Hotchkiss C E, Hall P D, Cline J M, Willingham M C, Kreitman R J, Gardin J, Latimer A, Ramage J, Feely T, DeLatte S, Tagge E P, Frankel A E
Departments of Pathology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, 27157, USA.
Toxicol Appl Pharmacol. 1999 Jul 15;158(2):152-60. doi: 10.1006/taap.1999.8691.
We developed a fusion toxin consisting of the catalytic and translocation domains of diphtheria toxin linked to human granulocyte-macrophage colony-stimulating factor (GM-CSF) (DTGM) for the treatment of patients with acute myeloid leukemia (AML). Our goal in this study was to determine the toxicity and pharmacokinetics of DTGM in cynomolgus monkeys (Macacca fascicularis), which possess cross-reactive GM-CSF receptors. Four groups of young adult monkeys (6 males and 12 females) were treated with five daily bolus iv infusions of 1, 5, 7.5, and 10 microgram/kg DTGM. Monkeys (2 males and 2 females) treated at 1 microgram/kg/day showed no significant side effects. Monkeys (2 males and 2 females) treated at 5 microgram/kg/day showed Grade 1-2 thrombopenia (NCI common toxicity criteria) on day 9. In contrast, monkeys (6 females) treated at 7.5 microgram/kg/day developed Grade 3 neutropenia, Grade 1-2 thrombopenia, Grade 1-3 anemia, and Grade 1-3 hypoalbuminemia. The neutropenia developed by day 4 in the 7.5 microgram/kg/day monkeys and by day 3 or 5 in the 10 microgram/kg/day monkeys and resolved in both groups by day 9, but the thrombopenia, anemia, and hypoalbuminemia persisted until day 16. Monkeys (2 male and 2 female) treated with 10 microgram/kg/day showed Grade 4 neutropenia that resolved by day 8 and Grade 2-3 anemia, hypoalbuminemia, and thrombopenia. Three of the animals developed sepsis. DTGM plasma half-life was 30 min with a peak concentration of 0.1 microgram/mL or 2 nM (1000-fold higher than the IC50 in vitro for AML blasts). Immune responses were minimal in all animals tested at 14 and 28 days with anti-DTGM levels <1 microgram/mL. All four animals at 10 microgram/kg died or were euthanized, and necropsies were performed. Animals necropsied on days 4 and 6 showed marked apoptosis and hypoplasia in the marrow, which was completely resolved for animals necropsied on day 9. No injury to other organs, including kidney, heart, liver, central nervous system, or lung, was seen. The drug was selectively toxic to malignant or differentiated myeloid cells with little toxicity to myeloid progenitors or other organs. Minimal effects in nontarget tissues make DTGM a promising candidate chemotherapeutic agent.
我们研发了一种融合毒素，它由白喉毒素的催化结构域和易位结构域与人类粒细胞巨噬细胞集落刺激因子（GM-CSF）连接而成（DTGM），用于治疗急性髓系白血病（AML）患者。我们在本研究中的目标是确定DTGM在食蟹猴（食蟹猕猴）中的毒性和药代动力学，食蟹猴具有交叉反应性GM-CSF受体。四组年轻成年猴（6只雄性和12只雌性）接受了为期五天的每日一次静脉推注，剂量分别为1、5、7.5和10微克/千克DTGM。以1微克/千克/天治疗的猴子（2只雄性和2只雌性）未显示出明显的副作用。以5微克/千克/天治疗的猴子（2只雄性和2只雌性）在第9天出现1-2级血小板减少症（美国国立癌症研究所通用毒性标准）。相比之下，以7.5微克/千克/天治疗的猴子（6只雌性）出现了3级中性粒细胞减少症、1-2级血小板减少症、1-3级贫血和1-3级低白蛋白血症。7.5微克/千克/天组的猴子在第4天出现中性粒细胞减少症，10微克/千克/天组的猴子在第3天或第5天出现中性粒细胞减少症，两组在第9天中性粒细胞减少症均得到缓解，但血小板减少症、贫血和低白蛋白血症持续到第16天。以10微克/千克/天治疗的猴子（2只雄性和2只雌性）出现4级中性粒细胞减少症，在第8天得到缓解，还出现了2-3级贫血、低白蛋白血症和血小板减少症。其中三只动物发生了败血症。DTGM的血浆半衰期为30分钟，峰值浓度为0.1微克/毫升或2纳摩尔/升（比AML原始细胞体外IC50高1000倍）。在第14天和第
