Melvin George

New and Emerging Drug Molecules Against Obesity

Obesity has become a growing pandemic of alarming proportions in the developed and developing countries over the last few decades. The most perturbing fact regarding obesity is the increased predisposition for coronary artery disease, congestive heart failure and sudden cardiac death. The modest efficacy of current anti-obesity agents such as orlistat and the increasing withdrawals of several anti-obesity agents such as sibutramine, rimonabant have led to huge gaps in the pharmacotherapy of obesity. Lorcaserin and Phentermine-topiramate combination (phen-top) are two drugs approved by US FDA in 2012. Lorcaserin, a 5HT2C agonist has moderate efficacy with an acceptable safety profile. Clinical trials with Phen-top have shown a reasonable efficacy but at the cost of risks such as teratogenicity and psychiatric disturbances. Cetilistat, a lipase inhibitor is claimed to have superior safety profile to orlistat and is in phase 3 clinical trials. Other promising anti-obesity molecules acting on the gut which are in clinical trials include exenatide and liraglutide. Drugs which act on the monoaminergic and opioid systems include bupropion-naltrexone and bupropion-zonisamide. Other novel first-in-class drugs which have been explored and have limited success in early clinical development include velneperit, tesofensine, and beloranib. Tesofensine is a triple monoamine re-uptake inhibitor, velneperit acts as a neuropeptide Y5 receptor antagonist and beloranib is a methionine amino peptidase 2 inhibitor. Novel targets such as histamine H3 receptor, VEGF, matrix-metalloproteinase, sirtuin receptors are also being investigated. This review is an attempt to describe the new and emerging molecules that are in clinical development for obesity.

Novel drug targets in clinical development for heart failure

BackgroundHeart Failure continues to be a leading cause of mortality and morbidity worldwide. The dismal prognosis of patients in acute heart failure (AHF) can be altered only by exploring novel drug molecules. Although the treatment for chronic heart failure (CHF) has seen remarkable progress, there is still a need to develop molecules that could improve the long-term survival outcomes.PurposeTo review the drug targets for acute and chronic heart failure and the molecules acting on these targets.MethodsThe article discusses on the mechanism of how the potential drug targets can be modulated to alter the pathophysiological processes in heart failure. Current evidence on molecules acting on these targets has also been described from published literature using the PubMed and Clinical Trials.gov databases.ResultsSome of the molecules that are currently being explored for AHF includeomecamtiv mecarbil which activates cardiac myosin ATPase, istaroxime an ionotropicagent that activates SERCA2a pump activity, ularitide and carperitide which are ANP(atrial natriuretic peptide) analogues and recombinant relaxin. Some of the targets forCHF include stabilization of ryanodine receptors, renin inhibition, neprilysin inhibition, neuregulins and SERCA2a gene therapy.ConclusionClinical trials in heart failure must be designed to minimize the risk of “drug failures.” Nevertheless, it is hoped that in the days to come, drugs with superior efficacy and safety will eventually be produced from the surge of molecules that are in the pipeline.

Newer antipsychotics and upcoming molecules for schizophrenia.

BackgroundThe management of schizophrenia has seen significant strides over the last few decades, due to the increasing availability of a number of antipsychotics. Yet, the diminished efficacy in relation to the negative and cognitive symptoms of schizophrenia, and the disturbing adverse reactions associated with the current antipsychotics, reflect the need for better molecules targeting unexplored pathways.PurposeTo review the salient features of the recently approved antipsychotics; namely, iloperidone, asenapine, lurasidone and blonanserin.MethodsWe discuss the advantages, limitations and place in modern pharmacotherapy of each of these drugs. In addition, we briefly highlight the new targets that are being explored.ResultsPromising strategies include modulation of the glutamatergic and GABAergic pathways, as well as cholinergic systems.ConclusionsAlthough regulatory bodies have approved only a handful of antipsychotics in recent years, the wide spectrum of targets that are being explored could eventually bring out antipsychotics with improved efficacy and acceptability, as well as the potential to revolutionize psychiatric practice.

Globalization of Clinical Trials – Where are We Heading?

