Celltrion's breast cancer drug Herzuma captures 74% market share in Japan

Celltrion said Thursday that its breast and gastric cancer treatment Herzuma (trastuzumab) captured a 74 percent market share in Japan as of November 2024, citing IQVIA data. 

Herzuma first surpassed the market share of the original product, Roche’s Herceptin, in the second quarter of 2021 and has remained the leader for three consecutive years, the Korean company said.

The company attributed the drug’s performance to several factors, including the approval of a three-week treatment regimen in August 2019, which covers over 90 percent of Japan’s breast cancer market. Other contributing factors included Japan’s regulatory environment favoring biosimilars and tailored sales strategies informed by local market analysis.

Cancer treatments in Japan fall under the Diagnosis Procedure Combination (DPC) patient classification method, which encourages the use of biosimilars by setting fixed medical costs. The system allows hospitals to retain savings from prescribing lower-cost medications, benefiting hospitals, the government, and patients by reducing overall medical expenses and out-of-pocket costs.

Vegzelma (bevacizumab), another Celltrion biosimilar for metastatic colorectal and breast cancer, achieved a 23 percent market share in November, tripling its performance from the previous year. Despite entering the market later than competitors, Vegzelma became the second most-prescribed biosimilar within a year of its launch, a Celltrion official said.

In the autoimmune disease treatment market, Celltrion’s Remsima (infliximab) held a 39 percent market share, maintaining its status as the most-prescribed biosimilar, the official added. Yuflyma (adalimumab), introduced more recently, captured an 8 percent share within a year. 

Celltrion also plans to expand its product offerings in Japan, targeting new areas such as allergy, ophthalmology, and bone diseases, while continuing to grow its presence in the oncology and autoimmune treatment markets.