胃癌靶向治疗进展 戴广海 解放军总医院肿瘤内科
2002年世界胃癌的病例分布 (GLOBOCAN 2002, 2004)
2002年世界各国胃癌发病率 (GLOBOCAN2002, 2004)
胃癌防治研究现状 局部进展与转移期胃癌(AGC)占60-80%,是当今治疗难题 胃癌临床分期现状 I 18% 56-71% TNM分期 占总体% 五年生存率% I 18% 56-71% II 15% 37% III 27% 11-18% IV 39% 5% AGC 66% 16-23%
恶性肿瘤综合治疗模式 社会心理支持 中医中药
分子靶向治疗 根据肿瘤发生发展的分子生物学特性,利用肿瘤细胞和正常细胞分子生物学上的差异,使用针对细胞受体、关健基因和调控分子为靶点的抗肿瘤治疗。 具有靶向性的表皮生长因子受体(EGFR)阻断剂, 针对某些特定细胞标志物的单克隆抗体, 针对某些癌基因和癌的细胞遗传学标志的药物, 抗肿瘤血管生成的药物, 抗肿瘤疫苗, 基因治疗
常用药物 单克隆抗体类: MabThera 美罗华( Rituximab,利妥昔单抗) Herceptin 赫赛汀(Trastuzumab,妥曲珠单抗) Erbitux 爱必妥、泰欣生(Cetuximab,西妥昔单抗) Panitumumab 帕尼单抗 临床研究中 Avastin ( Bevacizumab,贝伐单抗,) 小分子化合物: Glivec 格列卫(STI571, Imatinib,甲磺酸伊马替尼) Iressa 易瑞沙(ZD1839, Gefitinib,吉非替尼) Tarceva 特罗凯(OSI-774 ,erlotinib,埃罗替尼) Nexavar 多吉美(Sorafenib,索拉非尼) Sutent 苏坦 ( Sunitinib,SU11248,苏尼替尼) Zactima 范得他尼(ZD6474) 临床研究中 Lapatinib(兰帕替尼)临床研究中
胃癌靶向治疗 靶点 Ⅰ-Ⅱ期 EGFR IRRSA/TARCEVA 西妥昔单抗(C225) Her-2 Herceptin Lapatinib(未上市) VEGF Bevacizumab(Avastin) 多靶点 Sutent(Sunitinib)
人表皮生长因子受体家族(EGFR / HER family) Erb-b1 EGFR HER1 neu Erb-b2 HER2 Erb-b3 HER3 Erb-b4 HER4 TGF EGF (NRG1) HRG Epi -cell HB-GF Amp NRG1 NRG2 NRG3 NRG4 Tyrosine kinase domain Ligand binding Transmembrane 细胞的生长和分化开始于细胞外的信号传导的刺激, 在调节紊乱的时候正常的生长信号传导却会使人类细胞出现恶性增殖. 生长因子的受体可以磷酸化细胞浆蛋白而激活信号传导的过程.这些受体, 如酪氨酸激酶受体就是一种带有细胞外的生长因子结合末端的跨膜蛋白. 表皮生长因子的受体和配体是有酪氨酸激酶活性的受体家族的基本成员, 表皮生长因子受体在很多细胞中都有表达,包括源于上皮和间充质的细胞. EGFR的结构和功能 表皮生长因子受体(EGFR)是一个由原癌基因c-(erbB)-2编码的分子量为170kd的跨膜糖蛋白。它是四种具有结构和功能相似性的生长因子受体之一,这四种生长因子受体为:EGFR或人类EGF相关受体(HER)-1(ErbB-1)、HER2(neu或ErbB-2)、HER3(ErbB-3)和HER4(ErbB-4)。 EGFR由三个功能不同的区组成: l 连接配体的细胞外区(与不同的EGF相关性生长因子连接) l 跨膜区(将受体固定在细胞膜上) l 细胞内的酪氨酸激酶区(激活细胞内的反应级联) EGFR家族的其它成员具有与EGFR相似的结构,但也有某些不同的特征。EGFR与其家族的其它成员相比,其胞外区具有36-48%的同源性,激酶区具有60-82%的同源性,胞内区具有24-33%的同源性。值得注意的是,EGFR和HER2的酪氨酸激酶区具有82%的同源性,所以两种受体间存在着交叉反应性。 EGFR在所有三个胚层来源的正常细胞中都有表达,其中在上皮来源的细胞尤为显著。EGFR具有几种不同的配体,其中最重要的是表皮生长因子(EGF)和转化生长因子(TGF)-α。 EGFR家族受体型酪氨酸激酶及其配体 EGFR(erbB-1/HER1) 表皮生长因子(EGF) 转化生长因子(TGF)-α 双调蛋白(Amphiregulin) 表皮调节素(Epiregulin) 肝素结合的表皮生长因子 BTC(Betacellulin) </P< p> 神经调节素2-α(NRG2-α) HER2(brbB-2,c-neu) 未知 HER3(erbB-3) 神经调节素1、2(NRG1*、NRG2) HER4(erbB-4) 神经调节素1-4(NRG1-4) Betacellulin EGFR, epidermal growth factor receptor Prigent & Lemoine 1992; Earp et al 1995; Harari & Yarden 2000; Mendelsohn & Baselga 2000; Olayioye et al 2000 9
