Biosimilars: A Multidisciplinary Perspective

A biosimilar is an officially regulated and approved copy of an originator biologic therapy. Improved affordability and consequent wider patient access compared with biologics are a significant appeal of biosimilars. Regulatory guidelines for biosimilar development and approval are rigorous and undergoing constant refinement. The process of licensing approval for all biosimilars requires demonstration of comparability in quality, efficacy, and safety between the biosimilar and reference (originator) product, which is undertaken in a stepwise procedure of nonclinical and clinical evaluation. The approval of >20 biosimilars in Europe in several drug classes, including the first monoclonal antibody biosimilar, bears testimony to the increasing regulatory acceptance of these agents. In contrast, the clinical application of biosimilars remains underrecognized by physicians across therapy areas. Therefore, this article aims to provide a comprehensive review of the biosimilar development process and to provide multidisciplinary guidance on the potential therapeutic utility of biosimilars in clinical practice. Specifically, experts discuss clinical developments in the introduction of biosimilars across the disciplines of gastroenterology, nephrology, oncology, and rheumatology, and from a payer perspective, and also highlight a common need for ongoing pharmacovigilance, robust head-to-head clinical studies, and real-world data to establish the long-term risk-benefit profile of biosimilars. In conclusion, significant potential exists for biosimilars to revolutionize biologic therapy by widening patient access across therapy areas.

Methoxy polyethylene glycol-epoetin beta for the treatment of anemia associated with chronic renal failure

Since more than two decades erythropoiesis-stimulating agents are the main pillar for treatment of anemia associated with chronic kidney disease. Methoxy polyethylene glycol-epoetin beta (MPG-EPO), also called continuous erythropoietin receptor activator, is the longest acting erythropoiesis-stimulating agent currently available. MPG-EPO is characterized by an elimination half-life of approximately 137 h and offers extended dosing intervals up to 4 weeks. Numerous phase I/II studies and a comprehensive clinical phase III program demonstrated the feasibility of MPG-EPO therapy for anemia correction and maintenance of stable hemoglobin levels in adult chronic kidney disease patients. Due to patent disputes MPG-EPO was only available outside the US market so far. In view of a prevailing US market introduction, this review focuses on efficacy and safety data from pivotal trials, summarizes recent clinical research and finally tries to substantiate potential benefits associated with the use of this anti-anemic drug.

Novel iron-containing phosphate binders for treatment of hyperphosphatemia

INTRODUCTION

Hyperphosphatemia is a frequent complication of chronic kidney disease and is associated with increased mortality. Despite side effects, risk of accumulation and high costs, phosphate binders (PBs) have become the crucial cornerstone of therapy. The iron-containing PB sucroferric oxyhydroxide (SO) and ferric citrate hydrate (FCH) have entered the market and other candidates are prior market entry.

AREAS COVERED

A literature search was performed using MEDLINE and EMBASE databases to identify references on iron-containing PB with particular regard to efficacy, safety and potential benefits. Additional hand searches were conducted along with a full-text review of any citation that appeared relevant.

EXPERT OPINION

On the highly competitive market, where the 'ideal' PB is still unknown, novel substances that offer clear benefits over available drugs are desired. Although SO and FCH showed similar efficacy and safety compared to sevelamer, head-to-head studies with lanthanum carbonate are absent. Clinical 1-year data in a limited patient cohort suggested improved adherence for SO and a large randomized controlled trial showed significant reduction in hospitalizations and costs for FCH. Additional large randomized controlled trials have now to prove these possible advantages. Cost-effectiveness in comparison to other PB and the exclusion of significant harms under long-term treatment will determine the future use of both drugs.

Full thermoelectric characterization of InAs nanowires using MEMS heater/sensors

Precise measurements of a complete set of thermoelectric parameters on a single indium-arsenide nanowire (NW) have been performed using highly sensitive, micro-fabricated sensing devices based on the heater/sensor principle. The devices were fabricated as micro electro-mechanical systems consisting of silicon nitride membranes structured with resistive gold heaters/sensors. Preparation, operation and characterization of the devices are described in detail. Thermal decoupling of the heater/sensor platforms has been optimized reaching thermal conductances as low as 20 nW K(-1) with a measurements sensitivity below 20 nW K(-1). The InAs NWs were characterized in terms of thermal conductance, four-probe electrical conductance and thermopower (Seebeck coefficient), all measured on a single NW. The temperature dependence of the parameters determining the thermoelectric figure-of-merit of an InAs NW was acquired in the range 200-350 K featuring a minor decrease of the thermal conductivity from 2.7 W (m K)(-1) to 2.3 W (m K)(-1).

