Novel chemotherapeutics and other therapies for treating high-grade glioma

Introduction: Despite extensive research, high-grade glioma (HGG) remains a dire diagnosis with no change in the standard of care in almost a decade. However, recent advancements uncovering molecular biomarkers of brain tumors and tumor-specific antigens targeted by immunotherapies provide opportunities for novel personalized treatment regimens to improve survival.

Areas covered: In this review, the authors provide a comprehensive overview of recent therapeutic advancements in HGG. Furthermore, they describe new molecular biomarkers and molecular classifications, in addition to updated research on bevacizumab, targeted molecular therapies, immunotherapy and alternative delivery methods that overcome the blood–brain barrier to reach the target tumor tissue. Challenges regarding each therapy are also outlined. The authors also provide some insight into a novel non-chemotherapeutic treatment for malignant glioma, NovoTTFA, as well as a summary of current treatment options for recurrence.

Expert opinion: Current research for treating malignant gliomas are paving the path to personalized therapy, including immunotherapy, that involve integrated genomic and histolopathologic data, as well as a multi-modal treatment regimen. Immunotherapy will potentially be the next addition to the current standard of care, specialized to the antigens presented on the tumors. The results of the current trials of multi-antigen vaccines are eagerly anticipated.     

A review on phytochemical and pharmacological properties of Litsea coreana

Context: Litsea coreana H. Lév. (Lauraceae) is used as an ethnic herb or beverage in China. Substantial studies indicate that it contains a variety of compounds and shows diverse bioactivities with no toxicity.

Objective: This review analyzes and summarizes the ethnopharmacological applications, phytochemistry, and pharmacological activities and molecular mechanisms of L. coreana.

Methods: Related literature (from 1998 to 2016) was obtained and compiled via searching databases including Scopus, Web of Science, Google Scholar, CNKI and PubMed. Keywords (Litsea coreana, hawk tea, eagle tea and laoying cha) were used to select the articles.

Results: Studies indicate that L. coreana contains characteristic polysaccharides, polyphenols, essential oils, and numerious flavonoids, which exhibit remarkable bioactivities, such as hepatoprotection, hyperglycaemia, anti-inflammation, antioxidation and antibacterial, through multiple molecular mechanisms.

Conclusion: This paper provides a systematic review on the phytochemicals and pharmacological activities of L. coreana which should be useful for further study and application of this medicinal herb.     

Inhibitors of α-glucosidase and α-amylase from Cyperus rotundus

Context: A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion.

Objective: Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase.

Materials and methods: Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays.

Results: A new (2RS,3SR)-3,4′,5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity.

Discussion: The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents.

Conclusion: The isolated compounds may contribute to the antidiabetic property of C. rotundus.     

Systematic literature review of the health economic implications of early detection by screening populations at risk for type 2 diabetes

Background: Undetected/uncontrolled diabetes is associated with substantial morbidity and mortality and consequent costs. Early detection through screening identifies patients at risk, allowing for earlier treatment initiation.

Objectives: To determine the economic impact of screening for type 2 diabetes (T2DM).

Data sources: We systematically reviewed health economic analyses of screening programs for T2DM/pre-diabetes.

Study eligibility criteria: Published between 2000 and 2015 in any language. Articles must have reported costs of screening, test/patient outcomes and cost-effectiveness.

Participants and interventions: Any type of screening (universal, targeted, opportunistic) was accepted.

Methods: Data were extracted from Scopus/Medline/Embase, then tabulated.

Results: There were 137 studies identified, 108 rejected; 29 were analyzed. Screening types included 18 universal, 8 targeted and 8 opportunistic. One study screened for pre-diabetes, 16 for T2DM and 12 examined both. Fourteen (48%) reported costs of screening only, 9 (31%) costs of screening combined with interventions and 6 (21%) presented all costs separately. Screening was compared to no screening in 13 studies (45%); screening was cost-effective in 8 (62%), not cost-effective in 4 (31%) and neither in 1 (8%). When comparing different screening methods, 6 found targeted screening was cost-effective compared with universal screening (none found the opposite), 2 found opportunistic superior to universal. Sensitivity analyses generally confirmed primary findings. Cost drivers included prevalence of T2DM/pre-diabetes, type of blood test used and uptake of testing. For optimal cost-effectiveness, screening for both T2DM and pre-diabetes should be initiated around age 45–50, with repeated testing every 5 years.

