A phase II study investigating preoperative combination strategies for immunotherapy in patients with untreated, operable ER+, HER2-negative primary breast cancer (ECLIPSE).
This is an international, open label, window of opportunity phase II trial that its primary objective is to determine whether adding immune-modulatory agents to atezolizumab increases the probability of an immune response over atezolizumab alone in women with untreated, histologically confirmed, operable, ER+, HER2-negative breast cancer (by 2-fold Increase in GzmB+ CD8+ T cell levels from baseline to end of treatment sample). Sample size is 160 patients.
Eligible patients will be randomised with an approximately equal ratio (1:1:1:1) to one of four treatment arms (three experimental arms: (1) Atezolizumab + Cobimetinib, (2) Atezolizumab + Ipatasertib, (3) Atezolizumab + Cobimetinib + Bevacizumab and a control arm: Atezolizumab alone.
Patients will receive treatment for 3 weeks prior to surgery or neoadjuvant therapy. Thereafter, patients will either be considered for definitive surgery or primary medical treatment (e.g. neoadjuvant chemotherapy) at the discretion of the treating physician.