The last decade has witnessed a greater transparency in clinical research with the advent of clinical trial registries. The aim of the study was to describe the trends in the globalization of clinical trials in the last five years. We performed an internet search using the WHO International clinical trials registry platform (WHO ICTRP) to identify the clinical trials conducted from January 2007 to December 31, 2011 among 25 countries. Among the 25 countries, the United States, Japan and Germany occupy the top positions in the total number of clinical trials conducted. Clinical trials in the US (36312) constituted 31.5% of the total number of trials performed during this period. However over a period of five years both US and Western Europe appear to show a decline, while the emerging countries show a rise in clinical trials registered. Among the emerging countries China, India and Republic of Korea are most active regions involved in clinical trials. Cancer, diabetes and respiratory diseases were most widely researched areas overall. Although the study confirms the transition in the clinical trials research towards emerging countries, the developed regions of the world still contribute to more than 70% of the trials registered worldwide.

Value of pentraxin-3 and galectin-3 in acute coronary syndrome: a short-term prospective cohort study:

Background: Acute coronary syndrome (ACS) continues to be a leading cause of morbidity and mortality worldwide. Galectin-3 and pentraxin-3 are two prognostic biomarkers that have been studied in heart failure (HF). However, there are limited data on these biomarkers in the ACS population. The objective of the study was to determine the variables that are most affected by high concentrations of pentraxin-3 and galectin-3, and the influence they have on outcomes of all-cause mortality in patients with ACS. Methods: We included a total of 160 patients [ST elevation myocardial infarction (STEMI),n = 64; non STEMI/unstable angina (NSTEMI/UA), n = 38; and control subjects with chronic stable angina (CSA)/microvascular angina (MVA) n = 58]. Plasma pentraxin-3 and galectin-3 levels were assessed from these patients at the time of hospital admission. Major adverse cardiovascular events including all-cause mortality, rehospitalizations and coronary artery bypass graft surgery (CABG) were assessed at 6 months. Results: The median concentration of pentraxin-3 and galectin-3 were significantly higher in STEMI than in NSTEMI patients (p < 0.005) or controls (p < 0.005). Greater numbers of deaths (4 versus 0) were observed in STEMI patients with higher levels of these biomarkers. In addition, ACS patients with high levels of pentraxin-3 and galectin-3 had lower left ventricular ejection fraction (LVEF) (p < 0.005), and a moderate correlation was observed between LVEF and pentraxin-3 levels (r = -0.45, p < 0.005). Patients with higher galectin-3 levels were also observed to have a lower estimated glomerular fraction rate (eGFR), and a moderate correlation was observed between them (r = -0.34, p < 0.005). Conclusion: Pentraxin-3 and galectin-3 hold much promise in the ACS population as prognostic biomarkers.

Effect of tolvaptan on acute heart failure with hyponatremia – A randomized, double blind, controlled clinical trial

Objectives To assess the efficacy of tolvaptan in acute heart failure with hyponatremia using a randomized double-blinded placebo-controlled study design. Background Tolvaptan is a selective vasopressin receptor 2 antagonist. There are no published clinical trials on the utility of tolvaptan in acute heart failure with hyponatremia in the Indian population. Methods After screening and informed consent, 51 HF patients with hyponatremia were randomized using computer-generated randomization sequence to receive placebo or 15 mg of tolvaptan for 5 days along with conventional medical therapy. The patients perception of dyspnea using Likert score and the plasma sodium was measured at baseline and for the next 4 days. Results There was a mean improvement in sodium concentration by 5 mEq/L (p = 0.001) in patients receiving tolvaptan, whereas no significant improvement was seen in the placebo group (p = 0.33). Significant improvement in Likert score was observed in both the groups (p = 0.001), even though there was no difference between both the groups. Dry mouth and thirst were the most commonly occurring adverse effects observed in both the groups. There were no significant hemodynamic changes with tolvaptan therapy. Conclusion Tolvaptan at a dose of 15 mg is effective in reversing hyponatremia in acute heart failure and may be a suitable option in these patients.

GDF 15 - A Novel Biomarker in the Offing for Heart Failure

Background: Several diagnostic and prognostic biomarkers are being explored in heart failure. GDF-15 belongs to the transforming growth factor β (TGF-β) cytokine family that is highly up regulated in inflammatory conditions. We undertook this systematic review to summarize the current evidence on the utility of GDF-15 as a biomarker in heart failure. Design and Methods: Multiple electronic databases for studies that reported the association between GDF- 15 and heart failure were searched using different electronic databases such as MEDLINE, Science Direct, Springer Link, Scopus, Cochrane Reviews, and Google Scholar using pre-defined inclusion- exclusion criteria. Results: Twenty one original studies were identified that included data from 20,920 study participants. GDF 15 was found to be a strong prognosticator of all-cause mortality in heart failure patients. Several studies found the benefit of using GDF-15 as a component of a multi-biomarker strategy in prognosticating patients with heart failure. Conclusion: More studies are warranted to elucidate the molecular pathways involving GDF-15 and to see how knowledge about GDF-15 can be used to make therapeutic decisions in the clinic.

