Gastroenterology · Medical Literature
Histologic and combined histologic-endoscopic outcomes with mirikizumab in Crohn's disease: VIVID-1 trial results.
Abstract
Evaluation of microscopic inflammation is an emerging therapeutic target of Crohn's disease. The completed VIVID-1 trial evaluated histologic and combined histologic-endoscopic outcomes for mirikizumab relative to placebo and ustekinumab in moderately-to-severely active Crohn's disease. Two specimens from each of five intestinal segments (one ileal, four colonic) were obtained from the edge of ulcers, or the most inflamed mucosa at screening, and weeks (W)12 and 52. Histologic response was defined as the absence of epithelial neutrophils and epithelial damage, erosions and ulceration or ≥50% decrease in either the active Robarts Histopathology Index or the active Global Histologic Disease Activity Score, and was prespecified. Histologic remission was defined as absence of mucosal neutrophils, no epithelial damage, and no erosions and ulcers and was a prespecified endpoint. Post-hoc analyses included subgroup analyses, the proportions of patients achieving combined histologic-endoscopic outcomes, the agreement between histologic outcomes and endoscopic or clinical outcomes, segmental analyses, the assessment of cut-off points for fecal calprotectin, and the association between W12 histologic outcomes and selected W52 outcomes. At W12, mirikizumab was superior to placebo for histologic response (P < .0001) and histologic remission (P = .001), with similar rates to ustekinumab (P = .58 and P = .44, respectively). At W52, mirikizumab-treated patients showed greater histologic response (P = .008) compared to ustekinumab, especially in patients who previously failed biologic therapies (P = .006). Combined histologic-endoscopic response at W52 was numerically higher for mirikizumab (P = .06) and reached statistical significance among biologic-failed patients (P = .02); however, combined remission rates were comparable across treatment arms. Mirikizumab was superior to placebo in achievement of all histology-based endpoints. Mirikizumab showed higher rates compared to ustekinumab for achievement of histologic response at W52. Early histologic response among endoscopic non-responders was associated with 1-year endoscopic outcomes. ClinicalTrials.gov, NCT03926130.
Clinical relevance
In adults with moderately-to-severely active Crohn's disease, does mirikizumab achieve superior histologic and combined histologic-endoscopic outcomes compared with placebo and with ustekinumab as an active comparator over 52 weeks? __SNAPSHOT__ {"studyDesign":"Prespecified and post-hoc histologic sub-study of a Phase 3, multicenter, randomized, double-blind, double-dummy, placebo-controlled and active-controlled, treat-through trial (VIVID-1; NCT03926130)","setting":"324 sites (hospitals, medical centers, clinical practices, and research sites) across 33 countries in Europe, Asia, North America, Central/South America, and Australia","sampleSize":"Overall VIVID-1 safety population: n=1,150; efficacy population: n=1,065 (mirikizumab n=579, ustekinumab n=287, placebo n=199). The histologic sub-study population (Primary Analysis Set, PAS) is not separately enumerated in the available abstract.","population":"Adult patients with moderately-to-severely active Crohn's disease (baseline SES-CD ≥7, or ≥4 for isolated ileal disease) who had demonstrated intolerance, inadequate response, or loss of response to one or more approved biologic or conventional therapies","intervention":"Mirikizumab 900 mg IV at Weeks 0, 4, and 8 (induction), then 300 mg SC every 4 weeks from Weeks 12–52 (maintenance); biopsies from the edge of ulcers or most inflamed mucosa from one ileal and four colonic segments at screening, Week 12, and Week 52","comparator":"Ustekinumab (approximately 6 mg/kg IV at Week 0, then 90 mg SC every 8 weeks from Weeks 8–52) as active comparator; placebo (double-dummy) as control","primaryOutcome":"Histologic response (prespecified): absence of epithelial neutrophils and epithelial damage, erosions, and ulceration, OR ≥50% decrease in either the active Robarts Histopathology Index (RHI) or the active Global Histologic Disease Activity Score (GHDAS). Histologic remission (prespecified): absence of mucosal neutrophils, no epithelial damage, and no erosions or ulcers.","followUp":"52 weeks (biopsies at screening, Week 12, and Week 52)","fundingSource":"Industry (Eli Lilly and Company); multiple authors are Eli Lilly employees or shareholders; lead academic authors disclose extensive consulting/speaker relationships with Eli Lilly and other industry sponsors"}
Key findings
At Week 12 (induction), mirikizumab was statistically superior to placebo for both histologic response (p<0.0001) and histologic remission (p=0.001); absolute rates were not reported in the abstract. At Week 12, histologic outcomes with mirikizumab were similar to ustekinumab (histologic response: p=0.58; histologic remission: p=0.44), indicating no significant difference between active agents at induction. At Week 52 (end of maintenance), mirikizumab-treated patients demonstrated statistically greater histologic response compared with ustekinumab (p=0.008), with a more pronounced treatment difference in the biologic-failure subgroup (p=0.006). Combined histologic-endoscopic response at Week 52 was numerically higher for mirikizumab but did not reach statistical significance in the overall population (p=0.06); however, statistical significance was achieved in the biologic-failure subgroup (p=0.02). Combined histologic-endoscopic remission rates were comparable across all three treatment arms at Week 52. Early histologic response at Week 12 among patients who were endoscopic non-responders at Week 12 was associated with achievement of endoscopic response at Week 52. Absolute response rates, confidence intervals, number needed to treat, and number needed to harm for histologic endpoints are not reported in the available abstract. Adverse event data from the parent VIVID-1 trial (Lancet 2024): serious adverse events occurred in 10.3% of mirikizumab-treated patients, 10.7% of ustekinumab-treated patients, and 17.1% of placebo patients; the most common adverse event across all arms was COVID-19; three deaths occurred (one ustekinumab, two placebo), none attributed to study drug.
