Safety and pharmacokinetic effects of TNP-470, an angiogenesis inhibitor, combined with paclitaxel in patients with solid tumors: evidence for activity in non-small-cell lung cancer

Pharmacological Characterization of SDX-7320/Evexomostat: A Novel Methionine Aminopeptidase Type 2 Inhibitor with Anti-tumor and Anti-metastatic Activity

Methionine aminopeptidase type 2 (METAP2) is a ubiquitous, evolutionarily conserved metalloprotease fundamental to protein biosynthesis which catalyzes removal of the N-terminal methionine residue from nascent polypeptides. METAP2 is an attractive target for cancer therapeutics based upon its over-expression in multiple human cancers, the importance of METAP2-specific substrates whose biological activity may be altered following METAP2 inhibition, and additionally, that METAP2 was identified as the target for the anti-angiogenic natural product, fumagillin. Irreversible inhibition of METAP2 using fumagillin analogues has established the anti-angiogenic and anti-tumor characteristics of these derivatives; however, their full clinical potential has not been realized due to a combination of poor drug-like properties and dose-limiting central nervous system (CNS) toxicity. This report describes the physicochemical and pharmacological characterization of SDX-7320 (evexomostat), a polymer-drug conjugate of the novel METAP2 inhibitor (METAP2i) SDX-7539. In vitro binding, enzyme, and cell-based assays demonstrated that SDX-7539 is a potent and selective METAP2 inhibitor. In utilizing a high molecular weight, water-soluble polymer to conjugate the novel fumagillol-derived, cathepsin-released, METAP2i SDX-7539, limitations observed with prior generation, small molecule fumagillol derivatives were ameliorated including reduced CNS exposure of the METAP2i, and prolonged half-life enabling convenient administration. Multiple xenograft and syngeneic cancer models were utilized to demonstrate the anti-tumor and anti-metastatic profile of SDX-7320. Unlike polymer-drug conjugates in general, reductions in small molecule-equivalent efficacious doses following polymer conjugation were observed. SDX-7320 has completed a phase I clinical safety study in patients with late-stage cancer and is currently being evaluated in multiple phase Ib/II clinical studies in patients with advanced solid tumors.

A First-in-human, Dose-escalation Study of the Methionine Aminopeptidase 2 Inhibitor M8891 in Patients with Advanced Solid Tumors

Methionine aminopeptidase 2 (MetAP2) is essential to endothelial cell growth and proliferation during tumor angiogenesis. M8891 is a novel orally bioavailable, potent, selective, reversible MetAP2 inhibitor with antiangiogenic and antitumor activity in preclinical studies. The safety, tolerability, pharmacokinetics, and pharmacodynamics of M8891 monotherapy were assessed in a phase I, first-in-human, multicenter, open-label, single-arm, dose-escalation study (NCT03138538). Patients with advanced solid tumors received 7-80 mg M8891 once daily in 21-day cycles. The primary endpoint was dose-limiting toxicity (DLT) during cycle 1, with the aim to determine the maximum tolerated dose (MTD). Twenty-seven patients were enrolled across six dose levels. Two DLTs (platelet count decrease) were reported, one each at 60 and 80 mg/once daily M8891, resolving after treatment discontinuation. MTD was not determined. The most common treatment-emergent adverse event was platelet count decrease. M8891 plasma concentration showed dose-linear increase up to 35 mg and low-to-moderate variability; dose-dependent tumor accumulation of methionylated elongation factor 1α, a MetAP2 substrate, was observed, demonstrating MetAP2 inhibition. Pharmacokinetic/pharmacodynamic response data showed that preclinically defined target levels required for in vivo efficacy were achieved at safe, tolerated doses. Seven patients (25.9%) had stable disease for 42-123 days. We conclude that M8891 demonstrates a manageable safety profile, with dose-proportional exposure and low-to-moderate interpatient variability at target pharmacokinetic/pharmacodynamic levels at ≤35 mg M8891 once daily. On the basis of the data, 35 mg M8891 once daily is the recommended phase II dose for M8891 monotherapy. This study forms the basis for future development of M8891 in monotherapy and combination studies.

Significance

M8891 represents a novel class of reversible MetAP2 inhibitors and has demonstrated preclinical antitumor activity. This dose-escalation study assessed M8891 treatment for patients with advanced solid tumors. M8891 demonstrated favorable pharmacokinetics, tumoral target engagement, and a manageable safety profile, and thus represents a novel antitumor strategy warranting further clinical studies.

The Chemotherapeutic Potentials of Compounds Isolated from the Plant, Marine, Fungus, and Microorganism: Their Mechanism of Action and Prospects

Research on natural products mainly focuses on developing a suitable drug to treat human disease. There has been a sharp increase in the development of drugs from natural products. Most of the drugs that are available are from the terrestrial origin. Marine natural products are less explored. Oceans are considered as a vast ecosystem with a wide variety of living organisms and natural products that are unexplored. Large numbers of antitumor drugs are from natural sources such as plants, marine, and microorganisms. 80% new chemical entities that were launched over the past 60 decades were from a natural source. In this article, the anticancer potential from the natural source such as plants, fungi, microorganisms, marine, and endophytes has been reviewed. Emphasis is given on the compound from the marine, plant, and of bacterial origin. Finally, we consider the future and how we might achieve better sustainability to alleviate human cancer suffering while having fewer side effects, more efficacies, and causing less harm than the present treatments.

Cancer combination therapies by angiogenesis inhibitors; a comprehensive review

Abnormal vasculature is one of the most conspicuous traits of tumor tissue, largely contributing to tumor immune evasion. The deregulation mainly arises from the potentiated pro-angiogenic factors secretion and can also target immune cells' biological events, such as migration and activation. Owing to this fact, angiogenesis blockade therapy was established to fight cancer by eliminating the nutrient and oxygen supply to the malignant cells by impairing the vascular network. Given the dominant role of vascular-endothelium growth factor (VEGF) in the angiogenesis process, the well-known anti-angiogenic agents mainly depend on the targeting of its actions. However, cancer cells mainly show resistance to anti-angiogenic agents by several mechanisms, and also potentiated local invasiveness and also distant metastasis have been observed following their administration. Herein, we will focus on clinical developments of angiogenesis blockade therapy, more particular, in combination with other conventional treatments, such as immunotherapy, chemoradiotherapy, targeted therapy, and also cancer vaccines. Video abstract.

