Defining Satisfactory Methods of Treatment in Rare Diseases When Evaluating Significant Benefit-The EU Regulator's Perspective.

Since the implementation of the EU Orphan Regulation in 2000, the Committee for Orphan Medicinal Products at the European Medicines Agency has been evaluating the benefits of proposed orphan medicines vs. satisfactory treatment methods. This type of evaluation is foreseen in the Orphan Regulation as the orphan designation criterion called the "significant benefit." In this article, based on 20 years of experience, we provide a commentary explaining what is considered a satisfactory method of treatment in the context of the EU Orphan Regulation and for the purpose of the assessment of significant benefit. We discuss the challenges posed by continuously changing clinical practise, which is associated with the increasing number of treatment options, evolving nature of medicinal therapeutic indications and our understanding of them.

Regulatory Standards in Orphan Medicinal Product Designation in the EU.

Twenty years of orphan regulation in Europe have now elapsed, with almost 2,400 orphan designated medicinal products and more than 190 orphan products authorised in the EU. Alongside the evolution in understanding of rare diseases, considerable regulatory knowledge has also been accumulated regarding the level of evidence that would support inclusion of products into the framework. This article reviews publications and regulatory documents pertaining to orphan medicinal product designation in the EU and discusses the general expectations in submitted applications as reflected in the current regulatory practise. Important elements to recommend granting a European orphan designation are the key considerations of orphan condition, medical plausibility, seriousness, and prevalence, while significant benefit is also assessed when there are authorised medicinal products for the sought indication. This review attempts to clarify the specific concepts currently used in that regard and discusses how the available data can be used to justify the criteria for designation. Moving away from theoretical expectations or assumptions, it stresses that the applications have to be complemented with nosological and epidemiological justifications pertaining to the proposed condition, as well as relevant data in specific non-clinical in vivo models or in affected patients to support inclusion into the orphan scheme.

Nonclinical data supporting orphan medicinal product designations in the area of rare infectious diseases.

This review provides an overview of nonclinical in vivo models that can be used to support orphan designation in selected rare infectious diseases in Europe, with the aim to inform and stimulate the planning of nonclinical development in this area of often neglected diseases.

Demonstrating significant benefit of orphan medicines: analysis of 15 years of experience in Europe.

In the European Union demonstration of 'significant benefit' is mandatory if satisfactory methods exist for a disease targeted by a new orphan medicinal product. Significant benefit is required at the time of orphan designation, when it can be supported by preclinical studies, and at the time of marketing authorization, when clinical data are needed. For the first time, our work has identified, defined and organized the scientific grounds on which significant benefit is granted in the European Union, based on a review of the orphan medicinal products authorized in the years 2000-2015, and on the working experience of the Committee of Orphan Medicinal Products. The resulting conceptual framework is a tool for medicine developers to reflect on potential areas of advantage of their candidate products, and for a broad range of stakeholders to stimulate the discussion on the added value of orphan medicines across the whole development lifecycle.

Nonclinical data supporting orphan medicinal product designations: lessons from rare neurological conditions.

Here, we provide an in-depth literature and experience-based review of nonclinical models and data used to support orphan medicinal product designations (OMPDs) in rare neurodegenerative conditions. The Committee for Orphan Medicinal Products (COMP) of the European Medicines Agency updates its assessment processes based on scientific progress and aims to provide transparent criteria required in support of OMPDs. Thus, we also provide an updated analysis of existing nonclinical models in selected conditions and identify key features of nonclinical studies that are crucial for the support of OMPDs. This could not only inform future drug development in rare neurological conditions, but also indicate areas where the use of nonclinical models can be made more efficient.

Establishing rarity in the context of orphan medicinal product designation in the European Union.

In the European Union (EU) legislative framework for orphan medicinal product designation, establishing that a condition affects not more than five in 10,000 people is a prerequisite for applications based on rarity. Demonstrating this requirement to the Committee of Orphan Medicinal Products (COMP) can be a particularly challenging task for sponsors. Here, we identify and examine three common issues with the estimation of prevalence in orphan drug applications in the EU (the discernment between diagnosed and undiagnosed cases; the duration of the disease; and the need for an explicit contemporary conclusion) as critical factors for acceptable prevalence estimation. These concerns are discussed in detail based on recent examples of applications, which are reflected in published European Medicines Agency (EMA) documents.

Evolving prevalence of haematological malignancies in orphan designation procedures in the European Union.

