709 Optimizing the Definition of Clinical Response Using the Modified Mayo Score: An Analysis of a Phase 2 Study With Mirikizumab in Patients With Ulcerative Colitis
Bibliographic record
Abstract
INTRODUCTION: The 12-point Mayo Clinic Score (MCS), composed of four domains, has traditionally been used in defining regulatory endpoints for clinical remission in ulcerative colitis (UC) clinical trials. Clinical response has been defined as a reduction in MCS ≥3 points and ≥30 percent decrease from baseline (BL). Recent guidance from the FDA and EMA recommend use of the 9-point Mayo Score (Modified MCS; MMS) and its components for clinical trial endpoints, which excludes the physician's global assessment (PGA) subscore. 1,2 AMAC was a phase 2 randomized trial clinical trial of mirikizumab (miri), a p19-directed IL-23 antibody, in patients with moderate to severely active UC, which defined clinical response as decrease in the MMS of ≥2 points and ≥35% decrease from BL, and a decrease of ≥1 point in the rectal bleeding (RB) subscore from BL, or a RB score of 0 or 1. We performed a post-hoc analysis of AMAC data to demonstrate that given the MMS, a 30% reduction, along with RB reductions, is appropriate to capture improvement. METHODS: Contingency table analysis was used to evaluate MCS responders and non-responders by ≥30% and ≥35% MMS. Sensitivity and specificity were used to evaluate a representative percent improvement in MMS clinical response between MCS defined responder and non-responders. RESULTS: Using the MMS, removal of the PGA does not change the expected percentage difference from BL for responders compared to MCS when using the 30% clinical response definition. With total MCS as the anchor variable, the accurate classification rate with a ≥30% decrease in MMS is (124 + 110)/249 = 93.9%, and (127 + 104)/249 = 92.8% when using the ≥35% decrease (Table 1). The high classification rates show a very strong consistency between MMS and MCS at both cutoffs; however, sensitivity and specificity appears to be more balanced at a ≥30% decrease cutoff, with the two being close to equal (Figure 1). CONCLUSION: The more appropriate definition for identifying patients with UC in clinical response based on the MMS uses the ≥30% decrease from BL cutoff. This definition, along with a decrease of ≥2 points in the MMS from BL and ≥1 point in the RB subscore or a RB score of 0 or 1, is consistent with the prior definition using the total MCS.
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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 | 0.015 | 0.009 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.003 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".