FV-429 enhances the efficacy of paclitaxel in NSCLC by reprogramming HIF-1α-modulated FattyAcid metabolism

Solid tumors often exhibit hypoxia in their centers, which has been associated with a marked reduction in the sensitivity of the tumor cells to anti-tumor and chemotherapeutic interventions. Here, we found that the occurrence and progress of hypoxic insensitivity to paclitaxel in non-small cell lung cancer (NSCLC) are closely associated with the HIF-1α pathway. The HIF-1α protein upregulated the expression of adipose differentiation-related protein (ADRP), fatty acid synthase (FASN), and sterol regulatory element binding protein 1(SREBP1), while simultaneously downregulating carnitine palmitoyltransferase 1 (CPT1), thereby leading to a more pronounced uptake of lipids and reduced oxidation of fatty acids. Diminished levels of fatty acids led to reduced Wnt pathway activation and β-catenin nuclear translocation, leading to G2/M cell cycle arrest. In this study, FV-429, a derivative of the natural flavonoid wogonin, reprogrammed metabolism of cancer cells and decreased fatty acid levels. Moreover, paclitaxel-induced G2/M phase arrest in hypoxia-resistant NSCLC was hampered but FV-429 improved the sensitivity of these cancer cells to paclitaxel. FV-429 activated and modulated fatty acid metabolism in NSCLC cells, significantly reduced levels of fatty acids within cells and increased the oxidation of these fatty acids. The results of our study demonstrated that FV-429 could reshape fatty acid metabolism in hypoxia-induced paclitaxel-resistant NSCLC and enhance the sensitivity of NSCLC cells to paclitaxel through G2/M phase arrest deterioration, by inactivating the Wnt pathway, and suggested the possibility of using FV-429 as a promising candidate therapeutic agent for advanced NSCLC.

Discovery of natural product ovalicin sensitive type 1 methionine aminopeptidases: molecular and structural basis

Natural product ovalicin and its synthetic derivative TNP-470 have been extensively studied for their antiangiogenic property, and the later reached phase 3 clinical trials. They covalently modify the conserved histidine in Type 2 methionine aminopeptidases (MetAPs) at nanomolar concentrations. Even though a similar mechanism is possible in Type 1 human MetAP, it is inhibited only at millimolar concentration. In this study, we have discovered two Type 1 wild-type MetAPs (Streptococcus pneumoniae and Enterococcus faecalis) that are inhibited at low micromolar to nanomolar concentrations and established the molecular mechanism. F309 in the active site of Type 1 human MetAP (HsMetAP1b) seems to be the key to the resistance, while newly identified ovalicin sensitive Type 1 MetAPs have a methionine or isoleucine at this position. Type 2 human MetAP (HsMetAP2) also has isoleucine (I338) in the analogous position. Ovalicin inhibited F309M and F309I mutants of human MetAP1b at low micromolar concentration. Molecular dynamics simulations suggest that ovalicin is not stably placed in the active site of wild-type MetAP1b before the covalent modification. In the case of F309M mutant and human Type 2 MetAP, molecule spends more time in the active site providing time for covalent modification.

Nanoparticle drug delivery systems and their use in cardiac tissue therapy

Cardiovascular diseases make up one of the main causes of death today, with myocardial infarction and ischemic heart disease contributing a large share of the deaths reported. With mainstream clinical therapy focusing on palliative medicine following myocardial infarction, the structural changes that occur in the diseased heart will eventually lead to end-stage heart failure. Heart transplantation remains the only gold standard of cure but a shortage in donor organs pose a major problem that led to clinicians and researchers looking into alternative strategies for cardiac repair. This review will examine some alternative methods of treatment using chemokines and drugs carried by nanoparticles as drug delivering agents for the purposes of treating myocardial infarction through the promotion of revascularization. We will also provide an overview of existing studies involving such nanoparticulate drug delivery systems, their reported efficacy and the challenges facing their translation into ubiquitous clinical use.

Dual-therapy with αvβ3-targeted Sn2 lipase-labile fumagillin-prodrug nanoparticles and zoledronic acid in the Vx2 rabbit tumor model

Fumagillin, an unstable anti-angiogenesis mycotoxin, was synthesized into a stable lipase-labile prodrug and incorporated into integrin-targeted lipid-encapsulated nanoparticles (αvβ3-Fum-PD NP). Dual anti-angiogenic therapy combining αvβ3-Fum-PD NP with zoledronic acid (ZA), a long-acting osteoclast inhibitor with proposed anti-angiogenic effects, was evaluated. In vitro, αvβ3-Fum-PD NP reduced (P<0.05) endothelial cell viability without impacting macrophage viability. ZA suppressed (P<0.05) macrophage viability at high dosages but not endothelial cell proliferation. 3D MR neovascular imaging of rabbit Vx2 tumors showed no effect with ZA, whereas αvβ3-Fum-PD NP alone and with ZA decreased angiogenesis (P<0.05). Immunohistochemistry revealed decreased (P<0.05) microvascularity with αvβ3-Fum-PD NP and ZA and further microvascular reduction (P<0.05) with dual-therapy. In vivo, ZA did not decrease tumor macrophage numbers nor cancer cell proliferation, whereas αvβ3-Fum-PD-NPs reduced both measures. Dual-therapy with ZA and αvβ3-Fum-PD-NP may provide enhanced neo-adjuvant utility if macrophage ZA uptake is increased. From the Clinical Editor: Although anti-angiogenesis is one of the treatment modalities in the fight against cancer, many cancers become resistant to VEGF pathway inhibitors. In this article, the authors investigated the use of dual therapy using fumagillin, integrin-targeted lipid-encapsulated nanoparticles (αvβ3- Fum-PD NP) and zoledronic acid (ZA), in both in-vitro and in-vivo experiments. This combination approach may provide an insight to the design of future drugs against cancers.

Toward a Cancer Drug of Fungal Origin

Although fungi produce highly structurally diverse metabolites, many of which have served as excellent sources of pharmaceuticals, no fungi-derived agent has been approved as a cancer drug so far. This is despite a tremendous amount of research being aimed at the identification of fungal metabolites with promising anticancer activities. This review discusses the results of clinical testing of fungal metabolites and their synthetic derivatives, with the goal to evaluate how far we are from an approved cancer drug of fungal origin. Also, because in vivo studies in animal models are predictive of the efficacy and toxicity of a given compound in a clinical situation, literature describing animal cancer testing of compounds of fungal origin is reviewed as well. Agents showing the potential to advance to clinical trials are also identified. Finally, the technological challenges involved in the exploitation of fungal biodiversity and procurement of sufficient quantities of clinical candidates are discussed, and potential solutions that could be pursued by researchers are highlighted.

