respectively, with tumor concentrations less than one third of plasma. Full dCK inhibition, as evaluated by PET imaging, was observed as early as 3 hours following 25 mg/kg dosing and was maintained for 12 hours, with full recovery of enzyme activity after 36 hours. When DI-87 was administered as repeated doses in combination with thymidine, full dCK inhibition was maintained at 12 hours (25 mg/kg twice daily
背景脱氧
胞苷激酶(dCK)是通过补救途径生产核苷酸的必需酶;DI-87 是一种新型 dCK
抑制剂,处于临床前开发阶段,用于抗癌治疗。目前的研究利用 PET 成像来评估 PK-PD 关系并确定药物的最佳剂量。方法 口服 DI-87 后,使用质谱法对携带 C
EM 肿瘤的 NSG 小鼠进行血浆和肿瘤 PK 评估。在单剂量口服 DI-87、随后使用 [18F]CFA PET 探针和 PET 成像后评估 dCK 抑制。通过口服给予 DI-87 并同时腹膜内注射
胸苷来评估肿瘤生长抑制。结果 DI-87 的体外
EC50 为 10.2 nM,蛋白结合率低。血浆和肿瘤中的 DI-87 峰值浓度分别在 1-3 小时和 3-9 小时之间观察到,肿瘤浓度低于血浆的三分之一。通过 PET 成像评估,在 25 mg/kg 剂量给药后 3 小时即可观察到完全 dCK 抑制,并维持 12 小时,36 小时后酶活性完全恢复。当