Experimental and investigational phosphodiesterase inhibitors in development for asthma

Introduction: Severe, inadequately-controlled asthma remains a clinical challenge. For this reason, clinical trials and preclinical experimental studies on novel agents as an add-on therapies continue emerge. Phosphodiesterases (PDEs) are enzymes that regulate the function of immune cells by hydrolyzing cyclic guanosine monophosphate/cGMP and cyclic adenosine monophosphate/cAMP. PDEs are divided into subfamilies [PDE3, PDE4, PDE5 and PDE7] which are mainly found in the respiratory tract. Inhibitors of PDEs have already been approved for COPD and pulmonary hypertension.

Areas covered: The role of PDE inhibitors in asthma treatment and the possible mechanism of action via their anti-inflammatory and/or bronchodilating effect are discussed.

Expert opinion: Novel PDE inhibitors exhibiting fewer adverse events may have a role as add-on therapies in asthma treatment in the future. More clinical trials are necessary to prove their efficacy and evaluate their safety profile before approval by regulatory bodies is granted.     

An evaluation of peripapillar choroidal thickness in patients receiving systemic isotretinoin treatment

Purpose: Oral isotretinoin (13-cis retinoic acid, 13-cis RA) was approved for severe acne treatment by the FDA in 1982. The ocular side effects associated with oral isotretinoin use are mostly dose-dependent. Numerous ocular pathologies affect peripapillary choroidal layer primarily or indirectly.

Objective: Evaluation of the peripapillary choroidal layer in the patients receiving oral isotretinoin therapy may aid in explaining the pathophysiology of ocular side effects.

Methods: In this study, peripapillary choroidal thickness was assessed in the patients receiving oral isotretinoin treatment via optical coherent tomography technique.

Results: Significant difference was found in the superotemporal and temporal areas.

Conclusion: Oral isotretinoin treatment may affect the thickness of the peripapillary choroidal layer.     

A drug safety evaluation of abiraterone acetate in the treatment of prostate cancer

Introduction: To evaluate the safety profile characteristics of abiraterone acetate (AA) in the treatment of metastatic prostate cancer (mPCa).

Areas covered: In this literature review the authors evaluate safety data from phase III trials investigating the combination of abiraterone acetate plus prednisone (AAP) in patients with metastatic prostate cancer. In particular, the aim was to clarify its toxicity profile, long-term exposure impact, and the correlation with general health-related quality of life (HRQoL).

Expert opinion: Based on the studies reviewed, it appears that abiraterone acetate has favourable outcomes, is effective and well tolerated, mostly in asymptomatic or slightly symptomatic patients, and has recognised toxicity profile characteristics. Incidence of adverse events (AEs), such as mineralocorticoid- and corticosteroid-releated AEs, and hepatotoxicity is well known and widely described. Understanding the toxicity profile of AA could assist decision-making in clinical practice.     

Optimisation of the microencapsulation of lavender oil by spray drying

Background: Lavender oil consists of around 100 components and is susceptible to volatilisation and degradation reactions.

Aim: Microencapsulate lavender oil by spray drying using a biocompatible polymeric blend of gum acacia and maltodextrin to protect the oil components. Effect of total polymer content, oil loading, gum acacia, and maltodextrin proportions on the size, yield, loading, and encapsulation efficiency of the microparticles was investigated.

Methods: Morphology and oil localisation within microparticles were assessed by confocal laser scanning electron microscope. Structural preservation and compatibility were assessed using Fourier transform infra-red spectroscopy, differential scanning calorimetry, and gas chromatography–mass spectrometry.

Results: Lavender microparticles of size 12.42?±?1.79?µm prepared at 30 w/w% polymer concentration, 16.67 w/w% oil loading, and 25w/w% gum acacia showed maximum oil protection at high loading (12?mg w/w%), and encapsulation efficiency (77.89 w/w%).

Conclusion: Lavender oil was successfully microencapsulated into stable microparticles by spray drying using gum acacia/maltodextrin polymeric blend.     

