Celltrion expands subcutaneous pipeline as Herzuma SC heads to trial

Celltrion isn’t slowing down. Just a day after announcing that Remsima (infliximab) had officially become Korea’s first blockbuster biopharmaceutical, the company made another bold move by pushing further into the high-stakes market for subcutaneous (SC) biosimilars.

On Thursday, the Ministry of Food and Drug Safety (MFDS) greenlit a phase 1 clinical trial for CT-P6 SC, Celltrion’s SC version of Herzuma, its biosimilar to Roche’s Herceptin (trastuzumab).

The trial will compare the pharmacokinetics, safety, and immunogenicity of CT-P6 SC against Genentech’s Herceptin Hylecta, which combines trastuzumab with recombinant human hyaluronidase to enable subcutaneous injection. The study, set to take place in four Korean hospitals, marks Celltrion’s latest bet on a format that is rapidly reshaping the oncology market.

Herceptin has been a cornerstone breast cancer treatment for decades, originally available only as an intravenous (IV) formulation. But with the development of Herceptin Hylecta, SC versions have taken over. Industry sources estimate that more than half of Herceptin’s global sales now come from its SC formulation, underscoring the shift in patient and provider preference for quicker, more convenient administration. While IV infusions can take three to four hours, SC injections take just three to five minutes.

Celltrion isn’t new to the SC game. The company was the first to bring an SC biosimilar of infliximab to market with Remsima SC, a subcutaneous version of Johnson & Johnson’s Remicade biosimilar. That bet is paying off. Since its 2020 launch in Europe, Remsima SC has skyrocketed from just 1 percent market share to 21 percent as of the third quarter of 2024. The IV version of Remsima has already cemented its status as a global blockbuster, with over 1.2 trillion won ($823 million) in annual sales, dominating more than 60 percent of the European market and over 30 percent in the U.S.

Now, Celltrion is looking to replicate that success with Herzuma SC. A company spokesperson said Wednesday that Celltrion is “actively developing new biosimilars and innovative drugs to follow Remsima’s success” and is aiming for “the next blockbuster medication.” The spokesperson declined to comment on plans for the Herzuma biosimilar in a follow-up call Friday.

Beyond Herzuma SC, Celltrion has been aggressive in expanding its biosimilar pipeline. This month, the company secured European approvals for four new biosimilars, including Eydenzelt, an Eylea (aflibercept) biosimilar, and Stobocolo and Osenvelt, referencing Prolia and Xgeva (denosumab). The approvals bring the company’s European portfolio closer to the ambitious 11-product lineup it established in Korea last year.

Meanwhile, Celltrion continues to widen the scope of Remsima SC. Last Friday, the MFDS approved a phase 3 trial for the SC formulation in pediatric patients with Crohn’s disease and ulcerative colitis, an expansion beyond the already-approved adult indications. The study is set to begin in June, building on the therapy’s phase 3 success in adults, which led to regulatory nods in both the U.S. and Europe.