P498 Ustekinumab Real World Evidence Study (UndieS): study design with information about positioning and the choice of ustekinumab
Bibliographic record
Abstract
Abstract Background Strict eligibility criteria of phase 3 trials limit the external validity of their results. Well-designed real-world studies are intended to complement these by describing the effectiveness and safety of these medicines in routine clinical practice. As therapeutic options for the treatment of Crohn’s disease (CD) expands, the ideal sequence of medications, and the influences on this, needs defining. Methods UndieS is a phase IV, multi-centre, prospective, observational study of patients with CD initiated on ustekinumab as part of their routine care. 600 participants will be recruited from 22 centres across the UK with a follow-up period of 2 years. Assessments at baseline and weeks 8, 16/20, 56, 80 and 104 include modified Harvey-Bradshaw Index (mHBI), IBD-Control, Treatment Satisfaction Questionnaire for Medication and PRO-2. The primary outcome is steroid-free remission (mHBI ≤ 4) at one year. Secondary outcome measures include describing changes in disease activity, PROs and tolerability. Results Recruitment started in March 2020 with 437 patients recruited so far. The summary baseline characteristics are 50% male, median (range) age at consent 41 (18-91) years (14% > 65 years), median mHBI 5 (0-39). The median duration of Crohn’s disease before starting ustekinumab was 8 (0-60) years. Disease location (as per Montreal classification) is: L1: 35%, L2: 20%, L3: 44% and isolated L4: 1%. 24% of participants reported perianal disease. The proportion of participants using concomitant immunomodulators or oral corticosteroids on starting ustekinumab (15% and 11% respectively) is lower than in the UNITI clinical trial program. 59% of participants had a disease activity score suggesting that they would not meet the threshold required for entry into UNITI and suggested by NICE for moderately-to-severely active CD, although 81% of these had evidence of inflammation. Inadequate response to or adverse effects from a previous treatment was a common indication (52% of participants). 32% of the participants are bio-naïve; 64% and 10% have previous exposure to anti-TNF and vedolizumab respectively and 6% have been exposed to both. Details of prior biologic exposure is shown in figure 1. The most common reasons for the specific choice of ustekinumab were intolerance to immunomodulators and concern about infection risk. Bio-naïve patients were older (median 45 vs. 39 years; p=0.02) and had a shorter disease duration (7 vs. 9 years; p=0.04) than those with prior biologic exposure. Conclusion Our cohort is representative of those patients with CD being treated with ustekinumab in a real-world setting. Some important differences between these patients and those recruited to phase 3 clinical trials are identified.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.032 | 0.027 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.026 | 0.004 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".