Pharmacotherapy of neuroblastoma

Importance of the field: Neuroblastoma, a tumor of the sympathetic nervous system, is the most common extracranial solid tumor of early life. High risk disease in older children remains a therapeutic challenge, despite high-intensity therapy with correspondingly significant short- and long-term toxicities.

Areas covered in this review: We have reviewed therapy for neuroblastoma over the last three decades. This includes cytotoxic chemotherapy, immunotherapy, radionuclides, antiangiogenic compounds, and molecularly targeted agents. We provide a perspective on the incorporation of these drugs into therapy for neuroblastoma.

What the reader will gain: The reader will gain a better understanding of these novel agents and their targets in neuroblastoma. The reader will also gain insight into the need to define through sequential, carefully designed clinical trials, the roles and toxicities of these therapies, especially if the combination of targeted and conventional cytotoxic agents is used.

Take home message: Advanced-stage neuroblastoma in older infants and children remains a disease that is difficult to cure. New, targeted agents may improve both the therapeutic index and the outcome, but are, for the most part, in early development and present a challenge for clinical trial design given both the rarity of this disease and its responsiveness (albeit incomplete) to currently used cytotoxic agents.     

Mouse models in squamous cell lung cancer: impact for drug discovery

Introduction: Squamous cell lung cancer (SQCLC) is the second most common subtype of non-small cell lung cancer (NSCLC) and has limited therapeutic options. Its development is likely a result of a multistep process in response to chronic tobacco exposure, involving sequential metaplasia, dysplasia and invasive carcinoma. Its complex genomic landscape has recently been revealed but no driver mutations have been validated that could lead to molecularly targeted therapy as have emerged in lung adenocarcinoma. Few preclinical murine models exist for testing and developing novel therapeutics in SQCLC.

Areas covered: This review discusses the pathophysiology and molecular underpinnings of SQCLC that have limited the development of animal models. It then explores the advantages and limitations of a variety of existing mouse models and illustrates their potential application in drug discovery and chemoprevention.

Expert opinion: There are several challenges in the development of mouse models for SQCLC, such as lack of validated driver genetic alterations, unclear cell of origin, and difficulty in reproducing the sophisticated tumor microenvironment of human disease. Nevertheless, several successful SQCLC murine models have emerged, especially Patient Derived Xenografts (PDXs) and Genetically Engineered Mouse Models (GEMMs). Continued efforts are needed to generate more SQCLC animal models to better understand its carcinogenesis and metastasis and to further test novel therapeutic strategies.     

Investigational therapies for squamous cell lung cancer: from animal studies to phase II trials

Introduction: It remains challenging to treat squamous cell lung cancer (SCC) with limited therapeutic options. However, recent breakthroughs in targeted therapies and immunotherapies have shed some light on the management of this deadly disease.

Areas covered: The article first reviews the current treatment options for advanced SCC, especially recent FDA approved molecular agents (afatinib, ramucirumab and necitumumab) and immunotherapies (nivolumab, pembrolizumab and atezolimumab). We then provide an overview on investigational therapies with data ranging from preclinical to phase II studies, focusing on new cytotoxic agents, emerging molecularly targeted agents (including a PARP inhibitor for Homologous Recombinant Deficiency positive SCC) and novel immunotherapeutic strategies.

Expert opinion summary: Identification of potential therapeutic targets, development of novel clinical trials and the rapid approvals of immune checkpoint inhibitors have shifted the management paradigm for squamous cell lung cancer. On the other hand, continued efforts are needed to identify the predictive biomarkers and to investigate novel mechanistically-driven mono- and combination therapies. We need to learn more about the biology behind immune checkpoint blockade and tumor genomics in SCC for better patient selection and future trial design.     

Targeted therapy of hepatocellular cancer

Importance of the field: Hepatocellular cancer (HCC) is the fifth most common malignancy worldwide and third leading cause of cancer death. HCC is highly resistant to conventional systemic therapies, and prognosis for advanced HCC patients remains poor. However, identification of signaling pathways responsible for HCC growth and progression such as RAS/RAF/MEK/ERK or PI3K/AKT/mTOR has determined crucial molecular targets and led to development of novel promising targeted therapies.

Areas covered in this review: This article presents molecular mechanisms responsible for development and progression of HCC and strategies aimed to block important molecules involved in signal transduction. It also reviews the clinical studies evaluating efficacy and safety of novel targeted approaches for treatment of this malignancy.

