Aflibercept in the treatment of metastatic colorectal cancer

VEGF signaling: Role in angiogenesis and beyond

Angiogenesis is a crucial process for tissue development, repair, and tumor survival. Vascular endothelial growth factor (VEGF) is a key driver secreted by cancer cells, promoting neovascularization. While VEGF's role in angiogenesis is well-documented, its influence on the other aspects in tumor microenvironemt is less discussed. This review elaborates on VEGF's impact on intercellular interactions within the tumor microenvironment, including how VEGF affects pericyte proliferation and migration and mediates interactions between tumor-associated macrophages and cancer cells, resulting in PDL-1-mediated immunosuppression and Nrf2-mediated epithelial-mesenchymal transition. The review discusses VEGF's involvement in intra-organelle crosstalk, tumor metabolism, stemness, and epithelial-mesenchymal transition. It also provides insights into current anti-VEGF therapies and their limitations in cancer treatment. Overall, this review aims to provide a thorough overview of the current state of knowledge concerning VEGF signaling and its impact, not only on angiogenesis but also on various other oncogenic processes.

Update on Targeted Therapy and Immunotherapy for Metastatic Colorectal Cancer

Metastatic colorectal cancer remains a deadly malignancy and is the third leading cause of cancer-related death. The mainstay of treatment for metastatic colorectal cancer is chemotherapy, but unfortunately, even with recent progress, overall survival is still poor. Colorectal cancer is a heterogeneous disease, and the underlying genetic differences among tumors can define the behavior and prognosis of the disease. Given the limitations of cytotoxic chemotherapy, research has focused on developing targeted therapy based on molecular subtyping. Since the early 2000s, multiple targeted therapies have demonstrated efficacy in treating metastatic colorectal cancer and have received FDA approval. The epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and DNA mismatch repair pathways have demonstrated promising results for targeted therapies. As new gene mutations and proteins involved in the oncogenesis of metastatic colorectal cancer are identified, new targets will continue to emerge. We herein provide a summary of the updated literature regarding targeted therapies for patients with mCRC.

A review on emerging targeted therapies for the management of metastatic colorectal cancers

Colorectal cancers are among the most commonly found cancers over the world. In spite of the recent advancements in diagnosis and prognosis, the management of this metastatic condition remains a challenge. The utility of monoclonal antibodies in the healing of patients with colorectal cancer has opened a new chapter in the quest for newer therapies. The resistance to the standard treatment regimen made it mandatory to search for newer targets. Mutagenic alterations in the gene engaged in cellular differentiation and growth pathway have been the reason for resistance to treatment. The newer therapies target the various proteins and receptors involved in the signal transduction and down streaming pathways leading to cell proliferation. This review presents an insight into the newer targeted therapies for colorectal cancer involving tyrosine kinase blockers, epidermal growth factor receptors, vascular endothelial growth factor, immune checkpoint therapy, and BRAF inhibitors.

Advances of research of Fc-fusion protein that activate NK cells for tumor immunotherapy

The rapid development of bioengineering technology has introduced Fc-fusion proteins, representing a novel kind of recombinant protein, as promising biopharmaceutical products in tumor therapy. Numerous related anti-tumor Fc-fusion proteins have been investigated and are in different stages of development. Fc-fusion proteins are constructed by fusing the Fc-region of the antibody with functional proteins or peptides. They retain the bioactivity of the latter and partial properties of the former. This structural and functional advantage makes Fc-fusion proteins an effective tool in tumor immunotherapy, especially for the recruitment and activation of natural killer (NK) cells, which play a critical role in tumor immunotherapy. Even though tumor cells have developed mechanisms to circumvent the cytotoxic effect of NK cells or induce defective NK cells, Fc-fusion proteins have been proven to effectively activate NK cells to kill tumor cells in different ways, such as antibody-dependent cell-mediated cytotoxicity (ADCC), activate NK cells in different ways in order to promote killing of tumor cells. In this review, we focus on NK cell-based immunity for cancers and current research progress of the Fc-fusion proteins for anti-tumor therapy by activating NK cells.

