Objectives To evaluate the long-term maintenance of Psoriasis Area and Severity Index (PASI) ≤2 and PASI=0 responses with bimekizumab (BKZ), using the largest available two-year data pool, in patients with moderate to severe plaque psoriasis. Introduction • Long-term treatment efficacy is an important consideration in chronic diseases such as psoriasis. • BKZ has demonstrated high levels of skin clearance for the treatment of moderate to severe plaque psoriasis in phase 3/3b clinical trials.1–4 Methods • Data were pooled from the BE SURE, BE VIVID and BE READY phase 3 trials, the BE BRIGHT open-label extension (OLE), and BE RADIANT (48-week double-blinded phase 3b trial and ongoing OLE).1–5 • Patients included in these analyses were randomized at baseline to BKZ 320 mg every four weeks (Q4W) to Week 16, followed by BKZ Q4W or every eight weeks (Q8W) maintenance dosing for the remainder of the double-blinded period of the trials (Figure 1). • Upon OLE entry, patients received BKZ 320 mg Q4W or Q8W based on PASI (Psoriasis Area and Severity Index) response at the end of the feeder studies (Figure 1). • We report the proportion of patients achieving PASI ≤2 and PASI=0 through two years of treatment (OLE Week 48) among BKZ-randomized Week 16 PASI ≤2 and PASI=0 responders, who remained on the same BKZ maintenance dose upon entering the relevant OLE (Q4W/Q8W/Q8W or Q4W/Q4W/Q4W). • Missing data were imputed using non-responder imputation (NRI), modified NRI (mNRI), and observed case (OC). – For mNRI, patients who discontinued treatment due to lack of efficacy were considered non-responders; multiple imputation was used for all other missing data. Results • Baseline characteristics of Week 16 PASI ≤2 and PASI=0 responders who entered BE BRIGHT or the BE RADIANT OLE are reported in Table 1. • At Week 16, 87.1% of the 1,362 patients randomized to BKZ 320 mg Q4W at baseline of the feeder studies achieved PASI ≤2 (NRI; Figure 2A) and 62.4% achieved PASI=0 (NRI; Figure 2B). • Among Week 16 PASI ≤2 responders who entered the OLEs, 96.3% of the 349 patients on Q4W/Q8W/Q8W and 95.1% of the 449 patients on Q4W/Q4W/Q4W maintained PASI ≤2 through two years (OLE Week 48) (mNRI; Figure 2A). • Of the Week 16 PASI=0 responders who entered the OLEs, 83.8% of the 267 patients on Q4W/Q8W/Q8W and 85.1% of the 316 patients on Q4W/Q4W/Q4W maintained PASI=0 through two years (OLE Week 48) (mNRI; Figure 2B). Summary Presented at the 42nd Annual Fall Clinical Dermatology Conference | Las Vegas, NV | October 20–23, 2022 Conclusions A high proportion of patients who achieved complete or near- complete skin clearance at Week 16 maintained their response through two years, regardless of BKZ maintenance dosing regimen (Q4W/Q8W/Q8W or Q4W/Q4W/Q4W). D. Thaçi,1 A. Armstrong,2 M. Lebwohl,3 A. Blauvelt,4 C. Paul,5 L. Puig,6 M. Wang,7 V. Vanvoorden,8 C. Madden,7 S. Wiegratz,9 D. Deherder,10 K.B. Gordon11 Maintenance of bimekizumab efficacy through 2 years in patients with moderate to severe plaque psoriasis: Pooled results from five phase 3/3b trials Previously presented at SPIN 2022 Institutions: 1Institute and Comprehensive Center for Inflammation Medicine, University of Lübeck, Lübeck, Germany; 2Keck School of Medicine of USC, Dermatology, Los Angeles, California, USA; 3Icahn School of Medicine at Mount Sinai, New York, New York, USA; 4Oregon Medical