BRAF kinase inhibitors for treatment of melanoma: developments from early-stage animal studies to Phase II clinical trials

Introduction: Approximately, 30.4–66.0% of cutaneous melanomas possess a mutation in the BRAF gene that activates downstream signaling through the mitogen-activated protein (MAP) kinase pathway; this provides an attractive target for the treatment of advanced melanoma. Although BRAF inhibitors rapidly suppress melanoma growth, median progression-free survival remains unsatisfactory. Recent clinical trials have investigated drugs that can optimally enhance and prolong the anti-melanoma effects of BRAF inhibitors.

Area covered: This review discusses the development of BRAF inhibitor-based combination therapies for BRAF-mutant advanced melanoma.

Expert opinion: Future strategies for the treatment of advanced melanoma include novel combination therapies using BRAF/MEK inhibitors and immune checkpoints inhibitors or histone deacetylase inhibitors. These combination therapies might enhance antitumor responses against melanoma, prolonging survival in advanced melanoma patients. Further clinical studies are needed to optimize these novel combination therapies.     

Investigational luteinizing hormone releasing hormone (LHRH) agonists and other hormonal agents in early stage clinical trials for prostate cancer

Introduction: The treatment and management of prostate cancer continues to evolve; newer classes of agents and combination therapies are being developed and some are being investigated in early phase clinical trials.

Areas covered: We discuss investigational hormonal agents for the treatment of prostate cancer and focus primarily on luteinizing hormone releasing hormone (LHRH) agonists in early stage trials. We look at agents that target the hormonal axis, including anti-androgens, gonadotropins, estrogenic agents and progestogenic agents and other non-hormonal agents often used in combination with LHRH agonists. We review these candidates in the specific clinical niche in which they might find utility.

Expert opinion: Of all candidate compounds being evaluated in clinical trials, very few will receive FDA approval. Few, if any of the investigational agents discussed here will be used routinely in clinical practice for treating prostate cancer. Recognizing the reasons for the failure of agents to advance to later stage trials is important. Furthermore, a thorough understanding of the mechanisms underlying prostate cancer pathogenesis, including various points in the HGPA and parallel pathways, will help identify potentially actionable targets.     

Gender,subclinical organ damage and cardiovascular risk stratification in hypertensive patients

Background: The aims of the study were to assess subclinical organ damage in men and women with hypertension and its subsequent effect on cardiovascular risk, and use of new statistical methods for more precise estimation of cardiovascular risk using vascular cardiovascular risk factors: ankle–brachial index (ABI), intima–media thickness (IMT) and pulse wave velocity (PWV).

Methods: We studied 200 patients: 100 hypertensive and 100 normotensive. The parameters we evaluated included: patient age, ABI, IMT, PWV, serum uric acid and serum C-reactive protein (CRP). In addition, the cardiovascular risk according to the SCORE and Framingham scales was assessed.

Results: In the hypertensive group, there were significant correlations between ABI and the Framingham scale in both sexes. In hypertensive women, there were also significant correlations between IMT and the SCORE scale risk, and IMT and the Framingham scale risk.

In normotensive women, there were significant correlations between ABI and the SCORE scale risk, and between ABI and the Framingham scale risk. In normotensive men, there were significant correlations between PWV and the SCORE scale risk, and between PWV and the Framingham scale risk. Lastly, in the group of normotensive men, there were significant correlations between IMT and the SCORE scale risk, and IMT and the Framingham scale risk.

The possibility of correctly classifying a patient into the high-risk category by a logistic regression model using synchronous ABI, IMT and PWV was high – 74% for the risk according to the SCORE scale (66% in men, 88% in women), and 98% for the Framingham scale.

Conclusions: The addition of recognized subclinical target organ damage tests to the estimation of cardiovascular risk can significantly strengthen the prevention of cardiovascular disease.

Cardiovascular risk estimation follow-up with ABI, PWV and IMT increased the probability of correctly classifying people, especially women, into an at least high-risk category according to the SCORE scale, which has valuable therapeutic implications.     

