Introduction In GEMINI 1 and GEMINI 2, vedolizumab (VDZ) was safe and effective in patients (pts) with ulcerative colitis (UC) or Crohn’s disease (CD), respectively, on stable doses of immunosuppressants (IS).^1,2 The effect of discontinuing IS in pts who responded to VDZ induction therapy in these studies has not been characterised.

Methods Pts who responded to VDZ at week (wk) 6 were re-randomised to placebo (VDZ/PBO) or VDZ every 4 or 8 wks (VDZ/VDZ Q4W or Q8W) for 46 wks. At United States (US) sites, re-randomised pts discontinued IS use at wk 6. At non-US sites, pts could continue IS use. Efficacy, VDZ serum concentration, and immunogenicity data (via an enzyme-linked immunosorbent assay) were evaluated post hoc in pts with baseline IS use stratified by region.

Results At wk 52, rates of clinical remission and response (Table), mucosal healing (UC), durable clinical remission, and corticosteroid-free remission were numerically higher with VDZ, mostly irrespective of IS use. The US and non-US sites had similar numbers of patients who were positive for anti-VDZ antibodies during VD maintenance therapy (Table). Mean trough concentrations were similar between US and non- US pts at wk 46.

Conclusion Discontinuing IS did not appear to substantially affect efficacy of VDZ maintenance therapy. Interpretation of these post hoc analyses is limited by potential IS discontinuation in non-US pts and the relatively small sample sizes.

References 1 Feagan BG, et al. N Engl J Med. 2013;369:699-710; NCT00783718.

2 Sandborn WJ, et al. N Engl J Med. 2013;369:711-721; NCT00783692.

Disclosure of Interest B. Feagan Grant/research support from: Abbott/AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb (BMS), Janssen Biotech (Centocor), JnJ/Janssen, Roche/Genentech, Millennium, Pfizer, Receptos, Santarus, Sanofi, Tillotts, UCB Pharma, Consultant for: Abbott/AbbVie, Actogenix, Albireo Pharma, Amgen, AstraZeneca, Avaxia Biologics Inc., Avir Pharma, Axcan, Baxter Healthcare Corp., Biogen Idec, Boehringer-Ingelheim, Bristol-Myers Squibb, Calypso Biotech, Celgene, Elan/Biogen, EnGene, Ferring Pharma, Roche/Genentech, GiCare Pharma, Gilead, Given Imaging Inc., GSK, Ironwood Pharma, Janssen Biotech (Centocor), JnJ/Janssen, Kyowa Kakko Kirin Co Ltd., Lexicon, Lilly, Merck, Millennium, Nektar, Novartis, Novo Nordisk, Pfizer, Prometheus Therapeutics and Diagnostics, Protagonist, Receptos, Salix Pharma, Serono, Shire, Sigmoid Pharma, Synergy Pharma Inc., Takeda, Teva Pharma, TiGenix, Tillotts, UCB Pharma, Vertex Pharma, Warner-Chilcott, Wyeth, Zealand, Zyngenia, Speaker bureau with: Abbott/AbbVie, JnJ/Janssen, Takeda, Warner-Chilcott, UCB Pharma, Conflict with: Directorship as CEO and Senior Scientific Director, Robarts Clinical Trials Inc, Western University, London, Ontario, C. Siegel Grant/research support from: AbbVie, Janssen, Salix, Takeda, UCB, Consultant for: AbbVie, Amgen, Janssen, Lilly, Pfizer, Takeda, UCB, Speaker bureau with: AbbVie, Janssen, Takeda, G. Melmed Grant/research support from: Prometheus Labs, Consultant for: AbbVie, Celgene, Genentech, Given Imaging, Janssen, Luitpold, Takeda, UCB, K. Isaacs Grant/research support from: AbbVie, Given Imaging, Janssen, Luitpold, Pfizer, Takeda, and UCB, K. Lasch Employee of: Takeda Pharmaceuticals U.S.A., Inc., Deerfield, IL, USA, M. Rosario Employee of: Takeda Pharmaceuticals U.S.A., Inc., Deerfield, IL, USA, A. James Employee of: Takeda Development Centre Europe Ltd, London, UK, B. Abhyankar Employee of: Takeda Development Centre Europe Ltd, London, UK