Steady-state trough serum concentration of ustekinumab at Week 28 by baseline age groups will be reported.

Steady-state trough serum concentration of guselkumab at Week 28 by baseline age groups will be reported.

AUCss is defined as area under the curve at steady-state over a 12-week dosing interval of ustekinumab at Week 28 by baseline age groups.

AUCss is defined as area under the curve at steady-state over a dosing interval (4 or 8 weeks) of guselkumab at Week 28 by baseline age groups.

Percentage of Participants with jPsA achieving ACR pediatric 30 response at Week 24 will be reported. The ACR pediatric 30 response criteria is defined as a 30 percent (%) improvement (that is, a decrease in score) from baseline in greater than or equal to (\>=) 3 of the following 6 components, with worsening of \>=30% in no more than 1 of the following components: physician global assessment (PGA) of disease activity, patient/participant assessment of overall well-being, number of active joints (defined as swelling or loss of motion with pain and/or tenderness), number of joints with limited range of motion, physician function by childhood health assessment questionnaire (CHAQ) and C-reactive protein (CRP).

Percentage of Participants with jPsA achieving ACR pediatric 30 response at Week 24 will be reported. The ACR pediatric 30 response criteria is defined as a 30% improvement (that is, a decrease in score) from baseline in \>=3 of the following 6 components, with worsening of \>=30% in no more than 1 of the following components: PGA of disease activity, patient/participant assessment of overall well-being, number of active joints (defined as swelling or loss of motion with pain and/or tenderness), number of joints with limited range of motion, physician function by CHAQ and CRP.

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/ biological agent under study.

A SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly.

Number of participants with AEs leading to discontinuation of study intervention will be reported.

Number of participants with AEs of special interest (any newly identified malignancy case of active tuberculosis \[TB\], or opportunistic infection occurring after the first administration of study intervention\[s\]) will be reported.

Number of participants with abnormalities in clinical laboratory parameters (such as hematology and serum chemistry) will be reported.

Number of participants with injection-site reactions will be reported. An injection-site reaction is any adverse reaction at a subcutaneous (SC) study intervention injection-site.

Number of participants with AEs of worsening of the disease will be reported.

Number of participants with concomitant therapy due to loss of response will be reported.

Number of participants with clinical remission in induction period will be assessed. Clinical remission is defined as having a Pediatric Crohn's Disease Activity Index (PCDAI) score less than or equal to (\<=) 10 points. PCDAI is an index used to measure disease activity of pediatric patients with Crohn's Disease assessing abdominal pain, stool frequency, patient functioning, hematocrit, erythrocyte sedimentation rate, albumin, weight, height, abdominal tenderness or mass, perirectal disease, and extraintestinal manifestations. It ranges from 0 to 100; higher scores indicate more active disease.

Number of participants with reactions temporally associated with IV infusion in induction period will be reported.

Number of participants with SC injection-site reactions in maintenance period will be reported.

Serum ustekinumab concentrations will be reported.

Number of participants with clinical remission in maintenance period will be assessed. This will be assessed among participants who are in clinical response at induction week-8 (I-8). Clinical remission is defined as having a PCDAI score \<= 10 points. PCDAI is an index used to measure disease activity of pediatric patients with Crohn's Disease assessing abdominal pain, stool frequency, patient functioning, hematocrit, erythrocyte sedimentation rate, albumin, weight, height, abdominal tenderness or mass, perirectal disease, and extraintestinal manifestations. It ranges from 0 to 100; higher scores indicate more active disease.

Proportion of patients with steroid free clinical remission (patient reported outcome-2 remission: abdominal pain ≤ 1 AND stool frequency ≤ 3) and fecal calprotectin\<250µg/g at week 48. \[stool frequency (ST): average number of liquid stools for 1 week abdominal pain (AP): average scoring for abdominal pain for 1 week (0=none; 1=mild, 2=moderate; 3= severe)\]

Percentage of participants with clinical remission at Week 52 were assessed. Clinical remission was defined as a Crohn's Disease Activity Index (CDAI) score of less than (\<) 150 points (in general, CDAI score ranges from 0 to approximately 600; higher score indicates higher disease activities). The CDAI score is used to quantify the symptoms of participants with Crohn's Disease. A decrease in CDAI over time indicates improvement in disease activity.

