SB Hanauer, BE Sands, et al. Gastroenterology 2024;167: 919-923. Open Access PDF! Subcutaneous Infliximab (CT-P13 SC) as Maintenance Therapy for Inflammatory Bowel Disease: Two Randomized Phase 3 Trials (LIBERTY)

Methods: Two randomized, placebo-controlled, double-blind studies were conducted in patients with moderately to severely active CD or UC and inadequate response or intolerance to corticosteroids and immunomodulators. All patients received open-label CT-P13 IV 5 mg/kg at weeks 0, 2, and 6. At week 10, clinical responders were randomized (2:1) to CT-P13 SC 120 mg or placebo every 2 weeks until week 54 (maintenance phase) using prefilled syringes. 

Key findings:

• At week 54 in the CD study, statistically significant higher proportions of CT-P13 SC–treated patients vs placebo-treated patients achieved clinical remission (62.3% vs 32.1%; P < .0001) and endoscopic response (51.1% vs 17.9%; P < .0001)
• In the UC study, clinical remission rates at week 54 were statistically significantly higher with CT-P13 SC vs placebo (43.2% vs 20.8%; P < .0001).
• CT-P13 SC was well tolerated, with no new safety signals identified.
• The mean serum infliximab trough concentrations at weeks 14 and 54 were 13.2 and 14.8 mcg/mL with CD study and 14.6 and 16.3 with UC study, respectively.
  

Discussion:

• “The present findings are generally comparable with or numerically better than those observed in previous clinical trials that evaluated IV infliximab in patients with CD or UC…At week 50 in the SONIC trial, 35% of patients receiving infliximab achieved corticosteroid-free clinical remission,³⁰ compared with 40% of patients in the CT-P13 SC group in the current study.”
• “In terms of UC, the ACT 1 study⁴ found that patients receiving infliximab 5 mg/kg and 10 mg/kg were more likely to achieve clinical remission based on total Mayo score after 54 weeks (34.7% and 34.4%, respectively) compared with participants receiving placebo (16.5%), and in the current study, 43.2% and 20.8% of patients, all of whom had responded to induction therapy, achieved clinical remission at week 54 in the CT-P13 SC and placebo groups, respectively.”
• This study had a high rate of antidrug antibody detection (63.8%–65.1%)…” likely due to the use of highly sensitive, next-generation ADA assays, which have improved sensitivity compared with those used in historical studies… This suggests that route of administration of CT-P13 does not affect rates of ADA formation, and that the observed incidence of ADA is not unexpected.”
• “The decision to initiate CT-P13 SC maintenance therapy at week 10, 4 weeks after finishing CT-P13 IV induction therapy, was based on results of PK or pharmacodynamic model simulation.”

My take: These studies suggest that SC infliximab is likely to have similar efficacy as IV infliximab

Related blog posts:

• Vedolizumab and Infliximab: Expected Dosing When Switching From IV to SC Routes
• SC Infliximab versus Vedolizumab for Crohn’s Disease and for Ulcerative Colitis
• REMSWITCH: Infliximab IV to SC Study
• FDA-Approved Subcutaneous Infliximab (Zymfentra) Now Available
• Infliximab Injections Coming Soon