Phase I/II Trial of Imatinib and Bevacizumab in Patients With Advanced Melanoma and Other Advanced Cancers

Efficacy and safety of bevacizumab in patients with malignant melanoma: a systematic review and PRISMA-compliant meta-analysis of randomized controlled trials and non-comparative clinical studies

Background: Malignant melanoma is a highly aggressive cancer that spreads and metastasizes quickly. In recent years, the antiangiogenic drug bevacizumab has been trialed to treat malignant melanoma. We conducted the first meta-analysis to examine the efficacy and safety of bevacizumab combined with other drugs in malignant melanoma. Methods: We searched for randomized controlled trials (RCTs) and non-comparative clinical studies of bevacizumab combined with chemotherapy, targeted medicine, and interferon to treat malignant melanoma in PubMed, Embase, the Cochrane Library, and Web of Science. Meta-analysis of RCT was performed using Review Manager (version 5.4), and non-comparative meta-analysis was performed using R (version 4.0.3). The primary outcome was the objective response rate. Depending on the heterogeneity of the included studies, the pooled outcomes and 95% CI were calculated using either random-effects or fixed-effect models. Subgroup outcomes were calculated with possible relevant variables. Sensitivity analyses were carried out by excluding each study from the highly heterogeneous pooled results in turn. Funnel plot and Begg's test were used to test the included studies' potential publication bias. The level of significance was set at p < 0.05. Results: This meta-analysis included 20 trials: five RCTs and 15 non-comparative clinical studies with a total of 23 bevacizumab intervention arms. In 14 treatment arms, bevacizumab was combined with chemotherapy drugs such as fotemustine, dacarbazine, carboplatin/paclitaxel, and temozolomide. In six treatment arms, bevacizumab was combined with targeted medicines such as imatinib, everolimus, sorafenib, erlotinib, and temsirolimus. There were also six treatment arms that used bevacizumab in combination with interferon. The pooled objective response rate was 15.8% (95% CI, 11.4%-20.2%). Bevacizumab plus carboplatin/paclitaxel significantly increased the overall survival compared to carboplatin/paclitaxel (HR = 0.64, 95% CI, 0.49-0.85, p < 0.01). Fatigue, nausea, leukopenia, thrombocytopenia, and neutropenia were the most common adverse events. The pooled incidence of hypertension of all bevacizumab arms in malignant melanoma was 32.4% (95% CI, 24.5%-40.3%). Conclusion: This study showed that bevacizumab combined with chemotherapy might be effective and well-tolerated in patients with stage III or IV unresectable malignant melanoma. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=304625], identifier [CRD42022304625].

Primary mucosal melanoma of the larynx: systematic review of the literature and qualitative synthesis

PURPOSE

Primary mucosal melanoma of the larynx (PLM) is a rare entity among head and neck cancers. Due to its rarity, clear protocols of management are not available. A deeper knowledge of the clinical and biological behaviour of PLM is strongly needed.

METHODS

According to PRISMA process, we searched through electronic databases case reports, case series and review articles providing relevant clinical data. The survival analysis was performed with Kaplan-Meier survival curves, using disease free survival (DFS) and overall survival (OS) as endpoints.

RESULTS

1074 articles were initially screened, of which 37 studies describing 44 PLM cases were selected and included in the analysis. Mean age was 59.7 years with a mean follow-up time of 25.4 months. The most common symptom at presentation was hoarseness (52%), while the most involved laryngeal subsite was supraglottic region (62%). Most patients presented with an advanced stage. Tumour (T) and node (N) status at presentation did not influence OS nor DFS, whereas distant metastases (M) status resulted significantly associated with the reduction of OS and DFS time (Mantel-Cox: p < 0.0001 and p = 0.001, respectively). The laryngeal subsite and the type of surgery performed did not significantly impact on OS and DFS.

