CT-P47 Is Promising Biosimilar Candidate for Tocilizumab in RA Treatment

Josef S. Smolen, MD

Credit: Vienna School of Clinical Research

Phase 3 data presented at the Annual European Congress of Rheumatology (EULAR) 2024 found the biosimilar CT-P47 is similar in terms of efficacy, safety, and immunogenicity profile to the reference product, tocilizumab (RoActemra), for treating patients with moderate-to-severe rheumatoid arthritis (RA).¹

“The positive topline results from the Phase III study support the biosimilarity of CT-P47 to reference tocilizumab and also provide clinical evidence for the possibility of switching from reference tocilizumab to CT-P47,” said Josef S. Smolen, MD, emeritus professor of medicine at the Medical University of Vienna, Austria, in a press release.

Biosimilars have offered a more cost-effective option over biologic products for patients which helps improve patient access.² However, the US Food and Drug Administration (FDA) has not yet approved a biosimilar for tocilizumab. Celltrion filed for regulatory approval of CT-P47 for RA treatment with the FDA in January 2024 and European Medicines Agency (EMA) in February 2024.

In the presented study, investigators sought to compare the effectiveness and safety of the biosimilar CT-P47, a recombinant humanized monoclonal antibody that acts as an interleukin 6 receptor antagonist, with tocilizumab.¹

The study randomized 471 patients with moderate to severe RA to receive either CT-P47 or tocilizumab at 8 mg/kg every 4 weeks for the first 20 weeks. Before week 24, patients were re-randomized to either continue with tocilizumab or transition to CT-P47 up to week 48.

The primary endpoint was an improvement in disease activity score 28 (DAS28) using the erythrocyte segmentation rate at weeks 12 and 24. The estimated difference in DAS28 improvement between the 2 groups was -0.01 for week 12 and -0.1 for week 24. The confidence intervals fit within the margins of the estimated differences, suggesting the 2 treatments are equivalent in terms of their DAS28 score (week 12: 95% CI, - 0.26 to 0.24; week 24: 90% CI, - 0.30 to 0.10).

Patients on CT-P47 and tocilizumab also had similar mean serum concentrations up to week 32, the incidence of treatment-emergent adverse events, and anti-drug antibody positively. The findings suggest CT-P47 has comparable pharmacokinetics, safety, and immunogenicity.

Furthermore, another study compared the pharmacokinetic similarity between the CT-P47 autoinjector and the pre-filled syringe. Investigators found similarities in healthy participants.

Additionally, investigators assessed the usability of the CT-P47 autoinjector. Investigators saw CT-P47 autoinjector had better usability than the pre-filled syringe in patients with RA. Overall, the CT-P47 autoinjector was well-tolerated.

“We believe that administration of CT-P47 via an autoinjector presents an alternative delivery option to a pre-filled syringe in clinical practice and aims to improve treatment compliance,” said Taehun Ha, vice president and head of Europe division at Celltrion, in a press release. “The availability of tocilizumab biosimilars such as CT-P47 represents a great opportunity to reduce treatment costs, contributing to health-care budget sustainability, improved patient access, and lower disease burden…We remain committed to improving the quality of patients’ lives and the sustainability of healthcare systems whilst increasing physician choice and patient access to biologics.”

References

1. ^{Celltrion Showcases Promising Results in Phase III Study For CT-P47, A Biosimilar Candidate Of Roactemra® (Tocilizumab) In Patients With Rheumatoid Arthritis (RA) At EULAR 2024. Business Wire. June 13, 2024. https://www.businesswire.com/news/home/20240607689134/en/Celltrion-showcases-promising-results-in-phase-III-study-for-CT-P47-a-biosimilar-candidate-of-RoActemra%C2%AE-tocilizumab-in-patients-with-rheumatoid-arthritis-RA-at-EULAR-2024. Accessed June 18, 2024.}
2. ^{Pine, L. Tocilizumab Biosimilar CT-P47 Demonstrates Pharmacokinetic Equivalence. HCPLive. June 16, 2023. https://www.hcplive.com/view/tocilizumab-biosimilar-ct-p47-demonstrates-pharmacokinetic-equivalence. Accessed June 18, 2024.}