Anti-vascular Endothelial Growth Factor Receptor Research Articles

The predictive value of primary tumor location in patients with metastatic colorectal cancer: A systematic review.

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. It has been reported that left- and right-sided CRC harbor varying disease characteristics, which leads to a difference in prognosis and response to therapy. Recently, there have been retrospective studies about tumor location in metastatic CRC (mCRC) and its potential to predict the effect of anti-vascular endothelial growth factor and anti-epidermal growth factor receptor (anti-EGFR) therapies. In this review, we provide a comprehensive overview of the latest trials studying the predictive value of primary tumor location in mCRC and discuss biomarkers that might be associated with the differences in treatment response. Although data need to be interpreted with caution due to the absence of randomized trials stratified based on tumor location, patients with left-sided CRC seem to benefit more from anti-EGFR therapy than patients with right-sided CRC. Further clinical trials, stratified for tumor location, are warranted.

Imaging and Treatment of Primary Tumors and Metastases by Targeted Macrophage Therapy, Using Radiation Therapy-Directed Encapsulated Nanoparticles

Liposome-protamine-hyaluronic acid nanoparticles (LPH-NPs; 173 ± 7.2 nm in diameter) encapsulated in oxygen-rich microcapsules (3.6 ± 0.8 μm in diameter) that release their contents upon exposure to radiation were used in two radiotherapy sessions. We investigated primary tumor and metastasis imaging and macrophage-based therapy through silencing of “don’t eat me” signals and an increase in tumor-associated macrophages (TAMs) of M1 phenotype. For the first radiotherapy session, LPH-NPs, containing 5% iopamiron, and 250 nmol anti-CD47 small interfering RNA (siRNA) were mixed with 1.0 mL oxygen-rich solution (2200 ppm O2) containing 4.0% alginate, 3.0% hyaluronate, 1 mg ascorbate, and 1 μg/mL CD-40 and sprayed into 0.5 mmol/L FeCl2 supplemented with 1 μg/mL anti-vascular endothelial growth factor receptor (VEGFR)-1/2 antibody (Ab). The resultant microcapsules (1 × 1010) were intravenously (i.v.) administered into C57BL/6 mice with a primary MC38 tumor in the left hind leg and lung metastases, and their accumulation in the tumor was monitored by computed tomography (CT). Subsequently, the primary tumors and metastases were treated with 10 or 20 Gy 60Co γ-radiation. For the second session, microcapsules were generated by mixing LPH-NPs containing 200 μg anti-CD40 monoclonal Ab (moAb) and 900,000 IU interleukin (IL)-2, with the same oxygen-rich cocktail used in session one, and were sprayed into 0.5 mmol/L FeCl2 supplemented with 1 μg/mL anti-P-selectin Ab. They were then i.v. administered into the mice and allowed to interact with P-selectin for 9 h prior to a second radiotherapy with 10 or 20 Gy 60Co γ-radiation. In session one, the anti-VEGFR-1/2 microcapsules accumulated around the primary and metastatic tumors as detected by CT, and in response to the irradiation, they released anti-CD 47 siRNA LPH-NPs and oxygen-rich water, which silenced “don’t eat me” signals and increased tumor oxygen concentration, respectively. In session two, the microcapsules accumulated around the primary tumor through a P-selectin antigen-antibody reaction, and in response to the irradiation, they released anti-CD 40 moAb/IL-2 LPH-NPs and oxygen-rich water. Additionally, the radiation recruited TAMs in the tumors. The released anti-CD 40 moAb/IL-2 switched the phenotype of the recruited TAMs from M2 to M1, and the increased oxygen concentration due to the repeatedly released oxygen-rich water inhibited TAM repolarization from M1 to M2, leading to an increase in TAMs of M1 phenotype, which then attacked the tumors for which the “don’t eat me” signals were already silenced in session one. These treatments significantly increased the antitumor effect (EF 1.8) and reduced metastasis by 82.6%. Our CT-detectable microcapsules exhibited targeted macrophage therapy, improving tumor diagnosis and treatment.

