Antiarrhythmic properties of ranolazine – from bench to bedside

Introduction: Pharmacological management of cardiac arrhythmias is limited by the reduced availability of safe and effective antiarrhythmic agents.

Areas covered: Ranolazine is an agent currently used for the treatment of angina, which inhibits transmembrane ionic currents involved in several phases of the action potential in both the atrial and the ventricular cells. Due to its mechanism of action, ranolazine has been shown to exhibit antiarrhythmic properties that have been validated in the experimental models. This article recapitulates the mechanism of antiarrhythmic action of ranolazine, the existing clinical data, and the ongoing relevant clinical trials.

Expert opinion: The combination of the antiischemic properties of ranolazine with its antiarrhythmic potency and minimal proarrhythmia provides a promising background that could expand its therapeutic role in the management of atrial fibrillation and ventricular tachyarrhythmias. Data derived from adequately powered randomized clinical trials will determine whether the door to a new indication will open for ranolazine in the near future.     

Desvenlafaxine for the treatment of major depressive disorder

Introduction: Major depressive disorder (MDD) is a chronic and debilitating condition often characterized by inadequate treatment. Notwithstanding the availability of more than a dozen first-line agents across disparate classes (e.g., selective serotonin reuptake inhibitors), the majority of individuals with MDD do not achieve and sustain a recovered state. A substantial percentage of MDD patients require a treatment change due to poor efficacy or tolerability.

Areas covered: This review focuses on recent (≤ 5 years) literature describing the pharmacokinetics, efficacy, and tolerability of desvenlafaxine, one of the more recently approved antidepressant drugs. Published papers identified via PubMed search and congress presentations were included. Results from short-term, placebo-controlled, MDD trials and randomized withdrawal trials, as well as post hoc analyses in patient subgroups, are reviewed.

Expert opinion: Desvenlafaxine has been shown to be an effective antidepressant with a favorable safety and tolerability profile in the general MDD population and in important patient subgroups. It has several notable differences from other serotonin-norepinephrine reuptake inhibitors, and those differences suggest populations in which it may have the most clinical benefit.     

Lenalidomide as a novel treatment of acute myeloid leukemia

Introduction: Lenalidomide is an oral immunomodulatory drug derived from thalidomide. This drug has been approved by the Food and Drug Administration for transfusion-dependent anemia due to low-risk myelodysplastic syndromes (MDS) associated with deletion 5q abnormality with or without additional cytogenetic abnormalities and multiple myeloma in combination with dexamethasone. Trials have been conducted for its use in higher-risk MDS and acute myeloid leukemia (AML).

Areas covered: The pharmacokinetic and mechanism of action are discussed and clinical studies of lenalidomide in AML are reported herein in detail. An overview of safety and tolerability is also presented.

Expert opinion: Lenalidomide has clinical activity in AML with manageable toxicity. The population that would benefit from lenalidomide and optimal dose needs to be better defined. Recent trials have focused on combining lenalidomide with other agents active in MDS and AML and promising data are emerging.     

Efficacy of desvenlafaxine succinate for menopausal hot flashes

Introduction: The concern for the development of breast cancer, stroke, cardiovascular disease and deep venous thrombosis with the use of hormonal therapy has led to the development of alternative nonhormonal forms of therapy like desvenlafaxine for the management of hot flashes.

Areas covered: This review is based upon a PubMed search and clinical trials. The pharmacokinetics and pharmacodynamics of desvenlafaxine are reviewed. This review outlines the effects of desvenlafaxine in management of severity and frequency of vasomotor symptoms, sleep quality and quality of life in postmenopausal women. The potential adverse effects of desvenlafaxine are summarized.

Expert opinion: Based on the evidence from randomized clinical trials, desvenlafaxine is an alternate viable option for reducing the frequency and severity of hot flashes when other treatments fail. In clinical trials, it has been shown that desvenlafaxine reduced the frequency of hot flashes by 55 – 69%. In the trials so far it appears to have good safety and tolerability profile when the drug is initiated in titrating doses. The optimum dose is 100 mg/day and is to be started at 50 mg/day for 3 days and titrated to 100 mg/day. The most common adverse events reported were nausea, dry mouth, fatigue, constipation, diarrhea and somnolence.     

5-Azacytidine for the treatment of myelodysplastic syndromes

Introduction: 5-Azacytidine is a pyrimidine nucleoside analog of cytidine that undergoes incorporation into DNA and blocks DNA methyltransferase leading to hypomethylation and potentially beneficial re-expression of abnormally silenced genes. It is the first agent approved for use in patients with myelodysplastic syndromes (MDSs) based on its improvement in overall survival as monotherapy. Evidence of efficacy in combination with other agents is also accumulating.

