Celltrion(068270) said on the 24th that it has applied to the Ministery of Food and Drug Safety for marketing authorization of "CT-P51," a biosimilar (biosimilar) to the immuno-oncology therapy Keytruda (ingredient name pembrolizumab).
Keytruda is an immuno-oncology therapy used for various cancers, including Non-small cell lung cancer (NSCLC) and melanoma. In 2025, its global sales were about $31.7 billion (about 44 trillion won), the largest for a single drug.
Starting with the domestic application, Celltrion plans to sequentially seek approval for CT-P51 in major markets, including the United States, Europe and Canada. Its strategy is to rapidly expand market share by leveraging large-scale manufacturing facilities and a global direct sales network.
The company's application for "CT-P51" covers Keytruda's major indications, including Non-small cell lung cancer (NSCLC), melanoma, gastric cancer and head and neck cancer. In a clinical trial involving 228 patients with melanoma who had undergone complete resection, it confirmed the pharmacokinetic (PK) equivalence of CT-P51 and Keytruda, and said similar results were observed for safety and immunogenicity.
If CT-P51 is approved, Celltrion's oncology portfolio is expected to be further strengthened. Celltrion currently sells targeted anticancer biosimilars such as the breast and gastric cancer treatment "Herzuma" (trastuzumab), the hematologic cancer treatment "Truxima" (rituximab), and "Vegzelma" (bevacizumab), which is used for metastatic colorectal cancer, Non-small cell lung cancer (NSCLC), ovarian cancer and others.
In particular, Keytruda and bevacizumab are used in combination therapy for diseases such as ovarian and cervical cancer, so the company also expects synergy from expanding sales of CT-P51 and Vegzelma. Celltrion plans to pursue linkages with next-generation anticancer new drugs under development, including Antibody-Drug Conjugate (ADC) therapies.
A Celltrion official said, "To target the global Keytruda market worth about 44 trillion won, we will proceed with CT-P51's approval process without a hitch," adding, "We will sequentially pursue approvals in major global markets and maximize synergy between existing products and next-generation pipelines."
Immuno-oncology therapies are drugs that treat cancer by inducing the body's immune cells to attack cancer cells. Keytruda, launched in 2014 by MSD (Merck in the United States), is a representative blockbuster (a drug with annual sales of $1 billion or more) that has maintained the No. 1 spot in global sales.
In Korea, Keytruda's substance patent expires in 2028, and in the United States and Europe, it is set to expire in late 2029 and early 2031. Ahead of that, pharmaceutical and biotech corporations are competing to develop and launch Keytruda biosimilars. Samsung Bioepis also applied in Aug. to the Ministery of Food and Drug Safety for marketing authorization of "SB27," a Keytruda biosimilar candidate.