Specific active immunotherapy with the HEBERSaVax VEGF-based cancer vaccine: From bench to bedside

HEBERSaVax is a cancer therapeutic vaccine candidate based on the combination of a recombinant antigen representative of human vascular endothelial growth factor (VEGF), and clinically tested adjuvants. The vaccine has been shown to inhibit tumor growth and metastases in mice, and to induce VEGF-blocking antibodies and specific T-cell responses in several animal species, all with an excellent safety profile. After preclinical studies, two sequential phase 1 clinical trials were conducted with HEBERSaVax to assess safety, tolerance, and immunogenicity in patients with advanced solid tumors, at different antigen doses, and combined with two distinct adjuvants. HEBERSaVax was found to be safe and tolerable, with mainly low-grade local adverse effects. Immunized patients produced specific anti-VEGF IgG antibodies that blocked VEGF-VEGF Receptor 2 (KDR) interaction in an in vitro competitive ELISA assay. Gamma-IFN ELISPOT tests done with patient samples were positive after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with a mutated VEGF molecule. Patients surviving week 16 in the trials received voluntary off-trial monthly re-immunizations with HEBERSaVax, until death, intolerance, marked disease progression, or patient’s withdrawal of consent. No additional onco-specific treatment was administered. After up to 6 years of vaccinations, the safety profile of HEBERSaVax remained excellent, with patients showing positive results in the specific immune response tests. Evidence of clinical benefit has also been documented in some individuals. The results of these studies suggest that long-term vaccination with HEBERSaVax is a feasible strategy, and highlight the importance of continuing the clinical development program of this novel cancer therapeutic vaccine candidate.     

脂质体VEGFR2胞外区基因肿瘤疫苗的制备及其免疫激活体外抗肿瘤活性研究

目的:制备脂质体(LP)携带VEGFR2胞外区(exVEGFR2)肿瘤抗原pCMV质粒复合物基因疫苗,为肿瘤免疫治疗提供新的主动免疫疗法。方法:RT-PCR扩增含2个KpnⅠ和XbaⅠ限制性酶切位点的exVEGFR2序列,将其与pCMV质粒连接,构建pCMV/exVEGFR2质粒。Western blot检测exVEGFR2体外表达水平。用制备好的脂质体pCMV/exVEGFR2复合物(LP-pCMV/exVEGFR2)免疫C57BL/6小鼠,ELISA法检测其免疫激活活性。利用51 Cr释放实验分析CTLs介导的细胞毒活性。结果:成功扩增到exVEGFR2序列,并构建pCMV/exVEGFR2质粒;只有在pCMV/exVEGFR2转染COS-7细胞中,检测到与目的蛋白序列大小一致的相对分子质量为90000的VEGFR2特异性条带。LP-pCMV/exVEGFR2免疫小鼠6周后,ELISA法检测到强烈的特异性抗VEGFR2免疫激活效应;其免疫T细胞能够有效地介导体外VEGFR2阳性的CT-26结肠癌细胞毒性。结论:LP-pCMV/exVEGFR2能够有效地激活小鼠产生特异性抗VEGFR2免疫应答效应,并产生体外抗肿瘤细胞免疫毒性,为后期研究主动免疫治疗VEGFR2阳性肿瘤奠定实验基础。     

A human IgG-like bispecific antibody co-targeting epidermal growth factor receptor and the vascular endothelial growth factor receptor 2 for enhanced antitumor activity

Both Epidermal Growth Factor Receptor (EGFR) and the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) play critical roles in tumorigenesis. We hypothesized co-targeting EGFR and VEGFR2 using a bispecific antibody might have significant therapeutic potential. Here,we designed and produced a human IgG-like bispecific antibody (Bi-Ab) based on the variable regions of cetuximab (an anti-EGFR antibody) and mAb-04 (an anti-VEGFR2 antibody developed in our lab) . The Bi-Ab was found to inhibit the proliferation, survival and invasion of cancer cells via ablating phosphorylation of receptor and downstream signaling. In vivo efficacy was demonstrated against established HT-29 and SKOV-3 xenografts grown in nude mice. Studies revealed our Bi-Ab was able to restrain xenografted tumor growth and prolong survival of mice through inhibiting cell proliferation,promoting apoptosis and anti-angiogenesis. In contrast to cetuximab or mAb-04 alone, our Bi-Ab exhibits enhanced antitumor activity and has equal or slightly superior activity to their combination (Combi). It shows promise as a therapeutic agent, especially for use against tumors EGFR and/or VEGFR2 over-expressing malignancies.     

Recent advances in squamous non-small cell lung cancer: evidence beyond predictive biomarkers

Squamous non-small cell lung cancer (NSCLC) has always been characterized by a limited number of therapeutic options and by the lack of actionable biomarkers compared to its non-squamous counterpart. Recent clinical trials have led to the approval of new anti-neoplastic drugs available to both non-squamous and squamous NSCLC, consisting in a vascular-disrupting agent and two immune check-point inhibitors; additionally, a monoclonal antibody targeting the epidermal growth factor receptor (EGFR) is currently under evaluation by the Food and Drug Administration (FDA). While predictive molecular biomarkers have not been identified with consistency and are still highly demanded, these agents proved themselves noteworthy and can be considered a powerful addition to the available treatments for squamous NSCLC.     

