Celltrion Healthcare's biosimilar drug Herzuma (ingredient: trastuzumab) for breast and gastric cancer had more than 51 percent of the market share in Japan in June, overtaking the original therapies sold in the country.

The company said Herzuma took the top place in Japan with the reliability proved by the expanding prescriptions worldwide and becoming the first biosimilar to be launched in Japan's trastuzumab market.

In August 2019, Celltrion Healthcare obtained an indication for a three-week cycle method of Herzuma in treating more than 90 percent of breast cancer patients receiving trastuzumab in the country.

The strategy of supplying Herzuma via different channels where Celltrion Healthcare's Japanese branch and its partner Nippon Kayaku have advantages has also worked, Celltrion Healthcare said.

The company predicted Herzuma prescription to grow further in Japan. As hospitals are getting tougher due to decreased patient visits under the Covid-19 pandemic, medical institutions are likely to search for drugs like Herzuma on which Japan's diagnosis procedure combination (DPC) system is applied, to improve their financial status.

Celltrion also cited the Japanese government's policy change as another factor to positively affect Herzuma prescription. In June, Tokyo included a policy to promote biosimilar drugs in Prime Minister Yoshihide Suga's Honbebuto Paper for 2021.

Celltrion Healthcare said it plans to run more aggressive marketing, including online conferences, expanding product education and promotion for medical professionals to increase prescriptions.

"Celltrion's drugs are advancing globally beyond the U.S. and Europe with the recently announced bids for Herzuma and Truxima (ingredient: rituximab) in Brazil and the achievements made in Japan," a Celltrion Healthcare official said. "We will do our best to see outcomes in subsequent products, such as Remsima SC (ingredient: infliximab) and Yuflyma (ingredient: adalimumab)."