Areas covered: Key information on mechanisms of action is presented. Development, synthesis, and pharmacokinetics are also outlined. Key safety, tolerability, and efficacy data from clinical trials of 5-azacytidine as monotherapy as well as in combination are also presented.

Expert opinion: Our understanding of the molecular basis and pathogenesis of MDS continues to evolve rapidly. 5-Azacytidine has been shown to improve both overall survival and quality of life in patients with high-risk MDS. Currently, the oral route of administration is undergoing evaluation in clinical trials. Used as a monotherapy and also in novel combinations, 5-azacytidine has the potential to further improve the prognosis of some patients with MDS.     

Perifosine – a new option in treatment of acute myeloid leukemia?

Introduction: Perifosine is a novel targeted oral Akt inhibitor. In preclinical leukemia models, perifosine has an independent cytotoxic potential but also synergizes well with other rationally selected targeted agents. The evidence from clinical trials supporting the use of perifosine in the therapy of leukemias is limited. The optimal dose and schedule have yet to be defined. However, given its favorable toxicity profile and mechanism of action, the therapeutic potential of perifosine should be evaluated in well-designed clinical trials.

Areas covered: The role of the phosphatidylinositol-3 kinase (PI3K)/Akt zpathway in normal cells, cancer and leukemias is discussed. The mechanism of action of perifosine and the basic information on the development and chemical properties are summarized. The evidence from in vivo and in vitro studies is presented. The efficacy and side effect profile are summarized.

Expert opinion: The safety and tolerability profile of perifosine are satisfactory. The evidence from clinical trials in patients with leukemias is very limited. The preclinical data are encouraging. Perifosine has the potential to play a role in the treatment of leukemias in the future. Its role needs to be confirmed in clinical trials.     

Vercirnon for the treatment of Crohn's disease

Introduction: CCR9 antagonism is a promising new therapeutic approach for the treatment of Crohn's disease. CCR9 is expressed on the cell surface of memory/effector CD4⁺ T cells and selectively binds to the small intestinal lymphocyte chemoattractant CCL25 (TECK). Blockade of the CCR9/CCL25 interaction inhibits lymphocyte homing to the intestinal mucosa, thereby limiting inflammation and disease at this site.

Areas covered: This review details the current research on CCR9 antagonism and summarizes available clinical trial data for vercirnon, a selective CCR9 antagonist currently under development.

Expert opinion: If the results of ongoing large-scale clinical trials of vercirnon are in line with preliminary reports, CCR9 antagonism may have comparable efficacy to anti-TNF therapies and a potentially superior safety profile, making it the latest addition to the growing arsenal of immunomodulatory drug therapies available to combat Crohn's disease. Moreover, since vercirnon is an oral drug, its associated costs will likely be much lower than expensive infusion-based anti-TNF therapies, providing further economic benefits.     

Zucapsaicin for the treatment of neuropathic pain

Introduction: Neuropathic pain (NP) is a chronic disease that stems from a primary lesion or dysfunction of the central or peripheral nervous system. Zucapsaicin is a synthetic cis isomer of natural capsaicin that has shown therapeutic efficacy in pain accompanying osteoarthritis of the knee. It is also currently under investigation for the relief of severe pain in adults suffering from NP.

Areas covered: The authors provide an overview of the pharmacological properties of zucapsaicin based on available data from both preclinical and clinical trials. They also discuss its mechanism of action.

Expert opinion: The mechanism of action and clinical indications of zucapsaicin are similar to that of its naturally occurring isomer, capsaicin. However, in contrast to capsaicin, zucapsaicin is better tolerated. In the future, zucapsaicin could become a valuable drug for treating pain relief. Indeed, it is possible, in addition to providing NP relief, that it may have a use in treating osteoarthritic pain, headaches and pain that accompany intestinal diseases.     

Vandetanib for the treatment of lung cancer

Introduction: VEGF and EGFR are validated pathways for targeted therapy in non-small cell lung cancer (NSCLC). Once considered to be separate targets, VEGF and EGFR are now shown to have interconnected downstream pathways, potentiating the effectiveness of their dual signaling inhibition in cancer therapy. Molecules such as vandetanib that inhibit VEGFR and EGFR have also been reported to inhibit other receptors, including RET and additional kinases, and may be beneficial in treating patients with solid tumors.

