Tiragolumab, Atezolizumab and Chemotherapy in Triple Negative Breast Cancer

"Cohort A:~Tumor assessments by 18F-FDG PET/CT (per PERCIST v1.0) will be performed at: baseline, after the first 2 treatment cycles (between C2D15 and C3D1), and before surgery (after the last administration of neoadjuvant chemotherapy) Tumor assessment by 68Ga-FAPI-46 PET/CT will be performed at: baseline and before surgery (after the last administration of neoadjuvant chemotherapy).~Cohort B:~Tumor assessments by 18F-FDG PET/CT per PERCIST v1.0 will be performed at baseline, every 8 weeks (+/- 1 week) for the first 24 weeks, and every 12 weeks (+/- 1 week) thereafter until disease progression or treatment discontinuation, whichever is later.~Tumor assessments by 68Ga-FAPI-46 PET/CT will be performed at baseline and after the first 2 treatment cycles and will be synchronized with 18F-FDG PET/CT."

"Patients will undergo a mandatory biopsy of the primary tumor at baseline, after the first 2 treatment cycles and during the surgery. A lymph node biopsy will be performed at baseline if feasible in cohort A, and and in case of disease progression for cohort B (if clinically feasible).~In addition to the usual morphological and immunohistochemical (ER, PR, HER2+, CPS score, PD-L1 status with SP142 …) analyses in the cohort A and cohort B , exploratory analyses will be performed."

Blood samples will be collected at baseline. In addition for cohort A at cycles 2 and 3, within 21 days before surgery, 10 to 21 days after surgery and at cycle 8 after surgery. In addition for cohort B after the first 2 treatment cycles and in case of disease progression (if clinically feasible).