Cost-effectiveness of continuous erythropoietin receptor activator in anemia

Background

Erythropoiesis-stimulating agents (ESAs) are the mainstay of anemia therapy. Continuous erythropoietin receptor activator (CERA) is a highly effective, long-acting ESA developed for once-monthly dosing. A multitude of clinical studies has evaluated the safety and efficiency of this treatment option for patients with renal anemia. In times of permanent financial pressure on health care systems, the cost-effectiveness of CERA should be of particular importance for payers and clinicians.

Objective

To critically analyze, from the nephrologists’ point of view, the published literature focusing on the cost-effectiveness of CERA for anemia treatment.

Methods

The detailed literature search covered electronic databases including MEDLINE, PubMed, and Embase, as well as international conference abstract databases.

Results

Peer-reviewed literature analyzing the definite cost-effectiveness of CERA is scarce, and most of the available data originate from conference abstracts. Identified data are restricted to the treatment of anemia due to chronic kidney disease. Although the majority of studies suggest a considerable cost advantage for CERA, the published literature cannot easily be compared. While time and motion studies clearly indicate that a switch to CERA could minimize health care staff time in dialysis units, the results of studies comparing direct costs are more ambivalent, potentially reflecting the differences between health care systems and variability between centers.

Conclusion

Analyzed data are predominantly insufficient; they miss clear evidence and have to thus be interpreted with great caution. In this day and age of financial restraints, results from well-designed, head-to-head studies with clearly defined endpoints have to prove whether CERA therapy can achieve cost savings without compromising anemia management.

Predictors of adolescent smoking cessation and smoking reduction

OBJECTIVE

To investigate the processes of change, demographic, health- and smoking-related predictors of both smoking cessation and smoking reduction in adolescents.

METHODS

Data were drawn from a sample of 755 adolescent smokers who participated in a study testing the efficacy of a text messaging-based intervention for smoking cessation. Demographic, health- and smoking-related variables were assessed at baseline. Five processes of smoking cessation, derived from the Transtheoretical Model and the Social Cognitive Theory, as well as outcome measures were assessed at 6-month follow up. Univariate and multivariate regression analyses were conducted to identify baseline and process variables to predict smoking abstinence and smoking reduction.

RESULTS

Male gender (OR=0.43, p<.01), lower alcohol consumption (OR=0.90, p=.05) and a lower number of cigarettes smoked per day at baseline (OR=0.87, p<.01) predicted smoking abstinence. Baseline physical activity predicted smoking reduction (OR=1.04, p=.03). None of the examined process variables significantly predicted smoking abstinence. The process variable "counter-conditioning" predicted smoking reduction (OR=1.46, p=.03).

CONCLUSIONS

Baseline predictors of smoking cessation differ from predictors of smoking reduction. Dynamic or modifiable variables play an important role in predicting adolescent smoking cessation.

PRACTICE IMPLICATIONS

Counter-conditioning might be an important element in adolescent smoking cessation interventions.

Neuropsychological profile of children after an episode of neuroborreliosis

BACKGROUND

In the majority of patients with Lyme neuroborreliosis (LNB), neurological symptoms are transient. The extent of neuropsychological and neuropsychiatric problems in children is not well researched.

OBJECTIVES

The study aimed to investigate cognitive functions and behavioral problems in children after LNB.

PATIENTS AND METHODS

A total of 20 children between 6 and 16 years of age with an episode of LNB at least 4 month before neuropsychological testing were enrolled in the study and compared with 20 healthy controls. Children with LNB had cranial nerve palsies or meningoencephalitis, immunoglobulin G and immunoglobulin M antibodies for Borrelia burgdorferi in the peripheral blood, pleocytosis in the cerebrospinal fluid (leukocytes > 10 cells/μL) and/or an intrathecal synthesis of antibodies for B. burgdorferi.Neuropsychological tests assessing intellectual skills, memory, and executive functions were used. Two parental questionnaires assessing behavior, psychiatric problems, and executive functions were administered.

