Vandetanib for the treatment of thyroid cancer: an update

Drugging Hijacked Kinase Pathways in Pediatric Oncology: Opportunities and Current Scenario

Childhood cancer is considered rare, corresponding to ~3% of all malignant neoplasms in the human population. The World Health Organization (WHO) reports a universal occurrence of more than 15 cases per 100,000 inhabitants around the globe, and despite improvements in diagnosis, treatment and supportive care, one child dies of cancer every 3 min. Consequently, more efficient, selective and affordable therapeutics are still needed in order to improve outcomes and avoid long-term sequelae. Alterations in kinases' functionality is a trademark of cancer and the concept of exploiting them as drug targets has burgeoned in academia and in the pharmaceutical industry of the 21st century. Consequently, an increasing plethora of inhibitors has emerged. In the present study, the expression patterns of a selected group of kinases (including tyrosine receptors, members of the PI3K/AKT/mTOR and MAPK pathways, coordinators of cell cycle progression, and chromosome segregation) and their correlation with clinical outcomes in pediatric solid tumors were accessed through the R2: Genomics Analysis and Visualization Platform and by a thorough search of published literature. To further illustrate the importance of kinase dysregulation in the pathophysiology of pediatric cancer, we analyzed the vulnerability of different cancer cell lines against their inhibition through the Cancer Dependency Map portal, and performed a search for kinase-targeted compounds with approval and clinical applicability through the CanSAR knowledgebase. Finally, we provide a detailed literature review of a considerable set of small molecules that mitigate kinase activity under experimental testing and clinical trials for the treatment of pediatric tumors, while discuss critical challenges that must be overcome before translation into clinical options, including the absence of compounds designed specifically for childhood tumors which often show differential mutational burdens, intrinsic and acquired resistance, lack of selectivity and adverse effects on a growing organism.

Anlotinib in Locally Advanced or Metastatic Medullary Thyroid Carcinoma: A Randomized, Double-Blind Phase IIB Trial

PURPOSE

Medullary thyroid cancer (MTC) accounts for about 2% of all thyroid cancer, but has a relatively poor prognosis compared with differentiated thyroid cancer. Anlotinib is a novel multitarget tyrosine kinase inhibitor targeting VEGFR, PDGFR, FGFR, and c-Kit. This multicenter, randomized, double-blind, placebo-controlled phase IIB study (ALTER 01031 and NCT02586350) was conducted to investigate the efficacy and safety of anlotinib in MTC.

PATIENTS AND METHODS

Patients with histopathologically confirmed, unresectable locally advanced or metastatic MTC were enrolled and randomly assigned in a 2:1 ratio to receive anlotinib (12 mg once daily from day 1 to 14 every 3 weeks) or placebo. Patients in placebo group were allowed to receive open-label anlotinib after disease progression. The primary endpoint was progression-free survival (PFS); secondary endpoints included objective response rate (ORR), disease control rate (DCR), and overall survival (OS).

RESULTS

Ninety-one patients were enrolled. At data cutoff date, the median PFS was significantly prolonged in the anlotinib group than in the placebo group (20.7 months vs. 11.1 months, P = 0.029; HR, 0.53; 95% confidence interval, 0.30-0.95). The ORR of anlotinib treatment was 48.4%. The incidence of treatment-related adverse events (TRAE) was 100% and 89.7% in the anlotinib and placebo groups, respectively. The most common TRAEs of all grades in the anlotinib group were palmar-plantar erythrodysesthesia syndrome (62.9%), proteinuria (61.3%), and hypertriglyceridemia (48.4%).

CONCLUSIONS

Anlotinib demonstrates its efficacy and safety in this phase IIB trial for the treatment of MTC and may become a new choice for this rare disease, especially for Chinese patients.

