseases," said John McHutchison, MD, Chief Scientific Officer, Head of Research and Development, Gilead Sciences, in a statement. "These initial phase 3 data support the potential of filgotinib, in combination with select disease modifying drugs, to help patients with active rheumatoid arthritis who do not adequately respond to current biologic disease modifying agents. These data are particularly encouraging as we look ahead to phase 3 results from the ongoing FINCH 1 and 3 trials, which are exploring filgotinib in other populations of patients with rheumatoid arthritis."

The FINCH 2 study included 348 participants who were randomized 1:1:1 to 100mg filgotinib, 200mg filgotinib, and placebo. Patients had moderately-to-severely active rheumatoid arthritis and had not adequately responded to biologic disease-modifying anti-rheumatic drug(s) (bDMARDs); 23.7% of patients had received three or more bDMARDs.

The results at week 12 also showed that a greater proportion of patients receiving filgotinib 100mg or 200mg achieved ACR50 (respectively, 32.0%, P <.001; 42.9%, P <.001) compared to placebo (14.9%). Additionally, 14.4% (P <.05) and 21.8% (P <.001) of patients receiving filgotinib 100mg or 200mg achieved ACR70 at 12 weeks, compared to 6.8% of those receiving placebo.

At week 12, 37.3% (P <.001) and 40.8% (P <.001) of patients receiving 100mg, and 200mg reached a disease activity score (DAS28 [CRP]) of ≤3.2, compared to 15.5% of those receiving placebo.

"We are pleased that filgotinib has demonstrated significantly improved clinical responses in this difficult to treat population," said Walid Abi-Saab, MD, Chief Medical Officer at Galapagos. "The good tolerability in this study is also very encouraging."

Serious adverse events occurred in 3.4%, 5.2%, and 4.1% of patients in the placebo, 100mg, and 200mg groups. Rates of discontinuation due to treatment-emergent adverse events were similar between the 3 study groups and the companies reported that there were no new safety signals compared to previous studies.

Other clinical trials, including FINCH 1 and 3, are currently studying filgotinib in rheumatoid arthritis or other inflammatory conditions.