Enhertu (trastuzumab deruxtecan), an HER2-targeted antibody-drug conjugate (ADC) co-developed by AstraZeneca (AZ, NASDAQ: AZN) and Daiichi Sankyo (TYO: 4568), has been approved by the National Medical Products Administration (NMPA) for the treatment of unresectable or metastatic HER2-positive adult breast cancer patients who have previously received one or more anti-HER2 drugs. This approval marks a significant advancement in the treatment options available for patients with advanced breast cancer.
Approval Based on Phase III Study Data
The approval was based on positive data from the Phase III DESTINY-Breast03 study, which compared Enhertu with trastuzumab emtansine (T-DM1). The study showed that 75.8% of patients treated with Enhertu were alive with no disease progression after 12 months, compared to 34.1% for those treated with trastuzumab emtansine (95% confidence interval [CI]). The focus was on patients with HER2-positive unresectable and/or metastatic breast cancer who had previously received trastuzumab and taxane treatment. The latest data presented at the San Antonio Breast Cancer Symposium (SABCS) last year demonstrated that trastuzumab deruxtecan produced clinically significant improvements in both overall survival (OS) and progression-free survival (PFS). According to independent review, the median PFS of trastuzumab deruxtecan was prolonged by 22 months (median PFS 28.8 vs 6.8 months; P<0.000001).
Strategic Implications
AstraZeneca struck a USD 6.9 billion licensing deal with Daiichi Sankyo in April 2019 to jointly develop and commercialize Enhertu globally, with Daiichi retaining rights in Japan. The drug was first made available in China via the Bo’Ao Lecheng medical pilot zone in Hainan in November 2021 and was awarded breakthrough therapy designation (BTD) and priority review statuses in April 2022. This approval further solidifies the global impact of Enhertu and highlights the commitment of AstraZeneca and Daiichi Sankyo to bringing innovative treatments to patients with HER2-positive breast cancer.-Fineline Info & Tech