Safety concerns of biosimilar hormone products

Background: Currently, biotherapeutic medicines are the most effective options for the treatment of many severe and chronic diseases. For faster market entry of biotherapeutic products and their cost reduction, the principles of “biosimilarity” have been developed. Development and licensing of biosimilars is allowed only after the end of patent exclusivity of the original preparation period.

Purpose: Characteristics of the main safety parameters of biosimilar hormone preparations licensed by EMA.

Methods: This paper analyzes the results demonstrating the similarities and differences between biosimilar and reference hormone products indicated in the EPAR (public assessment report) for the examination of materials presented for the licensing of biosimilar products.

Results: During the development of biosimilar hormone medicines, differences in the glycosylation profile between biosimilar and reference preparations are revealed. As biotherapeutical preparations are produced by cells, the differences in glycosylation profile between biosimilar and referent preparation are predictable. While carrying out clinical studies, a high similarity of biosimilar and reference product effectiveness is shown, but some differences between them in the safety profile are revealed.

Conclusions: The study of biosimilar product safety has shown the necessity of further improvement in safety and standard approaches for the assessment of the immunogenicity of biosimilar products.     

Update upon the infection risk in patients receiving TNF alpha inhibitors

Introduction: TNF-α inhibitors can be administered either as monotherapy or in combination with other anti-inflammatory drugs or DMARDs in the treatment of chronic immune-mediated diseases.

Areas covered: Patients receiving TNF-α inhibitors are at high risk of infections. An update is made on the risk of infection in patients receiving TNF-α inhibitors and the strategies for mitigating against the development of these serious adverse events.

Expert opinion: Infliximab than etanercept appears to be responsible for the increased risk of infections. Re-activation of latent tuberculosis infection and the overall risk of opportunistic infections should be considered before beginning a course of TNF-α inhibitors. A careful medical history, Mantoux test/quantiferon-TB Gold In-tube Test and chest-X-ray should always be performed before starting TNF-α inhibitors. Particular attention should be paid to risk factors for Pneumocystis jirovecii infection. Hepatitis B and C virological follow-up should be considered during TNF-α inhibitors treatment. Finally, appropriate vaccinations for influenza, S. pneumoniae, and HBV should be administered to decrease the risk of infection, and patients who are at high risk of herpes zoster reactivation would benefit from a second vaccination in adulthood.     

Efficacy of nab-paclitaxel in treating metastatic melanoma

Introduction: Systemic treatment of metastatic melanoma has been revolutionized by the advent of checkpoint inhibitors and targeted agents which are widely accepted as standard front-line therapies. However, despite these major advances, a substantial portion of patients still fail checkpoint inhibitors and/or targeted agents and are not candidates for clinical trials.

Commonly used cytotoxics in these patients include paclitaxel, dacarbazine, platins, and temozolomide. The overall response rates of these agents are usually disappointing and short-lived.

Areas covered: Herein, the author provides a literature review of the role of nab-paclitaxel in metastatic melanoma including coverage of its pharmacokinetics, pharmacodynamics and efficacy.

Expert opinion: The role of chemotherapy in the treatment of metastatic melanoma is limited to patients who failed checkpoint inhibitors and, when applicable, targeted agents, and those not appropriate for clinical trials. nab-Paclitaxel has single agent activity in chemotherapy-naïve untreated metastatic melanoma which compares favorably to the activity of weekly paclitaxel or single agent dacarbazine. However, the activity in chemotherapy-pretreated patients is modest. Data on nab-paclitaxel in patients pretreated with targeted agents or check point inhibitors are lacking. Further advances are expected from new checkpoint inhibitors and targeted agents for the treatment of metastatic melanoma in addition to the optimal combination and sequencing of these agents.     

