BIMZELX® (bimekizumab-bkzx) demonstrates superior efficacy over SKYRIZI® (risankizumab-rzaa) in psoriatic arthritis: BE BOLD Week 16 data

BE BOLD Week 16 results

• BIMZELX met the primary endpoint for BE BOLD of superiority in ACR50 at Week 16, achieved by 49.1% receiving BIMZELX vs 38.4% receiving risankizumab, with statistical significance (p=0.0078).^1†
• The first ranked secondary endpoint, MDA at Week 16, was numerically higher in BIMZELX (43.0%) vs risankizumab (39.9%) at Week 16 but did not reach statistical significance within the prespecified testing hierarchy (p=0.4408).^1† Sequential testing stopped at this point due to the study design, and subsequent ranked secondary endpoints were descriptive only, with numerically higher proportions achieved with BIMZELX.¹
• Numerically higher proportions of those treated with BIMZELX vs risankizumab achieved the ranked secondary endpoint of simultaneous ACR50+PASI100 at Week 16 (33.5% vs 24.4%; nominal p=0.0800).^1‡ The ranked secondary endpoint of ACR50 at Week 4 was considered nominally significant for BIMZELX over risankizumab (19.9% vs 7.2%; nominal p<0.0001); endpoints are considered 'nominally significant' if the statistical test for that endpoint meets its pre‑specified alpha level (i.e., p<0.05 in this case) before accounting for multiplicity, hierarchy, or other adjustments required in a confirmatory analysis.^1,3†
• Of the exploratory endpoints: PASI100 at Week 16 was met by 53.4% treated with BIMZELX and 46.6% of those treated with risankizumab,^1‡ DAPSA LDA+REM, DAPSA score ≤14, at Week 16 was met by 65.3% treated with BIMZELX and 54.7% of those treated with risankizumab.^1†
• No new safety signals were identified in either treatment arm.¹ All Candida infections were mild or moderate; none were serious, systemic, or led to study discontinuation.¹ Rates of treatment-emergent adverse events (TEAEs) were 57.0% (158/277) with BIMZELX and 52.0% (143/275) with risankizumab.¹
• Serious TEAEs occurred in 5 (1.8%) BIMZELX-treated patients and 8 (2.9%) risankizumab-treated patients. Severe TEAEs were reported in 5 (1.8%) BIMZELX-treated patients and 5 (1.8%) risankizumab-treated patients.¹
• Discontinuations due to TEAEs were low and identical between treatment arms.¹ BE BOLD was not statistically powered to compare safety outcomes between BIMZELX and risankizumab.¹

^* nominally significant^1
† All results are assessed with non-responder imputation (NRI): All visits following discontinuation due to adverse events or lack of efficacy were treated as non-response. Results are reported from the Bimekizumab Total group (BKZ Total), which includes those receiving BIMZELX 160 mg every four weeks (Q4W) in those with no or mild psoriasis (n=248), and those receiving BIMZELX 320 mg every four weeks to Week 16 and then every eight weeks thereafter (Q4W/Q8W) in those with moderate or severe psoriasis (n=29).¹ Those in the risankizumab group (n=276) received risankizumab 150 mg at baseline, Week 4, and Week 16 regardless of whether the recipient had no or mild psoriasis (n=245), or moderate or severe psoriasis (n=31)^1
‡ In a subgroup of people also living with psoriasis affecting at least 3% of body surface area at baseline.¹ In this subgroup: BKZ Total, n=176 [BIMZELX 160 mg Q4W n=147; BIMZELX 320 mg Q4W/Q8W n=29]; risankizumab group, n=176.¹ Differences between BIMZELX and risankizumab in ACR50+PASI100 at Week 16 and PASI100 at Week 16 were not statistically significant¹

