Ceralasertib combined with PARPi was found active in BRCA2‐mutated TNBC PDX210 and in BRCA1/2 mutant high grade serous ovarian cancer (HGSOC) PDX models progressing on PARPi with a significant tumor regression and increase in overall survival (OS).211. This evidence concerns the gene BRCA1 and ovarian serous adenocarcinoma.