Autophagy as a molecular target for cancer treatment

Autophagy is an evolutionarily conserved catabolic mechanism, by which eukaryotic cells recycle or degrades internal constituents through membrane-trafficking pathway. Thus, autophagy provides the cells with a sustainable source of biomolecules and energy for the maintenance of homeostasis under stressful conditions such as tumor microenvironment. Recent findings revealed a close relationship between autophagy and malignant transformation. However, due to the complex dual role of autophagy in tumor survival or cell death, efforts to develop efficient treatment strategies targeting the autophagy/cancer relation have largely been unsuccessful. Here we review the two-faced role of autophagy in cancer as a tumor suppressor or as a pro-oncogenic mechanism. In this sense, we also review the shared regulatory pathways that play a role in autophagy and malignant transformation. Finally, anti-cancer therapeutic agents used as either inhibitors or inducers of autophagy have been discussed.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Cell surface receptors and associated signaling pathways)

BACKGROUND

The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) consensus document on the safety of targeted and biologic therapies.

AIMS

To review, from an infectious diseases perspective, the safety profile of therapies targeting cell surface receptors and associated signaling pathways among cancer patients and to suggest preventive recommendations.

SOURCES

Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family.

CONTENT

Vascular endothelial growth factor (VEGF)-targeted agents (bevacizumab and aflibercept) are associated with a meaningful increase in the risk of infection, likely due to drug-induced neutropaenia, although no clear benefit is expected from the universal use of anti-infective prophylaxis. VEGF tyrosine kinase inhibitors (i.e. sorafenib or sunitinib) do not seem to significantly affect host's susceptibility to infection, and universal anti-infective prophylaxis is not recommended either. Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab or panitumumab) induce neutropaenia and secondary skin and soft tissue infection in cases of severe papulopustular rash. Systemic antibiotics (doxycycline or minocycline) should be administered to prevent the latter complication, whereas no recommendation can be established on the benefit from antiviral, antifungal or anti-Pneumocystis prophylaxis. A lower risk of infection is reported for anti-ErbB2/HER2 monoclonal antibodies (trastuzumab and pertuzumab) and ErbB receptor tyrosine kinase inhibitors (including dual-EGFR/ErbB2 inhibitors such as lapatinib or neratinib) compared to conventional chemotherapy, presumably as a result of the decreased occurrence of drug-induced neutropaenia.

IMPLICATIONS

With the exception of VEGF-targeted agents, the overall risk of infection associated with the reviewed therapies seems to be low.

Synthesis of 4-phenyl-5,6-dihydrobenzo[h]quinazolines and their evaluation as growth inhibitors of carcinoma cells

The synthesis of various benzo[h]quinazoline analogs was accomplished through the reaction of chalcone with guanidine. The synthesized compounds were screened for their anticancer potential against different cancer cells.

The multi-targeted tyrosine kinase inhibitor vandetanib plays a bifunctional role in non-small cell lung cancer cells

Vandetanib, a multikinase inhibitor, is a target of drug treatments for non-small cell lung cancer (NSCLC). However, phase II and III clinical trials have not conclusively demonstrated the curative effects of vandetanib for NSCLC, and the reasons for this are unknown. In the present study, we use the NSCLC cell line Calu-6 as a model to determine the cellular and biological effects of vandetanib. Our results demonstrate that vandetanib impairs Calu-6 cell migration and invasion. We find that vandetanib can directly inhibit RET activity, which influences the Rho-JNK pathway. Overexpression of a constitutively active Rho GTPase antagonizes the inhibitory effects of vandetanib on Calu-6 cells invasion and JNK pathway activation. In addition, vandetanib induces autophagy by increasing the level of reactive oxygen species (ROS) in Calu-6 cells, and blockade of autophagy or ROS effectively enhances the cell death effect of vandetanib. In this study, we find vandetanib is of a double effect in some NSCLC cells, presenting new possibilities for the pharmacological treatment of NSCLC and introducing a novel role for vandetanib in treatment options.

Patterns of thyroid hormone levels in pediatric medullary thyroid carcinoma patients on vandetanib therapy

BACKGROUND

Tyrosine kinase inhibitors (TKIs) have been associated with elevated TSH as a drug class effect. Prior studies of vandetanib in adults with medullary thyroid carcinoma (MTC) described an increase in levothyroxine (LT) requirement. We studied TSH, free T4, and LT dosing in children and adolescents enrolled in the phase I/II trial of vandetanib for medullary thyroid cancer (MTC).

