Dasatinib用于治疗对伊马替尼耐药的Ph染色体阳性白血病

背景:Bcr-Abl酪氨酸激酶抑制剂伊马替尼(imatinib)可有效治疗Ph染色体阳性白血病,但是会复发,主要是由于白血病亚型的副产物与伊马替尼耐药的Bcr-Abl突变。我们研究了以大部分伊马替尼耐药的Bcr-Abl突变体为靶点的B c r-Abl抑制剂dasatinib在治疗慢性骨髓性白血病(CML)和Ph阳性急性淋巴细胞白血病(ALL)患者中的作用。方法:患有CML或者Ph阳性ALL且对伊马替尼不能耐受或者对伊马替尼耐药的患者被收录入Ⅰ期剂量递增研究(dose-escalationstudy)中。口服dasatinib(15～240mg/d),每日1次或2次,每4周为1个疗程。结果:在40例慢性期CML患…     

Bcr-Abl激酶抑制剂尼罗替尼的药理与临床评价

慢性粒细胞性白血病(CML)和费城染色体阳性急性淋巴细胞白血病(Ph ALL),是由Bcr-Abl癌基因引起的.伊马替尼能抑制Bcr-Abl蛋白酪氨酸激酶活性,是一种有效的治疗慢性期CML的药物,但由于其耐药点突变,使加速期或急变期CML和Ph ALL患者常常复发.尼罗替尼是第2代Bcr-Abl激酶抑制剂,效果比伊马替尼强20倍,对伊马替尼耐药和不能耐受的患者(T3151除外)有广泛的活性.Ⅰ/Ⅱ期临床试验表明,尼罗替尼对伊马替尼耐药或不能耐受的CML患者仍能获得血液学和细胞遗传学的缓解.现对尼罗替尼的药理作用、药动学、药物相互作用、安全性进行综述.     

伊马替尼耐药慢性粒细胞白血病的药物治疗

伊马替尼(imatinib)是一种酪氨酸激酶抑制剂。通过占据BCR-ABL融合蛋白的ATP结合位点抑制BCR-ABL蛋白的自身磷酸化和底物磷酸化,使BCR-ABL阳性细胞的增生受抑制或者凋亡。伊马替尼是治疗CML的临床一线用药,随着其耐药的出现,不断研发的新药是CML患者新的希望。     

伊马替尼治疗Ph阳性进展期慢性粒细胞白血病

目的:观察伊马替尼治疗Ph阳性进展期慢性粒细胞白血病(CML)的疗效和耐药情况,研究改善伊马替尼耐药的方法。方法:32例Ph阳性进展期CML病人,其中加速期12例,急变期20例,每日口服伊马替尼600或800mg,持续3～9mo。结果:CML加速期病人血液学完全缓解率和总有效率分别为42%和83%,主要细胞遗传学缓解率25%,持续完全血液学缓解病例占25%。CML急变期各类型病人血液学完全缓解率和总有效率分别为20%和55%,主要细胞遗传学缓解率15%,持续完全血液学缓解病例占10%。CML急变期原发耐药和继发耐药分别为45%和20%,联合化疗与暂停伊马替尼对继发耐药可暂时改善其耐药性,但药物有效时间明显缩短。结论:伊马替尼对初治或复治的CML加速期和急变期病人均有效,可作为非移植CML治疗的标准一线方案,伊马替尼治疗CML急变期的原发耐药和继发耐药率较高,联合化疗和暂停伊马替尼可暂时改善其耐药性。     

针对Abl-T315I突变的Bcr-Abl蛋白激酶抑制剂的研究进展

Bcr-Abl融合基因与慢性粒细胞白血病(CML)的发病发展密切相关.直接作用于Bcr-Abl蛋白的小分子药物是目前治疗CML的重要方法,受到广泛的关注.伊马替尼作为首个上市的Bcr-Abl蛋白激酶抑制剂,在靶向治疗慢性粒细胞白血病上取得了很大成功,但Bcr-Abl基因的突变导致其出现耐药性,尤其以Abl-T315I突变的耐药程度最高.本文综述了近年正在开发中的针对Abl-T315I突变的Bcr-Abl蛋白激酶抑制剂.     