Optimization techniques for novel c-Met kinase inhibitors

Introduction: c-Met kinase plays an important part in the regulation of cell growth, invasion and anti-apoptosis. This enzyme is also an important target in cancer treatment. Through structural optimization and structure-activity studies of drugs currently on the market and those still in clinical trials, a great number of novel c-Met kinase inhibitors have been developed. This review focuses on recent developments in research regarding novel c-Met inhibitor synthesis, optimization, and structure-activity relationship (SAR) studies.

Area covered: In this review, the authors discuss the representative research of c-Met inhibitors published in recent years. Furthermore, it provides background research of c-Met kinase inhibitors, the introduction of drugs on the market and in clinical research, and the research progress of novel small molecule inhibitors. In particular, this review emphasizes the important role of ‘5-atoms linker’ in the design of some novel c-Met enzyme inhibitors.

Expert opinion: Discovering novel c-Met kinase inhibitors via natural product chemistry may become a new research field. Though it is difficult, the key to developing better c-Met kinase inhibitors is structural optimization.     

Zoledronic acid for the treatment of prostate cancer

Introduction: Prostate cancer remains the most common solid tumor afflicting men in the developed world. Metastatic prostate cancer is a source of great morbidity and mortality especially due to osseous involvement that gives rise to significant symptoms of pain or pathologic fractures or cord compression. Bisphosphonates had been widely used in the treatment of metastatic prostate bone metastases given their demonstrated benefit with a delay of skeletal-related events (SREs) but without prostate-specific antigen (PSA) response or overall survival benefit.

Areas covered: In this review, the authors summarize the available literature on the clinical studies that led to the development and regulatory approval of zoledronic acid in men with metastatic prostate cancer. The authors also provide their expert opinion and future perspectives on this therapeutic.

Expert opinion: Zoledronic acid is an established adjunctive treatment and bone-targeted therapy for the supportive care of men with metastatic castration-resistant prostate cancer. Efforts to study its utility in earlier phases of metastatic hormone-sensitive prostate cancer has not shown superior outcomes compared with standard androgen deprivation therapy (ADT) or docetaxel alone.     

Pharmacoeconomic evaluation of sodium-glucose transporter-2 (SGLT2) inhibitors for the treatment of type 2 diabetes

Introduction: Clinicians have many safe and effective options for the treatment of type 2 diabetes that can improve glycemic control and effect other cardio-metabolic parameters. Sodium-glucose transporter-2 inhibitors (SGLT-2) are the most recent class of therapies, have a novel mechanism of action, and provide good glycemic efficacy and a favorable cardiovascular risk profile. Cost-effectiveness data can play an important role in assessing the benefits of this class of therapy in anti-diabetes treatment regimens.

Areas covered: This review summarizes all the available evidence regarding the cost-effectiveness of SGLT-2 inhibitors. For the purposes of this article, the authors have performed a systematic review of pharmacoeconomic analyses through a non-restricted literature until June 2018.

Expert opinion: The available analyses demonstrate that SGLT-2 inhibitors are a more cost-effective option compared to other oral anti-diabetes therapies and insulin in the treatment of individuals with uncontrolled type 2 diabetes. Future studies should examine populations with renal and liver disease and expand data of some SGLT-2 inhibitors to patients at high cardiovascular risk and hard endpoint data.     

Efficacy of istradefylline for gait disorders with freezing of gait in Parkinson’s disease: A single-arm,open-label,prospective, multicenter study

Background: Gait disorders are common in Parkinson’s disease patients who respond poorly to dopaminergic treatment. Blockade of adenosine A_2A receptors is expected to improve gait disorders. Istradefylline is a first-in-class selective adenosine A_2A receptor antagonist with benefits for motor complications associated with Parkinson’s disease.

Research design and methods: This multicenter, open-label, single-group, prospective interventional study evaluated changes in total gait-related scores of the Part II/III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Freezing of Gait Questionnaire (FOG-Q) in 31 Parkinson’s disease patients treated with istradefylline. Gait analysis by portable gait rhythmogram was performed.