RESULTS

Intellectual skills, memory, and executive functions of children after an episode of LNB were within the normal range. In the subcategory of working memory, children after an episode of LNB performed worse than controls. The questionnaires did not reveal behavior or psychiatric problems, although there was a tendency that children after an episode of LNB had more physical complaints.

CONCLUSION

Neuropsychological deficits resulting from LNB in childhood are rare. Most children had a good cognitive, emotional, and behavioral outcome.

Persistent nasal methicillin-resistant staphylococcus aureus carriage in hemodialysis outpatients: a predictor of worse outcome

Background

Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a well defined risk factor for subsequent bacteremia and death in various groups of patients, but its impact on outcome in patients receiving long-term hemodialysis (HD) is under debate.

Methods

This prospective interventional cohort study (performed 2004 to 2010) enrolled 289 HD outpatients of an urban dialysis-unit. Nasal swab cultures for MRSA were performed in all patients upon first admission, at transfer from another dialysis facility or readmission after hospitalisation. Nasal MRSA carriers were treated in a separate ward and received mupirocin nasal ointment. Concomitant extra-nasal MRSA colonization was treated with 0.2% chlorhexidine mouth rinse (throat) or octenidine dihydrochloride containing antiseptic soaps and 2% chlorhexidine body washes (skin). Clinical data and outcome of carriers and noncarriers were systematically analyzed.

Results

The screening approach identified 34 nasal MRSA carriers (11.7%). Extra-nasal MRSA colonization was observed in 11/34 (32%) nasal MRSA carriers. History of malignancy and an increased Charlson Comorbidity Index were significant predictors for nasal MRSA carriers, whereas traditional risk factors for MRSA colonization or markers of inflammation or malnutrition were not able to discriminate. Kaplan-Meier analysis demonstrated significant survival differences between MRSA carriers and noncarriers. Mupirocin ointment persistently eliminated nasal MRSA colonization in 26/34 (73.5%) patients. Persistent nasal MRSA carriers with failure of this eradication approach had an extremely poor prognosis with an all-cause mortality rate >85%.

Conclusions

Nasal MRSA carriage with failure of mupirocin decolonization was associated with increased mortality despite a lack of overt clinical signs of infection. Further studies are needed to demonstrate whether nasal MRSA colonization represents a novel predictor of worse outcome or just another surrogate marker of the burden of comorbid diseases leading to fatal outcome in HD patients.

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.

New strategies for managing anemia of chronic kidney disease

Anemia is a prevalent and premature comorbidity in chronic kidney disease (CKD) and associated with multiple adverse clinical consequences including increased mortality. Today Erythropoiesis-stimulating agents (ESAs), together with iron supplementation, are the cornerstones of therapy for correcting anemia in CKD patients. As no generally accepted dosing algorithms for these agents exist, current recommendations prefer a partial but not complete anemia correction thereby favoring a more conservative and individualized ESA and iron dosing. Here we discuss in detail current evidence derived from large randomized trials about the proposed hemoglobin targets to aim at in CKD and End-Stage renal disease patients and report recent data from the thriving European market of biosimilar erythropoietins. We summarize promising investigational strategies including peginesatide and prolyl hydroxylase inhibitors for stabilization of the hypoxia inducible factor and provide a clinical review of novel high dose iron formulations like ferumoxytol or iron (III)-carboxymaltose. Taking these findings together, treatment strategies for anemia of CKD have got considerably more complicated so that a careful balance between maximization of patient`s quality of life while minimizing all risks associated with anemia treatment has become a major task of current nephrology.

Defect structures in ZnO studied by high-resolution structural and spectroscopic imaging

