NCT03928743: BE MOBILE 2

A Study to Evaluate the Efficacy and Safety of Bimekizumab in Subjects With Active Ankylosing Spondylitis

Completed Phase 3 Results posted Last updated 24 December 2025

What this trial tests

Phase 3 trial testing Bimekizumab in Ankylosing Spondylitis in 332 participants. Completed in 8 August 2022.

Timeline

25 April 2019

Primary endpoint
3 September 2021

8 August 2022

Quick facts

Lead sponsor	UCB Biopharma SRL
Phase	Phase 3
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	quadruple
Primary purpose	treatment
Enrollment	332
Start date	25 April 2019
Primary completion	3 September 2021
Estimated completion	8 August 2022
Sites	83 locations across France, Japan, Netherlands, Belgium, United Kingdom, Germany, Hungary, Poland

Drugs / interventions tested

• Bimekizumab (BIMEKIZUMAB) — full drug profile →
• Placebo

Conditions studied

• Ankylosing Spondylitis — all drugs for Ankylosing Spondylitis →

Sponsor

UCB Biopharma SRL — full company profile →

Who can join

18 and older, any sex, with Ankylosing Spondylitis. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Percentage of Participants With Assessment of SpondyloArthritis International Society 40% Response Criteria (ASAS40) Response at Week 16 Primary · Week 16

ASAS40 response was defined as relative improvements of at least 40% and absolute improvement of at least 2 units on a 0 to 10 Numeric Rating Scale (NRS), where 0 is "not active" and 10 is "very active" in at least 3 of the 4 domains: Patient's Global Assessment of Disease Activity (PGADA) assessed disease activity on a scale of 0 \[not active\] to 10 \[very active\], higher score=more disease activity, Pain assessment on a scale of 0 \[no pain\] to 10 \[most severe pain\], higher score=more severity, Function (Bath Ankylosing Spondylitis Functional Index (BASFI)) assessed participant's level

Group	Value	95% CI
Placebo (up to Week 16)	22.5
Bimekizumab 160 mg Q4W (up to Week 16)	44.8

Percentage of Participants With Assessment of SpondyloArthritis International Society 40% Response Criteria (ASAS40) Response in TNFα Inhibitor-naïve Participants at Week 16 Secondary · Week 16

ASAS40 response was defined as relative improvements of at least 40% and absolute improvement of at least 2 units on a 0 to 10 NRS, where 0 is "not active" and 10 is "very active" in at least 3 of the 4 domains: PGADA assessed disease activity on a scale of 0 \[not active\] to 10 \[very active\], higher score=more disease activity, Pain assessment on a scale of 0 \[no pain\] to 10 \[most severe pain\], higher score=more severity, Function (BASFI) assessed participant's level of ability on a scale of 0 \[easy\] to 10 \[impossible\], Inflammation (morning stiffness intensity and duration, mean o

Group	Value	95% CI
Placebo (up to Week 16)	23.4
Bimekizumab 160 mg Q4W (up to Week 16)	45.7

Percentage of Participants With Assessment of SpondyloArthritis International Society 20% Response Criteria (ASAS20) Response at Week 16 Secondary · Week 16

ASAS20 response was defined as relative improvements of at least 20% and absolute improvement of at least 1 unit on a 0 to 10 NRS, where 0 is "not active" and 10 is "very active" in at least 3 of the 4 domains: PGADA assessed disease activity on a scale of 0 \[not active\] to 10 \[very active\], higher score=more disease activity, Pain assessment on a scale of 0 \[no pain\] to 10 \[most severe pain\], higher score=more severity, Function (BASFI) assessed participant's level of ability on a scale of 0 \[easy\] to 10 \[impossible\], Inflammation (morning stiffness intensity and duration, mean of

Group	Value	95% CI
Placebo (up to Week 16)	43.2
Bimekizumab 160 mg Q4W (up to Week 16)	66.1

Change From Baseline in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Total Score at Week 16 Secondary · Baseline, Week 16

BASDAI is a validated self-reported instrument, which consisted of 6 questions to measure the disease activity of ankylosing spondylitis (AS) from the participant's perspective. It measured the severity of fatigue, spinal and peripheral joint pain and swelling, enthesitis, and morning stiffness (both severity and duration). Each question was rated using a numerical rating scale from 0 (none) to 10 (very severe), higher score=high disease activity. The BASDAI score was calculated by computing the mean of questions 5 and 6 and adding it to the sum of questions 1 to 4. This score was then divided