Notes to Editors

• ACR50: A 50% or greater improvement from baseline in American College of Rheumatology response criteria, including at least a 50% improvement in tender and swollen joint counts as well as 50% improvement in three additional criteria (physician global, patient global, patient pain, function, and CRP/erythrocyte sedimentation rate).⁴ This represents a stringent efficacy outcome in psoriatic arthritis.^5-6
• MDA: Minimal Disease Activity (MDA), a dichotomous endpoint (i.e., either it is reached or it is not) demonstrating minimum inflammatory disease. The MDA score comprises seven relevant disease-related domains (tender/swollen joint count, skin, physical function, pain, enthesis, general patient-based evaluation), such that achieving five or more of the seven indicates MDA.⁷ A participant in BE BOLD was considered as having MDA if five or more of the following seven criteria were fulfilled:⁸
  • Tender joint count ≤1
  • Swollen joint count ≤1
  • PASI ≤1 or BSA ≤3 (less than or equal to 3% body surface area affected)
  • PtAAP VAS ≤15 (Patient's Assessment of Arthritis Pain score ≤15: 0=no pain;100=most severe pain)
  • PGA-PsA VAS ≤20 (Physician's Global Assessment in Psoriatic Arthritis score ≤20: 0=very good, asymptomatic, no limitation of normal activities; 100=very poor, very severe symptoms which were intolerable, inability to carry out all normal activities)
  • HAQ-DI ≤0.5 (Health Assessment Questionnaire-Disability Index score ≤0.5: degree of difficulty experienced in eight domains of daily living activities [20 questions], total score [0–3] computed from item scores, with lower scores meaning less disability)
  • Tender enthesial points ≤1
• PASI100: 100% improvement from baseline in Psoriasis Area and Severity Index (PASI), indicating complete skin clearance.⁹
• DAPSA LDA+REM: Disease Activity Index for Psoriatic Arthritis (DAPSA) low disease activity (LDA)+remission(REM). DAPSA is a continuous scale incorporating tender/swollen joint counts, Patient Global Assessment (PtGA) of PsA activity, patient pain assessment and C-reactive protein (CRP) levels. DAPSA classifications validated for PsA include: ≤4 (REM), >4–≤14 (LDA), >14–≤28 (moderate disease activity) and >28 (high disease activity).^1,10

About psoriatic arthritis

Psoriatic arthritis (PsA) is a serious, highly heterogeneous, chronic, systemic inflammatory condition affecting both the joints and skin with a prevalence of 0.02 percent to 0.25 percent of the population.¹¹ Of people living with psoriasis, approximately 30 percent progress to also develop psoriatic arthritis.¹² It manifests as joint pain and stiffness, skin plaques, swollen toes and fingers (dactylitis), and inflammation of the sites where tendons or ligaments insert into the bone (enthesitis).¹³ The burden on those living with PsA extends beyond physical discomfort to reduced quality of life, with comorbidities including hypertension, cardiovascular disease, anxiety, and depression.¹⁴ In PsA, uncontrolled active disease can lead to long-term structural damage.¹⁵

About the BE BOLD trial

BE BOLD is a multicenter, randomized, double-blind, risankizumab-controlled, parallel-group study designed to evaluate the efficacy and safety of BIMZELX in adult study participants (n=553) with active psoriatic arthritis (PsA).^1,8 The study includes adults with active PsA who are naïve to biologic treatments or who had previous exposure to one tumor necrosis factor-inhibitor (TNFi) with an inadequate or intolerant response.⁸

The primary endpoint in BE BOLD is ACR50 at Week 16.⁸ The study has a double-blinded methodology until Week 24.¹⁶ In the study, participants were randomized 1:1 to receive either BIMZELX or risankizumab.¹⁶

For details about BE BOLD: https://clinicaltrials.gov/study/NCT06624228.

BIMZELX^® is a registered trademark of the UCB Group of Companies. SKYRIZI^® is a registered trademark of AbbVie Inc.

About BIMZELX^® (bimekizumab-bkzx) in the U.S.
BIMZELX is a humanized monoclonal IgG1 antibody that is designed to selectively inhibit both interleukin 17A (IL-17A) and interleukin 17F (IL-17F), two key cytokines driving inflammatory processes.² Elevated levels of IL-17A and IL-17F are found in lesional psoriatic skin.²

The approved indications for BIMZELX in the U.S. are:²

• Plaque psoriasis: BIMZELX is approved for the treatment of moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy
  
  
• Psoriatic arthritis: BIMZELX is indicated for the treatment of adult patients with active psoriatic arthritis
  
  
• Non-radiographic axial spondyloarthritis: BIMZELX is indicated for the treatment of adult patients with active non-radiographic axial spondyloarthritis with objective signs of inflammation
  
  
• Ankylosing spondylitis: BIMZELX is indicated for the treatment of adult patients with active ankylosing spondylitis
  
