Celltrion Presents More Data Showing Comparable Efficacy, Safety of Subcutaneous CT-P13 to IV Form

Korean drug maker Celltrion Healthcare recently presented new findings from a 2-part study at the European League Against Rheumatism European Congress of Rheumatology 2019 meeting about subcutaneous biosimilar CT-P13 (Inflectra, Remsima).

The company said subcutaneous CT-P13 may enhance treatment options for the use of biosimilar infliximab by providing high consistency in drug exposure and a convenient method of administration.

The proposed subcutaneous formulation of CT-P13 is currently under European Medicines Agency evaluation. The proposed formulation of the drug will also be studied in the United States in a phase 3 program in patients with inflammatory bowel disease.

The first part of the study investigated the pharmacokinetics, efficacy, and overall safety of CT-P13 in patients with rheumatoid arthritis during a treatment period of 1 year, as compared with the intravenous (IV) formulation of CT-P13. After enrolling 50 patients, 48 patients were randomly assigned at week 6 into 4 cohorts in a 1:1:1:1 ratio. The IV cohort received CT-P13 IV 3mg/kg every 8 weeks and the SC cohorts received CT-P13 SC 90mg, 120mg or 180mg, respectively, every 2 weeks up to week 54.

Overall, the efficacy and safety results of subcutaneous CT-P13 up to week 54 were comparable to those of the IV formulation. Disease improvement was assessed using 2 disease scores for RA, the disease activity score in a count of 28 joints with C-reactive protein (DAS28-CRP) and the American College of Rheumatology criteria for 20% improvement (ACR20) score. Results demonstrated that DAS28-CRP and ACR20 were comparable across all 4 cohorts, regardless of the route of administration or dosage of CT-P13. The safety profiles at week 6 in subcutaneous CT-P13 were comparable to CT-P13 IV and were similar to those previously reported for IV infliximab.

In the second part of the study, subcutaneous CT-P13 was shown to be noninferior in terms of efficacy and compared safety profiles compared with CT-P13 IV in people with RA over 30 weeks.

This study was followed by a phase 1/3 randomised controlled trial. A total of 362 RA patients were enrolled, of whom 348 were randomized at week 6 into 2 treatment arms in a 1:1 ratio (169 and 179 patients in SC 120mg biweekly or IV 3mg/kg arms every 8 weeks, respectively).

The trial showed that the mean change of DAS28-CRP from baseline to week 22 was similar between the 2 arms. The lower limit of the 95% CI (0.03) for the treatment difference in the change of DAS28-CRP from baseline was greater than the prespecified noninferiority margin (—0.6) indicating non-inferiority of CT-P13 SC compared to CT-P13 IV.

ACR20 responses were also similar between the 2 treatment arms up to week 22, and the safety profiles at week 6 were also comparable.