CONCLUSIONS

Treatment for PLM remains debated. Surgery with safe margins is recommended due to the high rates of local recurrence. Systemic therapy is advised for metastatic disease. However, the prognosis remains poor even after radical resection or targeted therapy.

Microbubble-Assisted Ultrasound for Imaging and Therapy of Melanoma Skin Cancer: A Systematic Review

Recent technological developments in ultrasound (US) imaging and ultrasound contrast agents (UCAs) have improved diagnostic confidence in echography. In the clinical management of melanoma, contrast-enhanced ultrasound (CEUS) imaging complements conventional US imaging (i.e., high-resolution US and Doppler imaging) for clinical examination and therapeutic follow-up. These developments have set into motion the combined use of ultrasound and UCAs as a new modality for drug delivery. This modality, called sonoporation, has emerged as a non-invasive, targeted and safe method for the delivery of therapeutic drugs into melanoma. This review focuses on the results and prospects of using US and UCAs as dual modalities for CEUS imaging and melanoma treatment.

Identification of Novel Molecular Therapeutic Targets and Their Potential Prognostic Biomarkers Based on Cytolytic Activity in Skin Cutaneous Melanoma

Skin cutaneous melanoma (SKCM) attracts attention worldwide for its extremely high malignancy. A novel term cytolytic activity (CYT) has been introduced as a potential immunotherapy biomarker associated with counter-regulatory immune responses and enhanced prognosis in tumors. In this study, we extracted all datasets of SKCM patients, namely, RNA sequencing data and clinical information from The Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database, conducted differential expression analysis to yield 864 differentially expressed genes (DEGs) characteristic of CYT and used non-negative matrix factorization (NMF) method to classify molecular subtypes of SKCM patients. Among all genes, 14 hub genes closely related to prognosis for SKCM were finally screen out. Based on these genes, we constructed a 14-gene prognostic risk model and its robustness and strong predictive performance were further validated. Subsequently, the underlying mechanisms in tumor pathogenesis and prognosis have been defined from a number of perspectives, namely, tumor mutation burden (TMB), copy number variation (CNV), tumor microenvironment (TME), infiltrating immune cells, gene set enrichment analysis (GSEA) and immune checkpoint inhibitors (ICIs). Furthermore, combined with GTEx database and HPA database, the expression of genes in the model was verified at the transcriptional level and protein level, and the relative importance of genes in the model was described by random forest algorithm. In addition, the model was used to predict the difference in sensitivity of SKCM patients to chemotherapy and immunotherapy. Finally, a nomogram was constructed to better aid clinical diagnosis.

Melanoma Targeted Therapies beyond BRAF-Mutant Melanoma: Potential Druggable Mutations and Novel Treatment Approaches

Melanomas exhibit the highest rate of somatic mutations among all different types of cancers (with the exception of BCC and SCC). The accumulation of a multimode of mutations in the driver oncogenes are responsible for the proliferative, invasive, and aggressive nature of melanomas. High-resolution and high-throughput technology has led to the identification of distinct mutational signatures and their downstream alterations in several key pathways that contribute to melanomagenesis. This has enabled the development of individualized treatments by targeting specific molecular alterations that are vital for cancer cell survival, which has resulted in improved outcomes in several cancers, including melanomas. To date, BRAF and MEK inhibitors remain the only approved targeted therapy with a high level of evidence in BRAFV600E/K mutant melanomas. The lack of approved precision drugs in melanomas, relative to other cancers, despite harboring one of the highest rates of somatic mutations, advocates for further research to unveil effective therapeutics. In this review, we will discuss potential druggable mutations and the ongoing research of novel individualized treatment approaches targeting non-BRAF mutations in melanomas.