Group	Value	95% CI
Placebo (up to Week 16)	-1.70	± 0.21
Bimekizumab 160 mg Q4W (up to Week 16)	-2.74	± 0.17

Percentage of Participants With Assessment of SpondyloArthritis International Society (ASAS) Partial Remission (PR) at Week 16 Secondary · Week 16

The Assessment of SpondyloArthritis International Society partial remission was defined as a score of less than or equal to (\<=) 2 units (on a scale of 0-10, where 0=no disease activity and 10=high disease activity) in each of the 4 domains. These 4 domains included: PGADA assessed disease activity on a scale of 0 \[not active\] to 10 \[very active\], higher score=more disease activity, Pain assessment on a scale of 0 \[no pain\] to 10 \[most severe pain\], higher score=more severity, Function (BASFI) assessed participant's level of ability on a scale of 0 \[easy\] to 10 \[impossible\], Infla

Group	Value	95% CI
Placebo (up to Week 16)	7.2
Bimekizumab 160 mg Q4W (up to Week 16)	24.0

Percentage of Participants With Ankylosing Spondylitis Disease Activity Score Major Improvement (ASDAS-MI) at Week 16 Secondary · Week 16

ASDAS-MI is achieved when there is a reduction (improvement) of greater than or equal to (\>=) 2.0 in the Ankylosing Spondylitis Disease Activity Score (ASDAS) relative to Baseline. ASDAS is calculated as the sum of the following components: 1) 0.121 × Total back pain (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Q2 result), 2) 0.058 × Duration of morning stiffness (BASDAI Q6 result), 3) 0.110 × Patient's Global Assessment of Disease Activity (PGADA), 4) 0.073 × Peripheral pain/swelling (BASDAI Q3 result), 5) 0.579 × (natural logarithm of the C-reactive protein (CRP) \[mg/L\] +

Group	Value	95% CI
Placebo (up to Week 16)	5.4
Bimekizumab 160 mg Q4W (up to Week 16)	25.8

Percentage of Participants With Assessment of SpondyloArthritis International Society (ASAS) 5/6 Response at Week 16 Secondary · Week 16

The Assessment of SpondyloArthritis International Society (ASAS) 5/6 response is defined as achieving at least 20% improvement in 5 of 6 domains: PGADA assessed disease activity on a scale of 0 \[not active\] to 10 \[very active\], higher score=more disease activity, Pain assessment on a scale of 0 \[no pain\] to 10 \[most severe pain\], higher score=more severity), Function (BASFI) assessed participant's level of ability on a scale of 0 \[easy\] to 10 \[impossible\], Inflammation (morning stiffness intensity and duration, mean of Q5 and Q6 of BASDAI defined as 6 item questionnaire: measured d

Group	Value	95% CI
Placebo (up to Week 16)	18.9
Bimekizumab 160 mg Q4W (up to Week 16)	49.3

Change From Baseline in Bath Ankylosing Spondylitis Functional Index (BASFI) at Week 16 Secondary · Baseline, Week 16

The Bath Ankylosing Spondylitis Functional Index (BASFI) assesses physical function in comprising 10 items relating to activities during the past week. Each item ranged from 0 ('Easy') to 10 ('Impossible'). The BASFI is the mean of the 10 scores such that the total score ranges from 0 to 10, with lower scores indicating better physical function. A negative value in BASFI change from Baseline indicates an improvement from Baseline. The higher the negative value the better the improvement.

Group	Value	95% CI
Placebo (up to Week 16)	-0.95	± 0.20
Bimekizumab 160 mg Q4W (up to Week 16)	-2.00	± 0.16

Change From Baseline in Nocturnal Spinal Pain Score Numeric Rating Scale (NRS) at Week 16 Secondary · Baseline, Week 16

Nocturnal spinal pain experienced by ankylosing spondylitis (AS) participants is measured by one question: pain in the spine at night due to AS?. When responding, the participant is to consider the average amount of pain in the preceding week. It is assessed on a numerical scale of 0 (no pain) to 10 (most severe pain) units. A lower score indicates less pain and a negative change represents an improvement.