TKI治疗慢性粒细胞白血病慢性期的新目标转换

第一代BCR-ABL酪氨酸激酶抑制剂（ TKIs）伊马替尼是慢性粒细胞白血病（ CML）慢性期的一线标准治疗。伊马替尼通过直接靶向作用于BCR-ABL激酶,极大的改善了CML病程。现在,第二代TKIs药物尼洛替尼和达沙替尼已被美国FDA批准为CML的一线治疗。2013年NCCN指南及ELN指南关于CML-CP治疗的疗效问题作了新的调整。该文主要就慢性粒细胞白血病慢性期一线治疗的新进展作一综述。     

伯舒替尼的药理研究及临床评价

慢性髓性白血病是一造血系统疾病,与融合基因Bcr-Abl相关,尽管采用酪氨酸激酶抑制剂伊马替尼治疗取得了显著疗效,但部分患者出现耐药或不能耐受。伯舒替尼为Src和Abl激酶的双重抑制剂,主要用于治疗对伊马替尼耐药或不能耐受的慢性髓性白血病,对一些实体瘤也有效。本文综述了其药理作用、药动学、药物相互作用、临床评价及不良反应等。     

慢性粒细胞白血病临床治疗药物选择

目的:为慢性粒细胞白血病患者治疗药物选择提供参考。方法:查阅国内外相关文献,综述分析已上市的临床用于治疗慢性粒细胞白血病的一线药物,包括酪酸激酶抑制剂伊马替尼、达沙替尼、尼罗替尼、博舒替尼、帕纳替尼和非酪酸激酶抑制剂高三尖杉酯碱的标准使用剂量、药效学、毒副作用、药物禁忌、药物相互作用。结果:第一代酪氨酸激酶抑制剂伊马替尼对未使用过其他酪氨酸激酶抑制剂治疗的初始患者有很好的疗效,但患者用药后很容易发生Bcr-Abl基因突变而耐受或者耐药。第二代酪氨酸激酶抑制剂达沙替尼、尼罗替尼、博舒替尼对大部分Bcr-Abl基因突变有效,对伊马替尼产生耐受或者耐药的患者有较好的治疗效果,但是均对T315I突变无效。第三代酪氨酸激酶抑制剂帕纳替尼对大部分Bcr-Abl基因突变有效,而且是目前唯一对T315I突变有效的已上市激酶抑制剂,但有严重的致血管阻塞、心脏衰竭和肝毒性的风险。另外,非酪氨酸激酶抑制剂高三尖杉酯碱主要用于难治性白血病患者。结论:在临床治疗中,应根据患者病情的发展阶段,用药、耐药情况及药物本身的疗效和毒副作用等综合评估,合理选择药物进行治疗,充分发挥药物疗效和提高药物使用安全性。     

伊马替尼血药浓度影响因素研究进展

伊马替尼是一种小分子酪氨酸激酶抑制剂（TKIs）,主要用于治疗费城染色体阳性的慢性粒细胞白血病（CML）和不可切除或发生转移的胃肠道间质瘤（GIST）。伊马替尼自上市以来显示出了较好的疗效,但研究发现,服用相同剂量药物时,达稳态时伊马替尼血浆谷浓度的差异大,而血浆谷浓度与药物反应及患者的临床获益密切相关。因此,研究伊马替尼血药浓度影响因素,对判断药物疗效、评价治疗效果、调整治疗方案和规避毒副反应等方面有重要意义。笔者将从病理生理状态、代谢酶和转运体的基因多态性、联合用药等方面探讨影响伊马替尼血药浓度的因素,旨在为临床合理用药、制定个体化给药方案提供参考。     

