Recent developments in colorectal cancer treatment by monoclonal antibodies

A growing understanding of the molecular mechanisms involved in cancer biology and continuous refinement of available technologies for drug discovery have prompted the development of new therapeutic tools targeting specific cancer-associated molecular pathways. Among these so-called biological therapies, monoclonal antibodies have now reached the time of clinical application. Besides initial development of the murine antibody edrecolomab, the impact of monoclonal antibodies on cancer therapy has recently been clearly demonstrated in colorectal cancer by targeting two major pathways critical to tumourigenesis: the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) signalling pathways. These antibodies showed significant clinical activity in advanced colorectal cancer, especially when combined with chemotherapy. This paper reviews the status of the monoclonal chimeric antibody cetuximab (Erbitux^®) and other anti-EGFR antibodies, and of bevacizumab (Avastin^®; an anti-VEGF humanised monoclonal antibody), in colorectal cancer treatment.     

Telbivudine: a new nucleoside analogue for the treatment of chronic hepatitis B

Telbivudine, β-L-2′-deoxythymidine (LdT), is a new β-L-nucleoside analogue with potent inhibitory activity against the hepatitis B virus. In invitro studies and animal models, telbivudine has demonstrated potent and specific antiviral activity against hepatitis B. Additionally, in preclinical animal toxicology studies, telbivudine showed no adverse side effects or adverse effects on mitochondrial function. The promising results of the early invitro and animal telbivudine studies prompted the development and initiation of Phase I andII human clinical trials. The Phase I clinical study demonstrated that end-of-treatment virological response rates were better for telbivudine recipients at multiple dosing levels as compared with placebo patients. The subsequent Phase IIb human clinical study demonstrated superior antiviral efficacy of telbivudine, significantly better ALT normalisation and better hepatitis B e-antigen loss as compared with lamivudine. Telbivudine was well tolerated with no identified safety issues. Virological breakthrough with telbivudine was significantly lower than with lamivudine.     

The developing trend of monoclonal antibodies in the treatment of colorectal cancer

Monoclonal antibodies (mAbs) against growth factors, receptors and tumor-specific/tumor-selective antigens represent a rapidly growing class of pharmaceutical agents which are poised to make a major impact on the treatment of colorectal cancer. mAbs targeting the epidermal growth factor receptor and the vascular endothelial growth factor have already been approved for the treatment of metastatic colorectal cancer. Other antibodies to the same and other molecular targets implicated in tumor growth and metastasis are undergoing intense preclinical and clinical evaluation. In both the neoadjuvant and adjuvant clinical settings, although mAbs are typically administered in combination with established cytotoxic chemotherapy regimens given their synergistic effect, several agents have demonstrated efficacy when given as monotherapy. At the same time, combination therapies with multiple targeted biological agents are actively being investigated. Existing clinical data and recent progress in preclinical and clinical studies of mAbs are reviewed.     

Bevacizumab in the treatment of breast cancer

The monoclonal antibody bevacizumab, targeted against the angiogenesis factor VEGF has clinical activity against several common cancers. In metastatic breast cancer it improves response rate and time to progression in combination with paclitaxel/docetaxel compared with paclitaxel/docetaxel alone; the drug is currently being investigated in other combination regimens and as adjuvant and neoadjuvant therapy in early breast cancer. It is generally well tolerated. Side effects, including hypertension, proteinuria, thrombosis and bleeding, are uncommon and usually managed easily. Based on the clinical efficacy of bevacizumab, other small-molecule oral antiangiogenesis agents are now also under development.     

Les antiangiogéniques : limites actuelles en oncologie thoracique

Antiangiogenic agents appear as major therapeutic options in renal, colorectal and breast cancer. Their part in thoracic oncology is still limited today except for bevacizumab. We review the current limits of antiangiogenic agents in terms of efficacy, activity, tolerance and therapeutic strategies. Problems about predictive biomarkers and cost-effectiveness of antiangiogenic agents in thoracic oncology are also mentioned.     

