Filgotinib Continues to Show Efficacy for RA in LTE Studies

Maya H. Buch, PhD

Credit: University of Manchester

Filgotinib 200 mg and 100 mg has continued to demonstrate safety and efficacy in people with rheumatoid arthritis (RA), according to updated 156-week data from the ongoing long-term extension (LTE) FINCH 4 study (NCT03025308).¹

“These findings confirm that filgotinib is an effective treatment option for clinically relevant patient populations (those with RA who have not responded adequately or are intolerant to previous DMARDs). Although numerical differences between the 2 filgotinib doses were observed in the maintenance of remission, the results indicate that filgotinib 100 mg had largely comparable efficacy to the higher dose. This provides reassurance that treatment remains effective in situations where the lower dose is recommended, for example, in those aged 65 years or older, those at increased risk of venous thromboembolism, MACE and malignancy or those with moderate or severe renal impairment,” lead investigator Maya H. Buch, PhD, Clinical Professor of Rheumatology, Centre for Musculoskeletal Research, University of Manchester, United Kingdom, and colleagues wrote.¹

Filgotinib, a preferential JAK 1 inhibitor, was initially evaluated in its 2 doses in people whose disease responded inadequately or were intolerant to 1 or more csDMARDs in the phase 3 FINCH 1–3 studies, each of which met their primary endpoints by demonstrating significantly more American College of Rheumatology 20% responses (ACR20) compared to placebo or methotrexate. Participants in FINCH 1, 2, or 3 were invited to participate in the FINCH 4 study LTE study.¹

In FINCH 4, participants continued filgotinib 200 mg or 100 mg from FINCH 1, 2 or 3, or received filgotinib 200 mg or 100 mg de novo. Buch and colleagues found that in participants with an inadequate response to methotrexate, 60.2% receiving de novo filgotinib 200 mg and 54.6% receiving de novo filgotinib 100 mg had an ACR20 at week 156, respectively, as did 67.3% of those who continued filgotinib 200 mg and 59.5% of those who continued filgotinib 100 mg.¹

Under Boolean 1.0 criteria, remission was achieved by 18.8% of the de novo filgotinib 200 mg and 15.4% of the de novo 100 mg group. Under Boolean 2.0 criteria, 21.1% of the de novo filgotinib 200 mg and 18.5% of the de novo filgotinib 100 mg group achieved remission. Overall, the efficacy and safety data in FINCH 4 were consistent with that seen in FINCH 1, 2, and 3.¹

“In conclusion, interim efficacy results from the FINCH 4 study confirm that beneficial effects of filgotinib 100 mg and 200 mg on disease activity measures were maintained up to week 156, independent of the initial background treatment (methotrexate-IR, bDMARD-IR and methotrexate-naïve groups). When Boolean 2.0 rather than Boolean 1.0 criteria were applied, remission rates were numerically higher and were more comparable with those reported using index-based criteria. Safety data observed during the long-term extension were in line with the known safety profile for filgotinib,” Buch and colleagues concluded.¹

A recent safety analysis of multiple investigations of filgotinib, including the FINCH 1, 2, 3, and 4 studies, were presented at June’s 2024 European Congress of Rheumatology (EULAR). The analysis also included the 2 phase 2 DARWIN studies and its LTE DARWIN 3 study.²

The Exposure-adjusted incidence rate (EAIR) per 100 patient-years of exposure (PYE) of serious infections was 2.2 (95% CI, 1.8-2.6) in the FIL100 cohort and 1.7 (95% CI, 1.5-2.0) in the FIL200 cohort. The EAIR/100 PYE of herpes zoster was 1.1 (95% CI, 0.8-1.4) and 1.4 (95% CI, 1.2-1.7) in the FIL100 and FIL200 groups, respectively. Over a 312-week period, the risk of all-cause mortality was comparable between FIL100 and FIL200.²

REFERENCES
1. Buch MH, Aletaha D, Combe BG, et alEfficacy and safety of filgotinib in patients with rheumatoid arthritis: week 156 interim results from a long-term extension studyRMD Open 2024;10:e004476. doi: 10.1136/rmdopen-2024-004476

2. Winthrop KL, Aletaha D, Caporali RF, Tanaka Y, et al. An Update on the Integrated Safety Analysis of Filgotinib in Patients with Moderate to Severe Active Rheumatoid Arthritis Over a Median of 4.3 Years. Presented at: EULAR. Vienna, Austria. June 12 – 15, 2024.