EGFR 在实体瘤中的表达 EGFR 在多种实体瘤中均有表达 结直肠癌 75–89 头颈癌 95–100 肺癌 (非小细胞肺癌) 40–80 乳腺癌 14–91 卵巢癌 35–77 肾细胞癌 50–90 肿瘤 表达率(%) 肺癌 (NSCLC) 头颈癌 (SCCHN) Cunningham et al. N Engl J Med 2004;351:337–345; Grandis et al. Cancer 1996;78:1284–1292; Salomon et al. Crit Rev Oncol Hematol 1995;19:183–232; Walker & Dearing. Breast Cancer Res Treat 1999;53:167–176; Folprecht et al. ASCO 2004 (Abstract #283).
EGFR选择性小分子酪氨酸激酶抑制剂 酪氨酸激酶激活需要ATP Gefitinib and OSI-774竞争性结合ATP 可逆性抑制剂 HN N O Cl F Gefitinib, Iressa® 酪氨酸激酶激活需要ATP Gefitinib and OSI-774竞争性结合ATP 可逆性抑制剂 口服小分子制剂 N HN O OSI-774** **OSI-774 = Erlotinib, Tarceva™
X X X X EGFR酪氨酸激酶抑制剂的作用机制 酶 TGFa Iressa Tarceva 核 细胞膜 肿瘤细胞 细胞增生 凋亡 TKIs such as ZD1839 and OSI-774 enter the cell and block tyrosine kinase activation. In this way, enzyme activity within the cell is inhibited, and the signal transduction cascade is not activated. Tarceva 【商 品 名】 Tavceva 【通 用 名】 Erlotinib OSI-774 R1415 CP358774 NSC718781 【中 文 名】 塔西法 【开发公司】 Roche 、Genentech 【销售公司】 Roche、 Genentech 【药物种类】 小分子化合物 【靶 点】 EGFR—TK 【作用机制】 Erlotinib在细胞内与底物竞争,抑??EGFR—TK磷酸化,阻断肿瘤细胞信号的转 导,,抑制肿瘤细胞的生长,诱导其调亡。 【临床阶段】 2004年11月18日美国FDA批准上市治疗晚期肺癌。 【用法用量】 150mg/天。 【适 应 证】 晚期Nsclc 。 【贮藏条件】 常温避光。 【毒副作用】 肝功能损伤,皮疹、腹泻,0.6%可能出现间质性肺炎,角膜损伤。 【剂 型】 片剂 【规 格】 25mg/100mg/150mg/粒 ,150MG*30粒=HKD22800 酶 细胞增生 X 核 凋亡 血管发生 X 转移 X
IRESSA ( gefitinib 易瑞沙) —— First EGFR-TKI 化学名:4-(3-氯-4-氟苯胺)-7-甲氧基-6-(3-异构亚丙氧基)喹唑啉 分子式:C22H24ClFN4O3 分子量:446.9 Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor 英文全称是epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) 。 相对于传统的细胞毒化疗, EGFR-TKI是完全不同的治疗方法。它能够阻断负责肿瘤生长的信号传导通路。 易瑞沙对一系列人类肿瘤尤其是非小细胞肺癌都有明显的临床治疗作用,而且药物的耐受性较好。 13
IRRESA在胃癌中的应用 化疗失败的IV期胃癌患者,75例; Iressa 250~500mg/d; 无有效病例,但中位生存时间 日本患者:非日本患者=210天:79天,P=0.0016
IRRESA在胃癌中的应用 胃癌:缓解率为1%,N=75(ASCO2003)
OSI-774(Tarceva) 奎哪唑啉类化合物,可选择性的直接抑制EGFR酪氨酸激酶并减少EGFR的自身磷酸化作用,从而导致细胞生长停止和走向凋亡。 目前,结合化、放疗的联合应用也正在进行中。