What the reader will gain: Inhibition of molecular targets (ligands, membrane receptors and receptor-associated kinases) represents a promising strategy for treatment of HCC; in the case of sorafenib, this has already been demonstrated to significantly improve survival of advanced HCC patients. This article reviews novel therapeutic approaches that are based on combinations of different targeted agents with or without classic cytotoxic drugs.

Take home message: Despite significant progress, advanced HCC remains an incurable disease, and the overall efficacy of recently approved targeted therapy (sorafenib) remains moderate. It is to be hoped that several ongoing clinical trials evaluating novel targeted approaches for treatment of HCC will lead to further improvement in the management of advanced disease.     

Novel inhibitors in development for hepatocellular carcinoma

Importance of the field: The multikinase inhibitor sorafenib was the first agent to demonstrate a survival benefit for patients with locally advanced or metastatic hepatocellular carcinoma (HCC). Although sorafenib represents a landmark in the treatment of HCC and proved molecularly targeted therapy to be effective in this disease, it represents just the first step towards an improvement in systemic therapy. Since then, novel inhibitors have been evaluated in early clinical trials, showing potential activity.

Areas covered in this review: This article aims to review novel inhibitors emerging in the field of advanced HCC. An Internet-based search was performed to identify abstracts, clinical trials (www.clinicaltrials.gov, last accessed 30 November 2009), and original research and review articles.

What the reader will gain: Readers will gain a comprehensive survey of current molecularly targeted therapy approaches in advanced HCC. In addition, challenges such as the design of clinical trials, the assessment of radiological response, the role of combination therapy, and future developments in molecularly targeted therapy are discussed.

Take home message: Sorafenib is the standard of care in patients with advanced HCC. However, promising novel inhibitors are under investigation. Combined molecularly targeted therapies according to an individual genomic and proteomic profiling will probably lead to more personalised medicine in advanced HCC.     

BIBF 1120/nintedanib: a new triple angiokinase inhibitor-directed therapy in patients with non-small cell lung cancer

Introduction: Several new targeted agents with anti-angiogenic properties have been developed recently, including vandetanib, sunitinib, sorafenib, bevacizumab and others. Tumor development, progression, metastasis are strongly linked to angiogenesis. Targeted agents like bevacizumab, a monoclonal antibody which targets VEGF, have been fully developed in several solid tumors. These new agents strongly advocate that targeting angiogenesis is one of the best approaches for cancer therapy.

Areas covered: Those agents that target additional pro-angiogenic intracellular signaling pathways beyond VEGF signaling have also the potential to contribute to anticancer therapies. The authors present here nintedanib (BIBF 1120), a triple angiokinase inhibitor. It targets not only VEGFRs, but also FGFR and PDGFR. All the available clinical information regarding Phase I – II trials and the toxicity and efficacy of BIBF 1120 both as single agent and in combination with cytotoxic agents in non-small cell lung cancer (NSCLC) is reviewed and discussed here.

Expert opinion: Up till now, Phase I and II trials with nintedanib showed an improvement for survival of advanced NSCLC patients. Tolerability profile seems to be acceptable in these clinical trials. However, Phase III trials are mandatory to translate these findings into clinical practice. The research for predictive biomarkers could improve the success of these anti-angiogenic agents.     

Vandetanib for the treatment of non-small-cell lung cancer

Introduction: The use of targeted therapies in the treatment of advanced non-small-cell lung cancer (NSCLC) is increasing, especially as conventional chemotherapy affords relatively small benefits at a cost of increased toxicity. Two of the more established therapeutic targets in NSCLC are the vascular endothelial growth factor receptor (VEGFR) and epidermal growth factor receptor (EGFR). Vandetanib is an orally available inhibitor of VEGFR and EGFR signalling and is an attractive therapeutic agent owing to the simultaneous inhibition of both pathways.

Areas covered: This review encompasses the clinical efficacy, safety and tolerability of vandetanib in advanced NSCLC. Of particular interest are the randomized Phase III clinical trials, which did not show clinically significant overall survival benefit for vandetanib monotherapy or in combination with standard chemotherapy regimens.

Expert opinion: Vandetanib has anti-tumour activity in NSCLC, with improved objective responses and disease control. However, significant survival benefits were not demonstrated in Phase III clinical trials and at present vandetanib is not in further development for use in NSCLC.     

Advances in chemotherapy in advanced non-small-cell lung cancer

Importance of the field: Lung cancer is the most common cancer in the world today, in terms of both incidence and mortality. Non-small-cell lung cancer (NSCLC) accounts for about 85% of all lung cancers diagnosis, and the majority of people diagnosed with NSCLC have advanced disease.

