Gastroenterology · Medical Literature
Effect of Mirikizumab on Clinical and Endoscopic Outcomes Based on Prior Advanced Therapy Failure in Patients With Moderately to Severely Active Ulcerative Colitis.
Abstract
Mirikizumab demonstrated efficacy in moderately-to-severely active ulcerative colitis, including in patients with prior advanced therapy failure (PATF) (Phase 3: LUCENT-1 [NCT03518086], LUCENT-2 [NCT03524092]). This post hoc analysis evaluates mirikizumab efficacy by number/mechanism of PATF. LUCENT-1 patients received 300 mg mirikizumab or placebo; mirikizumab induction responders entered LUCENT-2 and received 200 mg mirikizumab or placebo until week (W)52. Mirikizumab induction non-responders received extended induction with open-label 300 mg mirikizumab between W12 and W24. Extended induction responders received open-label 200 mg mirikizumab between W24 and W52. In each population, efficacy was analyzed by subgroups based on PATF number (0, 1, ≥ 2 [2-3]) and mechanism (including difficult-to-treat [DTT]: anti-TNF plus tofacitinib and/or vedolizumab). At baseline, 479/1162 patients (41.2%) had (≥ 1) PATF, of which 177 (37.0%) had DTT. Among mirikizumab-treated patients (n = 868), W12 clinical response was achieved by 69.8%, 63.9%, 45.3%, and 41.9% of the 0-PATF, 1-PATF, ≥ 2-PATF, and DTT subgroups, respectively. 42.1% (365/868) continued with maintenance treatment. Among W12 responders, 51.9% (0-PATF), 44.2% (1-PATF), 49.0% (≥ 2-PATF), and 42.9% (DTT) achieved clinical remission at W52. Over half of the patients (54.0% [147/272]) in the extended induction population had PATF; 51.0% (75/147) were DTT. At W24, clinical response was achieved by 62.4%, 41.4%, 49.5%, and 49.3% of the 0-PATF, 1-PATF, ≥ 2-PATF, and DTT subgroups. Of this 49.3% of the DTT subgroup (extended induction responders), 38.9% (14/36) achieved W52 clinical remission. Mirikizumab induction and maintenance is efficacious in moderately-to-severely active ulcerative colitis with or without prior failure of advanced therapy, including difficult-to-treat disease. LUCENT-1: NCT03518086; LUCENT-2: NCT03524092.
Clinical relevance
In patients with moderately to severely active ulcerative colitis, does mirikizumab demonstrate efficacy across subgroups defined by the number and mechanism of prior advanced therapy failure (PATF), including difficult-to-treat (DTT) disease? __SNAPSHOT__ {"studyDesign":"Post hoc subgroup analysis of two Phase 3 randomized, double-blind, placebo-controlled trials (LUCENT-1 [induction] and LUCENT-2 [maintenance])","setting":"Multinational; Phase 3 trial program (NCT03518086, NCT03524092); specific institution types not reported in the abstract","sampleSize":"n=1,162 (LUCENT-1 modified intent-to-treat population); mirikizumab-treated patients: n=868; PATF subgroup: n=479 (≥1 PATF), of whom n=177 had DTT disease; extended induction population: n=272","population":"Adults with moderately to severely active ulcerative colitis. At baseline, 41.2% (479/1,162) had ≥1 prior advanced therapy failure; 37.0% of PATF patients (177/479) met criteria for difficult-to-treat (DTT) disease, defined as anti-TNF failure plus tofacitinib and/or vedolizumab failure. Maximum number of PATF reported was three.","intervention":"Mirikizumab 300 mg IV every 4 weeks for 12-week induction (LUCENT-1); induction responders received 200 mg SC every 4 weeks until Week 52 (LUCENT-2). Induction non-responders received extended induction with open-label 300 mg mirikizumab IV from Week 12 to Week 24; extended induction responders then received open-label 200 mg SC mirikizumab from Week 24 to Week 52.","comparator":"Placebo (IV induction, SC maintenance); statistical comparison versus placebo performed using Fisher's exact test (or Cochran–Mantel–Haenszel test for the 1 anti-TNF subgroup)","primaryOutcome":"Clinical response at Week 12 (induction); clinical remission at Week 52 (maintenance); outcomes stratified by PATF subgroup (0-PATF, 1-PATF, ≥2-PATF, DTT). Clinical response defined as ≥2-point and ≥30% decrease in Modified Mayo Score from baseline plus rectal bleeding subscore of 0 or 1 or ≥1-point decrease from baseline. Clinical remission defined as 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":"52 weeks (12-week induction + 40-week maintenance); extended induction assessed at Week 24","fundingSource":"Industry (Eli Lilly and Company; inferred from LUCENT trial registration and author disclosures)"}
Key findings