标准一线化疗联用贝伐珠单抗在晚期非小细胞肺癌患者治疗中的成本-效果分析

目的从我国现阶段医疗卫生角度出发,评价四川地区一线化疗联用贝伐珠单抗治疗晚期非小细胞癌的成本-效果性。方法依据NCT00021060临床试验数据,结合四川地区医疗费用水平,采用成本-效果分析法,以增量成本-效果比为评价指标,评价标准一线化疗联用贝伐珠单抗在晚期非小细胞癌治疗方案的优劣,并分析结果敏感度。结果与标准一线化疗组相比,贝伐珠单抗组ICER为1 909 117.8元/年;敏感度分析结果提示,贝伐珠单抗使用成本和医疗检查成本对总成本影响最大,其他参数影响较小。结论从我国现阶段医疗卫生角度出发,与标准一线化疗相比,四川地区晚期非小细胞肺癌一线化疗联用贝伐珠单抗,不具有成本效果优势。     

贝伐珠单抗联合伊立替康与雷替曲塞治疗氟尿嘧啶耐药晚期结直肠癌的疗效和安全性

目的 观察贝伐珠单抗联合伊立替康与雷替曲塞方案在氟尿嘧啶类药物耐药后的晚期结直肠癌患者中的疗效及安全性。方法 收集中国医科大学附属第一医院2014—2019年收治的氟尿嘧啶类耐药的60例晚期结直肠癌患者,对照组30例,应用伊立替康联合雷替曲塞方案（IR）;实验组30例,应用IR联合贝伐珠单抗方案。分析比较两组患者的客观有效率（ORR）、疾病控制率（DCR）、无进展生存时间（PFS）及不良反应发生情况。结果 实验组和对照组ORR分别为6.67%和3.33%,DCR分别为66.67%和53.33%,两组ORR和DCR比较差异无统计学意义。实验组和对照组中位PFS分别为6.0个月和3.1个月,差异有统计学意义（P=0.020 4）。两组不良反应以Ⅰ/Ⅱ级多见,Ⅲ/Ⅳ级不良反应发生率低,实验组蛋白尿的发生率高于对照组,差异有统计学意义（P=0.001）。其余如出血、转氨酶升高、恶心、呕吐、腹泻、发热、皮疹、高血压等不良反应发生率均为实验组高于对照组,但差异无统计学意义。结论 贝伐珠单抗联合伊立替康与雷替曲塞方案可提高既往氟尿嘧啶类治疗耐药后的晚期结直肠癌患者的疗效,无进展生存期增加,不良反应可耐受,值得进一步研究。     

贝伐单抗介导的阿霉素白蛋白纳米粒的制备与优化

目的采用Box-Behnken效应面法优化贝伐单抗介导的阿霉素白蛋白纳米粒制备工艺。方法在采用去溶剂化-固化交联法制备出的阿霉素白蛋白纳米粒的基础上,用异型双功能交联剂NHS-PEG3500-MAL作为偶联剂,将贝伐单抗偶联到载药白蛋白纳米粒表面。以2-亚氨基硫烷盐酸盐用量、载药白蛋白纳米粒与贝伐单抗质量比、NHS-PEG3500-MAL用量为影响因素,以纳米粒粒径、载药量和包封率作为评价指标,用三因素三水平的Box-Be-hnken效应面法设计试验,并对免疫纳米粒的制备进行优化;考察制备出的免疫纳米粒的抗体活性保存率及稳定性。结果优化后的处方是2-亚氨基硫烷盐酸盐50μg、DOX-A-NPs与Bevacizumab质量比为27.5 mg.mg-1、NHS-PEG3500-MAL用量为8.8 mg,以此处方制得的免疫纳米粒粒径为(216.1±2.31)nm、载药量为(28.93±0.94)%、包封率为(80.39±2.83)%,测得值与预测值相差较小。结论采用Box-Behnken效应面法优化并制备阿霉素白蛋白免疫纳米粒是可行的。     

Intravitreal bevacizumab and ranibizumab injections for patients with polypoidal choroidal vasculopathy

Purpose

To compare the effectiveness of intravitreal injection of bevacizumab and ranibizumab in patients with treatment-naïve polypoidal choroidal vasculopathy (PCV).