Areas covered in this review: In this review the main advances achieved in the medical treatment of advanced NSCLC are discussed, regarding both targeted therapies and chemotherapy. Among targeted therapies, recent data on the anti-vascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab and the epidermal growth factor receptor tyrosyne kinase inhibitors (EGFR-TKIs) gefitinib and erlotinib are described. Among chemotherapeutic agents, the role of pemetrexed is discussed.

What the reader will gain: The reader will gain up-to-date information on the main advances, achieved in the last 3 years in the medical treatment of advanced NSCLC.

Take home message: Some recent advances have changed the face of the first-line chemotherapy of advanced NSCLC, giving physicians more options to tailor choice in this challenging setting.     

New drug targets in Kaposi sarcoma

Importance of the field: Kaposi sarcoma (KS) occurs as a result of Kaposi sarcoma-associated herpesvirus (KSHV) infection, typically in the context of an immunodeficient state such as coinfection with HIV or transplantation. Systemic treatment of KS has traditionally involved one of several chemotherapeutic agents either in combination or as single agents, which typically provides reasonable response rates and short-term control. However, recurrence of KS is common and progression-free intervals are short. For these reasons, new therapies are being sought.

Areas covered in this review: This review describes the contemporary pathobiology of KS targets, current limitations of standard treatment options, and examines the findings of completed and ongoing clinical trials of novel, molecularly targeted treatments for patients with KS.

What the reader will gain: The reader will be presented with key clinicopathological characteristics and the pathogenesis of KS. Standard therapy for KS is reviewed including local, regional and systemic treatments. Molecular targets related to LANA-mediated and vGPCR-mediated signaling, angiogenesis, apoptosis and KSHV replication are discussed in detail. The reader will be provided with a compilation of agents, their mechanism of action, and results on various molecularly target agents in KS.

Take home message: With the elucidation of novel pathogenic mechanisms of KS including KSHV replication, restoration of immune competence and signal transduction pathways utilized by KSHV in the propagation of KS, rational therapeutic targets have been identified.     

Advances in pharmacotherapy of small cell lung cancer

Introduction: Small cell lung cancer (SCLC) is an aggressive malignancy characterized by early metastatic dissemination and responsiveness to initial therapy. The incidence of SCLC has been declining over the past two decades. Limited-stage SCLC is a potentially curable disease with long-term survival of ～ 20% when treated with platinum-based chemotherapy plus concurrent thoracic radiation and prophylactic cranial irradiation. For patients with extensive-stage SCLC, survival can be increased with combination platinum-based chemotherapy, but the disease remains incurable.

Areas covered: This review looks at the current advances in pharmacotherapy for SCLC.

Expert opinion: Many chemotherapeutic strategies and newer cytotoxic agents have been evaluated in SCLC, and some had promising activity in early clinical trials. However, none have demonstrated consistent improvements in outcome over standard platinum-based treatment. Similarly, although many potential molecular targets have been identified in preclinical studies of SCLC, molecularly targeted therapy has yet to demonstrate any substantial activity in clinical trials. Nonetheless, future advances in this disease will undoubtedly depend on improvements in our understanding of the molecular mechanisms that drive the proliferation and survival of SCLC cells.     

Current and emerging treatment options in the management of advanced ovarian cancer

Introduction: Epithelial ovarian cancer is the most lethal gynecologic malignancy. Recent advances in understanding the biology and its molecular and histological diversity have led to mechanism based therapeutic strategies such as poly-ADP-ribose polymerase inhibitors (PARP) targeting homologous recombination deficient tumor cells and anti-angiogenic therapies. Clinical trial designs in ovarian cancer have to evolve to incorporate assessment of the genomic complexity and identify predictive biomarkers to improve precision of treatment and outcome.

Areas covered: This review summarizes present-day strategies used in the management of ovarian cancer and novel promising therapeutic approaches in development. The article is based on English peer-reviewed articles located on MEDLINE and related abstracts presented at major international meetings.

Expert opinion: Two types of molecular targeted therapies, anti-angiogenics and PARP inhibitors, have been shown to be active in randomized clinical trials and approved by regulatory agencies. Management of ovarian cancer is poised to change with the continued advancement of precision medicine that is founded upon improved understanding of disease biology; separation into histologically and molecularly defined subgroups; and the incorporation of this new knowledge into early phase drug development and novel clinical trial design.     