Hypoxia-dependent drivers of melanoma progression

Hypoxia, a condition of low oxygen availability, is a hallmark of tumour microenvironment and promotes cancer progression and resistance to therapy. Many studies reported the essential role of hypoxia in regulating invasiveness, angiogenesis, vasculogenic mimicry and response to therapy in melanoma. Melanoma is an aggressive cancer originating from melanocytes located in the skin (cutaneous melanoma), in the uveal tract of the eye (uveal melanoma) or in mucosal membranes (mucosal melanoma). These three subtypes of melanoma represent distinct neoplasms in terms of biology, epidemiology, aetiology, molecular profile and clinical features.In this review, the latest progress in hypoxia-regulated pathways involved in the development and progression of all melanoma subtypes were discussed. We also summarized current knowledge on preclinical studies with drugs targeting Hypoxia-Inducible Factor-1, angiogenesis or vasculogenic mimicry. Finally, we described available evidence on clinical studies investigating the use of Hypoxia-Inducible Factor-1 inhibitors or antiangiogenic drugs, alone or in combination with other strategies, in metastatic and adjuvant settings of cutaneous, uveal and mucosal melanoma.Hypoxia-Inducible Factor-independent pathways have been also reported to regulate melanoma progression, but this issue is beyond the scope of this review.As evident from the numerous studies discussed in this review, the increasing knowledge of hypoxia-regulated pathways in melanoma progression and the promising results obtained from novel antiangiogenic therapies, could offer new perspectives in clinical practice in order to improve survival outcomes of melanoma patients.

RTK Inhibitors in Melanoma: From Bench to Bedside

MAPK (mitogen activated protein kinase) and PI3K/AKT (Phosphatidylinositol-3-Kinase and Protein Kinase B) pathways play a key role in melanoma progression and metastasis that are regulated by receptor tyrosine kinases (RTKs). Although RTKs are mutated in a small percentage of melanomas, several receptors were found up regulated/altered in various stages of melanoma initiation, progression, or metastasis. Targeting RTKs remains a significant challenge in melanoma, due to their variable expression across different melanoma stages of progression and among melanoma subtypes that consequently affect response to treatment and disease progression. In this review, we discuss in details the activation mechanism of several key RTKs: type III: c-KIT (mast/stem cell growth factor receptor); type I: EGFR (Epidermal growth factor receptor); type VIII: HGFR (hepatocyte growth factor receptor); type V: VEGFR (Vascular endothelial growth factor), structure variants, the function of their structural domains, and their alteration and its association with melanoma initiation and progression. Furthermore, several RTK inhibitors targeting the same receptor were tested alone or in combination with other therapies, yielding variable responses among different melanoma groups. Here, we classified RTK inhibitors by families and summarized all tested drugs in melanoma indicating the rationale behind the use of these drugs in each melanoma subgroups from preclinical studies to clinical trials with a specific focus on their purpose of treatment, resulted effect, and outcomes.

Resistance to Molecularly Targeted Therapies in Melanoma

Malignant melanoma is the most aggressive type of skin cancer with invasive growth patterns. In 2021, 106,110 patients are projected to be diagnosed with melanoma, out of which 7180 are expected to die. Traditional methods like surgery, radiation therapy, and chemotherapy are not effective in the treatment of metastatic and advanced melanoma. Recent approaches to treat melanoma have focused on biomarkers that play significant roles in cell growth, proliferation, migration, and survival. Several FDA-approved molecular targeted therapies such as tyrosine kinase inhibitors (TKIs) have been developed against genetic biomarkers whose overexpression is implicated in tumorigenesis. The use of targeted therapies as an alternative or supplement to immunotherapy has revolutionized the management of metastatic melanoma. Although this treatment strategy is more efficacious and less toxic in comparison to traditional therapies, targeted therapies are less effective after prolonged treatment due to acquired resistance caused by mutations and activation of alternative mechanisms in melanoma tumors. Recent studies focus on understanding the mechanisms of acquired resistance to these current therapies. Further research is needed for the development of better approaches to improve prognosis in melanoma patients. In this article, various melanoma biomarkers including BRAF, MEK, RAS, c-KIT, VEGFR, c-MET and PI3K are described, and their potential mechanisms for drug resistance are discussed.

