Developmental Therapeutics Program, National Cancer Institute, Bethesda, MD 20852, USA.
Cancer Chemother Pharmacol. 2011 Aug;68(2):513-24. doi: 10.1007/s00280-010-1518-3. Epub 2010 Nov 18.
Characterize the preclinical pharmacokinetics, metabolic profile, multi-species toxicology, and antitumor efficacy of azurin-p28 (NSC 745104), an amphipathic, 28 amino acid fragment (aa 50-77) of the copper containing redox protein azurin that preferentially enters cancer cells and is currently under development for treatment of p53-positive solid tumors.
An LC/MS/MS assay was developed, validated, and applied to liver microsomes, serum, and tumor cells to assess cellular uptake and metabolic stability. Pharmacokinetics was established after administration of a single intravenous dose of p28 in preclinical species undergoing chronic toxicity testing. Antitumor efficacy was assessed on human tumor xenografts. A human therapeutic dose was predicted based on efficacy and pharmacokinetic parameters.
p28 is stable, showed tumor penetration consistent with selective entry into tumor cells and significantly inhibited p53-positive tumor growth. Renal clearance, volume of distribution, and metabolic profile of p28 was relatively similar among species. p28 was non-immunogenic and non-toxic in mice and non-human primates (NHP). The no observed adverse effect level (NOAEL) was 120 mg/kg iv in female mice. A NOAEL was not established for male mice due to decreased heart and thymus weights that was reversible and did not result in limiting toxicity. In contrast, the NOAEL for p28 in NHP was defined as the highest dose (120 mg/kg/dose; 1,440 mg/m(2)/dose) studied. The maximum-tolerated dose (MTD) for subchronic administration of p28 to mice is >240 mg/kg/dose (720 mg/m(2)/dose), while the MTD for subchronic administration of p28 to Cynomolgous sp. is >120 mg/kg (1,440 mg/m(2)/dose). The efficacious (murine) dose of p28 was 10 mg/kg ip per day.
p28 does not exhibit preclinical immunogenicity or toxicity, has a similar metabolic profile among species, and is therapeutic in xenograft models.
描述亲脂性、28 个氨基酸片段（aa50-77）的临床前药代动力学、代谢谱、多物种毒理学和抗肿瘤功效，该片段来自铜含量氧化还原蛋白 azurin，称为 azurin-p28（NSC745104），其优先进入癌细胞，目前正在开发用于治疗 p53 阳性实体瘤。
建立、验证了 LC/MS/MS 测定法，并应用于肝微粒体、血清和肿瘤细胞，以评估细胞摄取和代谢稳定性。在进行慢性毒性试验的临床前物种中，单次静脉注射 p28 后建立药代动力学。在人肿瘤异种移植模型中评估抗肿瘤功效。根据功效和药代动力学参数预测了人类治疗剂量。
p28 稳定，显示出与选择性进入肿瘤细胞一致的肿瘤穿透性，并显著抑制了 p53 阳性肿瘤的生长。p28 在物种间的肾清除率、分布容积和代谢谱相对相似。p28 在小鼠和非人类灵长类动物（NHP）中无免疫原性和毒性。雌性小鼠的无观察到不良作用水平（NOAEL）为 120mg/kgiv。由于心脏和胸腺重量减轻，雄性小鼠的 NOAEL 未建立，但这种情况是可逆的，不会导致限制毒性。相比之下，p28 在 NHP 中的 NOAEL 定义为最高剂量（120mg/kg/剂量；1440mg/m2/剂量）。p28 亚慢性给药的最大耐受剂量（MTD）在小鼠中为>240mg/kg/剂量（720mg/m2/剂量），而 p28 亚慢性给药的 MTD 在食蟹猴中为>120mg/kg（1440mg/m2/剂量）。p28 的有效（鼠）剂量为每天 10mg/kg ip。
p28 没有表现出临床前免疫原性或毒性，在物种间具有相似的代谢谱，并且在异种移植模型中具有治疗作用。
