Titles and Affiliations
Hematology/Oncology Clinical Fellow
Conquer Cancer, the ASCO Foundation
Research Area
Expanding the pool of patients with metastatic breast cancer who could benefit from targeted treatments.
Impact
Patients with metastatic breast cancer urgently need more effective targeted therapies, as many still rely on chemotherapy, which is lifesaving for many but is less precise and can cause more disruptive side effects. The antibody-drug conjugate trastuzumab deruxtecan (T-DXd, Enhertu®) has transformed care for some patients with metastatic breast cancer, but current testing methods may miss patients who could benefit. Researchers have found that even small amounts of HER2 present in tumor cells can trigger a response to T-DXd. For his Conquer Cancer research supported by BCRF, Dr. Peiffer is using a laboratory technique called flow cytometry that allows scientists to study individual cells to more accurately detect HER2.
What’s Next
Dr. Peiffer and his team will refine HER2 detection with flow cytometry to better predict who will be a good candidate for T-DXd. He will further test whether combining T-DXd with tucatinib, a drug that increases HER2 expression and is associated with improved responsiveness to HER2-targeted therapies, broadens its effectiveness in advanced laboratory experiments. These steps could personalize care, reduce reliance on traditional chemotherapy, and expand treatment options for patients with advanced breast cancer.
Biography
Daniel S. Peiffer, MD, PhD is a senior Hematology/Oncology Fellow at the University of Chicago, where he also completed his Internal Medicine Residency training. He earned his MD and PhD in Cell Biology from the Loyola Stritch School of Medicine. His doctoral research, conducted in Dr. Clodia Osipo’s lab, focused on how the transcription factor DAXX restricts the survival of tumor-initiating cells in hormone receptor-positive breast cancer. During his fellowship, Dr. Peiffer’s research has focused on understanding HER2-low and HER2-0 breast cancers and identifying therapeutic strategies to improve clinical outcomes for these subpopulations. Under the mentorship of Dr. Geoffrey Greene and Dr. Rita Nanda, he is currently investigating how HER2 expression patterns in HER2-low and HER2-0 breast tumors influence response to the antibody-drug conjugate (ADC) trastuzumab deruxtecan. Dr. Peiffer’s long-term research goal is to study how tumor cell membrane protein dynamics affect responses to ADCs, with the aim of more accurately predicting treatment efficacy at the individual patient level. His overarching career aspiration is to become an independent physician-scientist who leverages molecular and translational research to improve care for patients with breast cancer.
