Would you recommend olaparib for a patient with germline BRCA1 mutation and HER2+ metastatic breast cancer who has progressed through multiple lines of HER2-directed therapy including trastuzumab deruxtecan?
Answer from: Medical Oncologist at Academic Institution
Although OlympiAD (Robson et al., PMID 28578601) and EMBRACA (Litton et al., PMID 30110579) studied olaparib and talazoparib in HER2negative gBRCA mutant metastatic breast cancer, the activity is based on the mechanism of synthetic lethality in BRCA deficient tumors. Thus, it is reasonable to think ...
Answer from: Medical Oncologist at Academic Institution
True HER 2 amplified breast tumors are rare with germline BRCA 1 pathogenic variants (Evans et al., PMID 26888723). I would suggest confirming HER 2 expression/amplification with pathology.There is preclinical evidence of anti tumor activity of PARPi in trastuzumab resistant HER 2 expressing cell li...