Taiho Pharma, Haihe Biopharma Enter Into Agreement For Ovarian Cancer Drug Candidate Risovalisib

(RTTNews) - Taiho Pharma, a subsidiary of Otsuka Holdings Co., Ltd. (4578.T,OTSKF) and Haihe Biopharma Co., Ltd., a Chinese biopharmaceutical company, announced on Thursday that they have entered into an exclusive license agreement for PI3Ka Inhibitor Risovalisib.

As per the agreement, Taiho will receive exclusive rights from Haihe to develop, manufacture and commercialize Risovalisib in Japan for the treatment of ovarian clear cell carcinoma (OCCC).

In return, Haihe will receive an upfront payment, development and sales milestone payments, and royalties based on sales revenue from Taiho.

A New Drug Application (NDA) for Risovalisib, intended for the treatment of ovarian clear cell carcinoma, was submitted in Japan by Haihe Biopharma K.K., a fully owned affiliate of Haihe, in August 2025.

Ovarian clear cell carcinoma is a rare, highly aggressive subtype of epithelial ovarian cancer. Approximately 3,500 patients are diagnosed with ovarian clear cell carcinoma (OCCC) per year in Japan, according to reports.

Risovalisib is the PI3Ka (phosphatidylinositol 3-kinase alpha) inhibitor. PI3Ka is a protein that regulates key physiological processes such as cell proliferation, survival, and metabolism, thus making PI3Ka an important target for cancer-targeted therapy.

In June 2025, Risovalisib was granted orphan drug designation by the Japanese Ministry of Health, Labour and Welfare.

Commenting on the agreement, Jian Ding from Haihe, Academician of the Chinese Academy of Engineering, said, "We hope our collaboration will be able to provide a promising treatment option for patients with ovarian clear cell carcinoma and other PI3Ka-associated diseases."

On the Tokyo Stock Exchange, 4578.T shares had closed 2.14% higher at 8176 yen on the Nasdaq.