Erlotinib(Tarceva)和胃癌 食管腺/鳞细胞癌:缓解率为16%,N=17(ASCO 2004) 胃或胃食管交接部癌: N=26+44,缓解率为0+12%(1例CR)(ASCO2005)
Cetuximab(爱必妥) IgG1 (嵌合抗体) 150 kDa 特异性作用于EGFR及其异二聚体 阻断配体与EGFR结合 高亲和力 Kd = 0.39 nM (M-225 Kd = 1 nM),1 log > 自然配体 刺激受体内化 阻断受体二聚体化,酪氨酸激酶磷酸化,信号转导 M225, a murine monoclonal antibody, competitively binds to the EGFR and inhibits EGFR pathways. Clinical trials using murine monoclonal antibodies have been complicated by the development of the human antimouse antibody (HAMA) immune response. The HAMA response not only carries the risk of serious allergic reactions but also increases the clearance of the murine proteins. Thus, the clinical utility of murine monoclonal antibodies has been limited. Cetuximab is a human:murine chimeric anti-EGFR IgG monoclonal antibody that binds exclusively to the EGFR. Chimeric antibodies are composed of the variable regions of murine antibody (the regions responsible for antigen binding) and the constant region of the human Fc fragment.[1] Chimeric monoclonal antibodies have demonstrated specificity and a diminished incidence of immunologic reactions.[2,3] Cetuximab binds to the EGFR with a binding affinity that is approximately one log higher than natural ligands.[4] Cetuximab prevents binding of endogenous ligands and induces receptor internalization, which ultimately blocks the activities of the EGFR pathway. Owens RJ, Young RJ. The genetic engineering of monoclonal antibodies. J Immunol Methods 1994; 168:149–165. Shitara K, Kuwana Y, Nakamura K, et al. A mouse/human chimeric anti-(ganglioside GD3) antibody with enhanced tumor activities. Cancer Immunol Immunother. 1993; 36:373–380. LoBuglio AF, Wheeler RH, Trang J, et al. Mouse/human chimeric monoclonal antibody in man: kinetics and immune response. Proc Natl Acad Sci U S A. 1989; 86:4220–4224. Goldstein NI, Prewett M, Zuklys K, et al. Biological efficacy of a chimeric antibody to the epidermal growth factor receptor in a human tumor xenograft model. Clin Cancer Res. 1995; 1:1311–1318.
EGFR 西妥昔单抗(C225) 单药的临床研究尚在进行中(SWOG) + ECF或+伊立替康的研究尚在进行中(CALBG) + FOLFIRI的研究尚在进行中 +XP?