Contact-facilitated drug delivery with Sn2 lipase labile prodrugs optimize targeted lipid nanoparticle drug delivery

Sn2 lipase labile phospholipid prodrugs in conjunction with contact-facilitated drug delivery offer an important advancement in Nanomedicine. Many drugs incorporated into nanosystems, targeted or not, are substantially lost during circulation to the target. However, favorably altering the pharmacokinetics and volume of distribution of systemic drug delivery can offer greater efficacy with lower toxicity, leading to new prolonged-release nanoexcipients. However, the concept of achieving Paul Erhlich's inspired vision of a 'magic bullet' to treat disease has been largely unrealized due to unstable nanomedicines, nanosystems achieving low drug delivery to target cells, poor intracellular bioavailability of endocytosed nanoparticle payloads, and the substantial biological barriers of extravascular particle penetration into pathological sites. As shown here, Sn2 phospholipid prodrugs in conjunction with contact-facilitated drug delivery prevent premature drug diffusional loss during circulation and increase target cell bioavailability. The Sn2 phospholipid prodrug approach applies equally well for vascular constrained lipid-encapsulated particles and micelles the size of proteins that penetrate through naturally fenestrated endothelium in the bone marrow or thin-walled venules of an inflamed microcirculation. At one time Nanomedicine was considered a 'Grail Quest' by its loyal opposition and even many in the field adsorbing the pains of a long-learning curve about human biology and particles. However, Nanomedicine with innovations like Sn2 phospholipid prodrugs has finally made 'made the turn' toward meaningful translational success.

alphaVbeta3-targeted copper nanoparticles incorporating an Sn 2 lipase-labile fumagillin prodrug for photoacoustic neovascular imaging and treatment

Photoacoustic (PA) tomography enables multiscale, multicontrast and high-resolution imaging of biological structures. In particular, contrast-enhanced PA imaging offers high-sensitivity noninvasive imaging of neovessel sprout formation and nascent tubules, which are important biomarkers of malignant tumors and progressive atherosclerotic disease. While gold nanoparticles or nanorods have been used as PA contrast agents, we utilized high-density copper oleate small molecules encapsulated within a phospholipid surfactant (CuNPs) to generate a soft nanoparticle with PA contrast comparable to that from gold. Within the NIR window, the copper nanoparticles provided a 4-fold higher signal than that of blood. α_νβ₃-integrin targeting of CuNPs in a Matrigel^TM angiogenesis mouse model demonstrated prominent (p<0.05) PA contrast enhancement of the neovasculature compared with mice given nontargeted or competitively inhibited CuNPs. Furthermore, incorporation of a Sn 2 lipase-labile fumagillin prodrug into the CuNP outer lipid membrane produced marked antiangiogenesis in the same model when targeted to the α_νβ₃-integrin, providing proof of concept in vivo for the first targeted PA - drug delivery agent.

Synthesis and antiproliferative activity of ligerin and new fumagillin analogs against osteosarcoma

Ligerin (1) is a natural chlorinated merosesquiterpenoid related to fumagillin (2) exhibiting a selective antiproliferative activity against osteosarcoma cell lines and an in vivo antitumor activity in a murine model. Semisynthesis of ligerin analogs was performed in order to study the effects of the C3-spiroepoxide substitution by a halogenated moiety together with the modulation of the C6 chain. Results showed that all derivatives exhibited an in vitro antiproliferative activity against osteosarcoma cell lines and that chlorohydrin compounds were equally or more active than their spiroepoxy analogs. Among semisynthetic analogs, the parent compound 1 was the best candidate for further studies since it exhibited higher or equivalent activity compared to TNP470 (3) against SaOS2 and MG63 human osteosarcoma cells with a four times weaker toxicity against HFF2 human fibroblasts. Quantitative videomicroscopy analysis was conducted and allowed a better understanding of the mechanism of its antiproliferative activity.

Do anti-angiogenic cancer therapies increase risk of significant weight loss?

INTRODUCTION

Angiogenesis is important in many disease states such as cancer. Anti-angiogenic cancer drugs are in broad use for the treatment of cancers. However, currently most of these anticancer drugs result in some adverse effects in the patient.

AREAS COVERED

In this paper, we review evidence on the association between anti-angiogenic therapies and weight loss. We report on basic experiments and clinical trials that measure weight loss with anti-angiogenic cancer therapies.

EXPERT OPINION

Few strong associations are found between anti-angiogenic cancer therapies and weight loss, with the exception of some multikinase inhibitors in clinical trials. Anti-angiogenic cancer therapies appear safe in relation to weight loss, but the result needs to be established by further clinical trials.

Lagrangian Magnetic Particle Tracking Through Stenosed Artery Under Pulsatile Flow Condition

Drug delivery technologies are an important area within biomedicine. Targeted drug delivery aims to reduce the undesired side effects of drug usage by directing or capturing the active agents near a desired site within the body. This is particularly beneficial in, for instance, cancer chemotherapy, where the side effects of general (systemic) drug administration can be severe. Herein, a numerical investigation of unsteady magnetic drug targeting (MDT) using functionalized magnetic microspheres in partly occluded blood vessels is presented considering the effects of particle-fluid coupling on the transport and capture of the magnetic particles. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ansys fluent. An implantable cylindrical permanent magnet insert is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the flow Re, magnetic insert diameter, and its radial and axial position on the “targeting efficiency” is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug-carrying magnetic particles in a predesignated target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels.

Antiangiogenesis beyond VEGF inhibition: a journey from antiangiogenic single-target to broad-spectrum agents

Although the inhibition of angiogenesis is an established modality of cancer treatment, concerns regarding toxicity and drug resistance still constitute barriers to be overcome. For almost a decade since the approval of bevacizumab in 2004, the efforts on antiangiogenic therapeutics have been mainly focused in inhibiting the VEGF pathway. The ongoing understanding of the complexity of the angiogenic process has broadened the spotlight to include concurrent and downstream players to the list of targeted inhibitors. In this review, we summarize the currently existing and the promising antiangiogenic treatments, envisioning an apparent evolutionary trend towards the development of angiogenesis inhibitors of three modalities: single-target, multi-target, and broad-spectrum agents. The clinical efficacy and some structural aspects of monoclonal antibodies, small molecules, endogenous and synthetic angiogenesis inhibitors and their molecular targets are discussed, and the targeting of endothelial cells with the use of cytotoxic drugs in a metronomic schedule is appraised. The reader is invited to revisit current expectations about antiangiogenic therapy in an attempt to set consistent clinical endpoints from which patients could gain real and lasting clinical benefits.