A Proinflammatory Function of Toll-Like Receptor 2 in the Retinal Pigment Epithelium as a Novel Target for Reducing Choroidal Neovascularization in Age-Related Macular Degeneration

Current treatments for choroidal neovascularization, a major cause of blindness for patients with age-related macular degeneration, treat symptoms but not the underlying causes of the disease. Inflammation has been strongly implicated in the pathogenesis of choroidal neovascularization. We examined the inflammatory role of Toll-like receptor 2 (TLR2) in age-related macular degeneration. TLR2 was robustly expressed by the retinal pigment epithelium in mouse and human eyes, both normal and with macular degeneration/choroidal neovascularization. Nuclear localization of NF-κB, a major downstream target of TLR2 signaling, was detected in the retinal pigment epithelium of human eyes, particularly in eyes with advanced stages of age-related macular degeneration. TLR2 antagonism effectively suppressed initiation and growth of spontaneous choroidal neovascularization in a mouse model, and the combination of anti-TLR2 and antivascular endothelial growth factor receptor 2 yielded an additive therapeutic effect on both area and number of spontaneous choroidal neovascularization lesions. Finally, in primary human fetal retinal pigment epithelium cells, ligand binding to TLR2 induced robust expression of proinflammatory cytokines, and end products of lipid oxidation had a synergistic effect on TLR2 activation. Our data illustrate a functional role for TLR2 in the pathogenesis of choroidal neovascularization, likely by promoting inflammation of the retinal pigment epithelium, and validate TLR2 as a novel therapeutic target for reducing choroidal neovascularization.

CPEB4 immunohistochemical expression is associated to prognosis in stage IV colorectal carcinoma

The cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a RNA binding protein and translational regulator. It has been associated with tumor growth, vascularization and invasion and with tumor progression in breast, pancreas and lung carcinomas. To the best of our knowledge only one previous report has analyzed the prognostic value of CPEB4 in an experimental model of colorectal carcinoma. We have reviewed the files of patients with stage IV colorectal carcinoma metastatic to the liver. All the patients had received chemotherapy followed by hepatic metastasis resection and subsequent resection of the colon (liver-first approach). We have gathered demographic, analytical and morphological data of the primary tumors. We have performed immunohistochemical analysis of CPEB4 expression in these tumors and analyzed the potential prognostic value of this protein. 50 patients fulfilled inclusion criteria for the present study. All of them received preoperative chemotherapy based on platinum and also postoperative chemotherapy, with or without targeted drugs (18% received anti-epidermal growth factor receptor (EGFR) drugs and 24% anti-vascular endothelial growth factor receptor (VEGFR) drugs. 66% of the primaries were of sigmoid-rectal origin. CPEB4 expression was mainly cytoplasmic and it was scored as intense in 46% of the patients. Survival analysis revealed a significant association between progression free survival (PFS) and overall survival (OS) and CPEB4 immunohistochemical expression, which was independent in the multivariate analysis. CPEB4 behaves as a significant predictor of prognosis in stage IV colorectal carcinoma. The existence of CPEB4 specific inhibitors can open a new way for targeted therapy. Larger prospective studies are needed to confirm our promising results.

Pre-clinical longitudinal monitoring of hemodynamic response to anti-vascular chemotherapy by hybrid diffuse optics.

The longitudinal effect of an anti-vascular endothelial growth factor receptor 2 (VEGFR-2) antibody (DC 101) therapy on a xenografted renal cell carcinoma (RCC) mouse model was monitored using hybrid diffuse optics. Two groups of immunosuppressed male nude mice (seven treated, seven controls) were measured. Tumor microvascular blood flow, total hemoglobin concentration and blood oxygenation were investigated as potential biomarkers for the monitoring of the therapy effect twice a week and were related to the final treatment outcome. These hemodynamic biomarkers have shown a clear differentiation between two groups by day four. Moreover, we have observed that pre-treatment values and early changes in hemodynamics are highly correlated with the therapeutic outcome demonstrating the potential of diffuse optics to predict the therapy response at an early time point.

Delivery of therapeutics to posterior eye segment: cell-encapsulating systems.

Delivery of therapeutics to posterior eye segment: cell-encapsulating systems.