Conclusions/implications: Targeted screening appears to be cost-effective compared to universal screening.     

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.     

Can binimetinib,encorafenib and masitinib be more efficacious than currently available mutation-based targeted therapies for melanoma treatment?

Introduction: Historically, there were few effective and durable treatments for metastatic melanoma. Recently, mutation based targeted therapies have revolutionized treatment and outcomes for patients with metastatic melanoma. Specifically, inhibitors aimed at BRAF, NRAS, and C-KIT mutations are now commonly used in treatment for patients harboring the specific mutations.

Areas covered: A brief review of current BRAF, NRAS, and C-KIT inhibitors provides background for a thorough review of newly developed agents namely binimetinib, a MEK inhibitor, encorafenib a BRAF inhibitor, and masitinib which inhibits C-KIT.

Expert opinion: While the 3 novel agents reviewed here have potential for use in melanoma, optimal utilization will occur once a more personalized approach incorporating genomic, proteomic, and immunologic data guides therapeutic decisions.     

Challenges in molecular targeted therapy for gastric cancer: considerations for efficacy and safety

Introduction: The Cancer Genome Atlas Research Network recently proposed a molecular classification for gastric cancer (GC) into four subtypes based on comprehensive evaluation. While the mechanisms of molecular targeted therapies in GC were confirmed by multiple clinical studies, only a limited number of therapeutics for GC have been approved to date.

Areas covered: In this systematic review of the available literature, we discuss the completed and ongoing clinical trials of molecular targeted therapies in patients with GC, with a focus on their efficacy and safety profiles.

Expert opinion: Results of recent studies clearly demonstrated that trastuzumab and ramucirumab, monoclonal antibodies (mAbs) against human epidermal growth factor receptor 2 (HER2) and vascular endothelial growth factor (VEGF), respectively, improved overall survival (OS) in GC with manageable safety profiles. Careful surveillance of ongoing clinical trials and timely profiling and monitoring of genetic signatures are imperative to establish a strong foundation for precision medicine in GC.     

Hepatocellular carcinoma treatment: a comparative review of emerging growth factor receptor antagonists

Introduction: Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Over the last decade, sorafenib has been the only available therapeutic option for advanced HCC, although regorafenib recently showed a survival benefit compared with placebo in a second-line setting.

Areas covered: This review discusses key published and ongoing studies with targeted agents in HCC, molecular targets of HCC, the mechanism of resistance to sorafenib, and the role of biomarker-enriched clinical trials.

Expert opinion: The multiplicity of drivers and the existence of substantial molecular heterogeneity limit the benefits of targeted therapies in HCC. Based on molecular biology developments, a few biomarker-enriched clinical trials that target candidate driver genes are ongoing, and the outcomes of these are highly anticipated. Poor availability of tumor tissue and tumor heterogeneity in patients with HCC make liquid biopsy a very attractive option, although this technique remains to be validated.     

Taurine reduces blue light-induced retinal neuronal cell apoptosis in vitro

Background: The massive uptake of organic compatible osmolytes is a self-protective response to multiple stressors.

Objective: This study aimed to determine the protective effects of the osmolyte taurine against blue light-induced apoptosis in retinal neuronal cells in vitro.

Methods: Real-time PCR was used to measure osmolyte transport. Radioimmunoassays were performed to measure osmolyte uptake. Cell Counting Kit-8 assays were conducted to measure cellular viability. Flow cytometry analysis was used to measure apoptosis.

