Study With Atezolizumab in Combination With Trastuzumab and Vinorelbine in HER2-positive Advanced/Metastatic Breast Cancer

Immune checkpoint inhibitors given in monotherapy in advanced breast cancer have shown modest benefit in first-line, but very limited efficacy in later lines. Thus, combination therapies are needed. Response following anti-PD1/PD-L1 monotherapy is associated with large survival benefit in the advanced setting. Previous studies of the intrinsic subtypes have shown that Basal-like and HER2-E are associated with higher expression of immune-related genes or higher infiltration of stromal tumor infiltrating lymphocytes compared to the luminal subtypes. Immune infiltration in BC is associated with chemo/antiHER2 responsiveness and potentially benefit from anti-PD-1/PD-L1 inhibitors. In addition, one emerging biomarker of response to anti-PD-1 therapy is the tumor mutational burden (I.e. the total number of mutations per coding area of a tumor genome). The HER2-E and Basal-like profiles have been associated with high mutational burden. A range of studies have been initiated including several phase II/III studies evaluating atezolizumab in combination with different chemotherapeutic compounds routinely used in breast cancer, but none with predefined biomarker beyond the expression of PD-L1 by IHC

NCT Number	NCT04759248
Lead Sponsor	SOLTI Breast Cancer Research Group Collaborators: Roche Pharma AG
Conditions	Breast Cancer
Enrollment	55 participants
Start Date	2021-03-15
Primary Completion	2024-12-01 (estimated)
Study Completion	2027-07-01 (estimated)
Updated on ClinicalTrials.gov	2025-09-09