新型苯胺嘧啶类化合物FABl07抗慢性髓性白血病的实验研究

目的:研究一种新型苯胺嘧啶类Bcr/Abl酪氨酸激酶抑制FAB107在体内外抗慢性髓性白血病(chronic myeloid leukemia,CML)的作用.方法:应用MTT法、流式细胞术及Western Blot法检测FAB107对K562细胞增殖、细胞凋亡以及Bcr/Abl蛋白磷酸化的影响.采用中空纤维模型观察FAB107在体内对K562细胞增殖的影响.结果:FAB107可以明显抑制K562和K562/G3.0细胞增殖,分别比伊马替尼强10和90倍;0.1μmol·L-1的FABl07比1μmol·L-1的伊马替尼具有更强的诱导K562和K562/G3.0细胞凋亡作用(P＜0.01);FAB107对K562和K562/G3.0细胞Bcr/Abl蛋白磷酸化的抑制作用均优于伊马替尼;FAB107在体内对K562及K562/G3.0细胞生长呈剂量依赖性的抑制作用,并且抑制强度强于等摩尔浓度的伊马替尼.结论:FAB107在体内外均具有较强的抗CML及伊马替尼耐药的CML的作用,且作用强于伊马替尼.     

Second generation Abl kinase inhibitors and novel compounds to eliminate the Bcr-Abl/T315I clone

The first line therapy for chronic myeloid leukemia (CML) was dramatically altered within a few years of the introduction of Abl specific tyrosine kinase inhibitor, imatinib mesylate to the clinic. However, refractoriness and early relapse have frequently been reported, particularly in patients with advanced-stage disease. Point mutations within the Abl kinase domain that interfere with imatinib mesylate binding are most critical cause of imatinib resistance. To override resistance, several second generation ATP competitive Abl kinase inhibitors such as dasatinib, nilotinib and INNO-406 have been developed. Although, these novel inhibitors can inhibit the phosphorylation of most mutated Bcr-Abl except T315I, no ATP competitive Abl kinase inhibitors, which can inhibit the phosphorylation of Bcr-Abl/T315I, has been developed. Thus, Bcr-Abl/T315I is an important and challenging target for discovery of CML therapeutics. This review is focused on the three novel compounds reported in the recent patents (2004-2006) which claim the efficacy against Bcr-Abl/T315I.     

Specific targeted therapy of chronic myelogenous leukemia with imatinib

Chronic myeloid leukemia (CML) is characterized by the Philadelphia translocation that fuses BCR sequences from chromosome 22 upstream of the ABL gene on chromosome 9. The chimerical Bcr-Abl protein expressed by CML cells has constitutive tyrosine kinase activity, which is essential for the pathogenesis of the disease. Imatinib, an ATP-competitive selective inhibitor of Bcr-Abl, has unprecedented efficacy for the treatment of CML. Most patients with early stage disease achieve durable complete hematological and complete cytogenetic remissions, with minimal toxicity. In contrast, responses are less stable in patients with advanced CML. This review highlights the pathogenesis of CML, its clinical features, and the development of imatinib as a specific molecularly targeted therapy. Aspects of disease monitoring and side effects are covered as well as resistance to imatinib and strategies to overcome resistance, such as alternative signal transduction inhibitors and drug combinations. Perspectives for further development are also discussed.     

Relationship between elevated levels of the alpha 1 acid glycoprotein in chronic myelogenous leukemia in blast crisis and pharmacological resistance to imatinib (Gleevec) in vitro and in vivo

