Celltrion Healthcare presented Phase III data from the LIBERTY-CD and LIBERTY-UC clinical trials, for the investigational subcutaneous (SC) infliximab in inflammatory bowel disease (IBD) treatment at the United European Gastroenterology (UEG) Week 2023 in Copenhagen. Results from the LIBERTY studies, presented during a satellite symposium, evaluated the effectiveness of SC infliximab over placebo in patients with moderately to severely active Crohn's disease (CD) or ulcerative colitis (UC). SC infliximab had a similar safety profile to the placebo during the maintenance period.

The proportion of patients who experienced adverse events (AEs), serious AEs, infection in the SC infliximab and placebo groups were generally comparable. No new safety concerns were identified. LIBERTY-CD and LIBERTY-UC are registrational studies currently under review by the U.S. FDA as part of a Biologics License Application (BLA) submission.

If approved by the FDA, CT-P13 SC would be the first subcutaneous formulation of infliximab. Post-hoc analyses of the LIBERTY-CD and LIBERTY-UC studies were presented as posters at UEG Week 2023. The first post-hoc analysis examined the possible use of SC infliximab treatment without immunosuppressants and the second evaluated dose escalation in patients with loss of treatment response.

The first post-hoc analysis supports the efficacy and safety of SC infliximab as a monotherapy without immunosuppressants for CD and UC patients. After 54 weeks, there were no statistical differences in efficacy outcomes between monotherapy and combination therapy with immunosuppressants. The overall safety profile during the maintenance period was also comparable between the two groups, suggesting limited benefit of combination therapy with immunosuppressants for IBD patients treated with SC infliximab.

The second post-hoc analysis evaluated the impact of dose escalation of SC infliximab in managing the loss of response to treatment in IBD patients. The recommended dose for subcutaneous infliximab is 120 mg once every 2 weeks. Exploratory results suggest that dose escalation from 120mg to 240mg every two weeks may restore efficacy, while safety profiles, including immunogenicity and the incidence rate of adverse events, were shown to be comparable between patients with or without dose escalation.

In both UC and CD studies, patients showed improvement in terms of clinical remission [24.7% (20/81) in UC and 53.8% (21/39) in CD] or endoscopic response [28.2% (11/39) in CD] after dose escalation. Compared to the first dose escalation visits, patients on dose escalation had a statistically significant reduction in modified Mayo score (in UC) and CDAI score (in CD) at Week 54. In a separate presentation at UEG Week 2023, real-world data on switching from intravenous (IV) to SC infliximab were evaluated.

The findings may help support the practical application of this innovation. The European Commission authorized CT-P13 SC in 2020 for multiple indications including CD and UC. FDA approval decision for CT-P13 SC is anticipated within the fourth quarter of 2023.