By Kiara Ford
A promising breakthrough has recently emerged in the ongoing clinical trials for the datopotamab deruxtecan drug. AstraZeneca and Daiichi Sankyo have been conducting research as part of their TROPION-Breast01 trial, which seeks to determine the effects of datopotamab deruxtecan against single-agent chemotherapy for patients with inoperable or metastatic HR-positive, HER2-low or negative breast cancer who are not candidates for endocrine therapy or have already previously progressed on other interventions. This research is taking place through randomized, multicenter, open label trials with over 700 patients across Asia, Europe, North America, South America, and Africa.
Datopotamab deruxtecan is an antibody-drug conjugate, a class of drug which is designed for targeted therapies and most often used in treatment of cancer. There are currently more than 12 clinical trials ongoing worldwide to study the effects of the drug on multiple tumors, with a particular interest in its effects on hormone receptor-positive, HER2-low or negative breast cancer.
Breast cancer is classified as “hormone receptor-positive” after a biopsy to collect cancer cells. These cells are then tested to determine whether they contain proteins which can act as receptors for the hormones estrogen and progesterone. Cancer cells with receptors will require these same hormones to grow. Being hormone receptor-positive means that the cancer cells contain receptors for either estrogen, progesterone, or both. Hormone receptor-positive cancer typically grows slower than hormone receptor-negative cancer.
HER2-low or negative breast cancer is a categorization based on the level of human epidermal growth factor receptor 2 (HER2) proteins in breast cells. At the right level, HER2 proteins can help control the rate of breast cell growth and maintenance. In cancer patients, however, a high level of HER2 may indicate that the breast cancer is growing and spreading rapidly. Specific drugs and therapies which target HER2 proteins, but patients who are HER2-low or negative typically will not respond well to such treatments.
The most recent development from the datopotamab deruxtecan Phase III trials demonstrated that patients whose cancer was hormone receptor-positive and HER2 low or negative had “statistically significant and clinically meaningful improvement” toward the end goal of progression-free survival while taking the drug, compared to chemotherapy. Progression-free survival is the amount of time during or after treatment in which a patient continues to live with the disease without disease progression. The datopotamab deruxtecan trials seek to understand the drug’s impact on both progression-free survival and overall survival (the duration of life after initial diagnosis). This most recent study also suggests that datopotamab deruxtecan can have a positive impact on overall survival, but the data is still new and requires further study before any definitive statements are made.
These results are just the beginning of Phase III of the drug trials, and a greater understanding of datopotamab deruxtecan’s efficacy will become clearer as more data is gathered. Still, in the meantime, it is encouraging to see the drug yielding positive results for patients with hormone receptor-positive HER2-negative breast cancer.
Learn More:
On the Podcast: Breast Cancer Conversations
Is the Medicine Working? Exploring Treatment Efficacy in Breast Cancer
About the Author:
Kiara Ford is a recent graduate of Emerson College, where she majored in communication studies and minored in health and society. She is currently a community health worker trainee with the non-profit organization Asian Women for Health. She is passionate about patient advocacy and health equity, and hopes to raise awareness and increase understanding of patients’ rights through her work.
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