Functional Parameters Derived from Magnetic Resonance Imaging Reflect Vascular Morphology in Preclinical Tumors and in Human Liver Metastases

Purpose: Tumor vessels influence the growth and response of tumors to therapy. Imaging vascular changes in vivo using dynamic contrast-enhanced MRI (DCE-MRI) has shown potential to guide clinical decision making for treatment. However, quantitative MR imaging biomarkers of vascular function have not been widely adopted, partly because their relationship to structural changes in vessels remains unclear. We aimed to elucidate the relationships between vessel function and morphology in vivo Experimental Design: Untreated preclinical tumors with different levels of vascularization were imaged sequentially using DCE-MRI and CT. Relationships between functional parameters from MR (iAUC, K trans, and BATfrac) and structural parameters from CT (vessel volume, radius, and tortuosity) were assessed using linear models. Tumors treated with anti-VEGFR2 antibody were then imaged to determine whether antiangiogenic therapy altered these relationships. Finally, functional-structural relationships were measured in 10 patients with liver metastases from colorectal cancer.Results: Functional parameters iAUC and K trans primarily reflected vessel volume in untreated preclinical tumors. The relationships varied spatially and with tumor vascularity, and were altered by antiangiogenic treatment. In human liver metastases, all three structural parameters were linearly correlated with iAUC and K trans For iAUC, structural parameters also modified each other's effect.Conclusions: Our findings suggest that MR imaging biomarkers of vascular function are linked to structural changes in tumor vessels and that antiangiogenic therapy can affect this link. Our work also demonstrates the feasibility of three-dimensional functional-structural validation of MR biomarkers in vivo to improve their biological interpretation and clinical utility. Clin Cancer Res; 24(19); 4694-704. ©2018 AACR.

Pharmacodynamic and Pharmacokinetic Markers For Anti-angiogenic Cancer Therapy: Implications for Dosing and Selection of Patients

Angiogenesis is integral to tumour growth and invasion, and is a key target for cancer therapeutics. However, for many of the licensed indications, only a modest clinical benefit has been observed for both monoclonal antibody and small-molecule tyrosine kinase inhibitor anti-angiogenic therapy. Pre-clinical and clinical studies have attempted to evaluate circulating, imaging, genomic, pharmacokinetic, and pharmacodynamic markers that may aid both the selection of patients for treatment and define dosing. Correct dosing is likely to be critical in the context of vascular normalization to allow better delivery of concomitant anti-cancer therapy and novel imaging techniques hold much promise in the early evaluation of pharmacodynamic response to improve efficacy.

Treatment of Primary and Metastatic Multifocal Mucosal Melanoma of the Oral Cavity with Imatinib

Background

Mucosal melanoma of the oral cavity is a rare entity and accounts for less than 1–3% of all melanomas. Contrary to cutaneous melanoma, primary oral melanoma more commonly harbors mutations in c-KIT.

Methods

A 64-year-old man presented with asymptomatic, multiple, brown-to-black macules in the oral cavity. A biopsy was taken and histopathology exhibited mucosal melanoma. In molecular analysis, a c-KIT mutation was proven and a CT scan revealed pulmonary metastases. Due to the multifocality of the lesions, the metastases, and the mutation status, a therapy with imatinib was initiated.

Results

After 1 year of therapy, progressive disease in the lung was noticed. Therefore, the therapy was switched to a PD-1 antagonist and a CTL-4 antibody.

Conclusions

Our case suggests that imatinib may be considered as first-line treatment for both locally advanced and distant primary multifocal oral melanoma, for which surgery or radiotherapy of the primary tumor is impossible.

