Jon Amund Kyte, University of Oslo, Oslo, Norway discusses the ICON trial (NCT03409198), a randomized Phase IIb study evaluating chemotherapy combined with ipilimumab and nivolumab, in metastatic hormone receptor-positive breast cancer (BC) patients. Dr Kyte explains how the host immune response is predictive of chemotherapy efficacy in subgroups of BC patients and the role of ipilimumab in stimulating a patient’s anti-tumor response, in combination with nivolumab. This interview took place at the European Society for Medical Oncology (ESMO) 2022 Congress in Paris, France.