The tolerability profile was in line with what has been previously reported for olaparib and other PARP inhibitors.21, 22, 23 The most common grade 3–4 adverse event in both cohorts was anaemia (15 [31%] in the 300 mg cohort and 18 [37%] in the 400 mg cohort). Here, PARP1 is linked to anemia (phenotype).