There is a promising treatment under investigation for advanced breast cancer patients. Researchers are focusing on the drug trastuzumab deruxtecan for those with ERBB2-low metastatic breast cancer, characterized by low levels of the HER2 protein.
A phase 3 trial, HORIZON-Breast06, is assessing its effectiveness compared to standard chemotherapy. The trial involved 551 women from 73 Chinese hospitals, who were randomly assigned to either receive the drug intravenously every three weeks or a physician’s choice of chemotherapy. The trial period extended from June 2023 to August 2025.
Trastuzumab deruxtecan significantly slowed cancer progression compared with chemotherapy. The median time without tumor growth was 16.4 months with the drug versus 6.8 months with chemotherapy. Tumors shrank in 75.5% of patients treated with the drug, compared to 41.2% with chemotherapy.
The FDA has approved a once-daily pill for deadly cancer after noticing improved survival rates in patients. At 12 months, 90.6% of trastuzumab deruxtecan patients were alive, against 81.4% of the chemotherapy group.
Published in JAMA, the study shows the drug offers significant progression-free survival benefits for patients with ERBB2-low advanced breast cancer. Dr. Loren Rourke from Texas praised the findings as “incredibly encouraging” for living with advanced breast cancer, where extra months matter.
Rourke emphasized the benefits across different breast cancer types. Still, she noted side effects were more prevalent. More than 84% of patients experienced serious side effects, compared with nearly 68% in the chemotherapy group.
The researchers pointed to manageable side effects like anemia, stressing the importance of addressing fatigue, blood count drops, and infection risks. Rourke highlighted the need for further studies to determine if the treatment helps patients live longer.
As more research is needed, the findings represent a significant step forward. The ability to delay cancer progression may substantially impact patients’ lives.