Gastroenterology · Medical Literature
Mirikizumab as Induction and Maintenance Therapy in Chinese Patients with Ulcerative Colitis: A Subpopulation Analysis of the Randomized, Global Phase 3 LUCENT-1 and LUCENT-2 Trials.
Abstract
Mirikizumab, a p19-directed anti-interleukin-23 antibody, demonstrated efficacy in patients with moderately-to-severely active ulcerative colitis in the global phase 3 LUCENT-1 induction (NCT03518086) and LUCENT-2 maintenance (NCT03524092) trials. The aim was to conduct a pre-specified Chinese subpopulation analysis of LUCENT-1 and LUCENT-2. In LUCENT-1, patients were randomized 3:1 to mirikizumab 300 mg or placebo intravenously every 4 weeks (Q4W) for 12 weeks. In LUCENT-2, patients with a clinical response to mirikizumab at week 12 of LUCENT-1 were re-randomized 2:1 to mirikizumab 200 mg or placebo via subcutaneous injection Q4W for 40 weeks. The primary endpoint in both trials was clinical remission at study end, defined as a Mayo stool frequency subscore of 0, or 1 with a ≥ 1-point decrease from baseline, rectal bleeding subscore of 0, and an endoscopic subscore of 0 or 1 (excluding friability). Among 183 Chinese patients included in the LUCENT-1 induction trial, clinical remission rates at week 12 were higher with mirikizumab 300 mg (n = 140) versus placebo (n = 43) (18.6% vs. 7.0%; common risk difference 11.5%). Among 80 patients who responded to mirikizumab and underwent randomization again in the LUCENT-2 maintenance trial, clinical remission rates at week 40 were higher with mirikizumab 200 mg (n = 56) versus placebo (n = 24) (50.0% vs. 12.5%; common risk difference 40.4%). During induction and maintenance, the incidence of adverse events was comparable between the mirikizumab and placebo groups. Mirikizumab was effective and well tolerated in the subpopulation of Chinese patients with moderately-to-severely active ulcerative colitis, consistent with the overall trial population. Clinicaltrials.gov (NCT03518086 and NCT03524092).
Clinical relevance
In Chinese patients with moderately-to-severely active ulcerative colitis, does mirikizumab (a p19-directed anti-IL-23 antibody) achieve superior rates of clinical remission compared with placebo during both a 12-week induction phase and a 40-week maintenance phase? __SNAPSHOT__ {"studyDesign":"Pre-specified subpopulation analysis of two randomized, double-blind, placebo-controlled Phase 3 trials (LUCENT-1 induction and LUCENT-2 maintenance); sequential design with re-randomization of induction responders","setting":"Chinese patient sites participating in the global multicenter LUCENT-1 (NCT03518086) and LUCENT-2 (NCT03524092) trials","sampleSize":"LUCENT-1: n=183 (mirikizumab n=140, placebo n=43); LUCENT-2: n=80 mirikizumab induction responders re-randomized (mirikizumab n=56, placebo n=24)","population":"Chinese adults with moderately-to-severely active ulcerative colitis eligible for the global LUCENT trials","intervention":"LUCENT-1: Mirikizumab 300 mg IV every 4 weeks (Q4W) for 12 weeks; LUCENT-2: Mirikizumab 200 mg SC Q4W for 40 weeks","comparator":"Placebo IV Q4W (LUCENT-1) and placebo SC Q4W (LUCENT-2)","primaryOutcome":"Clinical remission at study end (Week 12 for LUCENT-1; Week 40 for LUCENT-2), defined as Mayo stool frequency subscore of 0 or 1 (with ≥1-point decrease from baseline), rectal bleeding subscore of 0, and endoscopic subscore of 0 or 1 (excluding friability)","followUp":"12 weeks (LUCENT-1 induction); 40 weeks (LUCENT-2 maintenance)","fundingSource":"Industry (Eli Lilly; inferred from global LUCENT trial sponsorship; not explicitly re-stated in the subpopulation abstract)"}
Key findings
In LUCENT-1 (induction), clinical remission rates at Week 12 were 18.6% with mirikizumab 300 mg IV vs. 7.0% with placebo among 183 Chinese patients, yielding a common risk difference of 11.5% (p-value not reported; confidence interval not reported in the abstract). The NNT to achieve one additional clinical remission during induction is approximately 9 (calculated: 1/[0.186−0.070] = 8.6). In LUCENT-2 (maintenance), among the 80 Chinese patients who responded to mirikizumab induction and were re-randomized, clinical remission rates at Week 40 were 50.0% with mirikizumab 200 mg SC vs. 12.5% with placebo, yielding a common risk difference of 40.4% (p-value not reported; confidence interval not reported in the abstract). The NNT for maintenance of remission is approximately 3 (calculated: 1/[0.500−0.125] = 2.7). The incidence of adverse events was reported to be comparable between mirikizumab and placebo groups during both induction and maintenance phases; specific adverse event types, rates, and serious adverse events were not detailed in the abstract.
