What is the recommended dosing regimen for ustekinumab (Stelara) in adult patients with psoriasis, psoriatic arthritis, and Crohn's disease?

Stelara (Ustekinumab) Dosing

For psoriasis and psoriatic arthritis, dose ustekinumab based on body weight: 45 mg for patients ≤100 kg or 90 mg for patients >100 kg, given subcutaneously at weeks 0 and 4, then every 12 weeks; for Crohn's disease and ulcerative colitis, give a single weight-based IV induction dose (260-520 mg), followed by 90 mg subcutaneously at week 8, then every 8 weeks thereafter. 1

Psoriasis and Psoriatic Arthritis Dosing

Adult Patients

Standard Dosing Algorithm:

• Patients ≤100 kg: 45 mg subcutaneously at weeks 0,4, then every 12 weeks 2, 1
• Patients >100 kg: 90 mg subcutaneously at weeks 0,4, then every 12 weeks 2, 1

The weight-based dosing is critical because the 90 mg dose demonstrates superior efficacy in heavier patients, though 45 mg remains effective 1. This represents a Grade A recommendation from the AAD-NPF guidelines 2.

Dose Intensification for Inadequate Response: If patients fail to achieve adequate response on standard dosing, escalate to either:

• Higher dose (90 mg instead of 45 mg in patients ≤100 kg), OR
• More frequent dosing (every 8 weeks instead of every 12 weeks during maintenance) 2

This dose intensification strategy carries a Grade A recommendation and is supported by the PHOENIX 2 trial, where partial responders receiving 90 mg every 8 weeks achieved PASI 75 in 68.8% versus 33.3% who continued every 12 weeks (p=0.004) 3.

Pediatric Patients (6-17 years)

Weight-Based Dosing:

• <60 kg: 0.75 mg/kg subcutaneously at weeks 0,4, then every 12 weeks 1
• 60-100 kg: 45 mg subcutaneously at weeks 0,4, then every 12 weeks 1
• >100 kg: 90 mg subcutaneously at weeks 0,4, then every 12 weeks 1

For patients <60 kg, calculate the exact volume from the 45 mg/0.5 mL vial using the FDA-provided dosing tables 1.

Psoriatic Arthritis-Specific Considerations

For psoriatic arthritis without significant plaque psoriasis, all patients receive 45 mg regardless of weight 1. However, patients with co-existent moderate-to-severe plaque psoriasis weighing >100 kg should receive 90 mg to adequately treat both conditions 1.

Crohn's Disease and Ulcerative Colitis Dosing

Induction Phase (IV)

Single weight-based IV infusion at week 0:

• ≤55 kg: 260 mg (2 vials) 1
• >55 to 85 kg: 390 mg (3 vials) 1
• >85 kg: 520 mg (4 vials) 1

This weight-tiered approach ensures adequate drug exposure for induction of remission in inflammatory bowel disease.

Maintenance Phase (Subcutaneous)

90 mg subcutaneously at week 8 (8 weeks after IV induction), then every 8 weeks thereafter 1

Critical distinction: The maintenance interval for IBD is every 8 weeks, not every 12 weeks as used in psoriasis/psoriatic arthritis. This more frequent dosing reflects the different pharmacodynamic requirements for intestinal inflammation.

Dose Escalation in Crohn's Disease

For patients losing response on standard every-8-week dosing, shortening the interval to every 4 weeks (90 mg subcutaneously) is effective. In a retrospective cohort of 110 patients, dose interval shortening resulted in:

• Median Harvey Bradshaw Index decreased from 4.5 to 3 (p=0.002)
• Median CRP decreased from 8 mg/L to 3 mg/L (p=0.031)
• 28% achieved clinical remission among those with active disease 4

While every-4-week dosing is off-label in the United States, it represents a viable rescue strategy before switching biologics 4.

Important Clinical Caveats

Treat-to-Target Considerations: The 2025 AGA guidelines make no recommendation for or against treating to endoscopic remission versus symptomatic remission in Crohn's disease 5. The STARDUST trial showed no significant difference in clinical or endoscopic remission rates between endoscopic monitoring versus standard care approaches (62% vs 70% clinical remission, 38% vs 30% endoscopic remission) 5.

Safety Profile: Across 6,280 patients in integrated phase II/III trials, ustekinumab demonstrated:

• Infection rates: 125.4 per 100 patient-years (similar to placebo at 129.4)
• Major adverse cardiovascular events: 0.5 per 100 patient-years
• Malignancies: 0.4 per 100 patient-years
• Deaths: 0.1 per 100 patient-years 6

Administration Pearls:

• Rotate injection sites (upper arms, gluteal regions, thighs, abdomen) 1
• Avoid areas that are tender, bruised, erythematous, or indurated 1
• The needle cover contains latex—avoid in latex-sensitive patients 1
• No preservatives—discard unused product 1

Combination Therapy: Ustekinumab can be combined with topical corticosteroids, methotrexate, or narrowband UVB phototherapy to augment efficacy in psoriasis, though monotherapy remains the standard approach 2.