Efficacy and safety of aflibercept plus chemotherapy in metastatic colorectal cancer: A systematic review and PRISMA-Compliant single-arm Meta-Analysis of noncomparative clinical studies and randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Aflibercept, a recombinant protein designed to suppress the vascular endothelial growth factor (VEGF) signalling pathway, has been used in patients with metastatic colorectal cancer (mCRC). We conducted the first meta-analysis to systematically review the efficacy and safety of aflibercept in mCRC.

METHODS

PubMed Central/Medline, Embase and cochrane library were systematically searched for randomized controlled trials and single-arm clinical trials on aflibercept plus chemotherapy for the treatment of mCRC through 9 September 2021.

RESULTS

Ten studies comprising 2049 patients met the inclusion criteria. The pooled estimate rates were 16.0% for 12mPFS, 64.4% for 12mOS, 32.5% for ORR, 83.5% for DCR, while the rates of III/IV AEs rate were 80.2% respectively. The pooled estimate rates were 16.8% for III/IV diarrhoea, 22.3% for III/IV hypertension, 29.5% for III/IV neutropenia, 7.3% for III/IV proteinuria and 8.6% for III/IV oral mucositis.

CONCLUSIONS

Analysis of data from randomized controlled trials(RCT) and single-arm clinical trials confirmed the good efficacy of aflibercept plus chemotherapy in mCRC, while the safety of the treatment is concerning.

KSI-301: antibody biopolymer conjugate in retinal disorders

KSI-301 is a new intravitreal anti-vascular endothelial growth factor (VEGF) antibody biopolymer conjugate under investigation for the treatment of age-related macular degeneration (AMD), diabetic macular oedema (DME) and retinal vein occlusion (RVO). Preclinical and early clinical trials so far have shown promising results in retinal vascular diseases. When using anti-VEGF agents for treatment of retinal disorders, the frequency of injections and follow-up visits has increased the treatment burden, greatly affecting the treatment outcome. There are new anti-VEGF agents in the horizon with extended duration of action, durability, safety profile and efficacy, which seem to address the above issues. PubMed search and Medline search were performed on newer anti-VEGF agents, KSI-301, antibody biopolymer conjugate in retina, KODIAK KSI-301, DAZZLE study, GLEAM study, GLIMMER study, GLOW study and BEACON study. This review article showcases the biophysical properties and ongoing trials related to KSI-301. Moreover, we discuss the efficacy and safety profile of KSI-301 on the basis of the results of available trials.

Network analysis and the impact of Aflibercept on specific mediators of angiogenesis in HUVEC cells

Angiogenesis, inflammation and endothelial cells’ migration and proliferation exert fundamental roles in different diseases. However, more studies are needed to identify key proteins and pathways involved in these processes. Aflibercept has received the approval of the US Food and Drug Administration (FDA) for the treatment of wet AMD and colorectal cancer. Moreover, the effect of Aflibercept on VEGFR2 downstream signalling pathways has not been investigated yet. Here, we integrated text mining data, protein‐protein interaction networks and multi‐experiment microarray data to specify candidate genes that are involved in VEGFA/VEGFR2 signalling pathways. Network analysis of candidate genes determined the importance of the nominated genes via different centrality parameters. Thereupon, several genes—with the highest centrality indexes—were recruited to investigate the impact of Aflibercept on their expression pattern in HUVEC cells. Real‐time PCR was performed, and relative expression of the specific genes revealed that Aflibercept modulated angiogenic process by VEGF/PI3KA/AKT/mTOR axis, invasion by MMP14/MMP9 axis and inflammation‐related angiogenesis by IL‐6‐STAT3 axis. Data showed Aflibercept simultaneously affected these processes and determined the nominated axes that had been affected by the drug. Furthermore, integrating the results of Aflibercept on expression of candidate genes with the current network analysis suggested that resistance against the Aflibercept effect is a plausible process in HUVEC cells.

