A Study of Ustekinumab in Participants With Active Polymyositis and Dermatomyositis Who Have Not Adequately Responded to One or More Standard-of-care Treatments

Minimal improvement was defined as IMACS TIS greater than or equal to (\>=) 20 in participants with polymyositis (PM)/dermatomyositis (DM). Criteria used the 6 IMACS core set measures: physician global activity (PhGA)(0-10), patient global activity (PtGA)(0-10), manual muscle testing-8 (MMT-8)(0-80), muscle enzymes (creatine kinase, Aldolase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase), extramuscular assessment of myositis disease activity assessment tool (MDAAT)(0-10), and health assessment questionnaire disability index (HAQ-DI)(0-3). Absolute percent change in each core set measure was calculated as final value minus baseline value divided by range\*100. Total improvement score was calculated by sum of 6 core set improvement scores. Total improvement score ranged from 0 to 100 where higher scores indicated greater improvement. This was categorized into 3 categories (minimal \[improvement \>=20\], moderate \[improvement \>=40\] and major \[improvement \>=60\]).

Time frame: Week 24

Population: All randomized analysis set included all participants who were randomized in this study.

Change from baseline in extramuscular assessment by MDAAT at Week 24 was reported. This validated tool measure the degree of disease activity of extramuscular organ systems and muscle on a 0-10 cm VAS. Extramuscular activity ranged between 0 and 10 via VAS where, 0 cm = absent and 10 cm = maximum disease activity.

Time frame: Baseline, Week 24

Population: All randomized analysis set included all participants who were randomized in this study.

Change from baseline in FI-2 at Week 24 was reported. The FI-2 was a functional outcome developed for participants with adult PM or DM to assess muscle endurance in 7 muscle groups (shoulder flexion \[0-60\], shoulder abduction \[0-60\], head lift \[0-60\], hip flexion \[0-60\], step test \[0-60\], heel lift \[0-120\], and toe lift \[0-120\]). Each muscle group was scored as the number of correctly performed repetitions with 60 or 120 maximal number of repetitions depending on muscle group. The FI-2 was performed unilaterally, preferably on the participant's dominant side for muscle groups of shoulder, hip, and step test. The FI-2 score ranged from 0-60 or 0-120 depending on the muscle group. Higher score indicated better muscle endurance.

Time frame: Baseline, Week 24

Population: All randomized analysis set included all participants who were randomized in this study. Here, 'n' (number analyzed) signifies participants who were evaluable for this outcome measure for given categories.

Change from baseline in MMT-8 score at Week 24 was reported. Manual Muscle Testing was a partially validated tool to assess muscle strength. MMT-8 total score ranged from 0-80, where maximal score was sum of scores from 8 muscle groups (Deltoid middle \[left/right\], Biceps brachii \[left/right\], Gluteus maximus \[left/right\], Gluteus medius \[left/right\], Quadriceps \[left/right\], Wrist extensors \[left/right\], Ankle dorsiflexors \[left/right\], Neck flexors \[axial\]) and each muscle group was scored on a 0 to 10-point scale. The sides (right or left) used for calculating the total score. Higher score indicated greater muscle strength, that is, less impairment of muscle.

Time frame: Baseline, Week 24

Population: All randomized analysis set included all participants who were randomized in this study.

Change from baseline in muscle enzyme levels (creatine kinase, lactate dehydrogenase) at Week 24 was reported.

Time frame: Baseline, Week 24

Population: All randomized analysis set included all participants who were randomized in this study. Here, 'n' (number analyzed) signifies participants who were evaluable for this outcome measure for given categories.

Change from baseline in PhGA at Week 24 was reported. Physician Global Activity was a partially validated tool to measure the global evaluation by the physician of the participant's overall disease activity at the time of assessment using a 0-10 cm VAS, where 0 cm= no evidence of disease activity and 10 cm= extremely active or severe disease activity. Negative values indicated improvement from baseline.

Time frame: Baseline, Week 24

Population: All randomized analysis set included all participants who were randomized in this study.

Percentage of participants who experienced disease worsening up to Week 24 based on consensus criteria for worsening was reported. Criteria for disease worsening in a clinical trial were based on international consensus guideline developed by the IMACS. The worsening of disease was defined as 1 of the following criteria: Worsening of the Physician Global Activity by \>=2 centimeter (cm) on a 10-cm visual analogue scale (VAS) and worsening of findings of MMT-8 by \>= 20 percent (%) from baseline; worsening of MDAAT-global extramuscular organ disease activity (a composite of constitutional, cutaneous, skeletal, gastrointestinal, pulmonary, and cardiac activity) by \>=2 cm on a 10-cm VAS from baseline; worsening of any 3 of 6 IMACS core set (PhGA, PtGA, MMT-8, muscle enzymes, MDAAT, and HAQ-D) activity measures by \>= 30% from baseline.

Time frame: Up to Week 24

Population: All randomized analysis set included all participants who were randomized in this study.