Group	Value	95% CI
Placebo (up to Week 16)	-1.68	± 0.25
Bimekizumab 160 mg Q4W (up to Week 16)	-3.16	± 0.20

Change From Baseline in Ankylosing Spondylitis Quality of Life (ASQoL) Total Score at Week 16 Secondary · Baseline, Week 16

The Ankylosing Spondylitis Quality of Life (ASQoL), a validated disease-specific 18-item questionnaire, has been developed specifically for measuring health-related quality of life (HRQoL) in participants with ankylosing spondylitis and has shown to be responsive in axial spondyloarthritis (axSpA). Each statement on the ASQoL is given a score of 1=Yes or 0=No. A score of "1" was given where the item was affirmed, indicating adverse quality of life. All item scores were summed to generate the total score ranging from 0 to 18 with a higher score indicating worse health-related quality of life. A

Group	Value	95% CI
Placebo (up to Week 16)	-3.07	± 0.41
Bimekizumab 160 mg Q4W (up to Week 16)	-4.59	± 0.32

Change From Baseline in the Short Form 36-Item Health Survey (SF-36) Physical Component Summary (PCS) Score at Week 16 Secondary · Baseline, Week 16

SF-36 is a 36-item HRQoL instrument with recall period of 4 weeks. Items are grouped into 8 domains: Physical Functioning (10 items), Role Physical (4 items), Bodily Pain (2 items), General Health (5 items), Vitality (4 items), Social Functioning (2 items), Role Emotional (3 items), Mental Health (5 items) and 1 item for Health Transition during last year. PCS and Mental Component Summary (MCS) scores are calculated from 8 domains (excluding Health Transition item). Each of SF-36 derived raw scores range from 0 to 100; higher score = better function. PCS score is calculated from 8 domain score

Group	Value	95% CI
Placebo (up to Week 16)	5.17	± 0.82
Bimekizumab 160 mg Q4W (up to Week 16)	8.54	± 0.67

Change From Baseline in Bath Ankylosing Spondylitis Disease Metrology Index (BASMI) at Week 16 Secondary · Baseline, Week 16

The Bath Ankylosing Spondylitis Disease Metrology Index characterizes the spinal mobility of participants with axial Spondyloarthritis (SpA) and Ankylosing Spondylitis. It is a disease-specific measure consisting of 5 clinical measures to reflect participant axial status: cervical rotation; tragus to wall distance; lateral lumbar flexion; lumbar flexion (modified Schober test); intermalleolar distance. According to the linear definition of the BASMI a score of 0 to 10 was calculated for each item based on the measurement. The mean of the 5 scores provides the total BASMI score (ranging from 0

Group	Value	95% CI
Placebo (up to Week 16)	-0.17	± 0.09
Bimekizumab 160 mg Q4W (up to Week 16)	-0.45	± 0.07

Adverse events — posted to ClinicalTrials.gov

Time frame: From Baseline (Day 1) until Safety-Follow-Up (up to Week 68). Reporting threshold: 5%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Double Blind Treatment Period (up to Week 16): Placebo

Serious: 1/111 (1%)

Deaths: 0/111

Double Blind Treatment Period (up to Week 16): Bimekizumab 160 mg Q4W

Serious: 5/221 (2%)

Deaths: 0/221

Maintenance Period (Week 16 up to Week 52): Bimekizumab 160 mg Q4W

Serious: 15/319 (5%)

Deaths: 0/319

Overall Period (up to Week 48 + 20 Weeks SFU): Bimekizumab 160 mg Q4W

Serious: 20/330 (6%)

Deaths: 0/330

Serious adverse events (21 terms)