Ramucirumab combined with FOLFOX as front-line therapy for advanced esophageal, gastroesophageal junction, or gastric adenocarcinoma: a randomized, double-blind, multicenter Phase II trial

We report the first randomized, Phase II trial of ramucirumab, an anti-vascular endothelial growth factor receptor-2 monoclonal antibody, as front-line therapy in patients with advanced adenocarcinoma of the esophagus or gastric/gastroesophageal junction (GEJ). Patients from the USA with advanced esophageal, gastric, or GEJ adenocarcinoma randomly received (1:1) mFOLFOX6 plus ramucirumab (8 mg/kg) or mFOLFOX6 plus placebo every 2 weeks. The primary end point was progression-free survival (PFS) with 80% power to detect a hazard ratio (HR) of 0.71 (one-sided α = 0.15). Secondary end points included evaluation of response and overall survival (OS); an exploratory ramucirumab exposure-response analysis was undertaken. Of 168 randomized patients, 52% of tumors were located in the stomach/GEJ and 48% in the esophagus. The trial did not meet the primary end point of PFS [6.4 versus 6.7 months, HR 0.98 (95% confidence interval 0.69-1.37)] or the secondary end point of OS (11.7 versus 11.5 months) in the intent-to-treat (ITT) population. Objective response rates (45.2% versus 46.4%) were similar between arms. Most Grade ≥3 toxicities did not differ significantly between arms, yet premature discontinuation of FOLFOX and ramucirumab (for reasons other than progressive disease) was more common among ramucirumab- versus placebo-treated patients. In an exploratory analysis that censored for premature discontinuation, the HR for PFS favored the ramucirumab arm (HR 0.76), particularly in patients with gastric/GEJ cancer. An exploratory exposure-response analysis indicated that patients with higher ramucirumab exposure had longer OS. The addition of ramucirumab to front-line mFOLFOX6 did not improve PFS in the ITT population. NCT01246960.

Adverse events risk associated with anti-VEGFR agents in the treatment of advanced nonsmall-cell lung cancer: A meta-analysis.

To perform this meta-analysis, we investigated the risk of the most clinically relevant adverse events related to antivascular endothelial growth factor receptor (VEGFR) agents in advanced nonsmall-cell lung cancer (NSCLC).A comprehensive literature search for studies published up to October 2015 was performed. Prospective randomized controlled phase II/III clinical trials that comparing therapy with or without anti-VEGFR agents for advanced NSCLC were included for analysis. Summary relative risk (RR) and 95% confidence intervals (CIs) were calculated using random effects or fixed effects according to the heterogeneity among included trials.A total of 11,701 patients from 18 clinical trials were included for analysis. Pooled RR showed that the use of anti-VEGFR agents significantly increased the risk of developing hypertension (RR 4.71, 95% CI 3.29-6.73, P < 0.001) and fatal adverse events (RR 1.33, 95% CI 1.12-1.58, P = 0.001). No statistically significant differences were found for gastrointestinal (GI) perforation (P = 0.41), arterial or venous thromboembolic events (P = 0.49 and P = 0.16, respectively), or hemorrhagic events (P = 0.81). Sensitive analysis indicated that the significance estimate of pooled RR of fatal adverse event (FAEs) was not significantly influenced by omitting any single study.The use of anti-VEGFR agents in advanced NSCLC does significantly increase the risk of hypertension and fatal adverse events, but not for arterial or venous thromboembolic events, GI perforation, or hemorrhagic events.

Ramucirumab combined with FOLFOX as front-line therapy for advanced esophageal, gastroesophageal junction, or gastric adenocarcinoma: a randomized, double-blind, multicenter Phase II trial.

