Change in IMT in the distal common carotid arteries (CCA), common bulbs (CB), and internal carotid arteries (ICA) as determined by ultrasound. Higher scores indicate worsening in cardiovascular risk assessment. Change: Week x observation minus Baseline observation.

Mean Total Cholesterol (TC), Low Density Lipoprotein (LDL) and Triglyceride (TGL) blood concentrations, lower values indicated improvement in cardiovascular risk. Mean High Density Lipoprotein (HDL), higher values indicated improvement in cardiovascular risk. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Mean serum homocysteine blood concentrations. Lower values of homocysteine indicate improvement in inflammation. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

ESR is a laboratory test that provides a non-specific measure of inflammation. The test assesses the rate at which red blood cells fall in a test tube. Normal range is 0-30 mm/hour (hr). A higher rate is consistent with inflammation. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

CRP is a laboratory measurement for evaluation of an acute phase reactant of inflammation through the use of an ultrasensitive assay. A decrease in the level of CRP indicates reduction in inflammation and therefore improvement. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

BASDAI a validated self assessment tool to determine disease activity in participant with Ankylosing Spondylitis (AS) using a Visual Analog Scale (VAS) of 0 (none) to 10 (very severe) centimeter (cm). Participant answered 6 questions measuring discomfort, pain and fatigue. Final BASDAI score averages the individual assessments for a final score range of 0-10. Change: Week x observation minus Baseline observation. Higher score indicates greater disability. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

BASDAI a validated self assessment tool used to determine disease activity in participants with AS. Utilizing a VAS of 0 (none) to 10 cm (very severe), participant's answered 6 questions measuring discomfort, pain and fatigue. BASDAI 50 response defined as at least a 50% improvement (decrease) from baseline in BASDAI. Baseline score - score at observation divided by Baseline score * 100 = greater than or equal to 50%.

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 20 = 20% improvement from baseline and an absolute change greater than or equal to (≥) 10 units on a 0-100 millimeter (mm) scale (0 mm = no disease activity; 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 40 = 40% improvement from baseline and an absolute change ≥ 20 units on a 0-100 mm scale (0 mm = no disease activity, 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 50 = 50% improvement (vs. baseline) and an absolute change ≥ 20 units on a 0-100 mm scale (0 mm = no disease activity, 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 70 = 70% improvement (vs. baseline) and an absolute change ≥ 20 units on a 0-100 mm scale (0 mm = no disease activity, 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

ASAS 5/6 consists of 6 domains: the 4 used in ASAS 20 (participant global assessment of disease activity, pain, function, inflammation measured on a 0-100 scale, where 0 = no disease activity and 100=high disease activity) plus spinal mobility and an acute phase reactant, C Reactive Protein (CRP). Achieving ASAS 5/6 requires a 20% improvement compared to baseline in ≥ 5 domains and no worsening in the remaining domain.

Partial remission defined as a score of less than 20 units (on a scale of 0-100, where 0 = no disease activity and 100 = high disease activity) in each of the 4 Assessment in Ankylosing Spondylitis (ASAS) domains: participant global assessment of disease activity, pain, function, and inflammation. For scale, 100=high disease activity.

BASMI is an objective measure of spinal mobility. The BASMI score is composed of 5 measures: cervical rotation, intermalleolar distance, modified Schober's test, lateral flexion and tragus to wall distance. Each measure was scored 0-2 (0=normal mobility, 2=severe reduction) to give a final score ranging 0 to 10. Lower score indicated better spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

While in a neutral position, the participant turned the head as far as possible to the right and then to the left. Using a goniometer the degrees of movement were measured. Two measurements on the right and 2 on the left were made. The best of the two measurements for each side (corresponding to the highest value), were then averaged. Higher score indicated greater spinal mobility. Actual rotation ranged from 3.0 to 99.0 degrees. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Measurement in cm of the distance between the medial malleoli when participant was lying supine with knees straight and feet pointed straight up with legs separated as far as possible, 2 attempts were measured. The best of the two measurements which corresponds to the highest value were reported. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Measurement in cm of distance between marks originally placed while participant was standing erect 10 cm above and 5 cm below the midpoint of a line that joins the posterior superior iliac spines. Distance between marks was re-measured with participant maximally bent forward, knees fully extended, with supine in full flexion. The measurement was carried out two times and best of the two measurements which corresponds to the highest value were reported. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Measurement in cm of distance between the tragus and wall from the right and left side while participant was standing with back against the wall; knees straight; scapulae, buttocks, and heels against the wall; with head in a neutral position. Two measurements on the right and 2 on the left were made. The best of the two measurements for each side (corresponding to the smallest value), were then averaged. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Measurement in cm of distance between participant's middle fingertip and the floor after bending sideways, without bending knees or lifting heels, while attempting to keep shoulders in same place (flexion position). Two measurements on the right and 2 on the left were made. The best of the two measurements for each side (corresponding to the highest value), were then averaged. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

