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 Annual European Congress of Rheumatology 2019 meeting about subcutaneous biosimilar CT-P13 (Inflectra, Remsima).

The company said that subcutaneous (SC) 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 (RA) 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 IV CT-P13 3 mg/kg every 8 weeks and the SC cohorts received SC CT-P13 90 mg, 120 mg or 180 mg, respectively, every 2 weeks up to week 54.

Overall, the efficacy and safety results of SC 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 DAS28 (CRP) and the 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 SC 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, SC CT-P13 was shown to be noninferior in terms of efficacy and compared safety profiles 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 patients with RA 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 noninferiority of CT-P13 SC compared with 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.

In a separate study, a 5-year analysis of medical records years of people with RA and ankylosing spondylitis (AS) showed that long-term treatment with CT-P13 was safe and efficacious based on drug survival, disease activity measurements, and adverse events. The study included patients who switched from reference infliximab to CT-P13, and drug survival was similar between patients who were naïve at the start of CT-P13 treatment and switched from reference to CT-P13.

Researchers collected and analyzed data from 491 patients (154 RA and 337 AS), including 19 and 118 switched patients with RA and AS, respectively. The probabilities of drug survival at year 5 for patients with RA were 0.42 and 0.53, respectively for naïve and switched patients. The probabilities of drug survival at year 5 for patients with AS were 0.64 and 0.72, respectively for naïve and switched patients.