New Breast Cancer Trial Tests Chemo-Free Approach
Personalized medicine aims to spare patients toxic neoadjuvant treatment
A groundbreaking clinical trial is exploring whether select early-stage breast cancer patients can safely skip standard chemotherapy. The TEODOR trial, sponsored by the Austrian Breast & Colorectal Cancer Study Group (ABCSG), is investigating a tailored strategy using advanced DNA testing and endocrine sensitivity markers.
Personalized Treatment Pathway
This phase 2, multicenter study (NCT07084558) aims to identify women with hormone receptor-positive (HR+), HER2-negative breast cancer who might benefit from an alternative to neoadjuvant chemotherapy. This pre-surgical treatment, while effective, can cause significant short- and long-term side effects.
The trial will enroll approximately 250 patients across 15 Austrian sites. It represents a collaboration between ABCSG and Natera, the developers of the personalized circulating tumor DNA (ctDNA) test, Signatera.
The trial’s design centers on prior research showing that patients with a ctDNA-negative status at diagnosis, who then receive chemotherapy, have a recurrence risk below 5%. TEODOR seeks to determine if a less toxic endocrine-based regimen can achieve similar outcomes for this favorable-prognosis group.
Trial Design and Endpoints
Patients will initially receive a 4-week course of endocrine therapy. Those who remain ctDNA-negative and exhibit good endocrine sensitivity, indicated by their Ki-67 proliferation index, will be randomly assigned. One group will continue with further endocrine therapy, while the other will undergo standard chemotherapy. This structure will directly compare the effectiveness of these two approaches.
The primary goal is to measure the rate of neoadjuvant therapy response, assessed through pathological complete response and the modified Preoperative Endocrine Prognostic Index (PEPI) score. Secondary endpoints include crucial long-term indicators like breast cancer recurrence rates and overall survival, validating the durability of an endocrine-only strategy.
“TEODOR is designed to examine whether we can use endocrine responsiveness and ctDNA status to optimize systemic therapy in the neoadjuvant setting,” said Michael Gnant, MD, FACS, FEBS, ABCSG president and principal investigator of the TEODOR trial. “This study marks a critical step toward more personalized medicine, leveraging the latest technologies to improve patient care.”
—Michael Gnant, MD, FACS, FEBS, President of ABCSG and Principal Investigator of the TEODOR Trial
The shift toward personalized medicine in oncology is gaining momentum, moving away from one-size-fits-all treatments. By utilizing molecular and biological markers, doctors can better categorize patients and tailor therapies for maximum effectiveness and minimal harm. For many early-stage HR+/HER2– breast cancer patients, avoiding chemotherapy could dramatically improve their quality of life, reducing side effects like nausea, hair loss, and long-term complications such as cardiotoxicity or neuropathy.
In the United States, breast cancer remains a significant health concern, with an estimated 313,510 new cases expected in 2024 alone (National Cancer Institute, 2024).
“With the TEODOR trial, our goal is to identify patients who may be able to safely forgo chemotherapy,” said Angel Rodriguez, MD, medical director of oncology at Natera. “We are proud to collaborate with ABCSG on this important trial, and we hope this study will support the role of Signatera in guiding neoadjuvant therapy in breast cancer.”
—Angel Rodriguez, MD, Medical Director of Oncology at Natera