Hyaluronic acid-doxorubicin nanoparticles for targeted treatment of colorectal cancer

Colorectal cancer, common in both men and women, occurs when tumors form in the linings of the colon. Common treatments of colorectal cancer include surgery, chemotherapy, and radiation therapy; however, many colorectal cancer treatments often damage healthy tissues and cells, inducing severe side effects. Conventional chemotherapeutic agents such as doxorubicin (Dox) can be potentially used for the treatment of colorectal cancer; however, they suffer from limited targeting and lack of selectivity. Here, we report that doxorubicin complexed to hyaluronic acid (HA) (HA-Dox) exhibits an unusual behavior of high accumulation in the intestines for at least 24 hr when injected intravenously. Intravenous administrations of HA-Dox effectively preserved the mucosal epithelial intestinal integrity in a chemical induced colon cancer model in mice. Moreover, treatment with HA-Dox decreased the expression of intestinal apoptotic and inflammatory markers. The results suggest that HA-Dox could effectively inhibit the development of colorectal cancer in a safe manner, which potentially be used a promising therapeutic option.

The role of PIGF blockade in the treatment of colorectal cancer: overcoming the pitfalls

Introduction: In colorectal cancer, anti-VEGF agents have demonstrated a survival benefit when combined with chemotherapy. However, development of resistance is very common. One of the mechanisms is due not to a failure in the VEGFR blockade, but rather to development of compensatory mechanisms of resistance, such as hypoxia-triggered upregulation of other proangiogenic factors, like placental growth factor (PlGF).Areas covered: This article summarizes the fundamental role of PlGF in the development of resistance to antiangiogenic treatment as well as the efficacy of aflibercept, ramucirumab, and regorafenib.Expert opinion: Aflibercept functions as a soluble decoy receptor precluding VEGFs and PlGF from binding to native VEGFR, and therefore preventing the emergence of resistance. Bevacizumab limits its function to preventing the interaction between VEGF-A and VEGFR. In combination with FOLFIRI (VELOUR trial), aflibercept improves survival in patients with metastatic CRC who are resistant or have progressed to oxaliplatin-based chemotherapy. Ramucirumab, a fully humanized immunoglobulin G1 (IgG-1) monoclonal antibody and regorafenib, a multikinase inhibitor, have significant improvement for overall survival as well as for progression-free survival in chemotherapy refractory settings.

Overview of Antibody Drug Delivery

Monoclonal antibodies (mAbs) are one of the most important classes of therapeutic proteins, which are used to treat a wide number of diseases (e.g., oncology, inflammation and autoimmune diseases). Monoclonal antibody technologies are continuing to evolve to develop medicines with increasingly improved safety profiles, with the identification of new drug targets being one key barrier for new antibody development. There are many opportunities for developing antibody formulations for better patient compliance, cost savings and lifecycle management, e.g., subcutaneous formulations. However, mAb-based medicines also have limitations that impact their clinical use; the most prominent challenges are their short pharmacokinetic properties and stability issues during manufacturing, transport and storage that can lead to aggregation and protein denaturation. The development of long acting protein formulations must maintain protein stability and be able to deliver a large enough dose over a prolonged period. Many strategies are being pursued to improve the formulation and dosage forms of antibodies to improve efficacy and to increase the range of applications for the clinical use of mAbs.

Efficacy of Subconjunctival Aflibercept Versus Bevacizumab for Prevention of Corneal Neovascularization in a Rat Model

PURPOSE

We aimed to evaluate the efficacy of subconjunctival aflibercept, a vascular endothelial growth factor trap compound, for the treatment of corneal neovascularization in a rat model.

METHODS

Chemical burn was produced in the central cornea of 31 male Sprague-Dawley rats. Animals were randomized to receive treatment with subconjunctival injection of 0.08 mL aflibercept (25 mg/mL), 0.05 mL bevacizumab (25 mg/mL), or 0.05 mL physiologic saline. Corneal neovascularization was evaluated on postinjury days 1, 3, 7, 9, and 13 by corneal photographs. The rats were killed on day 21 and samples were collected for histological and flat-mount immunofluorescence analyses.