Emerging growth factor receptor antagonists for the treatment of advanced melanoma

INTRODUCTION

Therapy for metastatic melanoma has undergone a rapid transformation over the past 5-10 years. Advances in immunotherapy with checkpoint inhibitors, including both anti-CTLA-4 and anti-PD-1/PD-L1, have led to durable responses in up to 50% of patients. As our understanding of the processes driving the transformation of melanocytes has improved, progress in targeted therapies has also continued. Areas covered: Angiogenesis and the tumor's dependence on an expanded vascular supply has been a target for novel therapies since the 1970's, as this tissue is derived from endothelial cells that are genetically stable in adults. A phase II trial studying combined therapy with bevacizumab (an inhibitor of angiogenesis) and ipilimumab found promising results. Other agents such as sorafenib have not been as successful, failing to extend progression free or overall survival in clinical trials. In this paper other targeted growth factor inhibitors will also be discussed. Expert opinion: Ultimately, melanoma may not be vulnerable solely to chemotherapy or targeted therapy, but may be efficaciously treated with immunotherapy due to its high mutational rate resulting in the expression of numerous neo-antigens. Therapies with combinations of agents including growth factor receptor and either other targeted therapies or immunotherapy may be a promising complimentary approach.

Treatment of NRAS-mutated advanced or metastatic melanoma: rationale, current trials and evidence to date

The disease course of BRAF (v-raf murine sarcoma viral oncogene homolog B1)-mutant melanoma has been drastically improved by the arrival of targeted therapies. NRAS (neuroblastoma RAS viral oncogene homolog)-mutated melanoma represents 15–25% of all metastatic melanoma patients. It currently does not have an approved targeted therapy. Metastatic patients receive immune-based therapies as first-line treatments, then cytotoxic chemotherapy like carboplatin/paclitaxel (C/P), dacarbazine (DTIC) or temozolomide (TMZ) as a second-line treatment. We will review current preclinical and clinical developments in NRAS-mutated melanoma, and analyze ongoing clinical trials that are evaluating the benefit of different targeted and immune-based therapies, either tested as single agents or in combination, in NRAS-mutant melanoma.

Quantitative magnetic resonance imaging biomarkers in oncological clinical trials: Current techniques and standardization challenges

Radiological imaging plays an important role in oncological trials to provide imaging biomarkers for disease staging, stratifying patients, defining dose setting, and evaluating the safety and efficacy of new candidate drugs and innovative treatment. This paper reviews the techniques of most commonly used quantitative magnetic resonance imaging (qMRI) biomarkers (dynamic contrast enhanced, dynamic susceptibility contrast, and diffusion weighted imaging) and their applications in oncological trials. Challenges of incorporating qMRI biomarkers in oncological trials are discussed including understanding biological mechanisms revealed by MRI biomarkers, consideration of rigorous trial design and standardized implementation of qMRI protocols.

Escaping Antiangiogenic Therapy: Strategies Employed by Cancer Cells

Tumor angiogenesis is widely recognized as one of the "hallmarks of cancer". Consequently, during the last decades the development and testing of commercial angiogenic inhibitors has been a central focus for both basic and clinical cancer research. While antiangiogenic drugs are now incorporated into standard clinical practice, as with all cancer therapies, tumors can eventually become resistant by employing a variety of strategies to receive nutrients and oxygen in the event of therapeutic assault. Herein, we concentrate and review in detail three of the principal mechanisms of antiangiogenic therapy escape: (1) upregulation of compensatory/alternative pathways for angiogenesis; (2) vasculogenic mimicry; and (3) vessel co-option. We suggest that an understanding of how a cancer cell adapts to antiangiogenic therapy may also parallel the mechanisms employed in the bourgeoning tumor and isolated metastatic cells delivering responsible for residual disease. Finally, we speculate on strategies to adapt antiangiogenic therapy for future clinical uses.

