Vedolizumab, Adalimumab, and Methotrexate Combination Therapy in Crohn’s Disease (EXPLORER)

BACKGROUND & AIMS: Although biologics have revolutionized the treatment of Crohn's disease (CD), an efficacy ceiling has been reached. Combining biologic therapies may improve remission rates. METHODS: EXPLORER, a phase 4, single-arm, open-label study, evaluated triple combination therapy with vedolizumab (300 mg on day 1, weeks 2 and 6, and then every 8 weeks), adalimumab (160 mg on day 2, 80 mg at week 2, then 40 mg every 2 weeks), and methotrexate (15 mg weekly) in biologic-naïve patients with newly diagnosed, moderate- to high-risk CD. Endoscopic remission at week 26 (primary end point; Simple Endoscopic Score for CD ≤2), clinical remission at weeks 10 and 26 (secondary end point; Crohn's Disease Activity Index <150), and incidences of adverse events and serious adverse events were evaluated. RESULTS: Among 55 enrolled patients, the mean CD duration was 0.4 years, the mean baseline Simple Endoscopic Score for CD was 12.6, and the mean baseline Crohn's Disease Activity Index was 265.5. At week 26, 19 patients (34.5%) were in endoscopic remission. At weeks 10 and 26, 34 (61.8%) and 30 patients (54.5%), respectively, were in clinical remission. Post hoc Bayesian analysis showed that the probabilities that triple combination therapy produced a higher endoscopic remission rate (33.5%; 95% credible interval, 22.4-45.7) than placebo (14%), vedolizumab monotherapy (27%), or adalimumab monotherapy (30%) were 99.9% or higher, 86.3%, and 71.4%, respectively. Six patients had serious adverse events. CONCLUSIONS: Combination therapy resulted in endoscopic and clinical remission at week 26 in 34.5% and 54.5% of patients, respectively, with no safety signal related to the treatment regimen. This supports further evaluation of combination therapy in CD. CLINICALTRIALS: gov number: NCT02764762.