A phase II study of cetuximab (Cetuximab) with cisplatin and capecitabine (Xeloda) as 1st line treatment in advanced gastric cancer Methods: cisplatin 80mg/m2, capecitabine 2000mg/m2, d1-14, triweekly Cetuximab weekly (initially at 400 mg/m2, then subsequent doses at 250 mg/m2) 2008 ASCO , Abstract No: 15663
A phase II study of cetuximab (Cetuximab) with cisplatin and capecitabine (Xeloda) as 1st line treatment in advanced gastric cancer Results: N=25 1 CR 9 PR 13 SD 2 PD RR 40% DCR 92% Toxicities included Grade 3/4: neutropenia(14.2%) nausea/vomiting(11.1%) rash/desquamation (10.7%) fatigue (11.1%) diarrhea (6.3%) abdominal pain (6% ) Hand-Foot syndrome(2.8%) 2008 ASCO , Abstract No: 15663
A phase II study of cetuximab (Cetuximab) with cisplatin and capecitabine (Xeloda) as 1st line treatment in advanced gastric cancer Conclusions: Treatment with XP+C is well-tolerated and met the pre-specified criteria for objective response and disease Control. 2008 ASCO , Abstract No: 15663
Cetuximab in combination with cisplatin and docetaxel as first-line treatment in patients with locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma (Italian phase II DOCETUX study). Methods: Cetuximab weekly at 400 mg/m2 iv loading dose, and then at 250 mg/m2 iv maintenance dose cisplatin 75 mg/m2 iv d1 docetaxel 75 mg/m2 iv d1 every 3 weeks, for maximum of 6 cycles 2008 ASCO, Abstract No: 4575
The objective responses (RECIST) : 1 (2.4%) CR 16 (38.1%) PR, Cetuximab in combination with cisplatin and docetaxel as first-line treatment in patients with locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma (Italian phase II DOCETUX study). Results: The objective responses (RECIST) : 1 (2.4%) CR 16 (38.1%) PR, 40.5% CR + PR (95% CI: 25.7-55.3%) 16 (38.1%) SD 9 (21.4%) PD The PFS at 3 months is 80% (95% CI: 64.3-95.7%) Survival data are premature (75% of the pts are still alive) 2008 ASCO, Abstract No: 4575
Grade 3-4 toxicity (CTC v3.0): Cetuximab in combination with cisplatin and docetaxel as first-line treatment in patients with locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma (Italian phase II DOCETUX study). Grade 3-4 toxicity (CTC v3.0): 45.8% neutropenia (22.9% febrile neutropenia) 6.25% anemia 2.1% thrombocytopenia 22.9% asthenia 8.3% vomiting 6.3% stomatitis 4.2% diarrhea 4.2% hyperbilirubinemia 20% hyponatremia 16% hypokalemia 4% hypomagnesemia Skin reactions > 2 w as 31.3% Three deaths occurred within 60 days from start of therapy (1 bowel occlusion, 1 gastric bleeding, 1 PD). 2008 ASCO, Abstract No: 4575
