Introduction: STARDUST, a phase 3b randomized trial, compared treat-to-target (T2T) maintenance strategy vs standard of care (SoC) in Crohn’s disease (CD) patients (pts) treated with ustekinumab (UST). Here we describe Week (W) 48 endoscopic (1^o endpoint) and clinical results.

Methods: Adults with moderate–severely active CD ([CDAI] 220-450), [SES-CD] ≥ 3); received IV UST ∼6 mg/kg at W0 (baseline [BL]); SC UST 90 mg at W8. At W16, CDAI 70 responders were randomized 1:1 to T2T or SoC. T2T pts received SC UST q12w/q8w based on 25% improvement in SES-CD score vs BL and intensified to q4w from W16–48 if failure to meet: CDAI 70 point improvement, and CRP ≤ 10 mg/L or faecal calprotectin (FCal) # 50% reduction in SES-CD score vs BL).

Results: Of 500 pts, 441 achieved CDAI 70 response at W16 and were randomized to T2T (n = 220, 79.1%) or SoC (n = 221. 87.3%); and completed W48. More pts in T2T (37.7%) vs SoC (29.9%) achieved the 1^o endpoint at W48: (p = 0.0933; NRI, non-responder imputation). At W48, clinical response rates were T2T 68.2% and SoC 77.8% (p = 0.0212; NRI); clinical remission 61.4% vs 69.7% (NS;NRI), respectively; ≥ 50% improvement in FCal 39.4% vs 46.5% (NS;NRI)/63.1% vs 60.6% (NS; LOCF, last observation carried forward) and CRP 41.7% vs 53.3% (p = 0.032; NRI)/53.2% vs 57.2% levels (NS; LOCF), (Table). In T2T and SoC, 59.2% (122/206) and 53.2% (116/218) of pts started on UST q12w; of those, 59.8% (73/122) and 63.8% (74/116) were still on q12w at W48. Of pts who started on q8w, T2T, 40.5% (34/84) and SoC 78.4% (80/102) remained on q8w at W48. At W48, 17% (35/206) of pts were on UST q4w in T2T. No new safety signals were reported.

Conclusions: STARDUST is the first trial to use endoscopy to guide dose escalation in pts with CD. After 48W of maintenance therapy with UST, more pts achieved the endoscopic response with T2T vs SoC.