The formation of characteristic inversion domain structures in zinc oxide (ZnO) is triggered by the addition of trivalent Fe(3+) or In(3+) dopants. As-grown and inverted ZnO domains are separated by two types of inversion domain boundaries (IDBs): basal b-IDBs parallel to {0001}, and pyramidal p-IDBs parallel to {21¯1¯5} lattice planes in three equivalent variants. Cs-corrected analytical TEM/STEM is the method of choice for a comprehensive structural and compositional characterization of these materials. It is shown by electron and X-ray spectroscopic imaging in STEM that dopant species are essentially localized within both types of IDBs, whereas solid solubility of trivalent dopants within ZnO domains is rather low (<0.5at%). Under the assumption of one monolayer per IDB the relation between inversion domain structure and integral dopant concentration correlates well with integral EDS and EELS measurements in STEM over well defined sample regions. The presence of one close-packed monolayer of trivalent dopant ions within a b-IDB is unambiguously confirmed by atomic resolution STEM imaging. Columns of cations are clearly imaged in high-angle annular dark-field (HAADF) STEM imaging, whereas annular bright-field (ABF) STEM is capable of imaging both light and heavy atom columns simultaneously. It is shown that structural details in ABF images are directly interpretable even in specimen regions with thickness >50nm. The structural inversion associated with a stacking fault as a consequence of the presence of octahedrally coordinated In(3+) in the b-IDB is directly revealed by atomic resolution imaging. Column positions in atomic resolution ABF imaging in In2O3-ZnO nanorods show that the oxygen sub-lattice continues across the b-IDB with only marginal distortions, whereas the cation sub-lattice suffers a rigid shift relative to the oxygen lattice as a result of the coordination geometry of ZnO4 tetrahedrons sharing common oxygen ions with the InO6 coordination octahedrons.

Macro CK2 accumulation in tenofovir-treated HIV patients is facilitated by CK oligomer stabilization but is not predictive for pathology

BACKGROUND

Ubiquitous mitochondrial creatine kinase (uMtCK) accumulates as macroenzyme creatine kinase type 2 (macro CK2) in the serum of HIV-infected patients under a tenofovir disoproxil fumarate (TDF)-containing antiretroviral regimen. The genesis and clinical significance of this finding is unclear.

METHODS

A prospective observational 5-year follow-up study was performed on those patients in which macro CK2 appearance was initially described ('TDF switch study' cohort). In addition, tenofovir (TFV), its prodrug TDF and its active, intracellular derivative TFV diphosphate (TDP) were tested in vitro for their effects on different key properties of uMtCK to clarify possible interactions of uMtCK with TFV compounds.

RESULTS

In just under 5 years of continuous TDF treatment, only 4/12 (33%) patients remained macro CK2-positive, whereas 8/12 (66%) originally positive patients were macro CK2-negative at the end of follow-up. Prospective clinical follow-up data indicate that macro CK2 appearance under TDF is not associated with significant cell damage or occurrence of malignancies. A trend towards grade 1 hypophosphataemia suggests subclinical proximal tubular dysfunction in macro-CK2-positive patients, although it was not associated with a significant decrease in estimated glomerular filtration rate. In vitro, TFV, TDF and TDP did not interfere with uMtCK enzyme activity as competitive inhibitors or pseudo-substrates, but TFV and TDF stabilized the native uMtCK octameric structure in dilute solutions.

CONCLUSIONS

Appearance of octameric uMtCK as macro CK2 in the serum of TDF-treated patients is suggested to result from a combination of low-level mitochondrial damage caused by subclinical renal tubular dysfunction together with possible compensatory uMtCK overexpression and a putative concomitant stabilization of uMtCK octamers by higher levels of TFV in proximal tubules.

Leaching of metal(loid)s from a construction material: influence of the particle size, specific surface area and ionic strength

Construction materials are tested worldwide for a potential release of dangerous substances to prevent adverse effects on humans and biota. It is crucial to identify and understand the processes which are decisive for the release of hazardous substances. The current study compares the results of different test methods. Taking copper slag as model material, the influence of material particle size, eluant composition and ionic strength was tested. Ionic strength and salinity significantly influenced the release of metal(loid)s in the water phase. Furthermore, it was elucidated that colloids can cause methodological artefacts. The available specific surface area exhibited a positive correlation with the release of hazardous substances. The specific surface areas of materials were determined by the Brunauer, Emmett and Teller model (BET) and four other methods. The aluminium foil method showed the best results with regard to the statistical uncertainty, compared to a 3D laser scanning method. With help of the roughness factor λ it is possible to compare the results from surface area measurements with different material particle sizes (0-250 mm). This comparability offers the potential to match the release of metal(loid)s from laboratory studies with field applications and catchment area calculations/modelling, based on the release per m(2).

