Enhanced activity of monomethylauristatin F through monoclonal antibody delivery: Effects of linker technology on efficacy and toxicity
Enhanced activity of monomethylauristatin F through monoclonal antibody delivery: Effects of linker technology on efficacy and toxicity
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DOI：
10.1021/bc0502917
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发表时间：
2006-01-01
影响因子：
4.7
通讯作者：
Senter, PD
中科院分区：
文献类型：
--
作者：
Doronina, SO;Mendelsohn, BA;Senter, PD
我们之前已经证明，由cAC 10（抗CD 30）与抗有丝分裂剂单甲基奥瑞他汀E（MMAE）连接组成的抗体-药物偶联物（ADC）对抗原阳性肿瘤模型具有强效的体外和体内活性。MMAF是一种新型抗有丝分裂奥瑞他汀衍生物，其C-末端苯丙氨酸残基带电荷，与不带电荷的对应物MMAE相比，其细胞毒性活性减弱，最可能是由于细胞内通路受损。体外细胞毒性研究表明，mAb-马来酰亚胺基己酰基-缬氨酸-瓜氨酸-对氨基苄氧羰基-MMAF（mAb-L1-MMAF）偶联物在一大批CD 30阳性血液细胞系上的效力是游离MMAF的2200倍以上。与cAC 10-L1-MMAE一样，相应的MMAF ADC在耐受良好的剂量下诱导了已建立的异种移植肿瘤的治愈和消退。为了进一步优化ADC，产生了几种新的接头，其中L1接头内的各种组分被改变或缺失。最有前途的接头之一在药物和mAb之间含有不可裂解的马来酰亚胺基己酰基（L4）间隔基。cAC 10-L4-MMAF在体外与cAC 10-L1-MMAF对大量细胞系的效力大致相同，在体内的效力也相同。重要的是，cAC 10-L4-MMAF的耐受性是cAC 10-L1-MMAF MTD的> 3倍。LCMS研究表明，从cAC 10-L4-MMAF释放的药物是半胱氨酸-L4-MMAF加合物，其可能由靶细胞溶酶体内的mAb降解引起。这种新的连接体技术似乎非常适合于相对细胞不可渗透且耐受氨基酸取代的药物。因此，接头的改变对毒性具有显著影响，并导致具有大大改善的治疗指数的新ADC。
We have previously shown that antibody-drug conjugates (ADCs) consisting of cAC10 (anti-CD30) linked to the antimitotic agent monomethylauristatin E (MMAE) lead to potent in vitro and in vivo activities against antigen positive tumor models. MMAF is a new antimitotic auristatin derivative with a charged C-terminal phenylalanine residue that attenuates its cytotoxic activity compared to its uncharged counterpart, MMAE, most likely due to impaired intracellular access. In vitro cytotoxicity studies indicated that mAb-maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl-MMAF (mAb-L1-MMAF) conjugates were > 2200-fold more potent than free MMAF on a large panel of CD30 positive hematologic cell lines. As with cAC10-L1-MMAE, the corresponding MMAF ADC induced cures and regressions of established xenograft tumors at well tolerated doses. To further optimize the ADC, several new linkers were generated in which various components within the L1 linker were either altered or deleted. One of the most promising linkers contained a noncleavable maleimidocaproyl (L4) spacer between the drug and the mAb. cAC10-L4-MMAF was approximately as potent in vitro as cAC10-L1-MMAF against a large panel of cell lines and was equally potent in vivo. Importantly, cAC10-L4-MMAF was tolerated at > 3 times the MTD of cAC10-L1-MMAF. LCMS studies indicated that drug released from cAC10-L4-MMAF was the cysteine-L4-MMAF adduct, which likely arises from mAb degradation within the lysosomes of target cells. This new linker technology appears to be ideally suited for drugs that are both relatively cell-impermeable and tolerant of substitution with amino acids. Thus, alterations of the linker have pronounced impacts on toxicity and lead to new ADCs with greatly improved therapeutic indices.