Celltrion Unveils Follow-up Study on Phase 3 Clinical Trial of Prolia Biosimilar 'CT-P41'

Celltrion announced on the 15th that it has presented the 78-week research results from the Phase 3 follow-up study of CT-P41, a biosimilar developed from the osteoporosis treatment drug Prolia, at the 2024 World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (WCO-IOF-ESCEO).

Incheon Songdo Celltrion Plant 2 exterior view. / Incheon - Photo by Hyunmin Kim kimhyun81@

The 24th World Congress on Osteoporosis held this year is a globally renowned international academic conference related to osteoporosis. It took place from the 11th to the 14th (local time) in London, UK. At the conference, Celltrion disclosed detailed data for the first time from the global Phase 3 follow-up study of CT-P41, conducted on 479 postmenopausal women aged 50 to 80 with osteoporosis, through oral and poster presentations.

The clinical trial set the primary endpoint as the change in lumbar spine bone mineral density at 52 weeks compared to baseline in both the CT-P41 and original drug administration groups. The results showed that the difference between the two groups fell within the pre-defined equivalence margin, demonstrating therapeutic equivalence. Pharmacodynamic primary endpoint evaluation, based on the area under the effect curve for the first six months of s-carboxy-terminal telopeptide (CTX), a major bone metabolism marker, also confirmed pharmacodynamic equivalence between the CT-P41 and original drug groups.

Additionally, pharmacokinetics, safety, and immunogenicity results were similar in both treatment groups. Even after switching from the original drug group to the CT-P41 group at 52 weeks, the results between the groups remained comparable. The company stated, "In conclusion, the efficacy, pharmacokinetics, pharmacodynamics, immunogenicity, and safety results between CT-P41 and the original drug were similar."

Amgen's osteoporosis treatment 'Prolia'
Photo by Amgen

Prolia, the osteoporosis treatment drug, was developed by the multinational pharmaceutical company Amgen. Its active ingredient, denosumab, is also approved under the brand name Xgeva for preventing bone metastasis complications in cancer patients and treating giant cell tumor of bone. The combined global sales of the two products reached $6.16 billion (approximately 8.5113 trillion KRW) last year, making it a blockbuster drug. The patents in the United States and Europe are set to expire in February and November of next year, respectively.

A Celltrion representative said, "CT-P41, for which approval applications have been completed in major global countries, revealed the Phase 3 follow-up results for the first time at the World Congress on Osteoporosis, confirming once again the similarity in efficacy, pharmacodynamics, and safety compared to the original drug. We will proceed smoothly with the remaining approval procedures for CT-P41 to expand our product portfolio in the osteoporosis treatment market and solidify our leading position." Celltrion has applied for approval of CT-P41 for all indications held by Prolia and Xgeva in major countries including the United States, South Korea, and Canada.