Clinical trials in India: Where do we stand globally?

Aims: To evaluate the trend of clinical trials in India over the last 4 years compared to the well-established countries using clinical trial registries since the advent of clinical trial registry of India (CTRI). Materials and Methods: The data of clinical trials registered in India, United States (US), and European Union (EU) were obtained from websites of CTRI, clinicaltrial.gov and EU clinical trial registry, respectively from July 20, 2007 to August 29, 2011 for a period of 4 years. Trials registered in Australia, Canada, China, and Japan were obtained from WHOs international clinical trial registry platform for the same period. We used search words for the common diseases such as diabetes, hypertension, etc., Results: The total number of clinical trials registered during the study period was 67,448 across seven study nations. Clinical trials from India constituted only 2.7% of the total number of trials carried out, compared to US constituting 47% of the total number of trials registered, followed by 18% from EU and 11% from Japan. However, India, China, and Japan have been found to show an increase of 3.7%, 5.1%, and 13.1% increase in the number of trials registered in 2011 compared to 2007. In contrast, US and EU showed a decline of 11.3% and 11.95% respectively in the total number of trials registered in 2011 compared to 2007. Conclusions: Although India shows gradual increase in trials registered since the advent of CTRI, still it continues to lag behind established countries in clinical research.

Molecular analysis of the LDLR gene in coronary artery disease patients from the Indian population

BACKGROUND Cardiovascular disease is a leading cause of mortality in Indian population. Mutations in LDLR, APOB and PCSK9 genes may lead to Familial Hypercholesterolemia, an autosomal dominant disorder which in turn leads to cardiovascular diseases. The primary objective of this study is to analyze these genes in CAD patients of Indian population. METHODS A total of 30 patients were selected out of 300 CAD patients based on UK-Simon Broome criteria from South India. The gDNA was isolated by organic extraction method and the exons and exon-intron boundaries of LDLR gene, APOB (exon 26) and PCSK9 (exon 7) were screened by PCR-high resolution melt analysis. The amplicons showing shift in melting pattern were sequenced to find out the variation. RESULTS This study reports three novel variations, an intronic deletion c.694+8_694+18del in intron 4, a synonymous variation c.966 C>T [p. (N322=)] in exon 7 and a deletion insertion c.1399_1340delinsTA [p. (T467Y)] in exon 10, two recurrent variations c.862G>A [p. (E288K)] in exon 6 and a splice site variation c.1845+2T>C in exon-intron junction of exon 12 in LDLR gene and PCSK9 gene had c.1180+17C>T change in intron 7. However there are no pathogenic variations in APOB and PCSK9 genes in Indian population. In silico analysis predicted all the variations as pathogenic except the synonymous variation. CONCLUSION This report adds five new variations to the spectrum of LDLR variations in Indian population. This study also suggests that UK Simon Broom criteria can be followed to categorize FH patients in Indian population.

Evaluation of Endothelial and Platelet Derived Microparticles in Patients with Acute Coronary Syndrome

BACKGROUND Microparticles (MP) are a nuclear fragments of membrane released by the damaged cell during stress. Elevated levels of MP have been found in patients with acute coronary syndrome (ACS) owing to the damage in the endothelium. AIM To determine if the levels of endothelial and platelet microparticles (EMP & PMP) in patients with ACS influenced the severity of the disease. MATERIALS AND METHODS This was a prospective cohort study performed in 63 ACS patients (ST elevation myocardial infarction- STEMI-28, non ST elevation myocardial infarction -NSTEMI-35). After obtaining consent, blood samples were collected from the patients and processed by flow cytometry. RESULTS The NSTEMI group had higher levels of EMP {792.11(327.59-1661.49) vs 300.35 (176.3-550.46), p=0.001} and PMP {218.87(86.65-439.77) vs 114.45(50.34-196.75), p= 0.007} as compared to the STEMI group. However, it was found that the EMP (r=-0.438, p=0.001) and PMP (r= -0.316, p=0.024) negatively correlated with Global Registry of Acute Coronary Events score (GRACE in-hospital score) for the entire cohort. CONCLUSION The levels of microparticles are elevated in ACS patients and may reflect a protective effect in patients with acute coronary syndrome.