Practice implications
This pre-specified subpopulation analysis suggests that mirikizumab produces directionally consistent efficacy in Chinese patients with moderately-to-severely active UC compared with the global LUCENT trial population, with a substantial remission benefit particularly during the maintenance phase. However, several important caveats apply. First, this summary is based solely on the published abstract; the full dataset, including confidence intervals, p-values, secondary endpoints (e.g., endoscopic remission, histologic remission, mucosal healing), and detailed safety data, were not available for review. Second, the subgroup sample sizes are small—especially in LUCENT-2 (n=80 total)—meaning the analysis is underpowered to detect statistically significant treatment differences independently and should not be interpreted as a formal confirmatory trial. Third, only induction responders entered LUCENT-2, introducing selection bias favorable to mirikizumab; the maintenance remission rates cannot be applied to the broader intent-to-treat Chinese population. Fourth, the induction remission rate with mirikizumab (18.6%) is numerically lower than reported in the overall global trial (~24.2% in NEJM 2023 data), which may reflect differences in baseline disease severity, prior therapy exposure, or simply small-sample variability—this difference was not formally tested. The findings are most applicable to Chinese patients with moderately-to-severely active UC who have not adequately responded to conventional therapies, consistent with the enrollment criteria of the parent LUCENT trials. Patients with prior biologic failure were included in the global trials, but the proportions within this Chinese subpopulation are not reported in the abstract. Practice change based solely on this subpopulation analysis is not warranted; it is best viewed as regulatory-supportive evidence for mirikizumab use in Chinese patients. __LIMITATIONS__ Small subgroup sample sizes (n=183 in LUCENT-1; n=80 in LUCENT-2) severely limit statistical power for independent hypothesis testing.,No confidence intervals or p-values are reported in the abstract for the Chinese subpopulation; formal statistical significance cannot be determined from available data.,Enriched sequential design: only mirikizumab induction responders entered LUCENT-2, inflating apparent maintenance remission rates relative to a true intention-to-treat population.,Only abstract-level data were available for this summary; secondary endpoints, subgroup analyses, and granular safety data could not be evaluated.,Generalizability is limited to Chinese patients enrolled at LUCENT trial sites; community-based or treatment-naive populations may differ.,Industry sponsorship (Eli Lilly) of the parent trials introduces potential for sponsor influence on study design, endpoint selection, and reporting.,The proportion of biologic-experienced vs. biologic-naive patients within the Chinese subpopulation is not reported in the abstract, limiting applicability stratification.,The lower absolute induction remission rate in the Chinese subpopulation (18.6%) vs. the global population is not formally addressed, and potential explanatory factors (e.g., prior therapy history, baseline severity) are unreported.,No long-term safety or efficacy data beyond 40 weeks of maintenance are provided for this subpopulation. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ In this pre-specified but small Chinese subpopulation analysis of the global LUCENT trials, mirikizumab demonstrated numerically higher clinical remission rates than placebo at both Week 12 (induction: 18.6% vs. 7.0%, risk difference 11.5%) and Week 40 (maintenance: 50.0% vs. 12.5%, risk difference 40.4%), with comparable adverse event incidence. These findings are directionally consistent with the global trial results and provide supporting evidence for mirikizumab efficacy in Chinese patients with moderately-to-severely active UC, but the small sample sizes and absence of reported confidence intervals or p-values preclude independent confirmatory conclusions. This analysis is best regarded as regulatory-supportive data rather than standalone practice-changing evidence.