Endoscopic response defined as showing a reduction from baseline in simple endoscopic score for Crohn's disease (SES-CD) of greater than or equal to (\>=) 50 percent (%). SES-CD is a validated instrument reflecting an endoscopist global appraisal of mucosal lesions in Crohn's disease. SES-CD grades lesions by location (5 bowel segments: ileum, right colon, transverse colon, left colon, and rectum) using 4 endoscopic variables: ulcer size, extent of ulcerated surface, extent of affected surface, and presence/type of narrowing. Total SES-CD is sum of 4 variables for all 5 bowel segments. Scores range from 0-60 with higher scores indicating more severe disease. Randomized participants who stopped treatment before reaching Week 48 due to any reason, or participants without endoscopic data at Week 48 were analyzed as nonresponders.

The PGA is used to determine the participant's psoriasis at a given time point. Overall lesions are graded for induration, erythema, and scaling. The participant's psoriasis is assessed as cleared (0), minimal (1), mild (2), moderate (3), marked (4), or severe (5). Higher scores indicate worse disease. Treatment Failure (TF) criteria- discontinued study agent due to lack of efficacy or adverse event of psoriasis or who started protocol-prohibited medication/therapy.

As per global definition, clinical remission is defined as a Mayo score less than or equal to (\<=)2 points, with no individual subscore greater than (\>)1. The Mayo score consists of 4 subscores (stool frequency, rectal bleeding \[RB\], endoscopy findings, and physician's global assessment \[PGA\]), rated as 0 (normal) to 3 (severe). Total score was calculated as the sum of 4 subscores and values range from 0 to 12 scores, where 3 to 5 = mild; 6 to 10 = moderate; and 11 to 12 = severe; higher scores indicate worsening of the disease. Participants who had a prohibited change in concomitant ulcerative colitis (UC) medication or an ostomy or colectomy prior to the Week 8 or who had all 4 Mayo subscores missing at Week 8 were considered not to be in clinical remission. Endoscopy subscore as assessed during central review of video of endoscopy was used.

As per US definition, clinical remission was defined as absolute stool number \<=3, a Mayo rectal bleeding subscore of 0 (no blood seen), and a Mayo endoscopy subscore of 0 (normal or inactive disease) or 1 (mild disease \[erythema, decreased vascular pattern, mild friability\]) without the physician's global assessment. Absolute stool number is average of daily stool number over the three days. The Mayo rectal bleeding and endoscopy findings subscores were rated as 0 (normal) to 3 (severe). Participants who had a prohibited change in concomitant UC medication or an ostomy or colectomy prior to the Week 8 or who were missing all 3 of the Mayo components pertaining to this outcome measure (OM) (absolute stool number, rectal bleeding subscore, and Mayo endoscopy subscore) at Week 8 were considered not to be in clinical remission. Endoscopy subscore as assessed during central review of the video of the endoscopy was used.

As per global definition, clinical remission was defined as a Mayo score \<=2 points, with no individual subscore \>1. The Mayo score consists of 4 subscores (stool frequency, rectal bleeding, endoscopy findings, and physician's global assessment), rated as 0 (normal) to 3 (severe). Total score was calculated as the sum of 4 subscores and values range from 0 to 12 scores, where 3 to 5 = mild; 6 to 10 = moderate; and 11 to 12 = severe; higher scores indicate worsening of the disease. Participants who had a prohibited change in UC medication or an ostomy or colectomy or used a rescue medication after clinical flare, or discontinued study agent due to lack of therapeutic effect or due to an AE of worsening of UC prior to the Week 44 or who had all 4 Mayo subscores missing at Week 44 were considered not to be in clinical remission. Endoscopy subscore as assessed during central review of the video of the endoscopy was used.

Per US definition, clinical remission: absolute stool number \<=3, a Mayo rectal bleeding subscore of 0 (no blood seen), and a Mayo endoscopy subscore of 0 (normal or inactive disease) or 1 (mild disease \[erythema, decreased vascular pattern, mild friability\]), without the physician's global assessment. Absolute stool number is average of daily stool number over the three days. The Mayo rectal bleeding and endoscopy findings subscores were rated as 0 (normal) to 3 (severe). Participants who had prohibited change in UC medication/ ostomy/ colectomy/ used rescue medication after clinical flare/ discontinued study agent due to lack of therapeutic effect/ due to AE of worsening of UC prior to Week 44 and who were missing all 3 of Mayo components pertaining to this OM (absolute stool number, rectal bleeding subscore, and Mayo endoscopy subscore) at Week 44 were considered not to be in clinical remission. Endoscopy subscore as assessed during central review of video of endoscopy was used.