Results: MDS-UPDRS Part III gait-related total scores significantly decreased at Weeks 4–12 from baseline with significant improvements in gait, freezing of gait, and postural stability. Significant decreases in MDS-UPDRS Part II total scores and individual item scores at Week 12 indicated improved daily living activities. At Week 12, there were significant improvements in FOG-Q, new FOG-Q, and overall movement per 48 h measured by portable gait rhythmogram. Adverse events occurred in 7/31 patients.

Conclusions: Istradefylline improved gait disorders in Parkinson’s disease patients complicated with freezing of gait, improving their quality of life. No unexpected adverse drug reactions were identified.

Trial registration: UMIN-CTR (UMIN000020288).     

A comparative safety review of histone deacetylase inhibitors for the treatment of myeloma

Introduction: Dysregulation of histone deacetylase (HDAC) activity is an epigenetic hallmark of multiple myeloma (MM), leading to aberrant gene expression and cellular signaling in myeloma cell growth, survival and resistance to therapy. Hyper-methylation at diagnosis is a frequent observation, which eventually may convert to hypo-methylation during advanced phases.

Areas covered: A literature search on ‘HDAC inhibitors’ and ‘multiple myeloma’ was carried out using PubMed and Google Scholar in the preparation of this overview on clinical efficacy and safety data.

Expert opinion: First-generation non-selective HDAC inhibitors have demonstrated minimal single-agent activity in refractory MM. Subsequently, combination therapy has proven an improvement in progression-free survival (PFS) but not response rates. The main concerns are associated with toxicities. Ongoing studies on new and more selective agents, i.e. Romidepsin or Ricolinostat, are promising in terms of better efficacy and less toxicity.     

The role of sodium glucose cotransporter-2 (SGLT-2) inhibitors in heart failure and chronic kidney disease in type 2 diabetes

Background: Heart failure (HF) and chronic kidney disease (CKD) are responsible for substantial morbidity and mortality in individuals with type 2 diabetes (T2D).

Methods: This review discusses the significance of these comorbidities of T2D and current options for managing them, with a focus on sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Based on a focused literature search of cardiovascular outcomes trials (CVOTs), this review assessed the effects of SGLT-2 inhibitors in individuals with T2D with or without established cardiovascular disease (CVD).

Results: In addition to effective glycemic control and weight loss, SGLT-2 inhibitor treatment of T2D prevents adverse cardiovascular and renal outcomes in individuals with and without these comorbidities. Reduced rate of hospitalization due to HF (HHF) and improved renal outcomes appear to be class effects of SGLT-2 inhibitors. Reduction in CV events may be more significant in individuals with established cardiovascular disease.

Conclusions: CVOTs and other studies confirm that the SGLT-2 inhibitors, mostly used in combination with other glucose-lowering drugs, offer several clinical benefits beyond improved glycemic control. These include reducing HHF risk and improving renal outcomes. HF and renal benefits are observed in individuals with and without established CVD, which may simplify therapeutic selection. Ongoing SGLT-2 inhibitor CVOTs will help clarify the potential of these drugs to treat T2D comorbid with different forms of HF (HF with preserved vs reduced ejection fraction) and different degrees of renal dysfunction, and in individuals with T2D vs pre-diabetes or normal glucose metabolism.     

An evaluation of the efficacy and safety of Tofogliflozin for the treatment of type II diabetes

Introduction: Accumulating data from recent studies has altered the gold standard of care for diabetes treatment. In patients with type 2 diabetes (T2D) and established cardiovascular disease (CVD) or those at high risk for CVD, subsequently to lifestyle changes and metformin therapy, the administration of an SGLT-2 inhibitor with established benefits for cardiovascular outcome (CVOT) should be considered.

Areas covered: Tofogliflozin is the most selective SGLT-2 inhibitor and has been approved for the treatment of T2D in Japan. This review summarizes the available data on Tofogliflozin as compared to other SGLT-2 inhibitors, and primarily the three SGLT-2 inhibitors with published CVOT: Empagliflozin, Canagliflozin and Dapagliflozin.