Nanotheranostics for personalized medicine

The application of nanotechnology in the biomedical field, known as nanomedicine, has gained much interest in the recent past, as versatile strategy for selective drug delivery and diagnostic purposes. The already encouraging results obtained with monofunctional nanomedicines have directed the efforts of the scientists towards the creation of "nanotheranostics" (i.e. theranostic nanomedicines) which integrate imaging and therapeutic functions in a single platform. Nanotheranostics hold great promises because they combine the simultaneous non-invasive diagnosis and treatment of diseases with the exciting possibility to monitor in real time drug release and distribution, thus predicting and validating the effectiveness of the therapy. Due to these features nanotheranostics are extremely attractive for optimizing treatment outcomes in cancer and other severe diseases. The following step is the attempt to use nanotheranostics for performing a real personalized medicine which will tailor optimized treatment to each patient, taking into account the individual variability. Clinical application of nanotheranostics would enable earlier detection and treatment of diseases and earlier assessment of the response, thus allowing screening for patients which would potentially respond to therapy and have higher possibilities of a favorable outcome. This concept makes nanotheranostics extremely appealing to elaborate personalized therapeutic protocols for achieving the maximal benefit along with a high safety profile. Among the several systems developed up to now, this review focuses on the nanotheranostics which, due to the promising results, show the highest potential of translation to clinical applications and may transform into concrete practice the concept of personalized nanomedicine.

Early treatment with fumagillin, an inhibitor of methionine aminopeptidase-2, prevents Pulmonary Hypertension in monocrotaline-injured rats

Pulmonary Hypertension (PH) is a pathophysiologic condition characterized by hypoxemia and right ventricular strain. Proliferation of fibroblasts, smooth muscle cells, and endothelial cells is central to the pathology of PH in animal models and in humans. Methionine aminopeptidase-2 (MetAP2) regulates proliferation in a variety of cell types including endothelial cells, smooth muscle cells, and fibroblasts. MetAP2 is inhibited irreversibly by the angiogenesis inhibitor fumagillin. We have previously found that inhibition of MetAP2 with fumagillin in bleomycin-injured mice decreased pulmonary fibrosis by selectively decreasing the proliferation of lung myofibroblasts. In this study, we investigated the role of fumagillin as a potential therapy in experimental PH. In vivo, treatment of rats with fumagillin early after monocrotaline injury prevented PH and right ventricular remodeling by decreasing the thickness of the medial layer of the pulmonary arteries. Treatment with fumagillin beginning two weeks after monocrotaline injury did not prevent PH but was associated with decreased right ventricular mass and decreased cardiomyocyte hypertrophy, suggesting a direct effect of fumagillin on right ventricular remodeling. Incubation of rat pulmonary artery smooth muscle cells (RPASMC) with fumagillin and MetAP2-targeting siRNA inhibited proliferation of RPASMC in vitro. Platelet-derived growth factor, a growth factor that is important in the pathogenesis of PH and stimulates proliferation of fibroblasts and smooth muscle cells, strongly increased expression of MetP2. By immunohistochemistry, we found that MetAP2 was expressed in the lesions of human pulmonary arterial hypertension. We propose that fumagillin may be an effective adjunctive therapy for treating PH in patients.

Circulating endothelial progenitor cells are up-regulated in a mouse model of endometriosis

Endometriosis is a debilitating disease characterized by the growth of ectopic endometrial tissue. It is widely accepted that angiogenesis plays an integral part in the establishment and growth of endometriotic lesions. Recent data from a variety of angiogenesis-dependent diseases suggest a critical role of bone marrow–derived endothelial progenitor cells (EPCs) in neovascularization. In this study we examined the blood levels of EPCs and mature circulating endothelial cells in a mouse model of surgically induced endometriosis. Fluorescence-activated cell sorting analysis revealed elevated levels of EPCs in the blood of mice with endometriosis compared with control subject that underwent a sham operation. EPC concentrations positively correlated with the amount of endometriotic tissue and peaked 1 to 4 days after induction of disease. In a green fluorescent protein bone marrow transplant experiment we found green fluorescent protein–positive endothelial cells incorporated into endometriotic lesions but not eutopic endometrium, as revealed by flow cytometry and immunohistochemistry. Finally, treatment of endometriosis-bearing mice with the angiogenesis inhibitor Lodamin, an oral nontoxic formulation of TNP-470, significantly decreased EPC levels while suppressing lesion growth. Taken together, our data indicate an important role for bone marrow–derived endothelial cells in the pathogenesis of endometriosis and support the potential clinical use of anti-angiogenic therapy as a novel treatment modality for this disease.

Preclinical therapeutic response of residual metastatic disease is distinct from its primary tumor of origin

Cancer-related deaths are caused principally by recurrence and metastasis arising from residual disease, whose therapeutic responses has been suggested to be substantially different from primary tumors. However, experimental animal models designed for evaluating the therapeutic responses of residual disease are mostly lacking. To overcome this deficiency, we have developed a preclinical model that recapitulates the progression for advanced nonsmall cell lung cancer (NSCLC). An archived Lewis lung carcinoma mouse tumor, propagated only through serial in vivo transplantation and never adapted to cell culture, was stably labeled using lentivirus-encoded biomarkers, consistently expressed through an RNA polymerase II promoter. Labeled tumors were inoculated into syngeneic immunocompetent mice to ensure superior tumor-host interactions. Primary tumors were resected on reaching a predetermined size, followed by treatment in a setting akin to postsurgical first-line adjuvant chemotherapy and routine imaging to monitor the progression of pulmonary metastasis. We discovered that efficacious treatment, instead of reducing disease growth rates, significantly prolonged disease-free survival and overall survival. As in the clinic, cisplatin-based regimes were more effective in this model. However, the response of metastases to specific agents could not be predicted from, and often opposed, their effects on subcutaneous "primary" tumors, possibly due to their distinct growth kinetics and host interactions. We here introduce a clinically relevant model of residual metastatic disease that may more accurately predict the therapeutic response of recurrent, metastatic disease.

Synergistic effect of antiangiogenic nanotherapy combined with methotrexate in the treatment of experimental inflammatory arthritis

AIM

This study examines the effect of combining the antiangiogenic effect of αvß₃-targeted fumagillin nanoparticles with the conventional antirheumatic drug methotrexate for the treatment of inflammatory arthritis.

METHOD

Arthritis was induced in mice by K/BxN serum transfer, and disease activity was monitored by clinical score and change in ankle thickness. Groups of mice received nanoparticles or methotrexate as single therapy or nanoparticles and methotrexate as combination therapy.