Reaction	System	Double Blind Treatment Per…	Double Blind Treatment Per…	Maintenance Period (Week 1…	Overall Period (up to Week…
Syncope	Nervous system disorders	—	—	—	—
Goitre	Endocrine disorders	—	—	—	—
Colitis ulcerative	Gastrointestinal disorders	—	—	—	—
Crohn's disease	Gastrointestinal disorders	—	—	—	—
Cholelithiasis	Hepatobiliary disorders	—	—	—	—
Hepatitis A	Infections and infestations	—	—	—	—
Viral infection	Infections and infestations	—	—	—	—
Depression	Psychiatric disorders	—	—	—	—
Sinus node dysfunction	Cardiac disorders	—	—	—	—
Hiatus hernia	Gastrointestinal disorders	—	—	—	—
Ileus paralytic	Gastrointestinal disorders	—	—	—	—
Diverticulitis	Infections and infestations	—	—	—	—
Cellulitis	Infections and infestations	—	—	—	—
Otitis media	Infections and infestations	—	—	—	—
Infectious pleural effusion	Infections and infestations	—	—	—	—
Erysipelas	Infections and infestations	—	—	—	—
Radius fracture	Injury, poisoning and procedural complications	—	—	—	—
Superficial spreading melanoma stage I	Neoplasms benign, malignant and unspecified (incl cysts and polyps)	—	—	—	—
Uterine leiomyoma	Neoplasms benign, malignant and unspecified (incl cysts and polyps)	—	—	—	—
Suicidal ideation	Psychiatric disorders	—	—	—	—
Rhinoplasty	Surgical and medical procedures	—	—	—	—

Other adverse events (5 terms — click to expand)

Reaction	System	Double Blind Treatment Per…	Double Blind Treatment Per…	Maintenance Period (Week 1…	Overall Period (up to Week…
Nasopharyngitis	Infections and infestations	—	—	—	—
Upper respiratory tract infection	Infections and infestations	—	—	—	—
Oral Candidiasis	Infections and infestations	—	—	—	—
Diarrhoea	Gastrointestinal disorders	—	—	—	—
Headache	Nervous system disorders	—	—	—	—

Most-reported serious reactions: Syncope, Goitre, Colitis ulcerative, Crohn's disease, Cholelithiasis, Hepatitis A, Viral infection, Depression.

Data from ClinicalTrials.gov NCT03928743 adverse events section.

Sponsor's own description

The purpose of the study is to demonstrate the efficacy, safety and tolerability of bimekizumab administered subcutaneously (sc) compared to placebo in the treatment of subjects with active ankylosing spondylitis (AS).

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. Antibodies to watch in 2020.
   Kaplon H, Muralidharan M, Schneider Z, Reichert JM. · · 2020 · cited 332× · PMID 31847708 · DOI 10.1080/19420862.2019.1703531
2. Targeted Immunotherapy for Autoimmune Disease.
   Jung SM, Kim WU. · · 2022 · cited 113× · PMID 35291650 · DOI 10.4110/in.2022.22.e9
3. Evolving understanding of autoimmune mechanisms and new therapeutic strategies of autoimmune disorders.
   Song Y, Li J, Wu Y. · · 2024 · cited 109× · PMID 39362875 · DOI 10.1038/s41392-024-01952-8
4. Dual neutralisation of interleukin-17A and interleukin-17F with bimekizumab in patients with active ankylosing spondylitis: results from a 48-week phase IIb, randomised, double-blind, placebo-controlled, dose-ranging study.
   van der Heijde D, Gensler LS, Deodhar A, Baraliakos X, et al · · 2020 · cited 106× · PMID 32253184 · DOI 10.1136/annrheumdis-2020-216980
5. The IL23-IL17 Immune Axis in the Treatment of Ulcerative Colitis: Successes, Defeats, and Ongoing Challenges.
   Noviello D, Mager R, Roda G, Borroni RG, et al · · 2021 · cited 105× · PMID 34079536 · DOI 10.3389/fimmu.2021.611256
6. Efficacy and safety of bimekizumab in axial spondyloarthritis: results of two parallel phase 3 randomised controlled trials.
   van der Heijde D, Deodhar A, Baraliakos X, Brown MA, et al · · 2023 · cited 87× · PMID 36649967 · DOI 10.1136/ard-2022-223595
7. Targeting interleukin-17 in chronic inflammatory disease: A clinical perspective.
   Zwicky P, Unger S, Becher B. · · 2020 · cited 66× · PMID 31727781 · DOI 10.1084/jem.20191123
8. Bimekizumab treatment in patients with active axial spondyloarthritis: 52-week efficacy and safety from the randomised parallel phase 3 BE MOBILE 1 and BE MOBILE 2 studies.
   Baraliakos X, Deodhar A, van der Heijde D, Magrey M, et al · · 2024 · cited 42× · PMID 37793792 · DOI 10.1136/ard-2023-224803