The IGA documents the investigator's assessment of the participants psoriasis at a given time point. Overall lesions are graded for induration, erythema, and scaling. The participants' psoriasis was assessed as cleared (0), minimal (1), mild (2), moderate (3), or severe (4).

Clinical responses for week (wk)28 sPGA responders randomized to every 12 weeks (q12wk) fixed-interval dosing (Group 1) vs. patient-tailored fixed-interval dosing (Group 2) were assessed using the static PGA (sPGA) measure. Investigators graded psoriasis lesions for induration (0=no plaque elevation to 5=severe plaque elevation), erythema (0=no evidence of erythema to 5=dusky to deep red coloration), and scaling (0=no evidence of scaling to 5=severe scaling). The sum of the 3 scales is divided by 3 and rounded to obtain a final sPGA score, defined as 0=cleared (except for residual discoloration), 1=minimal, 2=mild, 3=moderate, 4=marked or 5=severe.

An ACR 20 response is defined as a greater than or equal to 20 percent improvement from baseline in swollen (66 joints) and tender (68 joints) joint counts and greater than or equal to 20 percent improvement in 3 of the following 5 assessments: 1) Participant's assessment of pain by Visual Analog Scale (VAS) (0-10 cm), 2) Participant's global assessment of disease activity by VAS (0-10 cm), 3) Physician's global assessment of disease activity by VAS (0-10 cm) 4) Participant's assessment of physical function as measured by the "Disability Index of the Health Assessment Questionnaire" (HAQ-DI) (score of 0-3 in 8 functional areas) and 5) C reactive protein.

Percentage of participants with \>=75% improvement in PASI score at Week 12 from Baseline was reported. PASI is a widely used tool for the measurement of severity of psoriasis. The combination of redness, scaling, and thickness, as well as overall body involvement determine the PASI score. The scale ranges from 0 (best) to 72 (worst). Baseline visit refers to Week 0.

SRI-4 response was defined as greater than or equal to 4-point reduction in Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) total score, no new British Isles Lupus Assessment Group (BILAG) A and no more than 1 new BILAG B domain score and no worsening (less than 10 percent increase) from baseline in Physician's Global Assessment of Disease Activity (PGA). Composite response is defined as SRI-4 response in participants who do not meet treatment failure criteria. SLEDAI-2K assessment consists of 24 items with total score of 0 to 105, with higher scores representing increased disease activity. BILAG Index: assessing clinical signs, symptoms, or laboratory parameters related to SLE, divided into 9 organ systems. For each organ system: A=severe disease, B=moderate disease, C=mild stable disease, D=inactive, but previously active, E=inactive and never affected. The PGA assess disease activity on a visual analogue scale = from very well (0)-very poor (10).

The EASI score was used to measure the severity and extent of atopic dermatitis (AD) and measures erythema (E), infiltration (I), excoriation (Ex) and lichenification (L) on a scale of 0 (none) to 3 (severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no eruption) to 6 (greater than \[\>\] 90 percent \[%\]-100% eruption). The total score is the sum of the four body-region scores, maximum=72, minimum=0, with higher scores reflecting greater disease severity. The total qualitative score is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant and summed to yield the EASI score.

The ALP response was defined as a greater than 40 percent (%) decrease from Baseline in ALP concentration at Week 12.

Serum samples will be analyzed to determine concentrations of ustekinumab using a validated, specific, and sensitive immunoassay method.

Cmax is maximum observed serum concentration of ustekinumab.

AUC (0-Infinite) defined as area under the serum concentration versus time curve from time zero to infinity with extrapolation of the terminal phase will be evaluated.

Serum samples will be collected to measure seum concentrations of Ustekinumab.

The Cmax is the maximum observed plasma concentration of study drug.

The AUC(0-inf) is the area under the serum concentration versus time curve from time zero to infinity with extrapolation of the terminal phase.