Parallel In Vivo Assessment of Drug Phenotypes at Various Time Points during Systemic BRAF Inhibition Reveals Tumor Adaptation and Altered Treatment Vulnerabilities

PURPOSE

Treatment of BRAF-mutated melanoma tumors with BRAF inhibitor-based therapy produces high response rates, but of limited duration in the vast majority of patients. Published investigations of resistance mechanisms suggest numerous examples of tumor adaptation and signal transduction bypass mechanisms, but without insight into biomarkers that would predict which mechanism will predominate. Monitoring phenotypic response of multiple adaptive mechanisms simultaneously within the same tumor as it adapts during treatment has been elusive.

EXPERIMENTAL DESIGN

This study reports on a method to provide a more complete understanding of adaptive tumor responses. We simultaneously measured in vivo antitumor activity of 12 classes of inhibitors, which are suspected of enabling adaptive escape mechanisms, at various time points during systemic BRAF inhibition. We used implantable microdevices to release multiple compounds into distinct regions of a tumor to measure the efficacy of each compound independently and repeated these measurements as tumors progressed on systemic BRAF treatment.

RESULTS

We observed varying phenotypic responses to specific inhibitors before, during, and after prolonged systemic treatment with BRAF inhibitors. Our results specifically identify PI3K, PDGFR, EGFR, and HDAC inhibitors as becoming significantly more efficacious during systemic BRAF inhibition. The sensitivity to other targeted inhibitors remained mostly unchanged, whereas local incremental sensitivity to PLX4720 declined sharply.

CONCLUSIONS

These findings suggest redundancy of several resistance mechanisms and may help identify optimal constituents of more effective combination therapy in BRAF-mutant melanoma. They also represent a new paradigm for dynamic measurement of adaptive signaling mechanisms within the same tumor during therapy. Clin Cancer Res; 22(24); 6031-8. ©2016 AACR.

Anti-bevacizumab idiotype antibody vaccination is effective in inducing vascular endothelial growth factor-binding response, impairing tumor outgrowth

Tumors require blood supply and, to overcome this restriction, induce angiogenesis. Vascular endothelial growth factor (VEGF) plays an important role in this process, which explains the great number of antiangiogenic therapies targeting VEGF. The research and development of targeted therapy has led to the approval of bevacizumab, a humanized anti-VEGF monoclonal antibody (mAb), in clinical settings. However, side effects have been reported, usually as a consequence of bolus-dose administration of the antibody. This limitation could be circumvented through the use of anti-idiotype (Id) antibodies. In the present study, we evaluated the efficacy of an active VEGF-binding immune response generated by an anti-bevacizumab idiotype mAb, 10.D7. The 10.D7 anti-Id mAb vaccination led to detectable levels of VEGF-binding anti-anti-Id antibodies. In order to examine whether this humoral immune response could have implications for tumor development, 10.D7-immunized mice were challenged with B16-F10 tumor cells. Mice immunized with 10.D7 anti-Id mAb revealed reduced tumor growth when compared to control groups. Histological analyses of tumor sections from 10.D7-immunized mice showed increased necrotic areas, decreased CD31-positive vascular density and reduced CD68-positive cell infiltration. Our results encourage further therapeutic studies, particularly if one considers that the anti-Id therapeutic vaccination maintains stable levels of VEGF-binding antibodies, which might be useful in the control of tumor relapse.

Antiangiogenesis and vascular disrupting agents in cancer: circumventing resistance and augmenting their therapeutic utility

Angiogenesis is a process essential for tumor growth and metastasis. Inhibition of angiogenesis as an anticancer strategy has shown only moderately improved results and is beset with practical limitations, despite theoretical therapeutic advantages. Inevitably resistance develops, through redundancy of signaling pathways and selection for subclonal populations adapted for hypoxic conditions, with more invasive phenotypes. Antiangiogenic-targeted therapies may find improved efficacy in combination therapies; with others in this class, that directly or indirectly target separate pathways or different components of the same pathway, or with a separate class of tumor vasculature-disrupting agents. This review discusses the challenges and strategies for optimization of combination therapies including metronomic administration of drugs and the need for suitable prognostic and surrogate response biomarkers.