RESULTS

We found that animals treated with a pulse dose of fumagillin nanoparticles followed by methotrexate had significantly improved and sustained clinical response compared with those treated with either agent alone. Histological analysis confirmed a significant decrease in inflammatory cell influx, bone erosions, cartilage damage and angiogenesis with the combination therapy.

CONCLUSION

Analysis of plasma cytokine levels suggests that fumagillin nanoparticles enhanced the systemic anti-inflammatory effects of methotrexate. Antiangiogenic nanotherapy may represent a promising approach for the treatment of inflammatory arthritis when combined with a conventional antirheumatic drug.

Magnetic Drug Targeting in Partly Occluded Blood Vessels Using Magnetic Microspheres

Magnetic drug targeting can be used for treating stenosis and thrombosis in partly occluded blood vessels. Herein, a numerical investigation of magnetic drug targeting using functionalized magnetic microspheres in partly occluded blood vessels is conducted. An Eulerian-Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow. An implantable cylindrical permanent magnet insert is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted, and the influence of the flow Re, magnetic insert diameter, and its radial and axial position on the “targeting efficiency” is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug-carrying magnetic particles in a predesignated target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for an in vitro setup for the investigation of magnetic drug targeting in stenosed blood vessels.

The potential of nanomedicine therapies to treat neovascular disease in the retina

Neovascular disease in the retina is the leading cause of blindness in all age groups. Thus, there is a great need to develop effective therapeutic agents to inhibit and prevent neovascularization in the retina. Over the past decade, anti-VEGF therapeutic agents have entered the clinic for the treatment of neovascular retinal disease, and these agents have been effective for slowing and preventing the progression of neovascularization. However, the therapeutic benefits of anti-VEGF therapy can be diminished by the need for prolonged treatment regimens of repeated intravitreal injections, which can lead to complications such as endophthalmitis, retinal tears, and retinal detachment. Recent advances in nanoparticle-based drug delivery systems offer the opportunity to improve bioactivity and prolong bioavailability of drugs in the retina to reduce the risks associated with treating neovascular disease. This article reviews recent advances in the development of nanoparticle-based drug delivery systems which could be utilized to improve the treatment of neovascular disease in the retina.

Phase 1b study of motesanib, an oral angiogenesis inhibitor, in combination with carboplatin/paclitaxel and/or panitumumab for the treatment of advanced non-small cell lung cancer

PURPOSE

Motesanib is a small-molecule antagonist of vascular endothelial growth factor receptor 1, 2, and 3, platelet-derived growth factor receptor, and Kit. This phase 1b study assessed the safety, maximum tolerated dose (MTD), and pharmacokinetics, and explored the objective response of motesanib plus carboplatin/paclitaxel and/or the fully human anti-epidermal growth factor receptor monoclonal antibody panitumumab in advanced non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Patients with unresectable NSCLC received sequentially escalating doses of motesanib [50, 125 mg once daily; 75 mg twice daily] orally continuously plus carboplatin/paclitaxel (arm A; first line) or panitumumab (arm B; first and second line) once every 21-day cycle or 125 mg once daily plus carboplatin/paclitaxel and panitumumab (arm C; first line).

RESULTS

Forty-five patients received motesanib. Three dose-limiting toxicities occurred: grade 4 pulmonary embolism (n = 1; arm A, 50 mg once daily) and grade 3 deep vein thrombosis (n = 2; arm A, 125 mg once daily; arm C). The MTD was 125 mg once daily. Common motesanib-related adverse events were fatigue (60% of patients), diarrhea (53%), hypertension, (38%), anorexia (27%), and nausea (22%). Three cases of cholecystitis occurred but only in the 75-mg twice-daily schedule, which was subsequently discontinued. At 125 mg once daily, motesanib pharmacokinetics were not markedly changed with carboplatin/paclitaxel coadministration; however, exposure to paclitaxel was moderately increased. The objective response rates were 17%, 0%, and 17% in arms A, B, and C, respectively.

CONCLUSIONS

Treatment with motesanib was tolerable when combined with carboplatin/paclitaxel and/or panitumumab, with little effect on motesanib pharmacokinetics at the 125-mg once daily dose level. This dose is being investigated in an ongoing phase 3 study in NSCLC.

Roles of P67/MetAP2 as a tumor suppressor

A precise balance between growth promoting signals and growth inhibitory signals plays important roles in the maintenance of healthy mammalian cells. Any deregulation of this critical balance converts normal cells into abnormal or cancerous cells. Several macromolecules are being identified and characterized that are involved in the regulation of cell signaling pathways that connect to the cell cycle and thus they play roles as tumor promoters or tumor suppressors. In situ tumor formation needs active angiogenesis, a process that generates new blood vessels from existing ones either by splitting or sprouting. Several small molecule inhibitors and proteins have been identified as inhibitors of angiogenesis. One such protein, p67/MetAP2 also known as methionine aminopeptidase 2 (MetAP2), has been shown to bind covalently to fumagillin and its derivatives that have anti-angiogenic activity. In addition to fumagillin or its derivatives, several other small molecule inhibitors of p67/MetAP2 have been recently identified and some of these drugs are in phase III trials for cancer therapy. Although molecular details of actions toward tumor suppression by these drugs are largely unknown, a significant progress has been made to understand the structure-function relationship of p67/MetAP2 and its roles in the maintenance of the levels of phosphorylation of the proportional, variant-subunit of eukaryotic initiation factor 2 (eIF2 proportional, variant) and extracellular signal-regulated kinases 1 and 2 (ERK1/2). In this article, roles of p67/MetAP2 in the suppression of cancer development are also discussed.

Novel technologies for antiangiogenic drug delivery in the brain

Antiangiogenic therapies aimed at inhibiting the formation of tumor vasculature hold great promise for cancer therapy, with multiple compounds currently undergoing clinical trials. As with many forms of chemotherapy, antiangiogenic drugs face numerous hurdles in their translation to clinical use. Many such promising agents exhibit a short half-life, low solubility, poor bioavailability and multiple toxic side effects. Furthermore, when targeting malignant brain tumors the blood-brain barrier represents a formidable obstacle, preventing drugs from penetrating into the central nervous system (CNS). In this review, we discuss several preclinical antiangiogenic therapies and describe issues related to the unique conditions in the brain with regard to cancer treatment and neurotoxicity. We focus on the limitations of antiangiogenic drugs in the brain, along with numerous solutions that involve novel biomaterials and nanotechnological approaches. We also discuss an example in which modifying the properties of an antiangiogenic compound enhanced its clinical efficacy in treating tumors while simultaneously mitigating undesirable neurological side-effects.

