Daiichi Sankyo Datroway approved in Japan for breast cancer

Tokyo: Daiichi Sankyo's DATROWAY (datopotamab deruxtecan) has been approved in Japan for the treatment of adult patients with hormone receptor (HR) positive, HER2 negative (IHC 0, IHC 1+ or IHC 2+/ISH-) unresectable or recurrent breast cancer after prior chemotherapy.

In Japan, breast cancer is the most common cancer in women.1 Approximately 92,000 cases of breast cancer were diagnosed in Japan in 2022, with approximately 17,600 deaths. It is estimated that 70% of diagnosed cases are considered what has been historically called HR positive, HER2 negative breast cancer (measured as HER2 score of IHC 0, IHC 1+ or IHC 2+/ISH-).

DATROWAY is a TROP-2 directed medicine to be approved in Japan for HR positive, HER2 negative breast cancer and is the second DXd antibody drug conjugate (ADC) approved based on Daiichi Sankyo’s DXd ADC Technology.

The approval of DATROWAY by the Japan Ministry of Health, Labour and Welfare (MHLW) is based on results from the TROPION-Breast01 phase 3 trial. In this trial, DATROWAY significantly reduced the risk of disease progression or death by 37% compared to investigator’s choice of chemotherapy (hazard ratio [HR]=0.63, 95% confidence interval [CI]: 0.52-0.76; p<0.0001) in patients with HR positive, HER2 negative metastatic breast cancer as assessed by blinded independent central review (BICR). Median progression-free survival (PFS) was 6.9 months in patients treated with DATROWAY compared to 4.9 months in those treated with chemotherapy.

“This first global approval of DATROWAY provides patients in Japan with metastatic HR positive, HER2 negative breast cancer a new alternative to conventional chemotherapy, which is often associated with poor response rates,” said Wataru Takasaki, PhD, Senior Advisor, Daiichi Sankyo. “DATROWAY also is the second DXd antibody drug conjugate approved in Japan based on technology invented by Daiichi Sankyo, emphasizing our commitment to creating new, innovative standards of care for patients with cancer.” 

In TROPION-Breast01, adverse reactions occurred in 93.6% (337/360 patients) of the 360 patients (including 31 Japanese patients) in the DATROWAY (6 mg/kg) arm.

In Japanese patients, interstitial lung disease (ILD) occurred in 6.5% of patients treated with DATROWAY.

DATROWAY is approved in Japan with a Warning for ILD. As cases of ILD, including fatal cases, have occurred in DATROWAY-treated patients.

"DATROWAY is to be used in close collaboration with a respiratory disease expert. Patients should be closely observed during therapy by monitoring for early signs or symptoms of ILD (such as dyspnea, cough or fever) and performing periodical percutaneous oxygen saturation (SpO2) tests, chest X-ray scans and chest CT scans. If abnormalities are observed, discontinue administration of DATROWAY and take appropriate measures, such as corticosteroid administration. Prior to initiation of DATROWAY therapy, a chest CT scan should be performed and medical history taken to confirm the absence of any comorbidity or history of ILD with the patient and carefully consider the eligibility of the patient for DATROWAY therapy," the release stated.

Additional regulatory submissions for DATROWAY in breast cancer are under review in the EU, China, U.S. and other regions.