ABSTRACT This phase II trial examined the addition of ramucirumab, a vascular endothelial growth factor receptor-2 monoclonal antibody, to mFOLFOX6 as front-line therapy for patients with advanced gastric/GEJ or esophageal adenocarcinoma. A survival benefit was not observed in the ITT population, but an exploratory analysis suggested a potential benefit for ramucirumab in the gastric/GEJ cancer subgroup. Background We report the first randomized, Phase II trial of ramucirumab, an anti-vascular endothelial growth factor receptor-2 monoclonal antibody, as front-line therapy in patients with advanced adenocarcinoma of the esophagus or gastric/gastroesophageal junction (GEJ). Patients and methods Patients from the USA with advanced esophageal, gastric, or GEJ adenocarcinoma randomly received (1:1) mFOLFOX6 plus ramucirumab (8 mg/kg) or mFOLFOX6 plus placebo every 2 weeks. The primary end point was progression-free survival (PFS) with 80% power to detect a hazard ratio (HR) of 0.71 (one-sided α = 0.15). Secondary end points included evaluation of response and overall survival (OS); an exploratory ramucirumab exposure–response analysis was undertaken. Results Of 168 randomized patients, 52% of tumors were located in the stomach/GEJ and 48% in the esophagus. The trial did not meet the primary end point of PFS [6.4 versus 6.7 months, HR 0.98 (95% confidence interval 0.69–1.37)] or the secondary end point of OS (11.7 versus 11.5 months) in the intent-to-treat (ITT) population. Objective response rates (45.2% versus 46.4%) were similar between arms. Most Grade ≥3 toxicities did not differ significantly between arms, yet premature discontinuation of FOLFOX and ramucirumab (for reasons other than progressive disease) was more common among ramucirumab- versus placebo-treated patients. In an exploratory analysis that censored for premature discontinuation, the HR for PFS favored the ramucirumab arm (HR 0.76), particularly in patients with gastric/GEJ cancer. An exploratory exposure–response analysis indicated that patients with higher ramucirumab exposure had longer OS. Conclusion The addition of ramucirumab to front-line mFOLFOX6 did not improve PFS in the ITT population. Clinicaltrials.gov identifier NCT01246960.

Chemotherapy for advanced gastric cancer: future perspective in Japan.

Differences in clinical outcomes between advanced gastric cancer (AGC) in Asia and that in other regions have been discussed for a long time, although no major significant differences in molecular profiles have been reported. The anti-human epidermal growth factor receptor2 antibody trastuzumab and the anti-vascular endothelial growth factor receptor2 monoclonal antibody ramucirumab were both approved as a treatment for AGC on the basis of global phase3 trials including Japan. In recent years, others new agents for treatment of AGC have been investigated in global or Asian studies. Randomized phase2 trials in Japan showed a higher response rate to S-1 plus leucovorin and oxaliplatin than to standard S-1 plus cisplatin, which is the rationale for an ongoing phase3 trial in Asia (SOLAR trial). A recent global phase1 trial of the anti-programmed cell death1 monoclonal antibody pembrolizumab showed similar efficacy results in Asian patients and non-Asian patients, which led to large global phase2 and phase3 studies. Although the perspective of treatment of AGC in the near future depends on the results of ongoing large clinical trials, individualized choice of treatment based on more detailed molecular information will become important.

Advances in Systemic Therapy for Metastatic or Advanced Gastric Cancer.

In recent years, various new agents have been investigated for the treatment of advanced gastric cancer (AGC). The anti-HER2 antibody trastuzumab has been shown to prolong the overall survival of patients with HER2-positive AGC and has become a standard treatment. However, lapatinib, or ado-trastuzumab emtansine (T-DM1), did not show survival benefit in AGC, although it has shown remarkable efficacy for HER2-positive breast cancer. The efficacy of the anti-vascular endothelial growth factor receptor monoclonal antibody ramucirumab for pretreated gastric cancer is a milestone for antiangiogenic therapy for AGC. Early clinical trials of TAS-118, TAS-102, and STAT3 inhibitors; IMAB362 (anti-Claudin 18.2); and immune checkpoint inhibitors are all encouraging. These findings warrant further evaluation in larger clinical trials.