Practice implications
This analysis establishes that mirikizumab achieves statistically superior histologic outcomes compared with placebo at induction and compared with ustekinumab at 52 weeks, using prespecified definitions grounded in validated scoring instruments (RHI, GHDAS). The finding that early histologic response predicts 1-year endoscopic outcomes — even in endoscopic non-responders — is clinically important and suggests that histologic assessment may provide additive prognostic information beyond endoscopy alone. However, several caveats limit direct clinical translation: (1) Only the abstract was available for this review; absolute response rates, confidence intervals, and NNT/NNH values for histologic endpoints are not reported and cannot be independently verified. (2) Many post-hoc analyses — including subgroup analyses, combined endpoint analyses, fecal calprotectin cutpoint assessments, and segmental analyses — were not prespecified, introducing a substantial risk of inflated false-positive findings. (3) The biologic-failure subgroup, where the most striking differences versus ustekinumab appear, represents a pre-defined post-hoc analysis; the size of this subgroup is not reported. (4) The clinical relevance of histologic response over endoscopic response as a treatment target in Crohn's disease remains incompletely established; histologic inflammation persists in up to one-quarter of patients with endoscopic mucosal healing, but whether achieving additional histologic clearance independently improves long-term structural or clinical outcomes has not been demonstrated in this trial. (5) Patients enrolled required failure of or intolerance to standard therapies, limiting generalizability to biologic-naïve populations. (6) Extensive industry involvement in study design, data ownership, and authorship is present and should be considered when interpreting results. __LIMITATIONS__ Only the abstract is publicly available; effect sizes, confidence intervals, and absolute rates for histologic endpoints cannot be independently verified.,Multiple post-hoc analyses (subgroup, combined endpoints, fecal calprotectin thresholds, segmental analyses) inflate risk of false-positive findings; multiplicity control status for most histologic comparisons is not clearly reported in the abstract.,The histologic endpoint analyses for the prespecified population are noted as non-multiplicity-controlled, limiting inferential strength.,Biologic-failure subgroup analyses driving the most significant differences versus ustekinumab are post-hoc; subgroup sizes not reported.,The overall combined histologic-endoscopic response comparison versus ustekinumab did not reach statistical significance (p=0.06), and combined remission rates were not statistically different across arms.,Substantial industry funding and author conflicts of interest (multiple Eli Lilly employees as co-authors, lead academics with extensive Lilly relationships) introduce risk of sponsorship bias.,Histologic response as a treatment target in Crohn's disease has not been validated as a surrogate for long-term structural or clinical outcomes; its prognostic importance beyond endoscopy remains uncertain.,Biopsy sampling from the edge of ulcers or most inflamed mucosa may not fully capture heterogeneous, transmural, or proximal disease; sampling variability across time points is a known limitation in CD histology trials.,The 6:3:2 randomization ratio (mirikizumab:ustekinumab:placebo) results in an underpowered ustekinumab arm and may limit the reliability of head-to-head comparisons.,Follow-up limited to 52 weeks; durability of histologic response and its downstream clinical impact beyond 1 year are not reported in this analysis. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ In the VIVID-1 phase 3 trial, mirikizumab was superior to placebo for all histologic endpoints at Week 12 and demonstrated greater histologic response than ustekinumab at Week 52, with a particularly notable advantage in patients with prior biologic failure. However, the combined histologic-endoscopic remission did not differ between active treatment arms, many analyses were post-hoc and non-multiplicity-controlled, and absolute rates and confidence intervals for histologic endpoints are not reported in the available abstract. Histologic assessment provides additive prognostic information beyond endoscopy, but histologic healing is not yet an established, validated treatment target in Crohn's disease, and these findings should be considered hypothesis-generating pending full publication and independent replication.