RESULTS

In all rats, vascular sprouting began on day 3, reached maximum density on days 7-9, and spontaneously regressed thereafter. Mean burn area in the central cornea comprised ∼15% of the total corneal area. The aflibercept group had a significantly smaller relative area of neovascularization than both control group (P < 0.05, 12.27 ± 9.91, 29.66 ± 9.96 days 7) and bevacizumab group (P < 0.05, 12.27 ± 9.91, 21.27 ± 8.19 days 7 and 15.5 ± 10.25, 32.38 ± 9.44 days 9; Mann-Whitney test). On histological study, hematoxylin and eosin staining revealed blood vessels extending to the central cornea in the control and bevacizumab groups and limited to the periphery in the aflibercept group. Immunofluorescence study with an endothelial marker revealed a smaller area of staining in the aflibercept group.

CONCLUSIONS

Aflibercept effectively inhibits corneal neovascularization in a rat model of chemical burn-induced neovascularization and warrants further study for potential use in humans.

Examination of the foreign body response to biomaterials by nonlinear intravital microscopy

Implanted biomaterials often fail because they elicit a foreign body response (FBR) and concomitant fibrotic encapsulation. To design clinically relevant interference approaches, it is crucial to first examine the FBR mechanisms. Here, we report the development and validation of infrared-excited nonlinear microscopy to resolve the three-dimensional (3D) organization and fate of 3D-electrospun scaffolds implanted deep into the skin of mice, and the following step-wise FBR process. We observed that immigrating myeloid cells (predominantly macrophages of the M1 type) engaged and became immobilized along the scaffold/tissue interface, before forming multinucleated giant cells. Both macrophages and giant cells locally produced vascular endothelial growth factor (VEGF), which initiated and maintained an immature neovessel network, followed by formation of a dense collagen capsule 2-4 weeks post-implantation. Elimination of the macrophage/giant-cell compartment by clodronate and/or neutralization of VEGF by VEGF Trap significantly diminished giant-cell accumulation, neovascularization and fibrosis. Our findings identify macrophages and giant cells as incendiaries of the fibrotic encapsulation of engrafted biomaterials via VEGF release and neovascularization, and therefore as targets for therapy.

Use of non-invasive imaging to monitor response to aflibercept treatment in murine models of colorectal cancer liver metastases

The liver is the most frequent metastatic site in colorectal cancer (CRC), and relevant orthotopic in vivo models are needed to study the efficacy of anticancer drugs in the metastatic setting. A challenge when utilizing such models is monitoring tumor growth during the experiments. In this study, experimental liver metastases were established in nude mice by splenic injection of the CRC cell lines HT29 and HCT116, and the mice were treated with the antiangiogenic drug aflibercept. Tumor growth was monitored using magnetic resonance imaging (MRI) and bioluminescence imaging (BLI). Aflibercept treatment was well tolerated and resulted in increased animal survival in HCT116, but not in HT29, while inhibited tumor growth was observed in both models. Treatment efficacy was monitored with high precision using MRI, while BLI detected small-volume disease with high sensitivity, but was less accurate in end-stage disease. Apparent diffusion coefficient (ADC) values obtained by diffusion weighted MRI (DW-MRI) were highly predictive of treatment response, with increased ADC corresponding well with areas of necrosis observed by histological evaluation of aflibercept-treated xenografts. The results showed that the efficacy of the antiangiogenic drug aflibercept varied between the two models, possibly reflecting unique growth patterns in the liver that may be representative of human disease. Non-invasive imaging, especially MRI and DW-MRI, can be used to effectively monitor tumor growth and treatment response in orthotopic liver metastasis models.

The emerging role of immunotherapy in colorectal cancer

Modulation of the interaction between the immune system and the tumor microenvironment has long been a target of cancer research, including colorectal cancer (CRC). Approaches explored to date include vaccines (autologous, peptide, dendritic cell, viral and bacterial), cytokine therapy, toll-like receptors (TLRs), autologous cell therapy and checkpoint inhibition. Until recently these approaches have been shown to have only modest efficacy in reducing tumor burden. However, significant breakthroughs have been made, with the use of checkpoint inhibitors targeting programmed cell death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T lymphocyte antigen-4 (CTLA-4). Immunotherapy now represents a possible avenue of curative treatment for those with chemo-otherwise refractory tumors. Success with this approach to immunotherapy has largely been confined to tumors with high mutational burdens such as melanoma, renal cell carcinoma (RCC) and non-small cell lung cancer. This observation led to the exploration and successful use of checkpoint inhibitors in those with mismatch repair colorectal cancer which have a relatively high mutational burden. Ongoing trials are focused on further exploring the use of checkpoint inhibitors in addition to investigating the various combinations of immunotherapeutic drugs.