Cetuximab in combination with cisplatin and docetaxel as first-line treatment in patients with locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma (Italian phase II DOCETUX study). Conclusions: The combination of cetuximab and cisplatin/docetaxel appears to be active (78.6% of disease control rate), while the greater toxicity appears to be limited to neutropenia. 2008 ASCO, Abstract No: 4575
C225 was added at 400 mg/m2 week 1, then 250 mg/m2 weekly. Cetuximab (C225) plus irinotecan/cisplatin (CPT/Cis) for CPT/Cis-refractory esophageal cancer PROTOCOL: CPT 65 mg/m2 D1,8 Cis 30 mg/m2 D1,8 q3 weeks C225 was added at 400 mg/m2 week 1, then 250 mg/m2 weekly. 2008 ASCO, Abstract No: 45580
Cetuximab (C225) plus irinotecan/cisplatin (CPT/Cis) for CPT/Cis-refractory esophageal cancer RESULTS: 6 of 8 Pts were EGFR positive (2 1+/ 2 2+/2 3+ by IHC). Median TTP on prior CPT/Cis was 4.4 months (range, 1.8 to 14.4 months) 1 confirmed partial response (PR) was seen in a Pt with adenoCA (EGFR 3+) 2 Pts had stable disease (SD) and 5 had progressive disease (PD) 1 Pt with SD for 2.9 months had SCC (EGFR 2+) while the other with SD for 3.7 months had adenoCA (EGFR negative). 2008 ASCO, Abstract No: 45580
Significant grade 3/4 toxicities : lymphopenia (4 Pts, all grade 3) Cetuximab (C225) plus irinotecan/cisplatin (CPT/Cis) for CPT/Cis-refractory esophageal cancer Significant grade 3/4 toxicities : lymphopenia (4 Pts, all grade 3) neutropenia (1 Pt, grade 4) hypomagnesemia (1 Pt, grade 3) Rash was manageable, with 4 Pts with grade 1 and 3 Pts with grade 2 skin toxicity 1 Pt died of non-neutropenic sepsis from PD after 3 weeks of therapy (this Pt was off treatment for 3-4 weeks prior to death) 2008 ASCO, Abstract No: 45580
Cetuximab (C225) plus irinotecan/cisplatin (CPT/Cis) for CPT/Cis-refractory esophageal cancer CONCLUSION: Adding C225 to CPT/Cis for CPT/Cis-refractory esophageal cancer is well-tolerated; 1 PR has been observed to date. Accrual is ongoing to 25 Pts. 2008 ASCO, Abstract No: 45580
人表皮生长因子受体家族(EGFR / HER family) Erb-b1 EGFR HER1 neu Erb-b2 HER2 Erb-b3 HER3 Erb-b4 HER4 TGF EGF (NRG1) HRG Epi -cell HB-GF Amp NRG1 NRG2 NRG3 NRG4 Tyrosine kinase domain Ligand binding Transmembrane 细胞的生长和分化开始于细胞外的信号传导的刺激, 在调节紊乱的时候正常的生长信号传导却会使人类细胞出现恶性增殖. 生长因子的受体可以磷酸化细胞浆蛋白而激活信号传导的过程.这些受体, 如酪氨酸激酶受体就是一种带有细胞外的生长因子结合末端的跨膜蛋白. 表皮生长因子的受体和配体是有酪氨酸激酶活性的受体家族的基本成员, 表皮生长因子受体在很多细胞中都有表达,包括源于上皮和间充质的细胞. EGFR的结构和功能 表皮生长因子受体(EGFR)是一个由原癌基因c-(erbB)-2编码的分子量为170kd的跨膜糖蛋白。它是四种具有结构和功能相似性的生长因子受体之一,这四种生长因子受体为:EGFR或人类EGF相关受体(HER)-1(ErbB-1)、HER2(neu或ErbB-2)、HER3(ErbB-3)和HER4(ErbB-4)。 EGFR由三个功能不同的区组成: l 连接配体的细胞外区(与不同的EGF相关性生长因子连接) l 跨膜区(将受体固定在细胞膜上) l 细胞内的酪氨酸激酶区(激活细胞内的反应级联) EGFR家族的其它成员具有与EGFR相似的结构,但也有某些不同的特征。EGFR与其家族的其它成员相比,其胞外区具有36-48%的同源性,激酶区具有60-82%的同源性,胞内区具有24-33%的同源性。值得注意的是,EGFR和HER2的酪氨酸激酶区具有82%的同源性,所以两种受体间存在着交叉反应性。 EGFR在所有三个胚层来源的正常细胞中都有表达,其中在上皮来源的细胞尤为显著。EGFR具有几种不同的配体,其中最重要的是表皮生长因子(EGF)和转化生长因子(TGF)-α。 EGFR家族受体型酪氨酸激酶及其配体 EGFR(erbB-1/HER1) 表皮生长因子(EGF) 转化生长因子(TGF)-α 双调蛋白(Amphiregulin) 表皮调节素(Epiregulin) 肝素结合的表皮生长因子 BTC(Betacellulin) </P< p> 神经调节素2-α(NRG2-α) HER2(brbB-2,c-neu) 未知 HER3(erbB-3) 神经调节素1、2(NRG1*、NRG2) HER4(erbB-4) 神经调节素1-4(NRG1-4) Betacellulin EGFR, epidermal growth factor receptor Prigent & Lemoine 1992; Earp et al 1995; Harari & Yarden 2000; Mendelsohn & Baselga 2000; Olayioye et al 2000 32