The Committee for Orphan Medicinal Products (COMP) evaluates prevalence of rare conditions as one of the criteria for granting an orphan designation with a prevalence threshold of 5 in 10.000. At the time of Marketing Authorisation (MA) these criteria are reassessed to ensure they are still met. The COMP has noted discordance between the prevalence of certain haematological malignancies at the time of Orphan Designation and at the time of Marketing Authorisation. Consequently, we conducted a retrospective assessment of Chronic Lymphocytic Lymphoma and Multiple Myeloma/Plasma cell Myeloma as well as several other haematological rare aetiologies frequently subject of orphan designation. These were: Diffuse large B-Cell Lymphoma (DLBCL), Follicular Lymphoma (FL), Cutaneous T-Cell Lymphoma (CTCL), Mantle Cell Lymphoma (MCL) and Chronic Myeloid Leukaemia (CML). The review used submissions as well as recent publications and results from external and EMA databases. As a first step in the analysis, an increase over time in the number of people affected was evident for four conditions in the COMP designation documents, whereas for DLBCL, FL, CTCL and MCL there had been no significant change, since the introduction of the Regulation in 2000. Specifically, the prevalence estimates increased from 1.2 to 3.6 per 10,000 for multiple myeloma, from 0.4 to 1.7 in acute lymphoblastic leukaemia, and from 2.7 to 4.85 for chronic lymphocytic leukaemia/small lymphocytic leukaemia and 1 to 2 in 10,000 for chronic myeloid leukaemia. The reasons for the changes in the prevalence of these four haematological conditions over the last 15 years were not assessed but recent publications have alluded to better outcomes due to new treatments being made available. In addition, many orphan diseases have a median age of onset over 60 years so that also the aging of the population may be a relevant contributing factor.

Establishing medical plausibility in the context of orphan medicines designation in the European Union.

In the European Union, sponsors have the responsibility to demonstrate the "intention to diagnose, prevent or treat" a serious and rare condition before the Committee of Orphan Medicinal Products (COMP), for a medicinal product to meet the criteria for Orphan Designation. This requirement is commonly referred to as "medical plausibility" and the justification of this intention is assessed on the merits of each application by the COMP, which deliberates over the scientific evaluation of the evidence submitted. The scientific assessment of the applications for orphan designation by the Committee is based on the review of non-clinical (such as in vitro and in vivo) and/or clinical data submitted by the sponsor. Several challenges regarding the evidence provided emerge when the sponsor is applying for a designation at an early stage of development. Herein we discuss specific examples from the experience of the COMP, in order to elaborate on the type and level of evidence generally considered necessary for the purpose of justification of the intention to treat an orphan condition. Importantly, it is pointed out that bridging of data from other products, irrespectively of how comparable they may be, or from settings not directly associated with the condition as applied for designation, is by and large not a successful exercise and may only be exceptionally considered. It is further exemplified that, as reflected in the updated 'Guideline on the format and context of the applications for designation' and the guidance document 'Recommendation on elements required to support the medical plausibility and the assumption of significant benefit for an orphan designation' available on the EMA website, the sponsor should provide data with the specific product as applied for in specific models of the condition or in patients affected by the same condition subject of each application.

Use of biomarkers in the context of orphan medicines designation in the European Union.

The use of biomarkers within the procedures of the Committee of Orphan Medicinal Products (COMP) of the European Medicines Agency (EMA) is discussed herein. The applications for Orphan Medicinal Product designation in the EU are evaluated at two stages. At the time of orphan designation application, the file undergoes an assessment to establish whether the proposed condition is a distinct and serious condition affecting not more than 5 in 10,000 people in the EU, and whether the product is plausible as a therapy for that condition. In cases where therapies already exist, the significant benefit of the candidate product over existing therapies is also evaluated. The orphan criteria are reassessed at the time of marketing authorisation, so that marketing exclusivity for the product in the orphan medical condition can be granted. Within this context, biomarkers have been used in submissions in order to define an orphan condition and to justify that the criteria for orphan designation are met. The current work discusses specific examples from the experience of the COMP, where biomarkers have played a decisive role. Importantly, it identifies the proposal of sub-sets of non-rare conditions based on biomarkers as a challenging issue in the evaluation of applications. In particular two specific requirements for the candidate orphan medicines in relation to the biomarker-based subsets are highlighted: the "plausible link to the condition" and the "exclusion of effects outside the subset".

European regulation on orphan medicinal products: 10 years of experience and future perspectives.