Current targeted therapies in the treatment of advanced colorectal cancer: a review

Treatment strategies for metastatic colorectal cancer (mCRC) patients have undergone dramatic changes in the past decade and despite improved patient outcomes, there still exist areas for continued development. The introduction of targeted agents has provided clinicians with additional treatment options in mCRC, however, results have been mixed at best. These novel therapies were designed to interfere with specific molecules involved in the cellular carcinogenesis pathway and ultimately deliver a more focused treatment. Currently, their use in mCRC has been limited primarily as an adjunct to conventional chemotherapy regimens. This review explores the relevant cell-signaling networks in colorectal cancer, provides focus on the current targeted agent armamentarium approved for use in mCRC and explores the usefulness of predictive mCRC biomarkers.

New hope on the horizon for patients with metastatic colorectal cancer

Colorectal cancer is the second leading cause of cancer death in the USA. It is estimated that approximately 132,700 patients are diagnosed with, and more than 49,700 are expected to die of colorectal cancer each year. For many years, 5-fluorouracil was the only treatment option for patients with metastatic colorectal cancer but, over the last decade, the introduction and the US FDA approval of irinotecan, oxaliplatin and several monoclonal antibodies that target the VEGF and EGF receptor have markedly changed the therapeutic landscape. Most recently, regorafenib, ramucirumab and the novel orally active TAS-102 have also become available, presenting even more therapeutic options. In this review, we focus on emerging systemic therapy options for the management of advanced/metastatic colorectal cancer, particularly in the second-line/salvage settings, highlighting existing scientific evidence for the activity of, as well as future perspectives on, these more novel treatments.

Fc-fusion proteins and FcRn: structural insights for longer-lasting and more effective therapeutics

Nearly 350 IgG-based therapeutics are approved for clinical use or are under development for many diseases lacking adequate treatment options. These include molecularly engineered biologicals comprising the IgG Fc-domain fused to various effector molecules (so-called Fc-fusion proteins) that confer the advantages of IgG, including binding to the neonatal Fc receptor (FcRn) to facilitate in vivo stability, and the therapeutic benefit of the specific effector functions. Advances in IgG structure-function relationships and an understanding of FcRn biology have provided therapeutic opportunities for previously unapproachable diseases. This article discusses approved Fc-fusion therapeutics, novel Fc-fusion proteins and FcRn-dependent delivery approaches in development, and how engineering of the FcRn-Fc interaction can generate longer-lasting and more effective therapeutics.