The Abl tyrosine kinase inhibitor imatinb is becoming a standard for the treatment of chronic myelogenous leukemia (CML). However, Bcr-Abl gene mutations have been reported mainly in relapsing or resistant patients. In primary resistant patients, only few mutations have been documented so far, suggesting alternative mechanisms. We aimed to investigate if alpha 1 acid glycoprotein (AGP), an acute phase drug binding protein, could be a biological marker for pharmacological resistance to imatinib in nine patients in acute phase CML. All patients (3/3) with high AGP dosages (2.31+/-0.17 mg/mL; normal values, 0.5-1.3mg/mL) were primary resistant to imatinib whereas an early clinical response was observed for the six patients with normal AGP levels (1.13+/-0.2mg/mL). No mutation in the adenosine triphosphate domain of Abl were detected before the initiation of imatinib therapy. By using in vitro tests combining various imatinib concentrations (1-10 microM) with purified human AGP (1 and 3 mg/mL), we demonstrate that imatinib-induced apoptosis of K562 or fresh leukemic CML cells is abrogated or reduced. The same effect was observed using sera from donors with high AGP levels (1.9-3.28 mg/mL). In patients with CML in blastic phase, AGP levels could reflect pharmacological resistance to imatinib, suggesting that increased dosage of imatinib or the use of a competitor to drug binding should be recommended to optimize the therapeutic effect of the drug.     

Is AMN-107 a step forward from imatinib in the treatment of chronic myeloid leukaemia?

The Philadelphia (Ph) chromosome was the first consistent chromosome abnormality identified in cancer. It is found in 90% of patients with chronic myeloid leukaemia (CML) and in a subset of patients with acute lymphoblastic leukaemia. The effectiveness of the Bcr-Abl kinase inhibitor imatinib in these conditions reduces with advancing disease and/or the development of resistance to imatinib. AMN-107 inhibited the proliferation of haematopoietic cells expressing the mutants in Ph+ CML and acute lymphoblastic leukaemia with concentrations causing 50% inhibition of approximately 12 nM, making it more potent than imatinib. AMN-107 was also effective against several imatinib-resistant Bcr-Abl mutants, but not T3151. In mice transduced with Bcr-Abl, AMN-107 reduced mortality and tumour burden. In mice transduced with the E255V imatinib-resistant mutant of Bcr-Abl, AMN-107 delayed the onset of leukaemia. As AMN-107 is more potent and more selective for Bcr-Abl than imatinib, it may represent a step forward in the treatment of CML, but further animal (and then clinical) studies are needed to test this.     

Bcr-Abl tyrosine kinase inhibitors: a patent review

Introduction: Breakpoint cluster region Abelson (Bcr-Abl) tyrosine kinase (TK) is a constitutively activated cytoplasmic TK and is the underlying cause of chronic myeloid leukemia (CML). To date, imatinib represents the frontline treatment for CML therapy. The development of resistance has prompted the search for novel Bcr-Abl inhibitors.

Areas covered: This review presents a short overview of drugs already approved for CML therapy and of the compounds that are in clinical trials. The body of the article deals with Bcr-Abl inhibitors patented since 2008, focusing on their chemical features.

Expert opinion: The search for Bcr-Abl inhibitors is very active. We believe that a number of patented compounds could enter clinical trials and some could be approved for CML therapy in the next few years. Overall, Bcr-Abl inhibitors constitute a very appealing research field that can be expected to expand further.     

Rutin: therapeutic potential and recent advances in drug delivery

The Philadelphia (Ph) chromosome was the first consistent chromosome abnormality identified in cancer. It is found in 90% of patients with chronic myeloid leukaemia (CML) and in a subset of patients with acute lymphoblastic leukaemia. The effectiveness of the Bcr-Abl kinase inhibitor imatinib in these conditions reduces with advancing disease and/or the development of resistance to imatinib. AMN-107 inhibited the proliferation of haematopoietic cells expressing the mutants in Ph⁺ CML and acute lymphblastic leukaemia with concentrations causing 50% inhibition of ~ 12 nM, making it more potent than imatinib. AMN-107 was also effective against several imatinib-resistant Bcr-Abl mutants, but not T3151. In mice transduced with Bcr-Abl, AMN-107 reduced mortality and tumour burden. In mice transduced with the E255V imatinib-resistant mutant of Bcr-Abl, AMN-107 delayed the onset of leukaemia. As AMN-107 is more potent and more selective for Bcr-Abl than imatinib, it may represent a step forward in the treatment of CML, but further animal (and then clinical) studies are needed to test this.     

