Golimumab (MK-8259 / SCH900259) Treatment Withdrawal in Participants With Non-radiographic Axial Spondyloarthritis (GO-BACK) (MK-8259-038)

Clinical response is defined as Bath Ankylosing Spondylitis Disease Assessment Index (BASDAI) score improvement of ≥2.0 or ≥50% improvement within 3 months of the start of retreatment, relative to the mean of the two consecutive BASDAI scores that defined the flare. Sustained clinical response refers to participants who attained clinical response and maintained BASDAI criteria throughout the 3-month retreatment period. Response data was collected throughout Period 2 (12 months) and censored to include only the first 3 months after retreatment for a disease flare. The BASDAI is a summary of 6 participant-assessed measures rated on scales of 0 (none) to 10 (very severe): fatigue, spinal pain, joint pain/swelling, tenderness, morning stiffness, and duration of morning stiffness [0 (zero) to 10 (2 or more hours)]. The BASDAI score is the mean of responses to the 6 questions with a minimum of 0 and a maximum of 10. A higher score indicates greater disease activity.

The Kaplan-Meier analysis of time to first "flare" in Period 2 is represented by the percentage of participants who experienced a disease flare relative to baseline prior to the first dose of double-blind treatment in Period 2. Disease flare is defined as ASDAS at two consecutive visits that both show either absolute score ≥2.1 or a post-withdrawal increase of ≥1.1.

ASAS20 is a 20% improvement in response (per the Assessment in Ankylosing Spondylitis International Working Group) defined as meeting 2 criteria: 1) An improvement of ≥20% from Baseline and an absolute improvement from Baseline of ≥1.0 in at least 3 of 4 domains, and 2) Absence of deterioration from Baseline (defined as a ≥20% worsening and an absolute worsening of ≥1.0) in the potential remaining domain. Baseline for ASAS20 analysis is defined as the last ASAS score prior to the first dose of double-blind treatment in Period 2. The ASAS consists of 4 domains: the Patient Global Disease Assessment (PGDn), total back pain, function (Bath Ankylosing Spondylitis Functional Index [BASFI]), and morning stiffness (mean of questions 5 and 6 of Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Each domain is measured on a 10-point numeric scale from 0=no disease symptoms/impact to 10=extreme disease symptoms/impact, with a higher score indicating more severe impairment.

ASAS20 is a 20% improvement in response (per the Assessment in Ankylosing Spondylitis International Working Group) defined as meeting 2 criteria: 1) An improvement of ≥20% from Baseline and an absolute improvement from Baseline of ≥1.0 in at least 3 of 4 domains, and 2) Absence of deterioration from Baseline (defined as a ≥20% worsening and an absolute worsening of ≥1.0) in the potential remaining domain. Baseline for ASAS20 analysis is defined as the last ASAS score prior to the first dose of open-label retreatment in Period 2. The ASAS consists of 4 domains: the Patient Global Disease Assessment (PGDn), total back pain, function (Bath Ankylosing Spondylitis Functional Index [BASFI]), and morning stiffness (mean of questions 5 and 6 of Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Each domain is measured on a 10-point numeric scale from 0=no disease symptoms/impact to 10=extreme disease symptoms/impact, with a higher score indicating more severe impairment.

ASAS40 is a 40% improvement in response (per the Assessment in Ankylosing Spondylitis International Working Group) defined as meeting 2 criteria: 1) An improvement of ≥40% from Baseline and an absolute improvement from Baseline of ≥2.0 in at least 3 of 4 domains, and 2) No deterioration from Baseline in the potential remaining domain. Baseline for ASAS40 analysis is defined as the last ASAS score prior to the first dose of double-blind treatment in Period 2. The ASAS consists of 4 domains: the Patient Global Disease Assessment (PGDn), total back pain, function (Bath Ankylosing Spondylitis Functional Index [BASFI]), and morning stiffness (mean of questions 5 and 6 of Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Each domain is measured on a 10-point numeric scale from 0=no disease symptoms/impact to 10=extreme disease symptoms/impact, with a higher score indicating more severe impairment.

ASAS40 is a 40% improvement in response (per the Assessment in Ankylosing Spondylitis International Working Group) defined as meeting 2 criteria: 1) An improvement of ≥40% from Baseline and an absolute improvement from Baseline of ≥2.0 in at least 3 of 4 domains, and 2) No deterioration from Baseline in the potential remaining domain. Baseline for ASAS40 analysis is defined as the last ASAS score prior to the first dose of open-label retreatment in Period 2. The ASAS consists of 4 domains: the Patient Global Disease Assessment (PGDn), total back pain, function (Bath Ankylosing Spondylitis Functional Index [BASFI]), and morning stiffness (mean of questions 5 and 6 of Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Each domain is measured on a 10-point numeric scale from 0=no disease symptoms/impact to 10=extreme disease symptoms/impact, with a higher score indicating more severe impairment.