Antivascular agents for non-small-cell lung cancer: current status and future directions

Background: Despite improvements in surgery and chemo(radio)therapy which have allowed for modest advances in the treatment of patients with non-small-cell lung cancer (NSCLC), survival remains poor and further improvements are needed. Attention over recent years has focused, therefore, on targeted therapies, with notable success in the development of antivascular drugs. Objective: To summarize the current knowledge on antivascular therapy in patients with NSCLC. Method: Review of randomized controlled trials exploring treatment of NSCLC patients with antivascular drugs. Results/conclusion: Bevacizumab, a humanized monoclonal antibody against the vascular endothelial growth factor (VEGF), when added to cytotoxic chemotherapy, was the first treatment to prolong the overall survival of patients with advanced NSCLC beyond 12 months, a significant breakthrough in the management of advanced NSCLC. Small-molecule tyrosine kinase inhibitors and alternative antivascular strategies such as VEGF-trap and vascular disrupting agents are also being investigated and have shown promise in clinical trials. This review summarizes the most recent and important findings in antivascular agents in NSCLC.     

Pharmacological management of Kaposi's sarcoma

Introduction: Kaposi's sarcoma (KS) is an angioproliferative disease that occurs in four clinical-epidemiological forms sharing the same immunological and histopathological features, suggesting common etiological and pathogenic factors. Infection with the human herpesvirus 8, cytokine- and angiogenic factor-induced growth together with an immuno-dysregulated state represent fundamental conditions for the development of this tumor. Despite the recent improvements in KS management, it remains an incurable disease.

Areas covered: The growing knowledge of KS biology provides multiple opportunities for the development of rational, molecularly targeted therapies. The present review summarizes the current management of KS, including local and systemic conventional therapies, and thoroughly describes the results obtained with new pathogenesis-based anti-KS treatments.

Expert opinion: Kaposi's sarcoma represents a paradigm of how the elucidation of disease pathogenesis can drive the development of molecularly targeted treatments. The multifactorial pathogenesis of KS has led to the evaluation of many experimental agents targeting one or more specific factors or pathways involved in the development or progression of the disease. Although targeted therapy so far represents investigational treatment, clinical evaluation of several of these agents is yielding promising results.     

Molecular targeted therapy for patients with melanoma: the promise of MAPK pathway inhibition and beyond

Importance of the field: Recent discoveries have expanded the understanding of the molecular signaling events critical to melanomagenesis and led to the development of targeted therapeutic agents that are revolutionizing the treatment of patients with advanced melanoma.

Areas covered in this review: This article reviews current therapy and its limitations, describes the key pathogenic mechanisms in melanoma for which inhibitors have been tested, and summarizes the results of clinical trials involving molecularly targeted agents in this disease.

What the reader will gain: There has been an explosion of preclinical and clinical research aimed at targeting the key molecular alterations in melanoma for therapeutic benefit. These findings will be presented and placed in the proper clinical context, affording information regarding the current molecular targets in the melanoma and the activity and limitations of therapeutic agents directed against them.

Take home message: Greater understanding of the pathogenic mechanisms underlying melanoma development has prompted the development of new therapeutic approaches aimed at counteracting these processes. While progress made over the past few years has generated considerable excitement, the benefits of these new therapies are still limited by incomplete and transient tumor regressions. It is hoped that with further investigation, particularly into mechanisms of treatment de novo and acquired treatment resistance, these limitations can be overcome.     

Metformin in lung cancer: rationale for a combination therapy

Introduction: Metformin is a widely used antidiabetic drug, which also displays significant growth inhibitory and proapoptotic effects in several cancer models, including lung cancer, alone or in combination with chemotherapeutic drugs.

Areas covered: The role of metformin as a chemopreventive drug in lung cancer is still an object of debate as epidemiological studies have shown contrasting results. More preclinical data support its role as an adjuvant drug in the treatment of lung cancer, in combination with chemotherapy or targeted molecular drugs, although the complete mechanism of action of metformin is still unclear, and potentially may exert unexpected effects with contradictory clinical implications.

Expert opinion: Future perspective studies are required in nonsmall-cell lung cancer (NSCLC) patients to better investigate the effect of metformin action on the RAS/RAF/MAPK pathway and the best context in which to use metformin in combination with molecularly targeted agents.     

Targeted Agents in Preclinical and Early Clinical Development for the Treatment of Cancer Bone Metastases

Introduction: Bone is one of the preferential organs affected in patients with metastatic cancers. Bone metastases contribute substantially to morbidity and mortality in cancer patients, especially for those with breast and prostate cancer. Bisphosphonates and denosumab, potent inhibitors of osteoclastic bone resorption, are the current standard of care for bone metastases; however, their effects are palliative. Recent preclinical studies have revealed a variety of potential targets for the development of novel therapeutic agents. Some of these are currently being evaluated in clinical trials.