Herceptin (Trastuzumab, 妥曲珠单抗, 赫赛汀) Herceptin是一种针对HER-2/neu原癌基因产物的人/鼠嵌合单抗,能特异地作用于HER-2受体过度表达的乳腺癌细胞。1998年9月美国FDA批准上市,是第一个以癌基因为靶的HER-2阳性乳腺癌转移患者的治疗药物。
HER2 表位,可为高度可变的小鼠抗体片段识别 高度亲和力高 (Kd = 0.1 nM) 及特异性 95% 人, 5% 小鼠 降低了潜在免疫原性 增加了潜在激发免疫效应器的机制 人 IgG-1
Her-2 国际多中心研究正在进行中 已取得初步疗效
赫赛汀治疗HER-2 过表达的晚期胃肠道肿瘤11例临床观察 陈 丽,戴广海1,彭 亮,赵 宏,司海燕,焦顺昌 (解放军总医院肿瘤内科,北京 100853) 临床资料: 自2006年6月至2008年6月在我院住院治疗的11例晚期胃肠道肿瘤患者,女性3例,男性8例,年龄44岁~76岁、中位年龄57岁。患者均经病理检查确诊,其中胃癌9例,结肠癌2例。根据国际抗癌联盟(UICC)TNM分期标准,临床分期为Ⅳ期,Kamofsky评分70~90分,Her2 /neu均为( 灶状 +)至( + + +)。转移部位在肝脏6例,肺脏4例,淋巴结6例,骨骼2例;转移部位1个6例,2个3例,3个2例。初治患者7例(均为胃癌),复治4例。
赫赛汀治疗HER-2 过表达的晚期胃肠道肿瘤11例临床观察 陈 丽,戴广海1,彭 亮,赵 宏,司海燕,焦顺昌 (解放军总医院肿瘤内科,北京 100853) 治疗方法: 首次静滴赫赛汀 8 mg/kg,此后6mg/kg,每3周重复。 化疗: 多种方案(略)
赫赛汀治疗HER-2 过表达的晚期胃肠道肿瘤11例临床观察 陈 丽,戴广海1 ,彭 亮,赵 宏,司海燕,焦顺昌 (解放军总医院肿瘤内科,北京 100853) 不同肿瘤对Herceptin联合化疗的治疗反应性 肿瘤部位 例数 CR PR SD PD RR(%) 胃癌 肠癌 9 2 8 1 88.9 50.0
11例应用Herceptin联合化疗的晚期胃肠道肿瘤患者TTP曲线 TTP最短5.6个月,最长14个月,中位TTP 8.6个月
11例应用Herceptin联合化疗的晚期胃肠道肿瘤患者生存曲线
李XX,男,66岁,胃低分化腺癌,肝转移 HER-2 (++ ~ +++) 化疗方案: Herceptin 560mg D1, DDP 144mg D1, Xloda 1800mg Bid D1-15
李XX,男,66岁,胃低分化腺癌,肝转移 HER-2 (++ ~ +++) 化疗方案: Herceptin 560mg D1, DDP 144mg D1, Xloda 1800mg Bid D1-15
VEGF信号转导通路
Tumor angiogenesis 5. Intravasation 1. Secretion of Tumor angiogenic factors Tumor 4. Appearance of new tumor vasculature 2. Proteolytic destruction of ECM 3. Endothelial cell proliferation and migration The process of angiogenesis is complex, relying on a cascade of biochemical signals to initiate and progress vascular development. Sequential steps occur in the process of neovascularization: Release of specific angiogenic molecules triggers the degradation of the basement membrane by proteases. This allows endothelial cell migration into the interstitial space, and capillary sprouting. Endothelial cell proliferation then occurs at the migrating tip. This is followed by lumen formation, the generation of a new basement membrane with the recruitment of pericytes, formation of anastomoses, and finally blood flow. Sprouting capillary ECM, extracellular matrix
Summary of VEGF function VEGF is a key angiogenic regulator directly implicated in endothelial cell proliferation endothelial cell migration endothelial cell protease expression endothelial cell adhesion capillary tube formation vessel maturation/pericyte recruitment It also acts as a survival factor for newly formed vasculature Vascular Permeability Factor