Abstract 4195: Targeting the immune microenvironment to improve colorectal cancer anti-angiogenic therapy

Abstract Colorectal cancer (CRC) is the leading cause of cancer-related death worldwide. Anti-angiogenic therapy with bevacizumab has been proven efficacious in metastatic CRC. However, the improvement in overall survival has been modest and rather disappointing. Thus, there is an urgent need to identify the underlying mechanisms responsible for the resistance to anti-angiogenic therapy and develop strategies to overcome it. Clinical and preclinical interest in tumor immunotherapy has been renewed in a significant manner recently. However, the role of the immune microenvironment in colorectal cancer resistance to anti-angiogenic therapy is not well understood. We have developed miniaturized confocal endomicroscopy technique for spontaneous CRC models in mice. We also established a novel cecum window recently. These unique systems enable us to monitor the CRC and its immune microenvironment longitudinally with a video-rate intravital multi-photon microscope. Using these CRC models and in vivo imaging methods, we found that anti-vascular endothelial growth factor receptor 2 (VEGFR2) antibody increases infiltration of Gr1+ myeloid-derived suppressor cells (MDSCs) and they alter the tumor microenvironment toward an immune-suppressive condition to avoid attack of the host immune system. We also found that the Gr1+ MDSCs express CXCR4, which has important roles in cell-autonomous survival and chemotaxis, through its downstream signaling pathways. When we treat the VEGF signaling blocker together with a CXCR4-specific inhibitor, the level of the Gr1+ MDSC infiltration is dramatically decreased nearly to that of control group, and subsequently, tumor growth is significantly delayed compared to separate treatment of each inhibitor. Taken together, we identified Gr1+ MDSCs as key players in tumor resistance to anti-angiogenic therapy in CRCs, and the blockade of CXCR4 signaling has a synergistic effect with anti-VEGF therapy, proven by state-of-the-art in vivo imaging modalities. Citation Format: Keehoon Jung, Takahiro Heishi, Andy Yun, Timothy P. Padera, Rakesh K. Jain, Dai Fukumura. Targeting the immune microenvironment to improve colorectal cancer anti-angiogenic therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4195.

Chemotherapy plus targeted drugs in conversion therapy for potentially resectable colorectal liver metastases: a meta-analysis.

ObjectivesTo evaluate the safety and efficiency of the conversion therapy : chemotherapy plus anti-epidermal growth factor Receptor (EGFR) or anti-vascular endothelial growth factor receptor (VEGFR) monoclonal antibodies (MoAbs) with different rat sarcoma (RAS) status in patients with potentially resectable colorectal liver metastases (CRLM).MethodsRandomized controlled trials (RCTs) were identified and the association between RAS mutation and clinical outcome in CRLM patients treated with anti-EGFR or anti-VEGFR MoAbs was investigated. Searches were performed for data recorded between January 2005 and August 2015 in the Cochrane Library, MEDLINE, PubMed, and EMBASE. Objective response rates (ORR), conversion resection rates (CRR), R0 resection rates (R0R) and rate ratios (RR) were used to assess the strength of the association between different RAS status, MoAbs and conversion efficiency.ResultsIn the conversion therapy, ORR and RR were associated with patients with wild type RAS and different MoAbs. Patients treated with MoAbs: anti-VEGFR or anti-EGFR drugs, resulted in higher ORR, (RR=1.53, 95% confidence interval [CI]: 1.27-1.84, P < 0.05). Furthermore, anti-EGFR regimens displayed higher ORR compared with anti-VEGFR regimens in CRLM patients, (RR=1.15, 95%CI: 1.04-1.26, P < 0.05). However, CRLM patients with mutant type RAS did not benefit from anti-EGFR therapy, (RR=0.91, 95%CI: 0.76-1.08, P<0.05) and wild type RAS patients displayed higher ORR with anti-EGFR therapy, (RR=1.56, 95%CI: 1.16-2.01, P <0.05). In addition, the patients achieved higher resection rates (RR=1.67, 95%CI: 1.00-2.81, P ≤ 0.05) and R0 resection (RR=1.85, 95%CI: 1.04-3.27, P < 0.05).ConclusionWe noted that the addition of MoAbs (anti-EGFR or anti-VEGFR) to standard chemotherapy could improve conversion efficiency for patients with potentially resectable CRLM patients, and anti-EGFR therapies maybe more effective than anti-VEGFR therapies. RAS status is a potential predictive marker of the clinical benefit resulting from treatment with anti-EGFR MoAbs therapy in CRLM patients and anti-EGFR MoAbs therapy could displayed greater efficiency only in patients with wild type RAS.