Research Center, Portland, Oregon, USA; 5Toulouse University and CHU, Toulouse, France; 6Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; 7UCB Pharma, Raleigh, North Carolina, USA; 8UCB Pharma, Brussels, Belgium; 9UCB Pharma, Monheim, Germany; 10UCB Pharma, Braine-l’Alleud, Belgium; 11Medical College of Wisconsin, Milwaukee, Wisconsin, USA. References: 1Warren RB et al. N Engl J Med 2021;385:130–141, NCT03412747; 2Reich K et al. Lancet 2021;397:487–498, NCT03370133; 3Gordon KB et al. Lancet 2021;397:475–486, NCT03410992; 4Reich K et al. N Engl J Med 2021;385:142–152, NCT03536884; 5BE BRIGHT: NCT03598790. Author Contributions: Substantial contributions to study conception/design, or acquisition/analysis/ interpretation of data: DT, AA, ML, AB, CP, LP, MW, VV, CM, SW, DD, KBG; Drafting of the publication, or revising it critically for important intellectual content: DT, AA, ML, AB, CP, LP, MW, VV, CM, SW, DD, KBG; Final approval of the publication: DT, AA, ML, AB, CP, LP, MW, VV, CM, SW, DD, KBG. Author Disclosures: DT: Honoraria for participation on advisory boards, as a speaker, and for consultancy from AbbVie, Almirall, Amgen, Biogen, Boehringer Ingelheim, BMS, Celltrion, Eli Lilly, Galapagos, Janssen, LEO Pharma, Novartis, Pfizer, Regeneron, Samsung, Sanofi Genzyme, and UCB Pharma; research grants received from LEO Pharma and Novartis. AA: Has served as a research investigator and/or scientific advisor to AbbVie, Almirall, Arcutis, ASLAN, Boehringer Ingelheim, Bristol Myers Squibb, Dermavant, Dermira, Eli Lilly, EPI, Incyte, Janssen, LEO Pharma, Nimbus, Novartis, Ortho Dermatologics, Pfizer, Regeneron, Sun Pharma, Sanofi, and UCB Pharma. ML: Employee of Mount Sinai and receives research funds from AbbVie, Amgen, Arcutis, Avotres, Boehringer Ingelheim, Dermavant, Eli Lilly, Incyte, Janssen, Ortho Dermatologics, Regeneron, and UCB Pharma; consultant for Aditum Bio, Almirall, AltruBio, AnaptysBio, Arcutis, Aristea Therapeutics, Arrive Technologies, Avotres Therapeutics, BiomX, Boehringer Ingelheim, Bristol Myers Squibb, Cara Therapeutics, Castle Biosciences, Corrona, Dermavant Sciences, Dr. Reddy’s Laboratories, Evelo Biosciences, Evommune, Facilitation of International Dermatology Education, Forte Biosciences, Foundation for Research and Education in Dermatology, Helsinn Therapeutics, Hexima, LEO Pharma, Meiji Seika Pharma, Mindera, Pfizer, Seanergy, and Verrica. AB: Has served as a speaker (received honoraria) for AbbVie, Arcutis, Bristol Myers Squibb, Eli Lilly, Pfizer, Regeneron, Sanofi, and UCB Pharma, served as a scientific adviser (received honoraria) for AbbVie, Abcentra, Affibody, Aligos, Almirall, Alumis, Amgen, Anaptysbio, Arcutis, Arena, Aslan, Athenex, Bluefin Biomedicine, Boehringer Ingelheim, Bristol Myers Squibb, Cara Therapeutics, Dermavant, EcoR1, Eli Lilly, Escient, Evelo, Evommune, Forte, Galderma, HighlightII Pharma, Incyte, InnoventBio, Janssen, Landos, LEO Pharma, Merck, Novartis, Pfizer, Rapt, Regeneron, Sanofi Genzyme, Spherix Global Insights, Sun Pharma, TLL Pharmaceutical, TrialSpark, UCB Pharma, Vibliome, and Xencor, and has acted as a clinical study investigator (institution has received clinical study funds) for AbbVie, Acelyrin, Almirall, Amgen, Arcutis, Athenex, Boehringer Ingelheim, Bristol Myers Squibb, Concert, Dermavant, Eli Lilly , Evelo, Evommune, Galderma, Incyte, Janssen, Leo, Merck, Novartis, Pfizer, Regeneron, Sun Pharma, and UCB Pharma. CP: Consulting fees and/or grants from AbbVie, Almirall, Amgen, Boehringer Ingelheim, Celgene, GSK, Janssen Cilag, LEO Pharma, Eli Lilly, Novartis, Pierre Fabre, Pfizer, Sanofi Regeneron, and UCB Pharma. LP: Received consultancy/speaker’s honoraria from and/or participated in trials sponsored by AbbVie, Almirall, Amgen, Baxalta, Biogen, Boehringer Ingelheim, Celgene, Eli Lilly, Gebro, Janssen, JS BIOCAD, LEO Pharma, Merck-Serono, MSD, Mylan, Novartis, Pfizer, Regeneron, Roche, Samsung-Bioepis, Sandoz, Sanofi Genzyme, and UCB Pharma. MW, VV, CM, SW, DD: Employees and shareholders of UCB Pharma. KBG: Has received consulting fees from AbbVie, Almirall, Amgen, Boehringer Ingelheim, BMS, Celgene, Dermira, Eli Lilly, Janssen, Novartis, Pfizer, Sun Pharma, and UCB Pharma; research support from AbbVie, BMS, Celgene, Eli Lilly, Janssen, Novartis, and UCB Pharma. Acknowledgments: This study was funded by UCB Pharma. We thank the patients and their caregivers in addition to the investigators and their teams who contributed to this study. The authors acknowledge Natalie Nunez Gomez, MD, UCB Pharma, Monheim, Germany, for critical review, Yasha Najafi, MSc, Costello Medical, London, UK, for medical writing and editorial assistance, and the Costello Medical design team, UK for graphic design assistance. All costs associated with development of this poster were funded by UCB Pharma. Table 1 Baseline characteristics: BKZ-randomized Week 16 responders BKZ: bimekizumab; BSA: body surface area; DLQI: Dermatology Life Quality Index; IGA: Investigator’s Global Assessment; mNRI: modified non responder imputation; NRI: non-responder imputation; OC: observed case; OLE: open-label extension; PASI: Psoriasis Area and Severity Index; PASI 90: ≥90% improvement from baseline in PASI; Q4W: every four weeks; Q8W: every eight weeks; SD: standard deviation; Wk: week. A) PASI ≤2 Figure 1 Study design: Included patients Figure 2 Maintenance of PASI response through two years in BKZ-randomized Week 16 responders (pooled; mNRI, NRI, OC) B) PASI=0 PASI ≤2 responders (N=994) PASI=0 responders (N=719) Age (years), mean ± SD 45.0 ± 13.5 45.1 ± 13.3 Male, n (%) 689 (69.3) 497 (69.1) Caucasian, n (%) 871 (87.6) 642 (89.3) Weight (kg), mean ± SD 88.9 ± 20.7 87.9 ± 19.6 Duration of psoriasis (years), mean ± SD 18.2 ± 12.6 18.2 ± 12.6 PASI, mean ± SD 20.8 ± 7.5 20.8 ± 7.3 BSA (%), mean ± SD 26.3 ± 15.5 25.8 ± 15.0 IGA, n (%) 3: moderate 661 (66.5) 476 (66.2) 4: severe 330 (33.2) 242 (33.7) DLQI, mean ± SD 10.7 ± 6.4 10.9 ± 6.5 Any prior systemic therapy, n (%) 768 (77.3) 568 (79.0) Prior biologic therapy, n (%)a 382 (38.4) 282 (39.2) All BKZ-treated patients received BKZ 320 mg Q4W through Week 16. Data are reported for all patients with a response at Week 16 who enrolled in BE BRIGHT or the BE RADIANT OLE, regardless of dosing regimen. aPatients with multiple prior biologic use included in n (%). BKZ 320 mg Q4W OLE Week 48 Week 96 Week 100/104 OLE Week 16/24d Week 64 Week 76/80 OLE Week 0b Week 48 Week 52/56c BE RADIANT BE BRIGHTa Week 16 Response assessment Initial treatment period Maintenance period Open-label treatment period BE SURE, BE VIVID, BE READY, and BE RADIANT1–4 (pooled, double-blind) BKZ 320 mg Q8W BE BRIGHT and BE RADIANT5 (open-label extension) BKZ 320 mg Q4W N=1,362