Inhibition of VEGF signaling Inhibiting VEGF signaling inhibits growth of new tumor vessels decreases vascular density, diameter and permeability may induce regression of recently developed tumor microvessels Therapeutic inhibition of tumor angiogenesis should be effective in a broad range of solid malignancies Target tissue is in direct contact with blood, facilitating drug delivery The inhibition of VEGF signaling inhibits growth of new tumor vessels by preventing endothelial cell proliferation and migration. It also induces regression of recently developed tumor microvessels and decreases vascular density, diameter and permeability, which means that the inadequate vasculature is unable to support tumor growth. Therapeutic inhibition of tumor angiogenesis should be effective in a broad range of solid malignancies. As the target tissue is in direct contact with blood, this should facilitate drug delivery and means that toxicity to other normal tissues is expected to be low.
Approaches to the inhibition of VEGF signaling Ligands VEGF-A Anti-VEGF antibodies VEGF-B Monoclonal antibody VEGF-C VEGF-D Monoclonal antibodies (MABs) have been developed, which bind to some of the ligands for the VEGF receptors, such as VEGF-A. VEGF-A typically activates VEGFR-1 and -2, so that VEGF-A-dependent signaling via these receptors is inhibited by these agents. However, MABs do NOT exhibit activity against the other VEGF ligands, most notably VEGF-C or VEGF-D. As a result, signaling may still occur via these ligands. Blood vascular endothelial cell Lymphatic vascular endothelial cell VEGFR-1 VEGFR-2 VEGFR-3
Approaches to the inhibition of VEGF signaling Ligands VEGFR-TKIs VEGF-A VEGF-B VEGF-C VEGF-D Lymphatic vascular endothelial cell Blood vascular endothelial cell X VEGFR-TKI Inhibition X Small molecule VEGF signaling inhibitors have been designed to inhibit all three VEGF receptors at the intracellular domain, thereby blocking the signal at the receptor level irrespective of the activating ligand. These compounds are known as vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs). This means that, in addition to the inhibition of angiogenesis through their actions on VEGFR-1 and -2 receptors, VEGFR-TKIs can also act on VEGFR-3, the receptor that is believed to have a key role in lymphangiogenesis. VEGFR-1 VEGFR-2 VEGFR-3 Angiogenesis Lymphangiogenesis VEGFR-TKI, vascular endothelial growth factor receptor-tyrosine kinase inhibitor
血管内皮生长因子(VEGF) Bevacizumab,贝伐单抗,Avastin 重组人源化单克隆IgG1抗体1; 93%人源, 7% 鼠源 识别所有VEGF亚型并阻断VEGF功能2 半衰期将近20天 (范围11~50天)1 8x10–10M道尔顿 1Avastin™ (bevacizumab). Prescribing Information. 2004; 2Presta et al. Cancer Res. 1997;57:4593.