Among mirikizumab-treated patients (n=868) in the induction population, Week 12 clinical response rates declined with increasing PATF burden: 69.8% (0-PATF), 63.9% (1-PATF), 45.3% (≥2-PATF), and 41.9% (DTT subgroup). Absolute differences versus placebo and formal p-values for individual PATF subgroup comparisons are not reported in the abstract; p<0.05 was the pre-specified significance threshold using Fisher's exact test. Among Week 12 maintenance responders, Week 52 clinical remission rates were 51.9% (0-PATF), 44.2% (1-PATF), 49.0% (≥2-PATF), and 42.9% (DTT). In the extended induction population (n=272), 54.0% had PATF and 51.0% of those were DTT; Week 24 clinical response rates were 62.4% (0-PATF), 41.4% (1-PATF), 49.5% (≥2-PATF), and 49.3% (DTT). Of DTT extended induction responders, 38.9% (14/36) achieved Week 52 clinical remission. NNT cannot be calculated from the abstract data provided, as placebo response rates by PATF subgroup are not reported. Missing data were imputed by non-responder imputation. Adverse event data specific to PATF subgroups are not reported in the abstract; in the parent LUCENT trials, nasopharyngitis and arthralgia were more frequent with mirikizumab versus placebo, and opportunistic infections (n=15, including 6 herpes zoster) and cancers (n=8, including 3 colorectal) occurred among 1,217 mirikizumab-exposed patients across controlled and uncontrolled periods.
Practice implications
This post hoc analysis suggests that mirikizumab maintains clinically meaningful induction and maintenance response rates across all PATF subgroups, including patients with the most refractory DTT profile (anti-TNF plus tofacitinib and/or vedolizumab failure), though absolute response rates are numerically lower as PATF burden increases. The finding that nearly half (41.9%) of DTT patients achieved Week 12 clinical response and approximately 43% achieved Week 52 clinical remission is potentially clinically meaningful for a population with limited remaining treatment options. However, several important limitations constrain interpretation: this is a post hoc, non-pre-specified subgroup analysis, so results are hypothesis-generating rather than confirmatory; placebo response rates by subgroup are not reported in the abstract, precluding calculation of treatment differences or NNT/NNH; formal statistical significance of individual subgroup differences versus placebo is not reported; and the analysis is post hoc from industry-sponsored trials, introducing risk of selective reporting and optimistic effect estimation. Patients were enriched for those willing to enroll in trials and may not fully represent real-world refractory IBD populations. The findings support the use of mirikizumab across the PATF spectrum but should be interpreted alongside the full publication data, not the abstract alone. Only the abstract was available for this summary. __LIMITATIONS__ Post hoc subgroup analysis: not pre-specified, results are exploratory and hypothesis-generating only.,Placebo response rates by PATF subgroup not reported in the abstract; treatment differences (absolute risk reduction, NNT) cannot be calculated.,Formal p-values and confidence intervals for individual PATF subgroup comparisons versus placebo are not reported in the abstract.,Maintenance and extended induction populations are enriched for prior induction responders, introducing selection bias that inflates apparent efficacy in the most refractory subgroups.,Non-responder imputation for missing data may underestimate or overestimate true response rates depending on dropout patterns.,Industry funding (Eli Lilly) for the parent trials introduces potential for optimistic effect estimation and publication bias.,Maximum PATF of three limits generalizability to patients with more extensive prior therapy exposure.,DTT subgroup definition (anti-TNF plus tofacitinib and/or vedolizumab failure) may not align with all real-world definitions of difficult-to-treat UC.,Subgroup sample sizes (particularly DTT, ≥2-PATF) are likely small, reducing statistical power and precision of subgroup estimates.,Safety data specific to PATF subgroups are not reported; adverse event signal from parent trials (opportunistic infections, colorectal cancers) cannot be attributed to or stratified by refractory disease status.,Only the abstract was available; full methodology, complete results tables, and sensitivity analyses could not be reviewed. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ This post hoc analysis of the LUCENT-1/-2 Phase 3 program suggests that mirikizumab produces clinically meaningful induction and maintenance response rates in moderately to severely active UC regardless of PATF number or mechanism, including in difficult-to-treat patients with multi-class prior failures. Response rates decline numerically with increasing PATF burden, but remain substantial even in the DTT subgroup. These exploratory findings are hypothesis-generating and should not independently change practice; they are best used to inform individualized treatment discussions while awaiting prospective data in specifically enriched refractory populations.