Role of aflibercept in the treatment of advanced colorectal cancer

SUMMARY Colorectal cancer is the third most common cancer in men, representing 10% of cases, and the second most common cancer in women, representing 9.4% of cases, worldwide. It is estimated that 50–60% of patients will develop metastases during the course of their disease, while 15–25% will present with synchronous metastatic lesions, reducing the probability of 5-year survival to 12%. Colon cancer represents the fourth most common cause of death from cancer worldwide and the second most common cause in developed countries. First-line therapy of advanced or metastatic colorectal carcinoma (mCRC) usually consists of the administration of oxaliplatin or irinotecan in combination with leucovorin and 5-fluorouracil. In the first- or second-line settings, monoclonal antibodies can be added to chemotherapy. Bevacizumab (anti-VEGF monoclonal antibody) is utilized with fluoropyrimidine-containing regimens in combination with oxaliplatin or irinotecan. Cetuximab can be administered in combination with irinotecan or as a single agent in patients who have wild-type KRAS. Panitumumab has also been approved for third-line single-agent therapy in KRAS wild-type patients and recently in first- and second-line therapy in combination with chemotherapy. There are no standard second-line treatments of mCRC specifically used in combination with FOLFIRI, and no drugs have been approved for patients with prior bevacizumab treatment. Aflibercept is a new angiogenesis inhibitor with a unique mechanism of action. Aflibercept is a recombinant fusion protein consisting of VEGF-binding portions from extracellular domains of the human VEGFR1 and 2 fused to the Fc portion of human IgG1. Aflibercept acts as a soluble decoy receptor that binds to VEGF-A with higher affinity than its native receptors, as well as the related ligands PIGF and VEGF-B. Aflibercept interferes with the biological actions of VEGF by ‘trapping’ VEGF and preventing it from interacting with its receptors on endothelial cells, blocking the activation of VEGFRs and the subsequent proliferation of endothelial cells; this results in inhibition of the growth of new vessels. The role of aflibercept in the management of mCRC was studied in the VELOUR trial, which showed that its addition to the FOLFIRI regimen resulted in a survival benefit, giving a statistically significant log-rank test with p = 0.0032 (hazard ratio: 0.817; 95.34% CI: 0.713–0.937). This benefit was supported by subgroup and sensitivity analyses, the increased median progression-free survival, and improved response rates observed in the aflibercept arm. Aflibercept toxicity is acceptable, manageable and within the established range of other VEGF inhibitors.

Vascular endothelial growth factor inhibitors: investigational therapies for the treatment of psoriasis

Psoriasis is a common inflammatory autoimmune condition in which environmental factors and genetic predisposition contribute to the development of disease in susceptible individuals. Angiogenesis is known to be a key pathogenic feature of psoriasis. Local and systemic elevation of vascular endothelial growth factor (VEGF)-A has been demonstrated in the skin and plasma of patients with psoriasis and is known to correlate with improvement following some traditional psoriasis treatments. A number of VEGF inhibitors are licensed for the treatment of malignancies and eye disease and isolated case reports suggest that some individuals with psoriasis may improve when exposed to these agents. The small number of cases and lack of unified reporting measures makes it difficult to draw generalizations and underline the heterogeneity of psoriasis as a disease entity. Though not yet licensed for the treatment of psoriasis in humans, experimental data supports the potential of VEGF inhibitors to influence relevant aspects of human cell biology (such as endothelial cell differentiation) and to improve animal models of skin disease. Given the multi-factorial nature of psoriasis it is unlikely that VEGF inhibitors will be effective in all patients, however they have the potential to be a valuable addition to the therapeutic arsenal in selected cases. Current VEGF inhibitors in clinical use are associated with a number of potentially serious side effects including hypertension, left ventricular dysfunction, and gastrointestinal perforation. Such risks require careful consideration in psoriasis populations particularly in light of growing concerns linking psoriasis to increased cardiovascular risk.

Effect and safety of bevacizumab-containing chemotherapy treatment in Chinese patients with metastatic colorectal cancer

Purpose

To review the clinical data and treatment efficacy of bevacizumab in Chinese patients with metastatic colorectal cancer (mCRC).

Patients and methods

A total of 96 patients with mCRC treated by chemotherapy plus bevacizumab in the PLA General Hospital between December 2005 and August 2012 were analyzed retrospectively by overall response rate, disease-control rate, progression-free survival (PFS), and overall survival (OS). The tumor responses were assessed by the Response Evaluation Criteria in Solid Tumors guidelines.

Results

A total of 96 patients with mCRC were identified. Median age was 53.6 years. Eastern Cooperative Oncology Group performance status was 0–2. By the end of follow-up (August 20, 2012), 54 patients exhibited progression (56.3%), and 39 (40.6%) patients had died. A total of 27 (28.1%) achieved partial response, and 48 patients (50.0%) had stable disease, exhibiting an overall response rate of 28.1% and a disease-control rate of 78.1%. The response rates of the first-line, second-line, and third-line (or later) therapy were 41.7%, 21.9%, and 15.8%, respectively. The median durations of the PFS and OS were 8.13 months and 14.80 months, respectively. The median durations of the PFS were 12.70 months, 8.30 months, and 6.40 months for first-line, second-line, and third-line (or later) therapy, respectively, and the median durations of the OS were 24.03 months, 14.90 months, and 11.03 months for first-line, second-line, and third-line (or later) therapy, respectively.