Avastin (bevacizumab) 是第一种抗血管生长药物,可以阻断对肿瘤生长十分重要的血液供应,使肿瘤不能在体内播散。通过Ⅲ期临床试验说明能提高CPT11的疗效并延长病人的生存期。 Avastin单克隆抗体是第一个(2004年)被美国FDA批准上市的血管生成抑制剂,用于结直肠癌的一线治疗。 抗血管生成剂的最大优点之一是它不会产生肿瘤耐药,在联合化疗中十分有利。
VEGFR Bevacizumab抑制VEGFR 在转移性病变中+顺铂和伊立替康(MSKCC) 辅助ECF方案(MAGIC-2实验) AVAGAST: AVASTIN+DDP+XELODA PLACEBO+DDP+XELODA
Bevacizumab(BEV)联合CPT-11+DDP 一线治疗AGC --- II期临床试验(ASCO 2005) 胃癌靶向治疗 Bevacizumab(BEV)联合CPT-11+DDP 一线治疗AGC --- II期临床试验(ASCO 2005) N=24 3m PFS 89% 6m PFS 76% 16例可评价近期疗效 PR (12/16)75% MR 3 ,SD 1 BEV 15mg/kg d1 CPT 65mg/m2 d1,8 DDP 30mg/m2 d1,8 q3w 不良反应(24例): ¾级白细胞减少、恶心呕吐、腹泻 8% 血栓(4肺和2深静脉):6例(20%); 2例胃穿孔,2例几近穿孔(肿瘤部位) M.A. ShAh et al:ASCO 2005 abstr 4025
Phase II trial of docetaxel, cisplatin, irinotecan, and bevacizumab in metastatic esophagogastric cancer. Methods: bevacizumab 10mg/kg d1 docetaxel 30mg/m2 d 1, 8 cisplatin 25mg/m2 d 1, 8 irinotecan 50mg/m2 d 1, 8 3-week cycle. 2008 ASCO, Abstract No: 4552
Phase II trial of docetaxel, cisplatin, irinotecan, and bevacizumab in metastatic esophagogastric cancer. Results: 30 patients are evaluable for response: partial = 19 (63%) stable = 9 (30%) progression = 2 (7%). Grade III/IV toxicities : grade III neutropenia = 7 pts (22%) grade III diarrhea = 9 pts (28%) grade III nausea = 2 pts (6%) grade 4 thromboembolic events = 3 pts (9%) 2008 ASCO, Abstract No: 4552
Phase II trial of docetaxel, cisplatin, irinotecan, and bevacizumab in metastatic esophagogastric cancer. Conclusions: The combination of docetaxel, cisplatin, irinotecan and bevacizumab is well-tolerated and has a promising response rate in chemo-naive patients with esophagogastric cancer. UGT1A1 testing appears to predict the risk of severe diarrhea/neutropenia in this group of patients 2008 ASCO, Abstract No: 4552
胃癌靶向治疗小结 IREESA/TARCEVA可能有一定的疗效 C-225联合化疗初步显示具有一定的疗效 HERCEPTIN联合化疗对于HER-2阳性的胃癌肯定具有较好的疗效 AVASTIN联合化疗对于胃癌肯定具有一定的疗效 肯定的结论尚需扩大的随机对照的Ⅲ期临床研究验证
靶向治疗的特点 实际属于病理生理治疗,也就是封闭肿瘤发展过程中的关键受体和纠正其病理过程 具有非细胞毒性和靶向性; 具调节作用和细胞稳定(cytostatic)性作用; 不一定非达到剂量限制性毒性(DLT)和最大耐受剂量(MTD); 毒性的作用范围和临床表现与细胞毒性药物有很大的区别; 与常规治疗(化疗、放疗)合用有更好的效果等等; 疗效评价不单单是肿瘤缩小,更侧重于肿瘤稳定和生存质量提高及生存器延长; 最终目标: 力争使恶性肿瘤成为一个慢性病。
靶向治疗 肿瘤治疗的未来 细胞毒药物
谢谢各位!