METHODS

Data from 13 patients with multiple endocrine neoplasia type 2B (MEN 2B) and MTC were analyzed [6 M, 7 F, median age 13.0 y (9.1-17.3)] Eleven patients (85%) had undergone prior thyroidectomy and all received single-drug therapy with vandetanib for > 6 months. Confirmed compliance with vandetanib (67-150 mg/m(2)/day) and LT was a necessary inclusion criterion.

RESULTS

While on vandetanib treatment, all 11 athyerotic patients exhibited significantly increased TSH levels. The baseline TSH level was 4.37 mclU/ml (0.08 - 23.30); in comparison, the first peak TSH concentration on vandetanib was 15.70 mclU/ml (12.50 - 137.00, p = 0.0010). The median time to reach the initial peak of elevated TSH was 1.8 months (0.3 - 9.3). Free T4 levels remained within the normal reference range. An increase from a baseline LT dose of 91 mcg/m(2)/day (±24) to 116 mcg/m(2)/day (±24) was required in order to resume normative TSH levels (p = 0.00005), equal to an increase of 36.6% (±16.56) in the dosage of LT in mcg/day. For the 2 patients with intact thyroid glands, free T4 and TSH remained normal over a combined 6 patient years of follow up.

CONCLUSIONS

In our cohort of pediatric MTC patients, athyreotic patients with preexisting hypothyroidism developed increased TSH and reduced free T4 during the first few months of treatment with vandetanib, necessitating an increase in LT dosage. Additional patients with normal thyroid function before treatment and intact glands (n = 2) maintained normal thyroid function tests during treatment. Elevated TSH in athyreotic patients may be due to an indirect effect of vandetanib on the metabolism of thyroid hormone, or to altered TSH sensitivity at the pituitary. Proper recognition and management of abnormal thyroid hormone levels is critical in growing children on TKIs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00514046.

The modulation of ABC transporter-mediated multidrug resistance in cancer: a review of the past decade

ATP-binding cassette (ABC) transporters represent one of the largest and oldest families of membrane proteins in all extant phyla from prokaryotes to humans, which couple the energy derived from ATP hydrolysis essentially to translocate, among various substrates, toxic compounds across the membrane. The fundamental functions of these multiple transporter proteins include: (1) conserved mechanisms related to nutrition and pathogenesis in bacteria, (2) spore formation in fungi, and (3) signal transduction, protein secretion and antigen presentation in eukaryotes. Moreover, one of the major causes of multidrug resistance (MDR) and chemotherapeutic failure in cancer therapy is believed to be the ABC transporter-mediated active efflux of a multitude of structurally and mechanistically distinct cytotoxic compounds across membranes. It has been postulated that ABC transporter inhibitors known as chemosensitizers may be used in combination with standard chemotherapeutic agents to enhance their therapeutic efficacy. The current paper reviews the advance in the past decade in this important domain of cancer chemoresistance and summarizes the development of new compounds and the re-evaluation of compounds originally designed for other targets as transport inhibitors of ATP-dependent drug efflux pumps.

Thyroid dysfunctions induced by tyrosine kinase inhibitors

INTRODUCTION

Recently, tyrosine kinase inhibitors (TKIs) have emerged as a new class of anticancer therapy. Although generally considered less toxic than cytotoxic chemotherapy, TKIs do cause significant side effects including fatigue and hypertension. In addition, thyroid dysfunction is a well-known adverse effect of TKI.

AREAS COVERED

This review provides a comprehensive assessment of TKI-induced thyroid dysfunctions by sunitinib, sorafenib, pazopanib, imatinib, dasatinib, nilotinib, vandetanib, axitinib, motesanib and tivozanib. Furthermore, the potential mechanisms that result in this toxicity, the clinical impact of thyroid dysfunction in these patients and the controversies regarding treatment with thyroid hormone (TH) therapy are evaluated.

EXPERT OPINION

Detection of TKI-induced thyroid dysfunction requires routine monitoring of thyroid function and may necessitate treatment. Potential benefits in developing thyroid dysfunction and potential harm in treating it necessitate controlled studies. Finally, if treatment is pursued, appropriate dosing and timing of TH replacement will require prospective clinical evaluation.