Areas covered: This review covers the significance of targeting VEGF and EGFR in the treatment of NSCLC and the rationale behind their dual inhibition. Clinical trials that evaluate the use of vandetanib in the setting of refractory NSCLC are also explored.

Expert opinion: Vandetanib is currently not approved in the setting of NSCLC. However, its approval for medullary thyroid cancer makes it promising for identifying markers and potentially a NSCLC patient population who will benefit from the treatment.     

Dapagliflozin: a review on efficacy,clinical effectiveness and safety

Introduction: The prevalence of type 2 diabetes mellitus has reached epidemic proportions. Progressive deterioration in glycaemic control and the current limitations of existing therapies such as weight gain and hypoglycaemia led us to welcome the first of a new class of drugs. Sodium-glucose co-transporter 2 (SGLT2) inhibitors represent a novel mode of therapy independent of insulin secretion or action. By blocking glucose reabsorption in the kidney they lead to an increase in urinary glucose excretion with reduction in plasma glucose levels.

Areas covered: In this article, we will review inhibition of SGLT2 as a novel strategy for the treatment of type 2 diabetes mellitus with dapagliflozin. PubMed and MEDLINE were searched for literature published up to July 2012, for efficacy, clinical effectiveness and safety reports of dapagliflozin.

Expert opinion: Improvement in glycaemic control with a low risk of hypoglycaemia, concomitant weight loss and the potential of lowering of blood pressure make SGLT2 inhibition an attractive approach using dapagliflozin therapy. Many SGLT2 inhibitors are undergoing Phase III clinical trials and more are in Phase I and II clinical trials.     

Vemurafenib for the treatment of melanoma

Introduction: Metastatic melanoma is an aggressive disease resistant to chemotherapy. Recent clinical trials have reported improved survival for two novel agents; ipilimumab, a humanized, IgG1 monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and vemurafenib, a BRAF (v-raf murine sarcoma viral oncogene homolog B1) inhibitor targeting an activating mutation in the serine-threonine-protein kinase BRAF gene.

Areas covered: The authors reviewed preclinical and clinical data examining the safety of vemurafenib in melanoma. MEDLINE and EMBASE were searched using the medical subject heading ‘vemurafenib' and the following text terms: melanoma, BRAF inhibition, vemurafenib. This review provides the reader with an overview of current data examining the efficacy and safety of vemurafenib in metastatic melanoma.

Expert opinion: Vemurafenib is an oral agent licensed for patients with BRAF V600E mutation-positive inoperable and metastatic melanoma. The most common adverse effects observed in Phase III clinical trials were dermatological events, arthralgia and fatigue. Specific dermatological toxicities included development of cutaneous squamous cell cancers and keratoacanthomas. Prolongation of the QT interval was also reported. Regular dermatological assessments and electrocardiograms are recommended. Ongoing trials are examining vemurafenib in both the adjuvant setting and metastatic setting in combination with ipilimumab and MEK inhibitors (mitogen-activated protein kinase/extracellular signal-regulated kinase). Understanding and overcoming mechanisms of resistance to BRAF inhibitors is the focus of ongoing research.     

Nilotinib for treatment of gastrointestinal stromal tumors: out of the equation?

Introduction: Imatinib, a selective tyrosine kinase inhibitor (TKI), is currently the standard treatment for unresectable and metastatic gastrointestinal stromal tumors (GISTs). However, the disease control time by imatinib is limited due to intolerance or resistance. Nilotinib, a second-generation TKI, is expected to show enhanced clinical efficacy against advanced GIST.

Areas covered: PubMed and ClincalTrial.gov were searched to identify clinical trials of nilotinib for GIST. The key words used were GIST and nilotinib and/or AMN107. This review summarizes the clinical trials of nilotinib for advanced GIST and outlines current understanding of the clinical usefulness of nilotinib in GIST therapy.

Expert opinion: Clinical trials of nilotinib for advanced GIST were readily advanced from a Phase I study to Phase III studies. Unfortunately, the clinical utility of nilotinib was not demonstrated by the randomized control trials either in patients with imatinib-resistant GIST or in patients who used nilotinib as the first-line treatment. On the basis of the trial results, nilotinib is not recommended for GIST therapy generally. Nevertheless, a comparable number of patients showed significant response with different side-effect profiles from imatinib. Thus, this new TKI may still merit attention as an important alternative to imatinib in advanced GIST patients who are intolerant to imatinib.     

