Trial Design: International, open label, window of opportunity phase II trial that aims to evaluate the effects of immunotherapy-based treatment combinations in women with untreated, histologically confirmed, operable, oestrogen receptor positive, HER2-negative breast cancer. The study follows is designed with the flexibility to open new treatment arms as new treatments become available or modify the patient population. Eligible patients will be randomised with an approximately equal ratio (1:1:1:1) to one of four treatment arms: atezolizumab alone vs atezolizumab plus cobimetinib vs atezolizumab plus ipatasertib vs atezolizumab plus cobimetinib plus bevacizumab. 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 therapy) at the discretion of the treating physician.
ECLIPSE aims to evaluate combinations of immune-modulatory agents in order to convert oestrogen positive tumours to inflamed phenotypes using short-term preoperative treatment strategies with tumour tissue samples collected pre- and on completion of treatment. Eclipse will also investigate correlations between the microbiome and outcome.