UGT1A1 and neutropenia: Our pre-planned interim analysis of safety confirmed that the UGT1A1 homozygous and heterozygous genotypes were associated with a higher risk of severe neutropenia than the UGT1A1 wild-type genotype, consistent with the results of many previous studies (Ando et al, 2000; Innocenti et al, 2004; Marcuello et al, 2004; Rouits et al, 2004; Innocenti and Ratain, 2006; Hoskins et al, 2007; Minami et al, 2007; Kweekel et al, 2008; Liu et al, 2008; Innocenti et al, 2009; McLeod et al, 2010; Chen et al, 2014).