  
• Hidradenitis suppurativa: BIMZELX is indicated for the treatment of adults with moderate to severe hidradenitis suppurativa

BIMZELX U.S. IMPORTANT SAFETY INFORMATION

IMPORTANT SAFETY INFORMATION

Suicidal Ideation and Behavior
BIMZELX (bimekizumab-bkzx) may increase the risk of suicidal ideation and behavior (SI/B). A causal association between treatment with BIMZELX and increased risk of SI/B has not been definitively established. Prescribers should weigh the potential risks and benefits before using BIMZELX in patients with a history of severe depression or SI/B. Advise monitoring for the emergence or worsening of depression, suicidal ideation, or other mood changes. If such changes occur, instruct to promptly seek medical attention, refer to a mental health professional as appropriate, and re-evaluate the risks and benefits of continuing treatment.

Infections
BIMZELX may increase the risk of infections, including serious infections. Do not initiate treatment with BIMZELX in patients with any clinically important active infection until the infection resolves or is adequately treated. In patients with a chronic infection or a history of recurrent infection, consider the risks and benefits prior to prescribing BIMZELX. Instruct patients to seek medical advice if signs or symptoms suggestive of clinically important infection occur. If a patient develops such an infection or is not responding to standard therapy, monitor the patient closely and do not administer BIMZELX until the infection resolves.

Tuberculosis
Evaluate patients for tuberculosis (TB) infection prior to initiating treatment with BIMZELX. Avoid the use of BIMZELX in patients with active TB infection. Initiate treatment of latent TB prior to administering BIMZELX. Consider anti-TB therapy prior to initiation of BIMZELX in patients with a past history of latent or active TB in whom an adequate course of treatment cannot be confirmed. Closely monitor patients for signs and symptoms of active TB during and after treatment.

Liver Biochemical Abnormalities
Elevated serum transaminases were reported in clinical trials with BIMZELX. Test liver enzymes, alkaline phosphatase, and bilirubin at baseline, periodically during treatment with BIMZELX, and according to routine patient management. If treatment-related increases in liver enzymes occur and drug-induced liver injury is suspected, interrupt BIMZELX until a diagnosis of liver injury is excluded. Permanently discontinue use of BIMZELX in patients with causally associated combined elevations of transaminases and bilirubin. Avoid use of BIMZELX in patients with acute liver disease or cirrhosis.

Inflammatory Bowel Disease
Cases of inflammatory bowel disease (IBD) have been reported in patients treated with IL-17 inhibitors, including BIMZELX. Avoid use of BIMZELX in patients with active IBD. During BIMZELX treatment, monitor patients for signs and symptoms of IBD and discontinue treatment if new onset or worsening of signs and symptoms occurs.

Immunizations
Prior to initiating therapy with BIMZELX, complete all age-appropriate vaccinations according to current immunization guidelines. Avoid the use of live vaccines in patients treated with BIMZELX.

Most Common Adverse Reactions
Most common (≥ 1%) adverse reactions in plaque psoriasis and hidradenitis suppurativa include upper respiratory tract infections, oral candidiasis, headache, injection site reactions, tinea infections, gastroenteritis, herpes simplex infections, acne, folliculitis, other candida infections, and fatigue.

Most common (≥ 2%) adverse reactions in psoriatic arthritis include upper respiratory tract infections, oral candidiasis, headache, diarrhea, and urinary tract infections.

Most common (≥ 2%) adverse reactions in non-radiographic axial spondyloarthritis include upper respiratory tract infections, oral candidiasis, headache, diarrhea, cough, fatigue, musculoskeletal pain, myalgia, tonsillitis, transaminase increase, and urinary tract infections.

Most common (≥ 2%) adverse reactions in ankylosing spondylitis include upper respiratory tract infections, oral candidiasis, headache, diarrhea, injection site pain, rash, and vulvovaginal mycotic infection.

Please full U.S. Prescribing Information at www.UCB-USA.com/Innovation/Products/BIMZELX.