Methods

A total of 66 and 60 eyes of 121 consecutive patients who received intravitreal bevacizumab (1.25 mg) or ranibizumab (0.5 mg) injection for treatment of PCV were retrospectively reviewed. After initial three loading injections by month, injection was performed as needed. Main outcome measures included best corrected visual acuity (BCVA), foveal center thickness (FCT) as assessed by spectral domain optical coherence tomography (SD-OCT), and change in polypoidal lesion on indocyanine green angiography (ICGA).

Results

At 12 months, average number of injections was 4.72±1.84 in the bevacizumab group and 5.52±1.54 in the ranibizumab group. Mean logarithm of the minimum angle of resolution of BCVA from baseline at 12 months after injection improved by 0.11 in the bevacizumab group (P=0.02) and by 0.14 in the ranibizumab group (P=0.01). Average FCT decreased from 368±62.48 to 298±40.77 μm in the bevacizumab group (P=0.01) and from 371±50.79 to 286±36.93 μm in the ranibizumab group (P=0.01). Polyp regression rate was 24.2% (16 eyes out of 66 eyes) in the bevacizumab group and 23.3% (14 eyes out of 60 eyes) in the ranibizumab group. There was no statistically significant difference in BCVA improvement achieved, FCT improvement achieved, and polyp regression rate between groups.

Conclusion

Intravitreal injections of bevacizumab and ranibizumab have similar effects in stabilization of visual acuity, macular edema, and regression of polypoidal complex with PCV eyes.     

贝伐珠单抗单药及联合化疗对子宫内膜癌Ishikawa细胞增殖和凋亡的影响

目的： 探究贝伐珠单抗单药及联合紫杉醇加卡铂给药,对子宫内膜癌Ishikawa细胞增殖和凋亡的影响。方法： 体外培养Ishikawa细胞,MTT法检测贝伐珠单抗（Bev）、紫杉醇（T）、卡铂（C）抑制Ishikawa细胞增殖能力的变化,并计算半数抑制浓度（IC₅₀）。以不同浓度的Bev将实验设为4组,分别为A组：对照组;B组：低浓度组（Bev 2.5 mg·mL^-1）;C组：中浓度（Bev 5.5 mg·mL^-1）;D组：高浓度组（Bev 11 mg·mL^-1）。采用MTT法在24,48,72 h分别检测A、B、C、D 4组对Ishikawa细胞抑制增殖的作用。同时实验根据IC₅₀值还将不同浓度的Bev联合紫杉醇、卡铂分为4组,分别为a组（Bev 5.5 mg·mL^-1）;b组（Bev 2.5 mg·mL^-1+卡铂7.0 mg·mL^-1+紫杉醇10 μg·mL^-1）;c组（Bev 5.5 mg·mL^-1+卡铂7.0 mg·mL^-1+紫杉醇10 μg·mL^-1）;d组（Bev 11 mg·mL^-1+卡铂7.0 mg·mL^-1+紫杉醇10 μg·mL^-1）采用MTT法检测对Ishikawa细胞的抑制增殖作用;用Annexin V-FITC/PI双染,流式细胞仪分析48 h贝伐珠单抗A、B、C、D四组对Ishikawa细胞凋亡的影响。结果： MTT法测定出A、B、C、D 4组药物对Ishikawa细胞体外增殖抑制作用显著,并随着剂量的增大、时间的延长,抑制作用也明显增强;MTT法显示不同浓度Bev联合紫杉醇、卡铂,a、b、c、d 4个组均显著抑制Ishikawa细胞的增殖,与a组相比,Bev（5.5 mg·mL^-1）+紫杉醇、卡铂组对Ishikawa细胞有显著抑制增殖作用（P<0.05）,Bev（11 mg·mL^-1）+紫杉醇、卡铂组对Ishikawa细胞表现出更为显著的抑制增殖作用（P<0.01）;通过流式细胞仪检测48 h后A、B、C、D 4组均能诱导细胞的凋亡,且随着剂量增加作用也增强。与对照组比较,差异均有统计学意义（P<0.05）。结论： 贝伐珠单抗单药及联合卡铂和紫杉醇给药,均能在体外抑制人子宫内膜癌细胞株Ishikawa细胞增殖反应,且呈剂量和时间依赖性。