Azacitidine for myelodysplastic patients aged > 65 years: a review of clinical efficacy

Introduction: Therapeutic strategies for elderly patients affected by myelodysplastic syndromes (MDS) are scarce and only few patients have an advantage in performing allogeneic bone marrow transplant.

Areas covered: Primary endpoints for treatment of elderly MDS patients were not curative, but rather allowing to maintain a good quality of life through prolongation of overall survival. In this context, azacitidine showed to improve responses in this subset of patients compared to conventional established regimens, such as intensive or low-dose chemotherapy and best supportive care. Good safety profile of the drug was reported either when it was used inside or outside clinical trials. Improved quality of response was observed when the drug was administered beyond the first response, and it is now usually recommended to continue it at the same dose and schedule in responding patients.

Expert opinion: Evaluation of baseline prognostic factors and comorbidities may help to identify patients who can benefit from the prolonged administration of the drug. Real life data regarding efficacy and safety of azacitidine in MDS elderly patients are required in order to confirm the results of clinical trials.     

A review of iniparib in ovarian cancer

Introduction: Patients with metastatic ovarian cancer continue to experience high recurrence rates and significant morbidity from standard treatments. There is a great need for efficacious tumor-specific agents in ovarian cancer. Iniparib (BSI-201) is a targeted drug currently under investigation.

Areas covered: The authors identified the mechanistic and clinical data available on the role of iniparib in ovarian cancer. Iniparib was initially thought to act via the poly-ADP ribose polymerase 1 (PARP-1) pathway, but recent studies have shown only nonspecific interactions between the drug and PARP proteins. Although iniparib is only active in cancer cells, the exact mechanism of action remains unclear. Iniparib was well tolerated at all dose levels in Phase I studies of solid organ malignancies. Preliminary data from Phase II studies of iniparib for the treatment of platinum-sensitive and platinum-resistant recurrent ovarian cancer show improvement in survival compared to historic controls. There are currently no Phase III studies.

Expert opinion: Iniparib shows promise in early clinical trials; however, understanding the pathways of cytotoxicity will be crucial as cancer therapy becomes increasingly individualized.     

Evaluation of salmeterol xinafoate plus fluticasone propionate for the treatment of chronic obstructive pulmonary disease

Introduction: Current clinical guidelines recommend long-acting bronchodilators as the mainstay of the pharmacotherapy of patients with chronic obstructive pulmonary disease (COPD). Inhaled corticosteroids (ICS), in conjunction with long-acting beta-agonists (LABA), are routinely considered at severe and very severe stages of COPD when patients lack adequate response to single-therapy with LABAs. Although the study methodologies evaluating the clinical effectiveness of the combination therapy using salmeterol and fluticasone (SAL/FLU) for patients with COPD have been questioned, a number of studies have suggested that using ICS, in combination with a LABA agent, may improve survival of patients with COPD.

Areas covered: This article attempts to review the most current evidence for using SAL/FLU in the management of COPD and summarizes the results of outcome measures reported in randomized controlled trials.

Expert opinion: Until new forms of drug combinations are made available, the use of dual-therapy containing a LABA and ICS remain as the most logical and appropriate approach for the treatment of patients suffering from severe and very severe COPD with repeated exacerbations.     

Peginesatide for the treatment of renal disease-induced anemia

Introduction: Erythropoiesis-stimulating agents (ESAs) are the mainstay of treatment in anemic chronic kidney disease (CKD) patients. A tailored ESA therapy should combine maximal efficacy and safety with greatest convenience in dosing. Peginesatide, recently approved in the US for once-monthly dosing in adult patients on dialysis, is a promising novel PEGylated erythropoietin-mimetic peptide for the treatment of renal disease-induced anemia.

Areas covered: Published animal and human studies that evaluated the pharmacodynamics, pharmacokinetics, clinical efficacy and safety of peginesatide were critically analyzed.

Expert opinion: Peginesatide has a well-studied pharmacological and immunological profile, and latest published data favor the use of peginesatide in place of epoetin in dialysis patients. A more detailed evaluation of its safety profile particularly in trials with CKD patients not requiring dialysis is urgently needed, as peginesatide could be a perfect treatment solution for these patients. In addition, clinical long-term data and results from supplemental studies, e.g., with the PEGylated continuous erythropoietin receptor activator as comparator, should briefly follow. The fate of peginesatide on the highly competitive ESA market is currently not predictable and depends on safety and efficacy results of upcoming trials as well as finally on market and price policy.