ASAS partial remission is defined as a score of ≤2 in all 4 ASAS domains. Baseline for this analysis is defined as the ASAS score prior to the first dose of double-blind treatment in Period 2. The ASAS consists of 4 domains: Patient Global Disease Assessment (PGDn), total back pain, function (Bath Ankylosing Spondylitis Functional Index [BASFI]), and morning stiffness (mean of questions 5 and 6 of Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Each domain is measured on a 10-point numeric scale from 0=no disease symptoms/impact to 10=extreme disease symptoms/impact, with a higher score indicating more severe impairment.

ASAS partial remission is defined as a score of ≤2 in all 4 ASAS domains. Baseline for this analysis is defined as the ASAS score prior to the first dose of open-label retreatment in Period 2. The ASAS consists of 4 domains: Patient Global Disease Assessment (PGDn), total back pain, function (Bath Ankylosing Spondylitis Functional Index [BASFI]), and morning stiffness (mean of questions 5 and 6 of Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Each domain is measured on a 10-point numeric scale from 0=no disease symptoms/impact to 10=extreme disease symptoms/impact, with a higher score indicating more severe impairment.

BASDAI50 is defined as ≥50% improvement from baseline in the Bath Ankylosing Spondylitis Disease Assessment Index (BASDAI) score. Baseline for BASDAI50 analysis is defined as the last BASDAI score prior to the first dose of double-blind treatment in Period 2. The BASDAI is a summary of 6 participant-assessed measures rated on scales of 0 (none) to 10 (very severe): fatigue, spinal pain, joint pain/swelling, tenderness, morning stiffness, and duration of morning stiffness [0 (zero) to 10 (2 or more hours)]. The BASDAI score is the mean of responses to the 6 questions with a minimum of 0 and a maximum of 10. A higher score indicates greater disease activity.

BASDAI50 is defined as ≥50% improvement from baseline in the Bath Ankylosing Spondylitis Disease Assessment Index (BASDAI) score. Baseline for BASDAI50 analysis is defined as the last BASDAI score prior to the first dose of open-label retreatment in Period 2. The BASDAI is a summary of 6 participant-assessed measures rated on scales of 0 (none) to 10 (very severe): fatigue, spinal pain, joint pain/swelling, tenderness, morning stiffness, and duration of morning stiffness [0 (zero) to 10 (2 or more hours)]. The BASDAI score is the mean of responses to the 6 questions with a minimum of 0 and a maximum of 10. A higher score indicates greater disease activity.

Inactive disease status is defined as an ASDAS score <1.3. The ASDAS is a composite index assessing disease activity in axial spondyloarthropathies that consists of 4 self-assessed parameters and 1 laboratory parameter. The self-assessed parameters of back pain, duration of morning stiffness, Patient Global Disease Assessment (PGDn), and peripheral pain/swelling are individually scored on a numeric scale of 0 to 10, with 0 being low activity/impact and 10 being high activity/impact. The self-assessed criteria and the laboratory value of CRP are combined to provide the total ASDAS score, which has a lower limit of 0.6 and no defined upper limit. A higher score indicates greater disease activity.

Inactive disease status is defined as an ASDAS score <1.3. The ASDAS is a composite index assessing disease activity in axial spondyloarthropathies that consists of 4 self-assessed parameters and 1 laboratory parameter. The self-assessed parameters of back pain, duration of morning stiffness, Patient Global Disease Assessment (PGDn), and peripheral pain/swelling are individually scored on a numeric scale of 0 to 10, with 0 being low activity/impact and 10 being high activity/impact. The self-assessed criteria and the laboratory value of CRP are combined to provide the total ASDAS score, which has a lower limit of 0.6 and no defined upper limit. A higher score indicates greater disease activity.

This endpoint evaluated the safety and tolerability of withdrawing from or continuing treatment with golimumab in Period 2. An AE is defined as any untoward medical occurrence in a participant or clinical investigation participant administered a study treatment and which does not necessarily have to have a causal relationship with this treatment. An AE could be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a study treatment, whether or not considered related to the study treatment. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition that is temporally associated with the use of study treatment, is also an AE. The analysis includes AEs that occurred through 90 days after the last dose of study treatment.

This endpoint evaluated the safety and tolerability of withdrawing from or continuing treatment with golimumab in Period 2. An AE is defined as any untoward medical occurrence in a participant or clinical investigation participant administered a study treatment and which does not necessarily have to have a causal relationship with this treatment. An AE could be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a study treatment, whether or not considered related to the study treatment. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition that is temporally associated with the use of study treatment, is also an AE.