Table 6

Effect of UGT1A1*28 on the extent of SN-38 glucuronidation

GenotypeReferencenAUC0-t (0–24 h) ratioa SN-38G/SN-38 Mean ± SD (median)AUC0-inf (0–100 h) ratiob SN-38G/SN-38 Mean ± SD (median)
WtcThis study327.6 ± 4.1 (6.6)6.9 ± 3.5 (6.4)
Iyer et al. (16)99.3 ± 11n/a
HetThis study197.1 ± 3.6 (6.6)6.7 ± 3.2 (6.1)
Iyer et al. (16)74.0 ± 1.7n/a
VarThis study22.2, 5.2 (3.7)2.5, 4.6 (3.6)
Iyer et al. (16)42.4 ± 1.1n/a
  • a SN-38G/SN-38 AUC ratio based on nonparametric analysis of samples taken up to 24 h after irinotecan administration [trend analysis (Wt>Het>Var), P = 0.272].

  • b SN-38G/SN-38 AUC ratio based on NONMEM model [trend analysis (Wt>Het>Var), P = 0.300]; Iyer et al. (16) [trend analysis (Wt>Het>Var), P = 0.001].

  • c Wt, Wild type patient; Het, Heterozygous variant type patient; Var, Homozygous variant type patient; n/a, not available.