Drug evaluation: Nilotinib - a novel Bcr-Abl tyrosine kinase inhibitor for the treatment of chronic myelocytic leukemia and beyond

Chronic myelocytic leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl. Inhibitors ofBcr-Abl have significantly improved the treatment of CML. Most notable is the inhibitor imatinib, which produces remissions in all phases of CML and is the current standard of care. However, imatinib resistance occurs in a significant proportion of patients, mainly through the development of mutations in the Bcr-Abl tyrosine kinase domain that impair imatinib binding. Attempts to circumvent resistance to imatinib led to the discovery of nilotinib (Tasigna; Novartis AG), a novel, potent and selective oral Bcr-Abl kinase inhibitor. Preclinical and clinical investigations have demonstrated that nilotinib effectively overcomes imatinib resistance. Efficacy has been observed in models of CML and other myeloproliferative disorders that are driven by Bcr-Abl and related kinases. In a phase II clinical trial in CML, major cytogenetic response rates were 52 and 33% for chronic- and accelerated-phase disease, respectively. Nilotinib has been filed for approval in the US and EU for use in Philadelphia-positive leukemias in patients who are resistant or intolerant to imatinib. Nilotinib is undergoing clinical trials in patients with newly diagnosed CML, acute lymphoblastic leukemia and gastrointestinal stromal tumors, among other indications.     

Sequential treatment with flavopiridol synergistically enhances pyrrolo-1,5-benzoxazepine-induced apoptosis in human chronic myeloid leukaemia cells including those resistant to imatinib treatment

The Bcr-Abl kinase inhibitor, imatinib mesylate, is the front line treatment for chronic myeloid leukaemia (CML), but the emergence of imatinib resistance has led to the search for alternative drug treatments and the examination of combination therapies to overcome imatinib resistance. The pro-apoptotic PBOX compounds are a recently developed novel series of microtubule targeting agents (MTAs) that depolymerise tubulin. Recent data demonstrating enhanced MTA-induced tumour cell apoptosis upon combination with the cyclin dependent kinase (CDK)-1 inhibitor flavopiridol prompted us to examine whether this compound could similarly enhance the effect of the PBOX compounds. We thus characterised the apoptotic and cell cycle events associated with combination therapy of the PBOX compounds and flavopiridol and results showed a sequence dependent, synergistic enhancement of apoptosis in CML cells including those expressing the imatinib-resistant T315I mutant. Flavopiridol reduced the number of polyploid cells formed in response to PBOX treatment but only to a small extent, suggesting that inhibition of endoreplication was unlikely to play a major role in the mechanism by which flavopiridol synergistically enhanced PBOX-induced apoptosis. The addition of flavopiridol following PBOX-6 treatment did however result in an accelerated exit from the G2/M transition accompanied by an enhanced downregulation and deactivation of the CDK1/cyclin B1 complex and an enhanced degradation of the inhibitor of apoptosis protein (IAP) survivin. In conclusion, results from this study highlight the potential of these novel series of PBOX compounds, alone or in sequential combination with flavopiridol, as an effective therapy against CML.     

Nilotinib: a novel Bcr-Abl tyrosine kinase inhibitor for the treatment of leukemias

The successful introduction of the tyrosine kinase inhibitors has initiated a new era in the management of chronic myeloid leukemia (CML). Imatinib mesilate therapy has significantly improved the prognosis of CML. A minority of patients in chronic-phase CML--and more patients in advanced phases--are resistant to imatinib, or develop resistance during treatment. This is attributed, in 40-50% of cases, to the development of mutations in the Bcr-Abl tyrosine kinase domain that impair imatinib binding. Nilotinib (Tasigna) is a novel potent selective oral kinase inhibitor. Preclinical and clinical investigations demonstrate that nilotinib effectively overcomes imatinib resistance, and has induced high rates of hematologic and cytogenetic responses in CML post imatinib failure.