While participant stood with back against the wall and during maximal effort to touch head to the wall, the distance between the occiput (back of head) and the wall was measured. The measurement of two attempts was made and best of the two measurements which corresponds to the highest value were reported. Lower scores indicated improvement in spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Chest expansion defined as the difference in thoracic circumference during full expiration versus full inspiration, measured in cm at the fourth intercostal space (nipple line) while participant was standing. Measurement taken twice and best of the two measurements (corresponding to the highest value of inspiration and smallest value for expiration), were then averaged. Greater chest circumference indicated improvement in spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

Total of all reporting groups

Participants received matched placebo sc injection once per week for 52 weeks.

BA FMD =(maximum diameter -baseline diameter divided by baseline diameter) * 100%. Ultrasound images of BA at rest were followed by BP cuff inflated to at least 50 mm Hg above participants systolic BP for 5 minutes. Cuff released and reactive hyperaemia was produced. BA was imaged continuously from 30 seconds prior cuff inflation to 2 minutes after cuff deflation. Higher scores indicate improved endothelial function. Change: Week x observation minus Baseline observation.

mITT; n=number of participants evaluable at specific time point

Change in IMT in the distal common carotid arteries (CCA), common bulbs (CB), and internal carotid arteries (ICA) as determined by ultrasound. Higher scores indicate worsening in cardiovascular risk assessment. Change: Week x observation minus Baseline observation.

mITT; n=number of participants evaluable at specific time point; N=number of participants evaluable

Mean Total Cholesterol (TC), Low Density Lipoprotein (LDL) and Triglyceride (TGL) blood concentrations, lower values indicated improvement in cardiovascular risk. Mean High Density Lipoprotein (HDL), higher values indicated improvement in cardiovascular risk. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n=number of participants evaluable at specific time point; N=number of participants evaluable

Mean serum homocysteine blood concentrations. Lower values of homocysteine indicate improvement in inflammation. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point; N=number of participants evaluable

ESR is a laboratory test that provides a non-specific measure of inflammation. The test assesses the rate at which red blood cells fall in a test tube. Normal range is 0-30 mm/hour (hr). A higher rate is consistent with inflammation. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; N=number of participants evaluable; n= number of participants evaluable at specific time point

CRP is a laboratory measurement for evaluation of an acute phase reactant of inflammation through the use of an ultrasensitive assay. A decrease in the level of CRP indicates reduction in inflammation and therefore improvement. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; N=number of participants evaluable; n= number of participants evaluable at specific time point

BASDAI a validated self assessment tool to determine disease activity in participant with Ankylosing Spondylitis (AS) using a Visual Analog Scale (VAS) of 0 (none) to 10 (very severe) centimeter (cm). Participant answered 6 questions measuring discomfort, pain and fatigue. Final BASDAI score averages the individual assessments for a final score range of 0-10. Change: Week x observation minus Baseline observation. Higher score indicates greater disability. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

BASDAI a validated self assessment tool used to determine disease activity in participants with AS. Utilizing a VAS of 0 (none) to 10 cm (very severe), participant's answered 6 questions measuring discomfort, pain and fatigue. BASDAI 50 response defined as at least a 50% improvement (decrease) from baseline in BASDAI. Baseline score - score at observation divided by Baseline score * 100 = greater than or equal to 50%.

mITT; N=number of participants evaluable; n=number of participants evaluable at specific time point

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 20 = 20% improvement from baseline and an absolute change greater than or equal to (≥) 10 units on a 0-100 millimeter (mm) scale (0 mm = no disease activity; 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

mITT; N=number of participants evaluable; n=number of participants evaluable at specific time point

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 40 = 40% improvement from baseline and an absolute change ≥ 20 units on a 0-100 mm scale (0 mm = no disease activity, 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

mITT; N=number of participants evaluable; n=number of participants evaluable at specific time point