Expert opinion: Tofogliflozin’s higher selectivity profile increases the positive effects on cardiovascular (CV) outcomes and death and reduces side effects. However, the clinical data on Tofogliflozin from both clinical and real-world studies remain sparse and much less abundant than the other main 3 SGLT-2 inhibitors, thus calling for caution and underscoring the need for further research.     

An update on the safety and efficacy of oral antidiabetic drugs: DPP-4 inhibitors and SGLT-2 inhibitors

Introduction: Oral antidiabetic medications are important in many type 2 diabetes care plans

Areas covered: The article summarizes the cardiovascular and renal safety data for DPP-4 inhibitors and SGLT-2 inhibitors and specific safety data particular to each class.

Expert opinion: DPP-4 and SGLT-2 inhibitors provide unique anti-hyperglycemic mechanisms. The cardiovascular safety profiles of DPP-4 inhibitors are promising, but do not show the strong CV risk reduction of empagliflozin and canagliflozin. The heart failure signal associated with DPP-4 inhibitor use is unclear with differing agents, demonstrating increased risk or maybe even protective effects. The risk reduction in cardiovascular disease associated with SGLT-2 inhibitors has translated to recommendations to consider these therapies early in the treatment pathway. Both classes have potential safety concerns that necessitate appropriate patient selection and thorough education on potential side-effects. DPP-4 inhibitors are considered to have neutral or in some studies beneficial renoprotective effects. SGLT-2 inhibitor safety effects on the kidney are more complex. There are reports of acute kidney injury occurring soon after initiating SGLT-2 inhibitor therapy. However, there are large recent studies that have demonstrated the beneficial effect of SGLT-2 inhibitors in slowing the progression of established chronic kidney disease.     

Evaluation of the amount of nanoparticles emitted in LASER additive manufacture/welding

Objectives: The objective of this study was the evaluation of the professional exposure to nanoparticles during tasks performed in workstations for production of metallic parts by laser welding additive manufacturing.

Materials and methods: The study was developed in an installed additive manufacturing machine, having controlled temperature and humidity in an industrial unit where metal parts were being produced using stainless steel powders of granulometry of 10 to 35?μm.

Results and discussion: Monitoring of airborne nanoparticles emission was made using adequate equipment, which showed considerable number of nanoparticles over the baseline, having the same composition as the steel powder used.

Conclusion: It is concluded that the values of professional exposure to nanoparticles are high in these workstations and that the nanoparticles to which the workers are exposed are small in size (around 15?nm), thus having a strong capacity for alveolar penetration and, consequently, with a strong possibility of passing to the bloodstream, accumulating in the body.     

A patent review of arginine methyltransferase inhibitors (2010–2018)

Introduction: Protein arginine methyltransferases (PRMTs) are fundamental enzymes that specifically modify the arginine residues of versatile substrates in cells. The aberrant expression and abnormal enzymatic activity of PRMTs are associated with many human diseases, especially cancer. PRMTs are emerging as promising drug targets in both academia and industry.

Areas covered: This review summarizes the updated patented inhibitors targeting PRMTs from 2010 to 2018. The authors illustrate the chemical structures, molecular mechanism of action, pharmacological activities as well as the potential clinical application including combination therapy and biomarker-guided therapy. PRMT inhibitors in clinical trials are also highlighted. The authors provide a future perspective for further development of potent and selective PRMT inhibitors.

Expert opinion: Although a number of small molecule inhibitors of PRMTs with sufficient potency have been developed, the selectivity of most PRMT inhibitors remains to be improved. Hence, novel approaches such as allosteric regulation need to be further studied to identify PRMT inhibitors. So far, three PRMT inhibitors have entered clinical trials, including PRMT5 inhibitor GSK3326595 and JNJ-64619178 as well as PRMT1 inhibitor GSK3368715. PRMT inhibitors with novel mechanism of action and good drug-like properties may shed new light on drug research and development progress.