Efficacy and safety of upadacitinib maintenance therapy in patients with moderately to severely active Crohn's disease: 2-year results from the U-ENDURE Long-Term Extension study.

Background and aims: The long-term efficacy and safety of upadacitinib in patients with moderate to severe Crohn's disease (CD) were evaluated in the U-ENDURE Long-Term Extension (LTE) study. Here we report the results after 2 years of total maintenance treatment.

Methods: U-ENDURE is an ongoing 240-week LTE study conducted at 243 sites across 43 countries (first patient enrolled in LTE 21 March 2019). Patients who completed the 52-week maintenance study continued their previously assigned treatment, once-daily upadacitinib 15 mg or upadacitinib 30 mg. Efficacy was analyzed at week 48 of the LTE; safety was analyzed in the cumulative study population (combined 52 week maintenance and 48 week LTE) and the LTE study population only (cutoff date: 19 December 2023).

Results: From LTE week 0 to week 48, as-observed efficacy rates for clinical remission (per stool frequency/abdominal pain score, upadacitinib 15 mg: 78.3% to 82.9%; upadacitinib 30 mg: 84.7% to 76.6%; per CD Activity Index, upadacitinib 15 mg: 81.3% to 83.1%; upadacitinib 30 mg: 86.1% to 86.8%), endoscopic response (upadacitinib 15 mg: 59.6% to 67.1%; upadacitinib 30 mg: 71.2% to 69.6%), inflammatory biomarkers, and quality-of-life outcomes remained stable. The safety profile of the cumulative maintenance population observed through LTE week 48 was consistent with previous trials in the upadacitinib CD program. Treatment-emergent adverse event rates for the cumulative maintenance population were 283.1 and 273.4 events/100 patient-years for upadacitinib 15 mg and upadacitinib 30 mg, respectively. Event rates of serious treatment--emergent adverse events were 16.0 events/100 patient-years for upadacitinib 15 mg and 14.6 events/100 patient-years for upadacitinib 30 mg. The most common adverse events of special interest (≥ 5.0 events/100 patient-years) were hepatic disorder, lymphopenia, creatine phosphokinase elevation, herpes zoster, and anemia. There was 1 treatment-emergent adverse event of suicide leading to death.

Conclusion: Sustained clinical, endoscopic, quality-of-life, and biomarker outcomes were observed in patients who were initial responders to upadacitinib and completed 2 years of maintenance therapy, with no new safety signals identified.

Clinical trial identifier: U-ENDURE; ClinicalTrials.gov number, NCT03345823.