Single-Agent Therapies After Standard Combination Regimens.

Increasingly prolonged survival in metastatic colorectal cancer has paralleled the approval of new agents alone and in combination. Most recently, several new agents have sought approval in the heavily pretreated setting, after treatment with standard chemotherapies, alone and in combination, and with anti-vascular endothelial growth factor receptor and anti-epidermal growth factor receptor (for patients with RAS wild-type tumors). These agents have included the multitargeted tyrosine kinase inhibitor (TKI), regorafenib, and the novel antimetabolite combination, TAS-102. Both of these showed improvement in progression-free survival and overall survival compared with placebo controls and were approved in the United States and the rest of the world. Benefits of treatment and toxicities are discussed. Nintedanib, another multitargeted TKI, is already approved by the European Medicines Evaluation Agency for non-small cell lung cancer and has been studied in a similar phase III trial. Results are pending. The risks and benefits of each agent are discussed.

The ATOM trial: A multicenter, randomized phase II study of modified FOLFOX6 plus bevacizumab and modified FOLFOX6 plus cetuximab for colorectal cancer with liver-limited metastases.

TPS777 Background: It remains unresolved which antibody, anti-vascular endothelial growth factor or anti-epidermal growth factor receptor antibody, is the best targeted agent to combine with chemotherapy for patients having liver-limited metastases of KRAS Exon 2 or RAS wild-type colorectal cancer. Methods: The ATOM trial is a Japanese multicenter, randomized phase II study comparing modified FOLFOX6 plus bevacizumab with modified FOLFOX6 plus cetuximab in patients with unsuitable liver metastases for resection (5 or more liver metastatic lesions and/or maximum tumor diameter &gt; 5cm). Patients are enrolled and randomly assigned to receive either treatment in 1:1 ratio from May 2013 to April 2016. Stratification factors for randomization are synchronous or metachronous liver metastases, number (1–4 or ≥ 5) and size ( ≤ 5 cm or &gt; 5 cm) of metastatic lesions, and adjuvant chemotherapy with or without oxaliplatin-containing regimen. All patients are to be followed up to March 2017. Primary endpoint is progression-free survival (PFS). We employed a selection design based on hazard ratios. Planned sample size is 120 patients with 84 estimated PFS events based on the hypothesis to select the superior treatment with the 75.0 % selection probability if the difference of both treatments is a 1-year PFS rate of 5% and the inferior treatment has a 1-year PFS rate of 50%. Secondary endpoints are response rate, tumor shrinkage at week 8, liver resection rate, time to treatment failure, overall survival, quality of life, and adverse events. Exploratory endpoints include pathologic and morphologic assessments, which will be investigated in collaboration with radiologists and pathologists. The plasma factors relating to tumor angiogenesis are assessed sequentially to explore the association with treatment efficacies. As of Aug 20th 2015, 102 patients were enrolled. The results from this trial will show which targeted agents should be used to treat liver-limited diseases from colorectal cancer with WT RAS tumor. Clinical trial information: NCT01836653.

Targeted therapies for treatment of non-small cell lung cancer--Recent advances and future perspectives.

Non-small cell lung cancer (NSCLC) is one of the most deadly cancers worldwide, with poor prognosis once the disease has progressed past the point at which surgery is a viable option. Whilst chemotherapy has improved survival over recent decades, there is still great need for improvements in treatments for patients with advanced disease. Over the last decade, a variety of such drugs have received market approval for treating NSCLC, with a variety of others in the pipeline. Here, we review the development of targeted therapies for the treatment of advanced or metastatic NSCLC, including those already in clinical practice and those in early trials. The epidermal growth factor receptor (EGFR) inhibitors, gefitinib, erlotinib and afatinib; the anaplastic lymphoma kinase (ALK) inhibitor, crizotinib; and the anti-vascular endothelial growth factor receptor monoclonal antibody, bevacizumab, are already providing improved survival for patients with NSCLC. Moreover, the discovery of EGFR mutations and ALK rearrangements has enabled the identification of patients who are more likely to benefit from a specific drug. The recent approval of the immune checkpoint inhibitor nivolumab, along with the designation of alectinib and MPDL3280A as breakthrough therapies by the FDA, demonstrates how rapidly this area of research is expanding. Over the last decade there has been significant progress made in the treatment of advanced NSCLC, and the large and varied selection of drugs currently undergoing trials provide great promise for improving the prognosis of this highly prevalent and deadly form of cancer.