Results: Compared with normotonic stress, hypertonic stress-induced uptake of osmolytes, including betaine, myoinositol, and taurine, into the retinal neuronal cells. Blue light increased osmolyte transporter mRNA expression together with osmolyte uptake. Furthermore, taurine significantly suppressed blue light-induced retinal neuronal cell apoptosis.

Conclusion: The compatible osmolyte taurine may have an important role in cell resistance to blue light and cell survival.     

Echinacea biotechnology: advances,commercialization and future considerations

Context: Plants of the genus Echinacea (Asteraceae) are among the most popular herbal supplements on the market today. Recent studies indicate there are potential new applications and emerging markets for this natural health product (NHP).

Objective: This review aims to synthesize recent developments in Echinacea biotechnology and to identify promising applications for these advances in the industry.

Methods: A comprehensive survey of peer-reviewed publications was carried out, focusing on Echinacea biotechnology and impacts on phytochemistry. This article primarily covers research findings since 2007 and builds on earlier reviews on the biotechnology of Echinacea.

Results: Bioreactors, genetic engineering and controlled biotic or abiotic elicitation have the potential to significantly improve the yield, consistency and overall quality of Echinacea products. Using these technologies, a variety of new applications for Echinacea can be realized, such as the use of seed oil and antimicrobial and immune boosting feed additives for livestock.

Conclusions: New applications can take advantage of the well-established popularity of Echinacea as a NHP. Echinacea presents a myriad of potential health benefits, including anti-inflammatory, anxiolytic and antibiotic activities that have yet to be fully translated into new applications. The distinct chemistry and bioactivity of different Echinacea species and organs, moreover, can lead to interesting and diverse commercial opportunities.     

Monoterpenoids from the whole herb of Veronicastrum axillare

Context: Veronicastrum axillare (Sieb. et Zucc.) Yamazaki (Scrophulariaceae) embraces varieties of bioactivities such as anti-inflammatory, anti-pyresis and detoxification activity, while little is known of the phytochemical components of this medicinal plant.

Objective: To isolate and identify bioactive constituents from the whole herb of V. axillare.

Materials and methods: Ethanol extract of the whole herb of V. axillare was subjected to successive column chromatography. Chemical structures of the compounds were elucidated by detailed spectroscopic analyses on the basis of NMR, IR and HR-MS data.

Results: A new monoterpenoid, axillacetal A (1) and a known analogue, tarumal (2), were isolated from the whole herb of V. axillare. The structure of tarumal (2) was also revised according to our NMR data.

Discussion and conclusion: This is the first report on the isolation and authentication of novel chemical constituents from V. axillare.     

Role of osteopontin as a predictive biomarker for anti-EGFR therapy in triple-negative breast cancer

Objective: Effective targeted therapies for patients with triple-negative breast cancer (TNBC) present an unmet clinical need. There is evidence that TNBCs often have increased expression of the epidermal growth factor receptor (EGFR) and of osteopontin (OPN). OPN-mediated signaling can activate EGFR-dependent signaling pathways. Here, we assessed OPN as a potential predictive biomarker for response to anti-EGFR therapy in TNBC.

Research design and methods: Using two different TNBC cell lines, MDA-MB-468 and MDA-MB-231, we investigated the impact of stable expression of OPN on efficacy of the EGFR inhibitor erlotinib in vitro.

Results: We observed that breast cancer cells engineered to overexpress OPN are more sensitive to growth inhibition by erlotinib than control cells. The level of response was related to the level of OPN expression, possibly due to increased phosphorylation status of EGFR Tyr1068.

Conclusions: These results indicate that OPN expression levels are related to sensitivity of TNBC cells to growth inhibition by erlotinib. OPN thus is a promising predictive biomarker for anti-EGFR therapy in breast cancer.     

Emerging cell cycle inhibitors for acute myeloid leukemia

Introduction: AML therapy remains very challenging despite our increased understanding of its molecular heterogeneity. Outcomes with chemotherapy and targeted therapy remain poor. Targeting cell cycle regulators might complement chemotherapy and targeted therapy and help in improving outcomes.

