EFFICACY, SAFETY AND IMMUNOGENICITY OF SUBCUTANEOUS INFLIXIMAB (CT-P13 SC) MONOTHERAPY VERSUS COMBINATION THERAPY WITH IMMUNOSUPPRESSANTS – POST HOC ANALYSIS OF LIBERTY-CD AND LIBERTY-UC STUDY

Abstract

Abstract INTRODUCTION CT-P13 subcutaneous (SC) infliximab formulation demonstrated superiority over placebo in maintenance therapy in Crohn's disease (CD) and Ulcerative Colitis (UC) patients in two parallel 54 weeks studies (LIBERTY-CD and LIBERTY-UC). We performed a post-hoc subgroup analysis comparing patients treated with CT-P13 SC with and without combination immunosuppressants (IS) at baseline in CD and UC. AIMS & METHODS Patients with moderately to severely active CD and UC who responded at W10 to CT-P13 intravenous infliximab 5mg/kg (Weeks 0, 2 and 6) were randomized (2:1) to receive CT-P13 SC 120 mg (CT-P13 SC) or placebo every 2 weeks until W54 as maintenance therapy. IS (azathioprine [AZA], 6-mercaptopurine [6-MP], or methotrexate [MTX]) were allowed if patients maintained stable doses at least 8 weeks prior to W0, and stable doses were maintained up to W54. RESULTS 231 CD and 294 UC patients were randomized to receive CT-P13 SC maintenance therapy. Among them, 71 (30.7%) and 65 (22.1%) patients received CT-P13 SC with IS in CD and UC, respectively (In CD; 63, 4 and 4 patients of AZA, 6-MP, MTX, respectively, In UC; 63, 2 and 0 patients of AZA, 6-MP, MTX, respectively). There were no meaningful differences in efficacy outcomes at Week 54 by CT-P13 concentration tertiles at Week 54 between monotherapy and combination therapy groups in both studies (Table 1). In combined analysis of CD and UC patients, no statistically significant differences were seen in safety profile between monotherapy and combination therapy groups in the maintenance period except for infection rate (Table 2). In combined analysis of CD and UC patients, rate of anti-drug antibody [ADA] positive conversion up to W54 was statistically lower in combination therapy group (70.2% monotherapy vs 47.8% combination therapy [p<0.0001]). CONCLUSION No meaningful differences in efficacy outcomes at W54 were observed between monotherapy and combination therapy of CT-P13 SC in CD and UC patients. Concomitant IS use was associated with less ADA formation, whereas more infections are seen for combination therapy during maintenance period in CD and UC patients. The overall safety profile during maintenance period was otherwise comparable between monotherapy and combination therapy in CD and UC patients. This post-hoc analysis suggests limited benefit of concomitant IS with CT-P13 SC but a higher infection risk. Notably, patients were not randomized according to IS use nor were the studies ‘powered’ to demonstrate differences. Proportion of patients achieving efficacy outcomes at W54 by tertile of Serum concentrations of Infliximab (ng/mL) at W54 (Pharmacokinetic population) Safety results in maintenance period (Safety population)