Multistage Nanovectors Enhance the Delivery of Free and Encapsulated Drugs.

Nanoparticles have considerable potential for cancer imaging and therapy due to their small size and prolonged circulation. However, biological barriers can impede the delivery of a sufficient dose of a drug to the target site, thereby also resulting in the accumulation of toxic compounds within healthy tissues, and systemic toxicity. Multistage nanovectors (MSV) preferentially accumulate on inflamed endothelium, and can thus serve as carriers for drugs and nanoparticles. Herein, we describe the loading of free (i.e., melittin) and nano-encapsulated (i.e., doxorubicin-loaded micelles) drugs into MSV, and report the impact of surface charge and pore size on drug loading. For both drug formulations, negatively charged MSV (i.e., oxidized) with larger pores were shown to retain higher concentrations of payloads compared to positively charged (i.e., APTES-modified) MSV with small pores. Treatment of human umbilical vein endothelial cells (HUVEC) with melittin-loaded MSV (MEL@MSV) resulted in an 80% reduction in cell viability after 3 days. Furthermore, MEL@MSV conjugated with antivascular endothelial growth factor receptor 2 (VEGFR2) antibodies displayed preferential targeting and delivery of MEL to activated HUVEC expressing VEGFR2. Treatment of HUVEC and MCF7 cells with doxorubicin-loaded micelles (DOXNP@MSV) resulted in a 23% and 47% reduction in cell viability, respectively. Taken together, these results demonstrate increased loading of a payload in oxidized, large pore MSV, and effective delivery of free and nano-encapsulated drugs to endothelial and cancer cells.

Prognostic factors in second-line targeted therapy for metastatic clear-cell renal cell carcinoma after progression on an anti-vascular endothelial growth factor receptor tyrosine kinase inhibitor

Background: About 40% of metastatic clear-cell renal cell carcinoma (m-ccRCC) patients receive a second-line targeted therapy after failure of anti-vascular endothelial growth factor receptor tyrosine kinase inhibitors (anti-VEGFR-TKI). Efficacy of second-line therapy is usually limited and prognostic and predictive factors at the start of second-line therapy are lacking. To identify the subgroup of patients that will benefit from such treatment remains a challenge.Methods: We performed a multi-institutional, retrospective study of patients who received a second-line therapy after progression on an anti-VEGFR-TKI. Univariate and multivariate analyses were performed in order to identify prognostic factors for progressive disease (PD) as best response, progression-free survival (PFS) and overall survival (OS) on second-line therapy.Results: For the whole cohort of 108 patients, mOS from the start of second-line therapy was 8.9 months while mPFS on second-line therapy was 2.8 months. A total of 49/105 (47%) patients had PD, 50/105 (48%) stable disease (SD) and 6/105 (6%) a partial response (PR). On multivariate analysis, the following markers were associated with improved outcome on second-line therapy: a PFS on first-line therapy ≥12 months (HR for PFS: 1.961; p = 0.008) (HR for OS: 1.724; p = 0.037) and Fuhrman grade 1–2 tumors (HR for OS: 2.198; p = 0.007). Markers associated with poorer outcome on second-line therapy were: elevated serum lactate dehydrogenase (LDH) levels (HR for PFS: 0.511; p = 0.04) (HR for OS: 0.392; p = 0.017), low albumin (HR for OS: 0.392; p = 0.01) and elevated corrected calcium levels (HR for OS: 0.416; p = 0.01). The impact on OS of the Memorial Sloan Kettering Cancer Centre (MSKCC) and International Renal Cell Carcinoma Database Consortium (IMDC) prognostic scores as calculated at start of second-line therapy was validated in our patient series.Conclusions: Duration of first-line PFS, Fuhrman grade, serum LDH levels, albumin levels, corrected calcium levels and the MSKCC and IMDC scores calculated at start of second-line therapy are prognostic factors for m-ccRCC patients treated with second-line targeted therapy.