Areas covered: Here we cover the pre-clinical and clinical data for both for cyclin dependent kinase (CDK) and cell-cycle checkpoint inhibitors. While CDK inhibition can inhibit proliferation, checkpoint inhibitors can facilitate cell cycle progression in presence of DNA damage and can induce mitotic catastrophe.

Expert opinion: Though the preclinical data for cell cycle inhibitors in AML is compelling, the clinical translation so far has proven to be challenging. This is a reflection of the complexity of both, AML and cell cycle regulators. However, early introduction of cell-cycle active agents in combination with chemotherapy or targeted agents, identifying right sequence of use and identifying right biomarkers might pave the way into successful clinical translation.     

Retro-inverso follicle-stimulating hormone peptide-mediated polyethylenimine complexes for targeted ovarian cancer gene therapy

Background: The development of nanoparticle drug delivery systems with targeted ligands has the potential to increase treatment efficiency in ovarian cancer.

Methods: We developed a 21-amino acid peptide, YTRDLVYGDPARPGIQGTGTF (L-FP21) conjugated to polyethylenimine (PEI) and methoxy polyethylene glycol (mPEG) to prepare a nanoparticle drug vehicle to target follicle-stimulating hormone receptor (FSHR) in ovarian cancer. At the same time, we optimized the ligand of the nanoparticle vehicle using D-peptides, which consist of D-amino acids (D-FP21). Nanoparticle vehicles carrying the therapeutic gene plasmid growth-regulated oncogene alpha (pGRO-α) short hairpin RNA (shRNA) (FP21-PEG-PEI/pGRO-α) were prepared for further investigation.

Results: Compared with L-FP21, D-FP21 exhibited improved biological stability and higher uptake rate for FSHR-expressing ovarian cancer cells. The cytotoxicity of the L, D-FP21-PEG-PEI/pGRO-α complexes were significantly lower than that of the PEI/pGRO-α complex. The nanoparticle drug with the targeted ligand showed higher transfection efficiencies and improved anti-proliferation effects for ovarian cancer cells than that without the targeted ligand (mPEG-PEI/pGRO-α). Furthermore, an in vivo evaluation of an antitumor assay indicated that D-FP21-PEG-PEI/pGRO-α inhibited the growth of tumor spheroids considerably more than L-FP21-PEG-PEI/pGRO-α; their tumor inhibition rates were 58.5% and 33.3%, respectively.

Conclusions: D-FP21-PEG-PEI/plasmid DNA is a safe and efficient gene delivery vehicle for ovarian cancer targeted therapy.     

Investigational therapies currently in Phase II clinical trials for the treatment of pelvic serous carcinomas

Introduction: Pelvic serous carcinomas (PSCs) are a controversial entity, which mostly comprise fallopian tube carcinoma (FTC), primary peritoneal carcinoma (PPC) and serous ovarian carcinoma (OC). Despite incremental attention towards understanding pelvic serous carcinogenesis, the gold standard treatment and survival rates have not substantially changed in these last decades.

Areas covered: This review summarizes and gives a critical overview of the ongoing Phase II trials investigating therapies for PSC.

Expert opinion: Several novel molecules have been developed and are currently under investigation for the treatment of PSC, including FTC, PPC and serous OC. The trend of novel targeted agents is one towards individualized, tailored therapy, based on the molecular and biological differences that characterize tumors that seem similar based solely on histological analysis. The task of developing new molecules is particularly difficult for PSC, given the recurrent development of new patterns of drug resistance. However, even if current research is focused towards identifying the best treatments for each woman with a molecularly defined disease, a deeper knowledge of the molecular biology and genetics underlying FTC and its relation as a precursor of PSC is needed.     

Advancing pharmacological treatment options for advanced gastric cancer

Introduction: Gastric cancer is the third most common cause of cancer-related deaths worldwide. Improvement of conventional chemotherapy has been modest in the past decades.