[Acute kidney injury]

Acute kidney injury plays a pivotal role in intensive care medicine and exerts crucial adverse effects on the course of the disease and overall prognosis of the critically ill patient. Intensive renal support, including initiation of earlier dialysis or maximal uremic toxin removal by higher dosage and frequency of renal replacement therapy, and individualized selection of modality were not able to decrease excessive mortality in this population. Systemic acute inflammation, mediated, at least in part, by cytokines, and not secondary uremic side effects, seems to have a major impact on nonrenal organ damage. Assessment of short-term outcome in critically ill patients who develop acute kidney injury may underestimate the true burden of disease. The overall survival at 5 years in patients discharged alive after severe acute kidney injury necessitating renal replacement therapy is only 20-30%, comparable to cancer patients. In addition, acute renal damage was identified as an independent risk factor for progression of chronic renal insufficiency. Current research focuses on strategies for the prevention of acute kidney injury and on the establishment of effective biomarkers for the early recognition and accurate diagnosis of subclinical renal damage.

Activation of innate immune defense mechanisms contributes to polyomavirus BK-associated nephropathy

Polyomavirus-associated nephropathy (PVAN) is a significant complication after kidney transplantation, often leading to premature graft loss. In order to identify antiviral responses of the renal tubular epithelium, we studied activation of the viral DNA and the double-stranded RNA (dsRNA) sensors Toll-like receptor 3 (TLR3) and retinoic acid inducible gene-I (RIG-I) in allograft biopsy samples of patients with PVAN, and in human collecting duct cells in culture after stimulation by the dsRNA mimic polyriboinosinic:polyribocytidylic acid (poly(I:C)), cytokines, or infection with BK virus. Double staining using immunofluorescence for BK virus and TLR3 showed strong signals in epithelial cells of distal cortical tubules and the collecting duct. In biopsies microdissected to isolate tubulointerstitial lesions, TLR3 but not RIG-I mRNA expression was found to be increased in PVAN. Collecting duct cells in culture expressed TLR3 intracellularly, and activation of TLR3 and RIG-I by poly(I:C) enhanced expression of cytokine, chemokine, and IFN-β mRNA. This inflammatory response could be specifically blocked by siRNA to TLR3. Finally, infection of the collecting duct cells with BK virus enhanced the expression of cytokines and chemokines. This led to an efficient antiviral immune response with TLR3 and RIG-I upregulation without activation of IL-1β or components of the inflammasome pathway. Thus, PVAN activation of innate immune defense mechanisms through TLR3 is involved in the antiviral and anti-inflammatory response leading to the expression of proinflammatory cytokines and chemokines.

Kidney-specific cadherin correlates with the ontogenetic origin of renal cell carcinoma subtypes: an indicator of a malignant potential?

INTRODUCTION AND OBJECTIVES

To evaluate retrospectively kidney-specific cadherin (Ksp-cad) expression in renal cell carcinoma (RCC) subtypes and oncocytoma in correlation with its ontogenetic origin of distal and proximal tubules and to correlate Ksp-cad expression with tumour characteristics.

MATERIALS AND METHODS

Membranous and cytoplasmic expression of Ksp-cad was determined in 40 clear cell (ccRCC), 25 papillary (pRCC), 19 chromophobe carcinomas (chRCC), 27 oncocytomas (oncocytomas) (n = 111) and 32 benign kidney parenchyma specimens separated in distal tubules (DT) and proximal tubules (PT) by immunohistochemistry using tissue microarray technique. Staining intensity was quantified as a score ranging from 0 to 12. Comparison of data and correlation with tumour characteristics were done by Wilcoxon/Kruskal-Wallis tests (post hoc Tukey-Kramer analysis).

RESULTS

In benign renal tissue, membranous and cytoplasmic expression of Ksp-cad in the DT was significantly higher than that in the PT (12.0 ± 0 vs. 5.2 ± 0.3 and 6.3 ± 0.5 vs. 0.0 ± 0.0, respectively; (P < 0.05)). Membranous KSP-cad expression was significantly higher in chRCC (5.2 ± 0.8) and oncocytomas (3.7 ± 0.4) than that in ccRCC (0.8 ± 0.2) and pRCC (1.4 ± 0.4; P < 0.05), while expression between oncocytomas and chRCC did not differ significantly. In RCC, Ksp-cad expression was significantly associated with higher T stage and the occurrence of synchronous metastasis (P < 0.05). Higher N stages and grading tended to correlate with a lower Ksp-cad expression.

CONCLUSIONS

In this cohort, the origin of tumour subtypes-chRCC and oncocytomas develop from DT and ccRCC and pRCC from PT cells-is mirrored by the respective Ksp-cad expression. This raises the question whether DT-derived tumours have a less malignant potential than PT-derived tumours.