Update on Anti-Angiogenesis Therapy in Colorectal Cancer.

Angiogenesis is a complex biologic process critical to growth and proliferation of colorectal cancer. The safety and efficacy of various anti-angiogenic agents have been investigated in many treatment settings. Bevacizumab, an anti-vascular endothelial growth factor agent, has efficacy in both the first-line setting and beyond progression in metastatic colorectal cancer. The decoy vascular endothelial growth factor receptor aflibercept has been approved in combination with 5-fluorouracil, leucovorin and irinotecan-based chemotherapy in metastatic colorectal cancer patients whose disease has progressed on a prior oxaliplatin-based chemotherapy regimen. The multikinase inhibitor regorafenib is modestly effective in the refractory colorectal cancer setting but confers significant toxicity. Ramucirumab, an anti-vascular endothelial growth factor receptor 2 molecule, has efficacy in combination with 5-fluorouracil, leucovorin and irinotecan after disease progression on a first-line bevacizumab-, oxaliplatin- and fluoropyrimidine-containing regimen. Questions regarding optimal treatment setting, predictive biomarkers of response, and cost effectiveness of these anti-angiogenic agents and others are as yet unanswered.

Squamous Cell Carcinoma Xenografts: Use of VEGFR2-targeted Microbubbles for Combined Functional and Molecular US to Monitor Antiangiogenic Therapy Effects.

To assess the ability of vascular endothelial growth factor receptor type 2 (VEGFR2)-targeted and nontargeted ultrasonography (US) to depict antiangiogenic therapy effects and to investigate whether first-pass kinetics obtained with VEGFR2-targeted microbubbles provide independent data about tumor vascularization. Governmental approval was obtained for animal experiments. Vascularization in response to anti-vascular endothelial growth factor receptor or vehicle-control treatment (10 per group) in HaCaT-ras A-5RT3 xenografts was longitudinally assessed in mice by means of first-pass kinetics of nontargeted microbubbles (BR1, BR38; Bracco, Geneva, Switzerland) and VEGFR2-targeted microbubbles (BR55, Bracco) before and 4, 7, and 14 days after therapy. VEGFR2 expression was determined 8 minutes after BR55 injection with destruction-replenishment analysis. US data were validated with immunohistochemistry. Significant differences were evaluated with the Mann-Whitney test. First-pass analysis with BR1, BR38, and BR55 showed similar tendencies toward decreasing vascularization, with a stronger decrease in tumors treated with anti-VEGF antibody. The median signal intensity (in arbitrary units [au]) of anti-VEGF antibody-treated versus control tumors at day 14 was as follows: BR1, 5.2 au (interquartile range [IQR], 3.2 au) vs 11.3 au (IQR, 10.0 au), respectively; BR38, 6.2 au (IQR, 3.5) vs 10.0 au (IQR, 7.8); and BR55, 9.5 au (IQR, 6.0 au) vs 13.8 au (IQR, 9.8) (P = .0230). VEGFR2 assessment with BR55 demonstrated significant differences between both groups throughout the therapy period (median signal intensity of anti-VEGF antibody-treated vs control tumors: 0.04 au [IQR, 0.1 au] vs 0.14 au [IQR, 0.08 au], respectively, at day 4, P = .0058; 0.04 au [IQR, 0.06 au] vs 0.13 au [IQR, 0.09 au] at day 7, P = .0058; and 0.06 au [IQR, 0.11 au] vs 0.16 au [IQR, 0.15 au] at day 14, P = .0247). Immunohistochemistry confirmed the lower microvessel density and VEGFR2-positive area fraction in tumors treated with anti-VEGF antibody. Antiangiogenic therapy effects were detected earlier and more distinctly with VEGFR2-targeted US than with functional US. First-pass analyses with BR55, BR38, and BR1 revealed similar results, with a decrease in vascularization during therapy. Functional data showed that BR55 is not strongly affected by early binding of the microbubbles to VEGFR2. Thus, functional and molecular imaging of angiogenesis can be performed with BR55 within one examination.