Ustekinumab in paediatric patients with moderately to severely active Crohn's disease: UniStar study long-term extension results.

OBJECTIVES: To assess the efficacy, safety, immunogenicity, and pharmacokinetics through 240 weeks of ustekinumab treatment in paediatric patients from the long-term extension (LTE) of the phase 1, double-blind UniStar trial. METHODS: Paediatric patients with moderately to severely active Crohn's disease (CD) were randomised 1:1 and stratified by body weight (<40 or ≥40 kg) to low- or high-dose intravenous ustekinumab followed by a subcutaneous maintenance dose at Week 8. At Week 16, patients were eligible to enter the LTE at the discretion of the investigator and continued maintenance dosing every 8 weeks up to Week 240. RESULTS: Of the 34 patients who entered the LTE, 25 patients with evaluable data completed Week 48, and 41.2% (14/34) achieved clinical remission at Week 48. Among the 24 patients with Week-0 C-reactive protein (CRP) levels ≥3 mg/L, 29.2% (7/24) achieved normalisation of CRP at Week 48, while imputing missing data as failures. Through Week 240, the most common adverse events were infections (n = 28) and gastrointestinal disorders (n = 26). The most common serious adverse event was worsening of CD (n = 6). Only one patient had detectable antibodies to ustekinumab. Median serum ustekinumab concentrations remained consistent through Week 48, were detectable through Week 224, and trended lower in patients <40 kg. CONCLUSIONS: Efficacy and pharmacokinetics through 1 year and safety and immunogenicity through 4 years of ustekinumab treatment in paediatric patients with CD were generally comparable to those previously reported in adults.

Outcomes in Adult Inflammatory Bowel Disease Clinical Trials: Assessment of Similarity Among Participants with Adolescent-onset and Adult-onset Disease.

BACKGROUND AND AIMS: Most paediatric inflammatory bowel disease [IBD] studies are performed after medications are approved in adults, and the majority of participants in these studies are adolescents. We hypothesised that adolescent-onset IBD is not fundamentally different from adult-onset IBD. If this is correct, the value of delaying access to novel drugs in adolescents becomes questioned. METHODS: Data from 11 randomised, double-blind, placebo-controlled, adult Phases 2 and 3 trials of four biologics were analysed. Participants were categorised as having adolescent- or adult-onset disease [diagnosed 12 to <18, or ≥18 years]. Multivariable modelling explored the association between age at diagnosis and response to treatment, after adjustment for disease duration, extent, and severity at baseline. Data from dose arms were pooled to evaluate similarity of therapeutic response between adolescent- and adult-onset IBD within the same trial [not between doses or across trials]. Ratios of odds ratios [ORs] between the two groups were evaluated. RESULTS: Data from 6283 study participants (2575 with Crohn's disease [CD], 3708 with ulcerative colitis [UC]) were evaluated. Of 2575 study participants with CD, 325 were 12-<18 years old at diagnosis; 836 participants [32.4%] received placebo. Of 3708 participants with UC, 221 were 12-<18 years old at diagnosis; 1212 [33%] were receiving placebo. The majority of the ratios of ORs were within 2-fold, suggesting that responses in adolescent- and adult-onset participants are generally similar. CONCLUSION: Data presented lend support for extrapolating efficacy of biologics from adults to adolescents with IBD, which would facilitate earlier labelling and patient access.