Areas covered: We review recent important studies of metastatic or recurrent gastric cancer. For human epidermal growth factor receptors 2 (HER2) negative cancer, standard treatments are combinations of fluoropyrimidine and platinum with or without epirubicin or docetaxel in first-line therapy. Controversy exists regarding the use of triplet chemotherapies due to their toxicity. For HER2 positive cancer, standard treatments are combinations of fluoropyrimidine and cisplatin with trastuzumab. As second- or third-line treatment, taxanes or irinotecan prolonged survival compared with best supportive care alone, but the extension of overall survival was only 1 – 2 months. A recent study demonstrated that ramucirumab plus paclitaxel improved survival as a second-line therapy.

Expert opinion: Most trials have failed to demonstrate a benefit of targeted agents. It is important to identify predictive biomarkers to enrich an appropriate patient population for targeted agents such as HER2 status for trastuzumab.     

Dosing strategies to optimize currently available anti-MRSA treatment options (Part 2: PO options)

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a problematic pathogen in both outpatient and inpatient settings. Research to optimize the dosing of these agents is needed to slow the development of antimicrobial resistance and to decrease the likelihood of clinical failure.

Areas covered: This review summarizes the available data for orally administered antimicrobials routinely used as monotherapy for MRSA infections. We make recommendations and highlight the current gaps in the literature. A PubMed (1966 – Present) search was performed to identify relevant literature for this review.

Expert commentary: There is a vast divide in the amount of pharmacokinetic/pharmacodynamic data to guide dosing decisions for older MRSA agents compared with the oxazolidenones.

Five-year view: Additional retrospective data will become available for the older MRSA agents in severe MRSA infections.     

Conventional- versus high-dose vancomycin regimen in patients with acute bacterial meningitis: a randomized clinical trial

Objective: Efficacy of the conventional- versus high-dose vancomycin regimen in patients with acute bacterial meningitis was compared.

Methods: In a randomized clinical trial 44 patients with acute bacterial meningitis were randomly assigned to the conventional- or high-dose vancomycin groups. Clinical and laboratory parameters were used for evaluation of response to the treatment regimens.

Results: In the high-dose group, leukocytosis and fever resolved significantly faster than those in the conventional group. Furthermore, the length of hospitalization was shorter and Glasgow Coma Scale at the end of 10th day was significantly lower in the high dose compared to the conventional group. Trend of creatinine clearance changes did not differ significantly between the two groups.

Conclusion: In comparison to the conventional-dose regimen, the high-dose vancomycin regimen was associated with significantly more favorable clinical response without increase in the incidence of nephrotoxicity in patients with acute bacterial meningitis.     

Decreased viability and proliferation of CHANG conjunctival epithelial cells after contact with ultraviolet light-irradiated pollen

Context: Contact with pollen is the major reason for the development of allergic symptoms on the ocular surface leading to a significant increase of allergic diseases worldwide. Environmental changes such as increased ultraviolet (UV) radiation and air pollution are discussed as contributory causes for this increase.

Objective: We investigated the effect of UV light on the histamine content of pollen and examined if an irradiation of pollen affects the viability and proliferation of conjunctival cells.

Materials and methods: Alder (Alnus glutinosa) and hazel (Corylus avellana) pollen were irradiated for different time periods with sunlight, UV-A or UV-B light and the histamine content was analysed and compared with non-irradiated pollen. Conjunctival epithelial cells (CHANG cells) were exposed to irradiated and non-irradiated pollen followed by an assessment of cell viability with the colorimetric MTS test and the impedance-based measurement of cell proliferation using the xCELLigence real-time analysis system.

Results: UV light irradiation increased the histamine level of alder and hazel pollen in a dose-dependent manner. CHANG cells treated with irradiated pollen induced a statistically significant higher decrease of cell viability than treatment with non-irradiated pollen.

Discussion and conclusions: Our results indicate that UV light is able to alter pollen thus making them more harmful for conjunctival cells.