Combination targeted therapy of VEGFR inhibitor,sorafenib, with an mTOR inhibitor,sirolimus induced a remakable response of rapid progressive Uterine PEComa

Perivascular epithelioid cell tumor is a rare tumor. To date, there is no consensus of therapy to be recommended for unresectable disease. For a low incidence and a rarely curable disease, the finding of new therapy is essential.

Here we report the first case of a patient with perivascular epithelioid cell tumor whose disease had a rapid progression after surgery and had a rapid remarkable response of combination therapy of a VEGFR inhibitor, sorafenib, with an mTOR inhibitor, sirolimus.

This result may have potential to deliver a new treatment option and inhibiting the mTOR pathway combined with inhibiting the VEGF pathways may be a useful strategy for malignant PEComas.     

芩珠凉血合剂对豚鼠银屑病模型管内皮生长因子及其受体表达的影响

目的：研究芩珠凉血合剂对豚鼠银屑病模型血管内皮生长因子（VEGF）及其受体（VEGFR2）的影响,探讨其治疗寻常型银屑病的相关作用机制。方法：选择豚鼠32只,随机取8只为正常组;其余以5％心得安乳剂外涂耳部皮肤造模,使其产生银屑病样病理改变,并随机分为模型组、芩珠凉血合剂治疗组（治疗组）、复方氨肽素片对照组（对照组）,分别予蒸馏水或相应药物干预4周。检测治疗前后银屑病样皮损豚鼠血清VEGF水平、皮损组织中VEGF与VECFR2水平的变化,观察该变化与皮损表现的关系。结果：模型组豚鼠血清VEGF显著高于正常组。经药物干预治疗后,治疗组血清VEGF低于模型组和对照组,与正常组无统计学差异（P〉O．05）;而对照组与模型组无统计学意义（P〉0．05）,仍高于正常组（P〈0．05）。免疫组化切片经图像分析显示,模型组VEGF及其受体VEGFR2表达均高于其余3组。经治疗,两药物干预组豚鼠皮损处的VEGF表达仍高于正常组,且与模型组无统计学差异（P〉0．05）;但治疗组VEGFR2表达却有显著降低,与对照组和模型组有统计学差异（P〈0．05）。结论：芩珠凉血合剂能明显改善豚鼠银屑病样皮损,其作用机制可能与降低血清中VEGF水平和皮损处VEGFR2表达有关。     

Evaluating VEGFR1 genetic polymorphisms as a predisposition to AMD in a cohort from northern China

Objective: The association among genetic variants in VEGFR1 and a predisposition to age-related macular degeneration (AMD) in a northern cohort from China was evaluated.

Methods: A retrospective case-control correlation study was conducted on 432 cases and 906 gender-and ethnicity-matched controls. Whole DNA was isolated from peripheral blood samples after the individuals underwent detailed eye examinations. Eight single nucleotide polymorphisms (SNPs) in VEGFR1 genes were genotyped for all individuals using a MALDI-TOF technique. The distribution of genotypes was analyzed for Hardy-Weinberg equilibrium and the relationships among the genotype and allele frequencies with AMD were evaluated by age-adjusted logistic regression analysis. The measurement of linkage disequilibrium (LD) was carried out by Haploview 4.2. Bonferroni testing was employed to correct for multiple comparisons.

Results: Among the SNPs genotyped, p values of six SNPs were less than 0.05 between AMD cases and unaffected controls. However, after Bonferroni correction, the genotype and allele distributions of only two SNPs, rs9554322 and rs9582036 differed significantly between the controls and AMD patients. Further, the rs9554322 CC genotype conferred strong susceptibility to AMD (OR = 6.057, 95% CI: 3.099–11.839). Rs9943922 was also found to be significantly associated with AMD in the distributions for the genotype and allele recessive model (p = 0.004). The specific haplotype CA of rs9582036 and rs9554320 was associated with AMD (p = 0.035), but the correlation did not remain after correction.

Conclusions: The SNPs rs9554322, rs9582036 and rs9943922 were correlated with AMD. Gene variants in VEGFR1 were linked to a pronounced emerging risk for AMD in a population in northern China.     

链脲佐菌素诱导的小鼠糖尿病视网膜病模型及促血管新生分子的表达

目的：：建立链脲佐菌素( streptozotocin, STZ)诱导的小鼠增殖性糖尿病视网膜病( proliferative diabetic retinopathy, PDR)动物模型,并观察在增殖性糖尿病视网膜病发生、发展过程中血管内皮生长因子( vascular endothelial growth factor, VEGF)及其受体(VEGFR1, VEGFR2),金属基质蛋白酶(matrix metalloproteinase, MMP)2, MMP9表达的变化。方法：C57 BL/6 J小鼠连续5 d腹腔注射STZ (55 mg/kg )。末次注射后7d检测血糖浓度。糖尿病诱导成功的小鼠和正常小鼠继续饲养3~5 mo。实验结束后进行视网膜病理组织观察,并利用CD31免疫荧光染色检测视网膜血管的分布情况。采用实时定量荧光 PCR 分析检测 VEGF, VEGFR1, VEGFR2, MMP2, MMP9的基因表达。结果：视网膜组织病理观察和CD31免疫荧光染色实验结果均表明5月龄的糖尿病小鼠视网膜组织中血管数目明显比同月龄正常小鼠多。同时,与同月龄正常小鼠相比,5月龄糖尿病小鼠视网膜组织中 VEGF, VEGFR1, VEGFR2, MMP2, MMP9的基因表达也明显增加。结论：本研究表明STZ诱导的糖尿病小鼠在5月龄时发生