Phase II clinical trial - Sein métastatique HER2+

A Phase 2, open-label, multicenter international study will be performed to evaluate the efficacy of MCLA-128-based combinations. Three combination treatments will be evaluated, two in Cohort 1 and one in Cohort 2.;MCLA-128 is given in combinations in two metastatic breast cancer (MBC) populations, HER2-positive/amplified (Cohort 1) and Estrogen Receptor-positive/low HER2 expression (Cohort2).;Two combinations treatments will be evaluated in Cohort 1, the doublet and triplet. Initially MCLA-128 is given in combination with trastuzumab in the doublet. After the safety of the doublet has been assessed in 4-6 patients, MCLA-128 is given in combination with trastuzumab and vinorelbine in the triplet, in parallel to the efficacy expansion of the doublet.;The doublet and triplet combinations are both evaluated in two steps with an initial safety run-in followed by a cohort efficacy expansion. In total up to 40 patients evaluable for efficacy are included in both the doublet and triplet.;In Cohort 2 MCLA-128 is administered in combination with the same previous endocrine therapy on which progressive disease is radiologically documented. A total of up to 40 patients evaluable for efficacy are included in the Cohort 2.