The dynamics of tumour-vasculature interaction suggests low-dose, time-dense anti-angiogenic schedulings

OBJECTIVES

The administration schedule appears to be a particularly relevant factor in determining the effectiveness of an antiangiogenic drug. A better quantitative knowledge of the interactions between tumour growth and the development of its vasculature could help to design effective therapies.

MATERIAL AND METHODS

Biological and clinical inferences were derived from the analysis of a mathematical model proposed by Hahnfeldt et al. (1999), and some of its variants. In particular, we compared the effect of constant continuous infusion of an anti-angiogenic drug that induces vascular loss, to the effect of periodic, bolus-based therapy.

RESULTS AND CONCLUSIONS

The role of drug elimination rate and of dose fractionation was investigated, and we show that different schedulings, guaranteeing the same mean value of drug concentration, may exhibit very different long-term responses according to their concentration vs. time profile. For a large class of tumour growth laws, the profiles that approach the constant one are the most effective. This behaviour appears to depend on the 'cooperativity' of the tumour-vasculature interaction and on the functional form of the relationship between tumour growth and vasculature extent. Moreover, we suggest that a therapy approaching constant drug infusion might be advantageous also in the case of cytostatic anti-angiogenic drugs.

Involution of collagen-induced arthritis with an angiogenesis inhibitor, PPI-2458

Pannus formation, in both rheumatoid arthritis (RA) and collagen-induced arthritis (CIA), is angiogenesis-dependent. PPI-2458 [(1R)-1-carbamoyl-2-methyl]-carbamic acid-(3R,3S,5S, 6R)-5-methoxy-4-[(2R,3R)-2-methyl-3-(3-methyl-but-2-enyl)oxiranyl]-1-oxaspiro(2*5)oct-6-yl ester], a new fumagillin derivative known to inhibit methionine aminopeptidase 2 (MetAP-2) and endothelial proliferation at the late G(1) phase, was evaluated in CIA rats to study its potential to involute synovitis. Arthritic syngeneic LOU rats received either a vehicle control or various dosages of oral, intravenous, or subcutaneous PPI-2458. Plasma samples were analyzed to determine a pharmacokinetic profile of PPI-2458, and whole blood was evaluated by flow cytometry to assess the effect on lymphocyte subsets. At 15 mg/kg i.v., 30 mg/kg s.c., or 100 mg/kg p.o., there was a significant reduction in clinical severity scores (p < 0.001) and blinded radiographic scores (p < 0.001) compared with vehicle control groups. Structural damage was virtually eliminated with PPI-2458. Continuous inhibition of MetAP-2 was needed to maintain benefits, although pannus involution could be achieved with the inhibitor when escape flares occurred. Pharmacokinetic analysis after a single p.o. dose showed a rapid T(max) value of 15 min followed by biphasic elimination (t(1/2), approximately 20 min and t(1/2), approximately 5 h) and an estimated oral bioavailability of approximately 15%. Flow cytometry revealed a dose-dependent decrease in white blood cells and lymphocytes manifested as decreases in circulating CD3+ T cells and natural killer cells. PPI-2458, however, did not seem to be immunosuppressive, as determined by delayed-type hypersensitivity or IgG antibody assays. These studies indicate that the MetAP-2 inhibitor PPI-2458 can regress established CIA and that angiogenic mechanisms might be important targets in the treatment of other pannus-mediated diseases such as RA.

Discovery, identification, and characterization of candidate pharmacodynamic markers of methionine aminopeptidase-2 inhibition

The catalytic activity of methionine aminopeptidase-2 (MetAP2) has been pharmacologically linked to cell growth, angiogenesis, and tumor progression, making this an attractive target for cancer therapy. An assay for monitoring specific protein changes in response to MetAP2 inhibition, allowing pharmacokinetic (PK)/pharmacodynamic (PD) models to be established, could dramatically improve clinical decision-making. Candidate MetAP2-specific protein substrates were discovered from undigested cell culture-derived proteomes by MALDI-/SELDI-MS profiling and a biochemical method using (35)S-Met labeled protein lysates. Substrates were identified either as intact proteins by FT-ICR-MS or applying in-gel protease digestions followed by LC-MS/MS. The combination of these approaches led to the discovery of novel MetAP2-specific substrates including thioredoxin-1 (Trx-1), SH3 binding glutamic acid rich-like protein (SH3BGRL), and eukaryotic elongation factor-2 (eEF2). These studies also confirmed glyceraldehye 3-phosphate dehydrogenase (GAPDH) and cyclophillin A (CypA) as MetAP2 substrates. Additional data in support of these proteins as MetAP2-specific substrates were provided by in vitro MetAP1/MetAP2 enzyme assays with the corresponding N-terminal derived peptides and 1D/2D Western analyses of cellular and tissue lysates. FT-ICR-MS characterization of all intact species of the 18 kDa substrate, CypA, enabled a SELDI-MS cell-based assay to be developed for correlating N-terminal processing and inhibition of proliferation. The MetAP2-specific protein substrates discovered in this study have diverse properties that should facilitate the development of reagents for testing in preclinical and clinical environments.

An orally delivered small-molecule formulation with antiangiogenic and anticancer activity

Targeting angiogenesis, the formation of blood vessels, is an important modality for cancer therapy. TNP-470, a fumagillin analog, is among the most potent and broad-spectrum angiogenesis inhibitors. However, a major clinical limitation is its poor oral availability and short half-life, necessitating frequent, continuous parenteral administration. We have addressed these issues and report an oral formulation of TNP-470, named Lodamin. TNP-470 was conjugated to monomethoxy-polyethylene glycol-polylactic acid to form nanopolymeric micelles. This conjugate can be absorbed by the intestine and selectively accumulates in tumors. Lodamin significantly inhibits tumor growth, without causing neurological impairment in tumor-bearing mice. Using the oral route of administration, it first reaches the liver, making it especially efficient in preventing the development of liver metastasis in mice. We show that Lodamin is an oral nontoxic antiangiogenic drug that can be chronically administered for cancer therapy or metastasis prevention.

Comparative studies on conventional and microwave synthesis of some benzimidazole, benzothiazole and indole derivatives and testing on inhibition of hyaluronidase

We have synthesized twelve 2-substituted benzimidazole, benzothiazole and indole derivatives using on both microwave irradiation and conventional heating methods. The microwave method was observed to be more beneficial as it provides an increase of yield from 3% to 113% and a 95 to 98 % reduction in time. All compounds were tested by a stains-all assay at pH 7 and by a Morgan-Elson assay at pH 3.5 for hyaluronidase inhibitory activity at a concentration of 100 microM. The most potent compound was 2-(4-hydroxyphenyl)-3-phenylindole (12) with an IC(50) value of 107 microM at both pH 7 and 3.5.