For further information, contact UCB:

Investor Relations
Yvonne Naughton
T +44.175.344.7521
email yvonne.naughton@ucb.com

Sahar Yazdian
T +32.2.559.91.37
email sahar.yazdian@ucb.com

Corporate Communications
Laurent Schots
T +32.2.559.92.64
email laurent.schots@ucb.com

Brand Communications
Nicole Herga
T +1 773.960.5349
email nicole.herga@ucb.com

About UCB 
UCB, Brussels, Belgium (www.ucb.com), is a global biopharmaceutical company focused on the discovery and development of innovative medicines and solutions to transform the lives of people living with severe diseases of the immune system or of the central nervous system. With approximately 9,000 people in approximately 40 countries, the company generated revenue of €6.1 billion in 2024. UCB is listed on Euronext Brussels (symbol: UCB). Follow us on Twitter: @UCBUSA.

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References

1. McInnes I, et al. Bimekizumab efficacy and safety versus risankizumab in patients with active psoriatic arthritis: 16-week results from a head-to-head, multicentre, randomised, phase 3b study. 2026. EULAR. #LB0001.
2. BIMZELX (bimekizumab) U.S. PI. https://www.ucb-usa.com/Innovation/Products/BIMZELX. Last accessed: May 2026.
3. Bays HE. Alirocumab, Decreased Mortality, Nominal Significance, P Values, Bayesian Statistics, and the Duplicity of Multiplicity. Circulation. 2019 Jul 9;140(2):113-116.
4. Ogdie A, Coates LC, Mease P. Measuring Outcomes in Psoriatic Arthritis. Arthritis Care Res (Hoboken). 2020 Oct;72 Suppl 10(Suppl 10):82-109.
5. Ritchlin CT, et al. Bimekizumab treatment in biologic DMARD-naïve patients with active psoriatic arthritis: 52-week efficacy and safety results from the phase III, randomised, placebo-controlled, active reference BE OPTIMAL study. Ann Rheum Dis. 2023 Nov;82(11):1404-1414.
6. Felson DT, Anderson JJ, Boers M, Bombardier C, Furst D, Goldsmith C, Katz LM, Lightfoot R Jr, Paulus H, Strand V, et al. American College of Rheumatology. Preliminary definition of improvement in rheumatoid arthritis. Arthritis Rheum. 1995 Jun;38(6):727-35.
7. Queiro R, et al. Minimal disease activity (MDA) in patients with recent-onset psoriatic arthritis: predictive model based on machine learning. Arthritis Res Ther. 2022 Jun 24;24(1):153.
8. ClinicalTrials.gov. NCT06624228. Available at: https://www.clinicaltrials.gov/study/NCT06624228. Last accessed: May 2026.
9. Belinchón Romero I, et al; Psoriasis Group of the Spanish Academy of Dermatology and Venereology. PASI 100 response rates in moderate to severe psoriasis: a systematic literature review and analysis of clinical practice guidelines. J Dermatolog Treat. 2022 May;33(3):1661-1669.
10. Schoels MM, Aletaha D, Alasti F, Smolen JS. Disease activity in psoriatic arthritis (PsA): defining remission and treatment success using the DAPSA score. Ann Rheum Dis. 2016;75(5):811-818.
11. Ogdie A, Weiss P. The epidemiology of psoriatic arthritis. Rheum Dis Clin North Am. 2015;41(4):545-568.
12. Mease PJ, Gladman DD, Papp KA, et al. Prevalence of rheumatologist-diagnosed psoriatic arthritis in patients with psoriasis in European/North American dermatology clinics. J Am Acad Dermatol. 2013;69(5):729-735. doi: 10.1016/j.jaad.2013.07.023.
13. Mease PJ, Armstrong AW. Managing patients with psoriatic disease: the diagnosis and pharmacologic treatment of psoriatic arthritis in patients with psoriasis. Drugs. 2014 Mar;74(4):423-41.
14. Lee S, Mendelsohn A, Sarnes E. The burden of psoriatic arthritis: a literature review from a global health systems perspective. P T. 2010 Dec;35(12):680-9.
15. Kwok TSH, Sutton M, Cook RJ, Pereira D, Chandran V, Gladman DD. Musculoskeletal Surgery in Psoriatic Arthritis: Prevalence and Risk Factors. J Rheumatol. 2023 Apr;50(4):497-503.
16. UCB. Data on file.

US-BK-2600451
Date of preparation: May 2026
BIMZELX^® is a registered trademark of the UCB Group of Companies.
©2026 UCB, Inc., Smyrna, GA 30080. All rights reserved.

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