P123 Safety and efficacy of filgotinib, an update from the DARWIN 3 phase 2 long-term extension with a maximum of 8.2 years of exposure
Authors: Emery Paul , Westhovens Rene , Alten Reike H E , Dagna Lorenzo , Kavanaugh Arthur , Winthrop Kevin L , Barry Jane , Besuyen Robin , Corallo Claudio , Watson Chris , Martin Nicolas , Genovese Mark , Spindler Alberto J , Stanislavchuk Mykola , Greenwald Maria 
Published: April 2024

Abstract

Background/Aims
DARWIN 3 (NCT02065700) is a long-term extension (LTE) study assessing the safety and efficacy of filgotinib (FIL) in patients with rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX). In the DARWIN 1 (NCT01888874) and DARWIN 2 (NCT01894516) parent studies, patients received FIL in combination with MTX or FIL monotherapy, respectively. To provide an update on the safety and efficacy of FIL 200 mg (FIL200) in patients with RA, with or without MTX, with a maximum of 8.2 years of exposure.

Methods
Patients completing the DARWIN 1 and DARWIN 2 phase 2 studies could enter DARWIN 3, receiving FIL200[PE1] +/-MTX. The proportion of patients experiencing treatment-emergent adverse events (TEAEs) were reported, comprising data from both the parent and LTE studies. Efficacy was assessed from LTE baseline using the American College of Rheumatology (ACR) 20/50/70 criteria and DAS28-CRP, up to 264 weeks. Low disease activity and remission were defined as DAS28-CRP ≤3.2 and &lt;2.6, respectively.

Results
In total, 739 patients were enrolled in DARWIN 3. In the FIL + MTX vs FIL monotherapy groups, TEAEs were reported for 90.9% and 92.1% of patients, respectively (Table). The most common TEAE was infection. In both treatment groups, eight patients had a TEAE leading to death (1.6% and 3.3%, respectively). Exposure-adjusted incidence rates, censored at time of first event for major adverse cardiovascular event, venous thromboembolism, herpes zoster, infections, serious infections, non-melanoma skin cancer (NMSC), malignancies excluding NMSC, gastrointestinal perforations and TEAEs leading to death, will be reported. Through five years, ACR20/50/70 responses were maintained in 86.3%/66.7%/50.7% of the FIL + MTX group and 90.8%/74.8%/51.4% of the FIL monotherapy group, respectively (observed data). DAS28-CRP low disease activity and remission rates (non-responder imputation) at DARWIN 3 baseline were 46.1%/40.1% (FIL + MTX) and 29.6%/24.8% (FIL monotherapy). At Week 264, the proportion of patients achieving low disease activity and remission were 34.0%/34.3% (FIL + MTX) and 27.0%/24.8% (FIL monotherapy).

Conclusion
With a maximum of 8.2 years of exposure in patients with RA, the FIL safety profile is similar between the background MTX and monotherapy treatment arms. Both arms show sustained efficacy over time.

Disclosure
P. Emery: Consultancies; Consultant of: AbbVie, AstraZeneca, BMS, Boehringer-Ingelheim, Galapagos, Gilead, Lilly, Novartis, Pfizer, Roche, and Samsung. Member of speakers’ bureau; y Speakers bureau: AbbVie, AstraZeneca, BMS, Boehringer-Ingelheim, Galapagos, Gilead, Lilly, Novartis, Pfizer, and Samsung. Grants/research support; Grant/research support from: AbbVie, BMS, Lilly, Novartis, Pfizer, Roche, and Samsung. R. Westhovens: Consultancies; Celltrion, Galapagos, and Gilead,. Member of speakers’ bureau; Celltrion, Galapagos, and Gilead. R.H.E. Alten: Consultancies; AbbVie, Amgen, Biogen, BMS, Celltrion, Gilead, Janssen, Lilly, Medac, MSD, Mylan, Novartis, Pfizer, Roche, Sandoz, SanofiGenzyme, UCB, and VIATRIS. L. Dagna: Consultancies; AbbVie, Amgen, AstraZeneca, Biogen, Boehringer-Ingelheim, BMS, Celltrion, Eli Lilly & Company, Galapagos, GlaxoSmithKline, Janssen, Kiniksa Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme,. Grants/research support; AbbVie, BMS, Celgene, GlaxoSmithKline, Janssen, Kiniksa, Merck Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI,. A. Kavanaugh: Consultancies; Amgen, AbbVie, BMS, Pfizer, UCB, Janssen, Novartis, and Pfizer. K.L. Winthrop: Consultancies; AbbVie, AstraZeneca, BMS, Eli Lilly & Company, Galapagos, Gilead, GlaxoSmithKline, Novartis, Pfizer, Regeneron, Roche, Sanofi, and UCB. Grants/research support; BMS and Pfizer. J. Barry: Corporate appointments; Galapagos. Shareholder/stock ownership; Galapagos. R. Besuyen: Corporate appointments; Galapagos. Shareholder/stock ownership; Galapagos. C. Corallo: Corporate appointments; Galapagos. Shareholder/stock ownership; Galapagos. C. Watson: Corporate appointments; Galapagos. Shareholder/stock ownership; Galapagos. N. Martin: Consultancies; Galapagos. M. Genovese: Corporate appointments; Gilead Sciences. Shareholder/stock ownership; Gilead Sciences. A.J. Spindler: None. M. Stanislavchuk: Grants/research support; Amgen, AstraZeneca, Celgene, Eli Lilly, Galapagos, Gilead, Human Genome, Janssen, MSD, Nichi-Iko, Pfizer, and Roche. M. Greenwald: Grants/research support; AbbVie, Aclaris, Galapagos, Janssen, Lilly, and Nimbus.