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 50 = 50% improvement (vs. baseline) and an absolute change ≥ 20 units on a 0-100 mm scale (0 mm = no disease activity, 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

mITT; N=number of participants with evaluable; n=number of participants evaluable at specific time point

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 70 = 70% improvement (vs. baseline) and an absolute change ≥ 20 units on a 0-100 mm scale (0 mm = no disease activity, 100 mm = high disease activity) for ≥ 3 domains, and no worsening in remaining domain.

mITT; N=number of participants evaluable; n=number of participants evaluable at specific time point

ASAS 5/6 consists of 6 domains: the 4 used in ASAS 20 (participant global assessment of disease activity, pain, function, inflammation measured on a 0-100 scale, where 0 = no disease activity and 100=high disease activity) plus spinal mobility and an acute phase reactant, C Reactive Protein (CRP). Achieving ASAS 5/6 requires a 20% improvement compared to baseline in ≥ 5 domains and no worsening in the remaining domain.

mITT; N=number of participants evaluable; n=number of participants evaluable at specific time point

Partial remission defined as a score of less than 20 units (on a scale of 0-100, where 0 = no disease activity and 100 = high disease activity) in each of the 4 Assessment in Ankylosing Spondylitis (ASAS) domains: participant global assessment of disease activity, pain, function, and inflammation. For scale, 100=high disease activity.

mITT; N=number of participants evaluable; n=number of participants evaluable at specific time point

BASMI is an objective measure of spinal mobility. The BASMI score is composed of 5 measures: cervical rotation, intermalleolar distance, modified Schober's test, lateral flexion and tragus to wall distance. Each measure was scored 0-2 (0=normal mobility, 2=severe reduction) to give a final score ranging 0 to 10. Lower score indicated better spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n=number of participants evaluable at specific time point

While in a neutral position, the participant turned the head as far as possible to the right and then to the left. Using a goniometer the degrees of movement were measured. Two measurements on the right and 2 on the left were made. The best of the two measurements for each side (corresponding to the highest value), were then averaged. Higher score indicated greater spinal mobility. Actual rotation ranged from 3.0 to 99.0 degrees. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

Measurement in cm of the distance between the medial malleoli when participant was lying supine with knees straight and feet pointed straight up with legs separated as far as possible, 2 attempts were measured. The best of the two measurements which corresponds to the highest value were reported. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

Measurement in cm of distance between marks originally placed while participant was standing erect 10 cm above and 5 cm below the midpoint of a line that joins the posterior superior iliac spines. Distance between marks was re-measured with participant maximally bent forward, knees fully extended, with supine in full flexion. The measurement was carried out two times and best of the two measurements which corresponds to the highest value were reported. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

Measurement in cm of distance between the tragus and wall from the right and left side while participant was standing with back against the wall; knees straight; scapulae, buttocks, and heels against the wall; with head in a neutral position. Two measurements on the right and 2 on the left were made. The best of the two measurements for each side (corresponding to the smallest value), were then averaged. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

Measurement in cm of distance between participant's middle fingertip and the floor after bending sideways, without bending knees or lifting heels, while attempting to keep shoulders in same place (flexion position). Two measurements on the right and 2 on the left were made. The best of the two measurements for each side (corresponding to the highest value), were then averaged. Higher score indicated greater spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

While participant stood with back against the wall and during maximal effort to touch head to the wall, the distance between the occiput (back of head) and the wall was measured. The measurement of two attempts was made and best of the two measurements which corresponds to the highest value were reported. Lower scores indicated improvement in spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point

Chest expansion defined as the difference in thoracic circumference during full expiration versus full inspiration, measured in cm at the fourth intercostal space (nipple line) while participant was standing. Measurement taken twice and best of the two measurements (corresponding to the highest value of inspiration and smallest value for expiration), were then averaged. Greater chest circumference indicated improvement in spinal mobility. Change: Week x observation minus Baseline observation. Baseline value was used when present, otherwise valid screening value used as baseline if within 14 days of first test article injection.

mITT; n= number of participants evaluable at specific time point; Due to limited number of participants with visits after Week 12 analysis limited to Week 12

Participants received matched placebo sc injection once per week for 52 weeks.

Week 12; Internal Carotid Artery; Due to limited number of participants with visits after Week 12 analysis limited to Week 12