Exciting Advances in Breast Cancer Treatment with New Drugs and Technologies

Recent developments in the field of breast cancer treatment are generating significant excitement, with several promising updates emerging. On February 19, Hansai Aitai announced that its second phase clinical trial for HX009, in combination with the HER2-targeted antibody-drug conjugate trastuzumab deruxtecan, has been approved by China's National Medical Products Administration (NMPA). This trial targets patients with unresectable or metastatic triple-negative breast cancer (TNBC) who have previously received first or second-line systemic therapy and exhibit low or very low HER2 expression.

In January, Daiichi Sankyo and AstraZeneca received U.S. approval for trastuzumab deruxtecan to treat patients with hormone receptor-positive, HER2 low-expressing or ultra-low expressing breast cancer that is not amenable to surgery. AstraZeneca also gained approval for olaparib for a new indication in early high-risk breast cancer patients with harmful or suspected harmful germline BRCA mutations, following neoadjuvant or adjuvant chemotherapy.

These innovative drugs are breaking barriers in breast cancer treatment, especially for TNBC, which is particularly aggressive and often affects younger women. The absence of the three common receptor markers—estrogen receptor (ER), progesterone receptor (PR), and HER2—has made treatment options limited, traditionally relying on surgery, radiotherapy, and chemotherapy.

Currently, the treatment landscape for TNBC is constrained, with chemotherapy being the primary option in China. However, overseas, PD-(L)1 inhibitors and PARP inhibitors have been approved for first-line therapy. Gilead's sacituzumab govitecan, the world’s first Trop-2 targeted ADC, was approved in China in 2022 for previously treated advanced TNBC.

The breast cancer drug market is entering a harvest phase with multiple targets being explored. HER2 ADC drugs like Roche’s T-DM1 and AstraZeneca/Daiichi Sankyo’s DS-8201 are showing significant therapeutic potential, with over ten HER2 ADC drugs currently in clinical development.

Additionally, TROP2 has emerged as a crucial target for TNBC treatment, with several ADC drugs targeting this antigen, indicating considerable potential in clinical studies. The advent of PROTAC technology also offers new hope for ER-positive breast cancer, aiming to overcome treatment resistance by degrading specific pathogenic proteins.

As breast cancer treatments evolve, these innovations provide more options and hope for patients. The breakthroughs in TROP2 and HER2 ADCs not only enhance treatment precision but also significantly improve patient outcomes and survival rates. With the maturation of PROTAC technology, the future of breast cancer therapy promises to be more personalized, precise, and diverse.