In 2000, regulation on orphan medicinal products was adopted in the European Union with the aim of benefiting patients who suffer from serious, rare conditions for which there is currently no satisfactory treatment. Since then, more than 850 orphan drug designations have been granted by the European Commission based on a positive opinion from the Committee for Orphan Medicinal Products (COMP), and more than 60 orphan drugs have received marketing authorization in Europe. Here, stimulated by the tenth anniversary of the COMP, we reflect on the outcomes and experience gained in the past decade, and contemplate issues for the future, such as catalysing drug development for the large number of rare diseases that still lack effective treatments.

An atypical presentation of visceral leishmaniasis infection in a patient with rheumatoid arthritis treated with infliximab.

Tumor necrosis factor alpha (TNF-alpha) is a cytokine, implicated in the pathogenesis of many inflammatory diseases, as well as in the immune-mediated response to infection, especially against intracellular pathogens. TNF-alpha antagonists have represented a revolution in the management of connective tissue diseases, such as rheumatoid arthritis. However, the use of these agents has been implicated with the emergence of a growing number of opportunistic infections. Here we report the case of a visceral Leishmaniasis in a 77-year-old woman who had been previously treated for rheumatoid arthritis with infliximab. The atypical presentation of this patient, previously treated with an anti-TNF-alpha biologic agent, where no splenomegaly or hepatomegaly was identified, is emphasized.

Factors associated with success of market authorisation applications for pharmaceutical drugs submitted to the European Medicines Agency.

PURPOSE: To identify factors associated with success of Market Authorisation Applications (MAAs) for pharmaceutical drugs submitted to the European Medicines Agency (EMEA), with an emphasis on the Scientific Advice (SA) given by the Committee for Human Medicinal Products (CHMP). METHODS: MAAs with a CHMP decision (outcome) between 1 January 2004 and 31 December 2007 were included in the analysis. Factors evaluated were: company size, orphan drug (OD) status, product type, existence of SA, compliance with SA, therapeutic area and year of outcome. Compliance with SA was retrospectively assessed with reference to three critical clinical variables in pivotal studies: choice of primary endpoint, selection of control and statistical methods. RESULTS: Of 188 MAAs with an outcome, 137 (72.9%) were approved, whereas 51 (27.1%) were not approved or were withdrawn by the company. In the simple logistic regression analysis, company size [odds ratio (OR) 2.96, 95% confidence interval (CI) 1.92; 4.56, p < 0.0001) was positively correlated with a positive outcome, whereas OD status (OD vs. non-OD: OR 0.38, 95% CI 0.19; 0.77, p = 0.0067) was negatively correlated. A total of 59 (31.4%) MAAs had obtained SA related to one or more of the three critical variables. Thirty-nine of these were assessed as being compliant with SA. Obtaining an SA per se was not associated with outcome (SA vs. no-SA: OR 0.96, 95% CI 0.49; 1.88, p = 0.92), but complying with SA was significantly associated with positive outcome (compliant with SA vs. no-SA: OR 14.71, 95% CI 1.95; 111.2; non-compliant with SA vs. no-SA: OR 0.17, 95% CI 0.06; 0.47, p < 0.0001). Stepwise regression analysis revealed that company size and SA compliance were independent predictors of outcome. The proportion of the MAAs that had received SA increased from 22% in 2004 to 47% in 2007. Company size and product type were associated with the frequency of requesting SA (26, 33 and 46% for small, medium-sized and large companies, respectively; 16, 39 and 48% for known chemical substances, new chemical substances and biologics, respectively). Factors related to compliance with SA were company size and OD status (25, 60 and 84% for small, medium-sized, and large companies, respectively; 77 and 38% for non-OD and OD status, respectively). CONCLUSIONS: The strong association between company size and outcome suggests that resources and experience in drug development and obtaining regulatory approval are critical factors for a successful MAA. In addition, obtaining and complying with SA appears to be a predictor of outcome. Based on this analysis, companies, particularly smaller ones and those developing orphan drugs, are recommended to engage in a dialogue with European regulators via the SA procedure. Obtaining SA early in development and at major transition points as well as compliance with the advice given by the CHMP are recommended.

Angiopoietin-2 is increased in severe sepsis: correlation with inflammatory mediators.