Areas covered: This paper reviews the preclinical and early clinical development of molecularly targeted agents for the treatment of bone metastases. The agents are categorized according to their targets, osteoclasts, osteoblasts, metastatic cancer cells, and the bone microenvironment.

Expert opinion: Recent advances in our understanding of the molecular and cellular mechanisms of bone metastases have led to the development of novel therapeutic options. Although most of their effects have yet to be proved in clinical studies, it is the author’s belief that they will contribute significantly to improving the treatment outcome of patients with bone metastases in the near future.     

Emerging drugs for renal cell carcinoma

Importance of the field: The treatment of metastatic renal cell carcinoma (RCC) has evolved significantly over the past 5 years and targeted therapy has become the standard of care. However, complete and lasting responses to these drugs are still uncommon. Currently, novel agents are being tested in clinical trials.

Areas covered in this review: We discuss approved targeted agents in RCC and emphasize on emerging therapies. We searched the US National Library of Medicine (PubMed) using the terms ‘renal cell carcinoma’, ‘targeted therapy’ and ‘novel agents’, from 1990 to the present. We also searched for abstracts from the meetings of the American Society of Clinical Oncology and Genitourinary Cancers Symposium from 2007 to the present.

What the reader will gain: This paper provides understanding of the approved treatments for advanced RCC as well as the novel agents and their targeted biological pathways.

Take home message: Despite dynamic and recent advances in the management of metastatic RCC much about the molecular biology of this tumor has yet to be delineated. Even more so, strategies of sequential treatment, combination of targeted drugs, mechanisms of resistance, optimal dosages and scheduling remain areas of potential development interest.     

Targeting epidermal growth factor receptor in the treatment of non-small-cell lung cancer

Importance of the field: The management of non-small-cell lung cancer (NSCLC) has undergone a paradigm shift in the last decade, with the survival advantage demonstrated by the incorporation of anti-epidermal growth factor receptor (EGFR) agents to the standard treatment of advanced/metastatic NSCLC.

Areas covered in this review: We review the existing data regarding the distinct anti-EGFR agents in the NSCLC treatment and the potential role of the investigated biomarkers in the clinical outcome.

What the reader will gain: Tyrosine kinase inhibitors have been used in first-line, second-line and more settings with extremely good results in a subgroup of patients. Cetuximab remains the only anti-EGFR monoclonal antibody to show survival benefit when combined with a cytotoxic agent in the front-line setting. Anti-EGFR treatment is associated with a dramatic clinical benefit in a subgroup of patients, emphasizing the importance of customizing treatment. Several biomarkers have been investigated for their predictive or prognostic value. Validation of identification of biomarkers remains a focus of intense research that may ultimately guide therapeutic decision making, as none of these is considered ideal to discriminate responding from non-responding patients. However, the current evidence of the EGFR mutation analysis from a recent randomised trial suggests that EGFR mutation analysis is quite a good predictive marker for responsiveness to anti-EGFR TKIs. Moreover, the identification of surrogate markers to indicate optimal activity of the anti-EGFR agent is also needed. This review article provides data from large clinical trials using anti-EGFR agents and correlates these results with the tested biomarkers.

Take home message: EGFR inhibition has shown very encouraging results and has improved the outcome of the NSCLC treatment. However, a plateau of significant clinical benefit seems to have been reached and we believe that the time to move away from the traditional treatment approach to more individualizing therapies has come.     

Emerging paradigms in targeted treatments for Asian patients with NSCLC

Introduction: EGFR-targeted drugs have been successfully approved in many countries and have demonstrated higher efficacy and lower toxicity than chemotherapy in molecularly defined subgroups of patients. Significant advances in clinical trials and studies focusing on targeted therapies have rapidly developed in Asia.

Areas covered: In the present review article, all of the published data or meeting abstracts on completed or ongoing trials of targeted treatment for Asian patients with NSCLC were collected and analyzed.

Expert opinion: Routine molecular testing has been used clinically to identify mutations/fusions and guide patient selection for targeted therapies. Based on the evidence presented, we provided up-to-date treatment recommendations for Asian patients with advanced NSCLC. Future directions, including dividing Del19 and L858R patients into two distinct populations, will optimize therapeutic strategies for L858R patients and may inform rational trial design by considering the proportion of type of sensitive EGFR mutation as a stratification factor. Another important aspect to consider involves how to monitor resistance to TKIs, which will improve the outcome for lung cancer patients with driver gene mutations.