1062 - Multicenter Retrospective Analysis of the Safety and Efficacy of Sacituzumab Govitecan Combined with Radiotherapy: The French ATTENTION Study
Presenter(s)
A. Alati1, K. Debbi2, N. Scher3, C. Meynard4, A. Mavrikios5, F. Huguet6, J. Medioni7, H. Boudabous8, J. Gligorov9, J. P. Spano10, M. A. Benderra11, E. Assaf12, A. Bennassi2, A. Toledano3, L. Quero4, C. Chargari5, C. Durdux1, and Y. Belkacemi2; 1Department of Radiation Oncology, Georges Pompidou European Hospital, AP-HP, Paris Cité University, Paris, France, 2Department of Radiation Oncology and Henri Mondor Breast Center. Paris East University Hospital (UPEC) and INSERM Unit i-Biot, Creteil, France, 3Department of Radiation Oncology, Hartmann Radiotherapy Institute, Levallois-Perret, France, 4Department of Radiation Oncology, Saint-Louis University Hospital, Paris, France, 5Department of Radiation Oncology, La Pitie-Salpetriere University Hospital, Paris, France, 6Radiation Oncology Department, Tenon Hospital, AP-HP, Sorbonne University, Paris, France, 7Department of Medical Oncology.Centre of Early Clinical Trials in Cancer, European Georges Pompidou University Hospital, Paris, France, 8Medical Oncology, Hartmann institute, Levallois-Perret, France, 9Department of Medical Oncology, Tenon University Hospital. INSERM U938, Institut Universitaire de Cancérologie, Paris, France, 10Department of Medical Oncology, La Pitie-Salpetriere University Hospital, Paris, France, 11Department of Medical Oncology, Tenon University Hospital, Paris, France, 12Department of Medical Oncology, Henri Mondor University Hospital, Creteil, France
Purpose/Objective(s):
Based on the results of the ASCENT trial, Sacituzumab Govitecan (SG) has been approved for the treatment of recurrent and refractory triple-negative and hormone receptor-positive breast cancer (BC). With the expanding indications of SG across multiple cancers, data on its combination with radiotherapy (RT) are needed. The ATTENTION study was designed to assess the safety and efficacy of combined SG and RT.Materials/Methods:
We conducted a retrospective multicenter study from six French institutions. Eligibility criteria included all BC patients who received RT and SG between September 2021 and January 2025. Concomitant treatment was defined as RT administered within 4 days (d) before or after SG administration. Data were collected through an online questionnaire and centralized after medical record review and protocol validation by the local ethics committee. The primary endpoint was the safety according CTCAE v5.0 classification. Treatment responses were based on RECIST criteria and/or symptom improvement. First evaluation was conducted 4 to 12 weeks after RT.Results:
Fifty-five patients (63 lesions) were included. The median age was 56 years (37–82). SG and RT were administered concurrently in 37 lesions (median:3d), sequentially in 26 lesions (median:10d). Subtypes included HER2-/Hormone receptors (HR)- (30%), HER2-/HR+ (27%), HER2-low/HR+ (24%), HER2-low/HR- (18%), and HER2+ (2%). SG was given as 2nd-line in 16%, 3rd-line in 30%, and = 4th-line in 54%. RT was symptomatic in 57% and for progression in 43%, mostly targeting bone (49%) and brain (32%), using 3D RT (52%), stereotactic body RT (SBRT) (40%), or intensity-modulated RT (8%). With a median follow-up of 7.9 months (1.7–35.4), grade 1-2 toxicities occurred in 17 cases (27%), (three dermatitis, four esophagitis, one brain radionecrosis). No grade = 3 toxicity occurred with concomitant SG. The overall response rate was 25% complete and 80% partial responses. Median overall survival was 12.9 months (95% CI: 7.97 – 17.77).Conclusion:
The ATTENTION study is the largest study showing that SG and RT combination is feasible with manageable toxicity. Longer follow-up and prospective data are required.