A phase II trial of thalidomide and cyclophosphamide in patients with recurrent or refractory pediatric malignancies

BACKGROUND

Previous clinical and pre-clinical research has demonstrated synergy between anti-angiogenic agents and cytotoxic chemotherapy. This trial was undertaken to investigate whether the combination of cyclophosphamide and thalidomide would be active against pediatric tumors.

PROCEDURE

Patients with pediatric malignancies who had no remaining conventional therapeutic options were recruited from January 1999 to May 2001. They received thalidomide (6-12 mg/kg po every day; maximum daily dose 800 mg) and cyclophosphamide (1,200 mg/m2 IV every 28 days).

RESULTS

Twenty-seven patients were enrolled on the study. Seventeen were male and 10 were female. Median age at the time of registration was 15 years (range 1-54 years). The median number of prior treatment regimens was four. Twenty-one patients were evaluable for response; 1 had a partial response (Hodgkin disease), 1 demonstrated stable disease (neuroendocrine tumor), and 19 had progressive disease. The most common toxicities were hematological (leukocytopenia and neutropenia) and gastrointestinal. One patient experienced a grade 3 rash. Fatigue and daytime somnolence were variable. No peripheral neuropathy was observed.

CONCLUSION

The combination of thalidomide and cyclophosphamide as described herein has a modest and tolerable toxicity profile but little evidence of efficacy.

Changes in the antioxidant system by TNP-470 in an in vivo model of hepatocarcinoma

The objective of this study was to determine in a rat model of hepatocarcinoma (HCC) the effects of the antiangiogenic agent TNP-470 on antioxidant enzymes, including catalase (CAT), superoxide dismutases (Mn-SOD and Cu,Zn-SOD), and glutathione peroxidase (GPx). Tumor was induced in male Wistar rats by diethylnitrosamine and promoted by two-thirds hepatectomy plus acetaminofluorene administration. Experiments were carried out 28 weeks after initiating the treatment. TNP-470 was administered at 30 mg/kg, 2 times per week from weeks 20 to 28. Carcinomatous tissue was growing outside dysplastic nodules in rats with HCC. HCC caused oxidative stress demonstrated by increased lipid peroxidation and oxidized/reduced glutathione ratio that was accompanied by a reduced activity of antioxidant enzymes Cu,Zn-SOD, GPx, and CAT. In contrast, Mn-SOD activity and expression were higher in hepatocarcinoma than in control groups. These effects were absent in animals receiving TNP-470. No significant differences between untreated and TNP-470-treated rats were observed in the expression of the Cu,Zn-SOD, glutathione peroxidise, and CAT. We conclude that TNP-470 inhibits expression and activity of Mn-SOD induced by experimental hepatocarcinogenesis. Oxidative stress reduction by TNP-470 accounts for yet another anti-cancer effect of this molecule.

Angiogenesis and antiangiogenic therapy in endometriosis

Endometriosis, the presence of endometrium-like tissue outside of the uterine cavity, is a common disease among women of reproductive age. Typical symptoms include abdominal pain and painful menstruation. In addition, endometriosis is associated with reduced fertility. Current treatment modalities, the surgical removal of endometriotic lesions and the hormonal suppression of estrogen are associated with significant morbidity, side-effects and recurrence rates. Despite uncertainties about the pathophysiology of the disease it has recently become apparent that angiogenesis plays a pivotal role in endometriosis. This review focuses on a multitude of factors involved in the angiogenic phenotype of endometriosis demonstrating that many biological systems such as the immune system and steroid hormones are closely connected to angiogenic pathways in this disease. In addition, experimental and clinical data are discussed that concentrate on the inhibition of angiogenesis as a novel therapeutic approach for endometriosis.

Antitumor effect of TNP-470, an angiogenesis inhibitor, combined with ultrasound irradiation for human uterine sarcoma xenografts evaluated using contrast color Doppler ultrasound

Microvascular endothelial cells, which are recruited by tumors, have become an important target in cancer therapy. This study firstly examined the antitumor effect of angiogenesis inhibitor combined with ultrasound (US) irradiation for human cancer in vivo and evaluated its vascularity using color Doppler US in real time with a microbubble US contrast agent. A human uterine sarcoma cell line, FU-MMT-1, was used in vivo because this tumor is one of the most malignant neoplasms of the human solid tumors and it also has a poor response to any of the chemotherapeutic agents currently used, as well as to radiotherapy. In angiogenic inhibitors, TNP-470 was selected to use in an in vivo study, because this agent showed a higher inhibitory effect in tube formation assay in vitro, than that of FR118487, or thalidomide. The FU-MMT-1 xenografts in nude mice were treated using US at a low-intensity (2.0 w/cm(2), 1MHZ) for 4 min three times per week each after the subcutaneous injection of TNP-470 (30 mg/kg), an angiogenesis inhibitor, and this treatment was continued for 8 weeks. Either treatment of US alone or TNP-470 alone showed a suppression of tumor growth, in comparison to the non-treatment group (control), and a significantly enhanced effect was obtained using the combined treatment. A reduction in the intratumoral vascularity, which was evaluated using both color Doppler and immunohistochemistry, was significantly demonstrated using the combined treatment, in comparison to each treatment alone, and the control. No side-effect was observed in any mice in the combined treatment group. These results suggest that the antitumor effect of TNP-470 for uterine sarcoma was accelerated by US irradiation in vivo and this combination might be a potentially effective for new cancer therapy.

Emerging nanomedicine opportunities with perfluorocarbon nanoparticles

Perfluorocarbon (PFC) nanoparticles can serve as a platform technology for molecular imaging and targeted drug-delivery applications. These nanoparticles are approximately 250 nm in diameter and are encapsulated in a phospholipid shell, which provides an ideal surface for the incorporation of targeting ligands, imaging agents and drugs. For molecular imaging, PFC nanoparticles can carry very large payloads of gadolinium to detect pathological biomarkers with magnetic resonance imaging. A variety of different epitopes, including alpha(v)beta(3)-integrin, tissue factor and fibrin, have been imaged using nanoparticles formulated with appropriate antibodies or peptidomimentics as targeting ligands. Lipophilic drugs can also be incorporated into the outer lipid shell of nanoparticles for targeted delivery. Upon binding to the target cell, the drug is exchanged from the particle surfactant monolayer to the cell membrane through a novel process called 'contact facilitated drug delivery'. By combining targeted molecular imaging and localized drug delivery, PFC nanoparticles provide diagnosis and therapy with a single agent.