Conclusion

A bevacizumab-containing chemotherapy regimen was well tolerated and effective in Chinese patients with mCRC.

Current and Novel Treatment Options for Metastatic Colorectal Cancer: Emphasis on Aflibercept

Worldwide, colorectal cancer (CRC) is the third most frequently diagnosed cancer in men and the second in women. Metastatic disease develops in more than half of the patients and carries a poor prognosis. Over the past three decades, significant advances have been made in the treatment of metastatic colorectal cancer (mCRC). The development of new cytotoxic agents and the incorporation of target-specific agents in first-, second-, third-, and nowadays even fourth-line treatment has prolonged median overall survival up to 24–28 months. However, 5-year survival rates remain disappointingly low. This review summarizes the currently available cytotoxic treatment options for mCRC, and highlights the further emerging role of vascular endothelial growth factor (VEGF)-inhibiting strategies, emphasizing the role of aflibercept. Aflibercept is a recombinant fusion protein with high VEGF affinity, and is the second antiangiogenic agent to obtain registration in the treatment of mCRC.

Aflibercept for age-related macular degeneration: a game-changer or quiet addition?

PURPOSE

To describe the pharmacokinetics, preclinical studies, and clinical trials of the newly approved anti-vascular endothelial growth factor (VEGF) drug aflibercept (Eylea (VEGF Trap-Eye); Regeneron; and Bayer).

DESIGN

Review with editorial commentary.

METHODS

A review of the medical literature and pertinent Internet postings combined with analysis of key studies with expert opinion regarding the use of aflibercept for the treatment of exudative age-related macular degeneration.

RESULTS

Aflibercept, a fusion protein with binding domains from native VEGF receptors, binds VEGF-A, VEGF-B, and placental growth factors 1 and 2 with high affinity. Preclinical ophthalmologic studies demonstrated that aflibercept suppresses choroidal neovascularization in several animal models. The results of phase 1 and 2 trials showed excellent short-term suppression of choroidal neovascularization in patients with exudative age-related macular degeneration and suggested a longer durability of aflibercept compared with other anti-VEGF drugs. The pivotal phase 3 Vascular Endothelial Growth Factor (VEGF) Trap-Eye: Investigation of Efficacy and Safety in Wet Age-Related Macular Degeneration 1 and 2 trials showed that monthly and bimonthly aflibercept were noninferior to monthly ranibizumab at preventing vision loss (< 15-letter loss) with comparable vision gains and safety. Year 2 treatment involved monthly pro re nata injections with required injections every 3 months and maintained vision gains from the first year, with an average of 4.2 injections of aflibercept and 4.7 injections of ranibizumab.

CONCLUSIONS

Aflibercept promises to deliver excellent visual outcomes for exudative age-related macular degeneration patients while undergoing fewer injections compared with ranibizumab. With a wholesale cost of $1850 per dose, the cost per patient with aflibercept treatment promises to be lower than with ranibizumab.

Targeting the vasculature of visceral tumors: novel insights and treatment perspectives

BACKGROUND

Angiogenesis, the formation of new blood vessels from the endothelium of the existing vasculature, describes a crucial process in tumor growth, disease progression, and metastasis. Therefore, the upcoming strategy of inhibiting tumor angiogenesis has generated different treatment modalities, which have been transferred into clinical practice in recent years. Currently, this concept is applied to target the vasculature of different visceral tumors and intensive clinical research has just started.

MATERIALS AND METHODS

This review summarizes the modifications of systemic treatment of visceral tumors by targeting the vasculature in the past years. Moreover, novel targets and treatment strategies will be discussed to evaluate future directions.

RESULTS

Leading antiangiogenic drugs combined with systemic chemotherapy have been applied with increasing success during the last years. Therefore, the concept of combining vascular targeting agents with established chemotherapeutic regimens has been increasingly adopted into the therapies of different visceral tumors.

CONCLUSION

Targeting the vasculature of visceral tumors in combination with established standard tumor therapies includes major clinical potential for future therapy concepts.