Microscopic image of breast cancer cells
VIENNA, Austria – A groundbreaking trial launched in Austria is aiming to spare certain early-stage breast cancer patients the harsh side effects of chemotherapy, opting instead for a personalized approach using endocrine therapy. The TEODOR trial, sponsored by the Austrian Breast & Colorectal Cancer Study Group (ABCSG), is a Phase 2, multicenter study that will enroll approximately 250 patients across 15 sites.
Personalized Treatment Strategy
The core of the TEODOR trial’s innovative strategy is to leverage circulating tumor DNA (ctDNA) testing and assess endocrine responsiveness to guide treatment decisions. This personalized approach is designed for women with hormone receptor-positive (HR+), HER2-negative breast cancer. The trial seeks to identify patients who may safely skip neoadjuvant chemotherapy, a treatment regimen known for its significant short- and long-term side effects.
Did you know? Neoadjuvant chemotherapy can cause side effects like nausea, hair loss, and potentially long-term issues such as cardiotoxicity or neuropathy.
The trial’s design builds on previous studies where patients who tested negative for ctDNA at diagnosis and received chemotherapy showed a recurrence risk of less than 5%. Researchers are now investigating if a less toxic, equally effective alternative, like endocrine therapy alone, exists for this favorable-prognosis group.
Trial Design and Endpoints
The TEODOR trial protocol begins with a 4-week course of endocrine therapy. Patients who remain ctDNA-negative after this initial period and show favorable endocrine sensitivity, as indicated by the Ki-67 proliferation index, will be randomized into two arms. One arm will continue with additional endocrine therapy, while the other will receive standard chemotherapy. This direct comparison aims to evaluate the efficacy of these two strategies in a carefully selected patient population.
The primary endpoint for the TEODOR trial is the rate of neoadjuvant therapy response. This will be measured through pathological complete response and the modified Preoperative Endocrine Prognostic Index (PEPI) score, established metrics for treatment efficacy. Secondary endpoints include crucial long-term outcomes like breast cancer recurrence and overall survival, vital for confirming the sustained safety and effectiveness of the endocrine-only approach.
- The TEODOR trial investigates a personalized approach to neoadjuvant therapy for HR+, HER2-negative early-stage breast cancer.
- It aims to replace standard chemotherapy with endocrine therapy in selected patients using ctDNA testing and endocrine responsiveness.
- The study seeks to identify patients who can safely avoid chemotherapy, reducing treatment-related side effects.
- Key endpoints include neoadjuvant therapy response rates, recurrence, and overall survival.
A Shift Towards Personalized Oncology
Michael Gnant, MD, FACS, FEBS, president of ABCSG and principal investigator of the TEODOR trial, highlighted the study’s significance. “TEODOR is designed to examine whether we can use endocrine responsiveness and ctDNA status to optimize systemic therapy in the neoadjuvant setting,” he stated. “This study marks a critical step toward more personalized medicine, leveraging the latest technologies to improve patient care.”
Angel Rodriguez, MD, medical director of oncology at Natera, expressed enthusiasm for the collaboration. “With the TEODOR trial, our goal is to identify patients who may be able to safely forgo chemotherapy,” he said. “We are proud to collaborate with ABCSG on this important trial, and we hope this study will support the role of ctDNA testing in guiding neoadjuvant therapy in breast cancer.”
This trial reflects a broader movement in oncology to move away from one-size-fits-all treatments. By using molecular and biological markers, clinicians can better stratify patients, tailoring therapies for maximum efficacy and minimal toxicity. The potential for a significant number of patients to avoid chemotherapy would be a major advancement, improving their quality of life during treatment.