Dynamic contrast-enhanced MRI for oncology drug development

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising tool for evaluating tumor vascularity, as it can provide vasculature-derived, functional, and quantitative parameters. To implement DCE-MRI parameters as biomarkers for monitoring the effect of antiangiogenic or vascular-disrupting treatment, two crucial elements of surrogate endpoint, ie, validation and qualification, should be satisfied. Although early studies have shown the accuracy and reliability of DCE-MRI parameters for evaluating treatment-driven vascular alterations, there have been an increasing number of studies demonstrating the limitations of DCE-MRI parameters as surrogate endpoints. Therefore, in order to improve the application of DCE-MRI parameters in drug development, it is necessary to establish a standardized evaluation method and to determine the correct therapeutics-oriented meaning of individual DCE-MRI parameter. In this regard, this article describes the biophysical background and data acquisition/analysis techniques of DCE-MRI while focusing on the validation and qualification issues. Specifically, the causes of disagreement and confusion encountered in the preclinical and clinical trials using DCE-MRI are presented in detail. Finally, considering these limitations, we present potential strategies to optimize implementation of DCE-MRI. J. Magn. Reson. Imaging 2016;44:251-264.

Anti-vascular endothelial growth factor treatment induces blood flow recovery through vascular remodeling in high-fat diet induced diabetic mice

Diabetes mellitus (DM) leads to the development of microvascular diseases and is associated with impaired angiogenesis. The presence of vascular endothelial growth factor (VEGF) can block PDGF-BB dependent regulation of neovascularization and vessel normalization. We tested the hypothesis that the inhibition of VEGF improves blood flow in a mouse hindlimb ischemia model produced by femoral artery ligation. In this study, we examined the effect of bevacizumab, a humanized monoclonal antibody against VEGF-A, on blood perfusion and angiogenesis after hindlimb ischemia. We showed that bevacizumab induces functional blood flow in high fat chow (HFC)-fed diabetic mice. Treatment with bevacizumab increased the expression of platelet derived growth factor-BB (PDGF-BB) in ischemic muscle, and led to vascular normalization. It also blocked vascular leakage by improving the recruitment of pericytes associated with nascent blood vessels, but it did not affect capillary formation. Furthermore, treatment with an anti-PDGF drug significantly inhibited blood flow perfusion in diabetic mice treated with bevacizumab. These results indicate that bevacizumab improves blood flow recovery through the induction of PDGF-BB in a diabetic mouse hindlimb ischemia model, and that vessel normalization may represent a useful strategy for the prevention and treatment of diabetic peripheral arterial disease.

Blocking FGF2 with a new specific monoclonal antibody impairs angiogenesis and experimental metastatic melanoma, suggesting a potential role in adjuvant settings

Compelling evidence suggests that fibroblast growth factor 2 (FGF2), overexpressed in melanomas, plays an important role in tumor growth, angiogenesis and metastasis. In this study, we evaluated the therapeutic use of a new anti-FGF2 monoclonal antibody (mAb), 3F12E7, using for that the B16-F10 melanoma model. The FGF2 neutralizing effect of this antibody was certified by in vitro assays, which allowed the further track of its possible in vivo application. 3F12E7 mAb could be retained in B16-F10 tumors, as shown by antibody low-pH elution and nuclear medicine studies, and also led to reduction in number and size of metastatic foci in lungs, when treatment starts one day after intravenous injection of B16-F10 cells. Such data were accompanied by decreased CD34(+) tumor vascular density and impaired subcutaneous tumor outgrowth. Treatments starting one week after melanoma cell intravenous injection did not reduce tumor burden, remaining the therapeutic effectiveness restricted to early-adopted regimens. Altogether, the presented anti-FGF2 3F12E7 mAb stands as a promising agent to treat metastatic melanoma tumors in adjuvant settings.