Methionine aminopeptidase-2 as a selective target of myofibroblasts in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, scarring lung disease characterized by fibroblast accumulation and deposition of collagen. Factors that promote growth and/or survival of fibroblasts are potential therapeutic targets. Methionine aminopeptidase 2 (MetAP2), a member of the aminopeptidase family of proteases, has been implicated in cell proliferation in a variety of cell types, but its expression and function in the lung is not known. By immunohistochemistry, MetAP2 was expressed in many cell types, including fibroblasts, in IPF lungs. Fumagillin, an irreversible inhibitor of the enzymatic activity of MetAP2, attenuated collagen deposition in the bleomycin model of acute lung injury in mice. Treatment with fumagillin caused a selective reduction in the numbers of bromodeoxyuridine (BrdU)-positive myofibroblasts, but not type II alveolar epithelial cells, macrophages, or B- and T-lymphocytes in the lungs of bleomycin-treated mice. Incubation of primary rat lung fibroblasts with either fumagillin or with short interfering RNA that targeted MetAP2 led to reduced proliferation, as assessed by incorporation of BrdU. The profibrotic growth factor, platelet-derived growth factor, increased expression of MetAP2 in rat lung fibroblasts. We propose that MetAP2 plays a role in the proliferation of fibroblasts and myofibroblasts in fibrotic lung diseases and may serve as a novel pharmacologic target in IPF.

Cell-cycle inhibition by TNP-470 in an in vivo model of hepatocarcinoma is mediated by a p53 and p21WAF1/CIP1 mechanism

The objective of this study was to determine in a rat model of hepatocellular carcinoma (HCC) the effects of the antiangiogenic agent TNP-470 on cell proliferation and effectors of the apoptotic pathway, including p53, p21WAF1/CIP1, cyclin D, and cyclin E. Tumor was induced in male Wistar rats by diethylnitrosamine and promoted by two-thirds hepatectomy plus acetaminofluorene administration. Experiments were carried out at 28 weeks after initiating the treatment. TNP-470 was administered at 30 mg/kg, 3 times per week from 20 to 28 weeks. Serum levels of vascular endothelial growth factor (VEGF) and hepatocyte growth factor beta (HGFbeta) liver expression were increased by hepatocarcinogenesis (+38% and +183%, respectively), and treatment with TNP-470 was able to prevent the increase in these angiogenic factors induced by HCC. HCC coursed with reduced expression of p21WAF1/CIP1 and p53 (-63% and -60%, respectively). Hepatic expression of cyclin D and cyclin E were significantly increased in rats with HCC (+108% and +115%, respectively). In animals with experimental carcinogenesis, a significant increase in the expression of Cdk4 and CdK2 was also observed (+119% and +187%, respectively). These effects were prevented by TNP-470 administration. In conclusion, cell-cycle inhibition by TNP-470 is mediated at least in part by an activation of p21WAF1/CIP1 because of a p53-dependent mechanism, with reduction of the cyclin D-Cdk4 and cyclin E-Cdk 2 expression. These cytostatic effects should be considered when assessing the efficacy of TNP-470 for anti-angiogenic therapy. These findings may prove useful for the development of therapies for the treatment of human HCC.

Anti-angiogenic drugs: from bench to clinical trials

Angiogenesis, the generation of new capillaries through a process of pre-existing microvessel sprouting, is under stringent control and normally occurs only during embryonic and post-embryonic development, reproductive cycle, and wound repair. However, in many pathological conditions (solid tumor progression, metastasis, diabetic retinopathy, hemangioma, arthritis, psoriasis and atherosclerosis among others), the disease appears to be associated with persistent upregulated angiogenesis. The development of specific anti-angiogenic agents arises as an attractive therapeutic approach for the treatment of cancer and other angiogenesis-dependent diseases. The formation of new blood vessels is a complex multi-step process. Endothelial cells resting in the parent vessels are activated by an angiogenic signal and stimulated to synthesize and release degradative enzymes allowing endothelial cells to migrate, proliferate and finally differentiate to give rise to capillary tubules. Any of these steps may be a potential target for pharmacological intervention. In spite of the disappointing results obtained initially in clinical trials with anti-angiogenic drugs, recent reports with positive results in phases II and III trials encourage expectations in their therapeutic potential. This review discusses the current approaches for the discovery of new compounds that inhibit angiogenesis, with emphasis on the clinical developmental status of anti-angiogenic drugs.

Nanomedicine Opportunities in Cardiology

Despite myriad advances, cardiovascular-related diseases continue to remain our greatest health problem. In more than half of patients with atherosclerotic disease, their first presentation to medical attention becomes their last. Patients often survive their first cardiac event through acute revascularization and placement of drug-eluting stents (DES), but only select coronary lesions are amenable to DES placement, resulting in the use of bare metal or no stent, both of which lack the benefit of antirestenotic therapy. In other patients, transient ischemic attacks (TIAs) and stroke constitute the initial presentation of disease. In these patients, the diagnostic and therapeutic options are woefully inadequate. Nanomedicine offers options to each of these challenges. Antiangiogenic paramagnetic nanoparticles may be used to serially assess the severity of atherosclerotic disease in asymptomatic, high-risk patients by detecting the development of plaque neovasculature, which reflects the underlying lesion activity and vulnerability to rupture. The nanoparticles can locally deliver antiangiogenic therapy, which may acutely retard plaque progression, allowing aggressive statin therapy to become effective. Moreover, these agents may be useful as a quantitative marker to guide atherosclerotic management in an asymptomatic patient. In those cases proceeding to the catheterization laboratory for revascularization, nanoparticles incorporating antirestenotic drugs can be delivered directly into the wall of lesions not amenable to DES placement. Targeted nanoparticles could help ensure that antirestenotic drugs are available for all lesions. Moreover, displacement of antiproliferative agents from the intimal surface into the vascular wall is likely to improve rehealing of the endothelium, improving postprocedural management of these patients.

Nanomedicine opportunities for cardiovascular disease with perfluorocarbon nanoparticles

Nanomedicine promises to enhance the ability of clinicians to address some of the serious challenges responsible for cardiovascular mortality, morbidity and numerous societal consequences. Targeted imaging and therapy applications with perfluorocarbon nanoparticles are relevant to a broad spectrum of cardiovascular diseases, ranging from asymptomatic atherosclerotic disease to acute myocardial infarction or stroke. As illustrated in this article, perfluorocarbon nanoparticles offer new tools to recognize and characterize pathology, to identify and segment high-risk patients and to treat chronic and acute disease.