On 24 August 2026, Celltrion announced that it has applied to Korea’s Ministry of Food and Drug Safety for approval of CT-P51, biosimilar to MSD’s Keytruda® (pembrolizumab). This is the second biosimilar pembrolizumab application filed in Korea, following Samsung Bioepis’ application earlier this month for SB27.
Commencing with its Korean application, Celltrion plans to “sequentially pursue applications for CT-P51 in major global markets”, including the US, EU and Canada. According to Celltrion, it has a competitive advantage in relation to biosimilar pembrolizumab due to its large-scale in-house production facilities and its strong direct sales distribution network.
Celltrion’s Korean application regarding CT-P51 is based on clinical trial results in 228 patients with melanoma. In July 2026, Celltrion terminated its Phase 3 trial of CT-P51 in Europe in order to streamline its pembrolizumab development program. It also recently streamlined its US Phase 3 trial for CT-P51 in patients with untreated metastatic non-squamous non-small cell lung cancer by reducing the number of trial participants.
Pembrolizumab biosimilars have reportedly been launched in Paraguay (by Bioeticos in August 2025) and approved in Vietnam (by Biocad in November 2025) and Jordan (by Sana Pharma in February 2026).
There are multiple pembrolizumab biosimilars in development with competition to be the first mover in major markets heating up. In June 2026, Samsung Bioepis claimed to be the first developer of a pembrolizumab biosimilar to announce global phase 3 trial results. Formycon announced successful Phase 1 results in February 2026, with its US commercialisation partner, Zydus, expressing optimism that it is well-placed to file the first BLA in the US for biosimilar pembrolizumab. Formycon has also announced agreements for commercialisation of pembrolizumab biosimilar FYB206 with MS Pharma for the MENA region and Lotus for the Asia-Pacific.
Other companies with pembrolizumab biosimilars in clinical trials include Amgen, mAbxience, Sandoz, Shanghai Henlius, BioNTech, Qilu Pharmaceutical and Enzene. Alvotech and Dr Reddy’s have entered into a global collaboration and licence agreement to co-develop, manufacture and commercialise a Keytruda® biosimilar and Bio-Thera and Avalon are partnering on commercialisation of a pembrolizumab biosimilar (BAT3306) in Saudi Arabia/MENA.