OBJECTIVE: Angiopoietin (Ang)-2 is an endothelium-specific growth factor, regulated by proinflammatory stimuli, that destabilizes vascular endothelium and increases vascular leakage; consequently, Ang-2 may contribute to sepsis pathophysiology. We have studied 1) serum Ang-2 levels in critically-ill patients and investigated potential relationships with inflammatory mediators and indices of disease severity and 2) the effect of sepsis-related inflammatory mediators on Ang-2 production by lung endothelium in vitro. DESIGN: Prospective clinical study followed by cell culture studies. SETTING: General intensive care unit and research laboratory of a university hospital. SUBJECTS: Human and bovine lung microvascular endothelial cells and 61 patients (32 men). Patients were grouped according to their septic stage as having: no systemic inflammatory response syndrome (n = 6), systemic inflammatory response syndrome (n = 8), sepsis (n = 16), severe sepsis (n = 18), and septic shock (n = 13). INTERVENTIONS: Cells were exposed to lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-6. MEASUREMENTS AND MAIN RESULTS: Patients' serum Ang-2 levels were significantly increased in severe sepsis as compared with patients with no systemic inflammatory response syndrome or sepsis (p < .05 by analysis of variance). Positive linear relationships were observed with: serum tumor necrosis factor-alpha (rs = 0.654, p < .001), serum interleukin-6 (rs = 0.464, p < .001), Acute Physiology and Chronic Health Evaluation II score (rs = 0.387, p < .001), and Sequential Organ Failure Assessment score (rs = 0.428, p < .001). Multiple regression analysis revealed that serum Ang-2 is mostly related to serum tumor necrosis factor-alpha and severe sepsis. Treatment of human lung microvascular endothelial cells with all mediators resulted in a concentration-dependent Ang-2 reduction. Treatment of bovine lung microvascular endothelial cells with lipopolysaccharide and tumor necrosis factor-alpha increased Ang-2 release, and interleukin-6 reduced basal Ang-2 levels. CONCLUSIONS: First, patients' serum Ang-2 levels are increased during severe sepsis and associated with disease severity. The strong relationship of serum Ang-2 with serum tumor necrosis factor-alpha suggests that the latter may participate in the regulation of Ang-2 production in sepsis. Second, inflammatory mediators reduce Ang-2 release from human lung microvascular endothelial cells, implying that this vascular bed may not be the source of increased Ang-2 in human sepsis.

Regulation of Ang2 release by PTEN/PI3-kinase/Akt in lung microvascular endothelial cells.

Angiopoietin-2 (Ang2) is a Tie-2 ligand that destabilizes vascular structures, allowing for neovascularization or vessel regression depending on local vascular endothelial cell growth factor (VEGF) concentrations. Although various stimuli have been shown to affect Ang2 expression, information on the underlying mechanisms involved in Ang2 production in endothelial cells (EC) is just beginning to emerge. In the present study, we have used adenovirus-mediated gene transfer and pharmacological inhibitors to examine the role of the PTEN/PI3-K/Akt pathway on Ang2 release. Inhibition of PI3-kinase with wortmannin led to a stimulation of basal Ang2 release in EC, while overexpression of an active form of Akt reduced Ang2. In addition, adenovirus-mediated gene transfer of the phosphatase PTEN stimulated Ang2 release. Incubation of the cells with Ang1, an agent that activates the PI3-K/Akt pathway in EC, reduced Ang2 release. This effect of Ang1 could be prevented by wortmannin and LY-294002 pretreatment. Similarly, in VEGF-treated EC the increase in Ang2 production observed was greater in the presence of a PI3-K inhibitor. Our observations that PTEN acts as a positive modulator of Ang2 release, while activation of the PI3-K/Akt pathway downregulates Ang2, reveal an additional mechanism through which the PTEN/PI3-K/Akt pathway could affect the angiogenic process.

Vascular endothelial growth factor-mediated induction of angiogenesis by human rhinoviruses.

BACKGROUND: Human rhinoviruses, major precipitants of asthma exacerbations, infect the lower airway epithelium inducing inflammation. The possibility that viral infection may mediate angiogenesis, thus contributing to airway remodeling, has not been evaluated. OBJECTIVE: To investigate whether epithelial infection with rhinovirus mediates angiogenesis in vitro, evaluate possible modulation by an atopic environment, and confirm angiogenic factor induction after in vivo rhinovirus infection. METHODS: Bronchial epithelial cells were infected with rhinovirus and levels of vascular endothelial growth factor (VEGF), and angiopoietins were measured. The angiogenic effect of epithelial products was assessed in in vitro models of angiogenesis. PBMCs, obtained from patients with atopic asthma and normal controls, were exposed to rhinovirus; the ability of supernatants from these cultures differentially to affect rhinovirus-mediated epithelial VEGF production was evaluated. VEGF levels were measured in respiratory secretions from patients with asthma, before and during rhinovirus-induced exacerbations. RESULTS: Epithelial infection with rhinovirus specifically stimulated mRNA expression and release of VEGF, but not angiopoietins, in a time-dependent and dose-dependent manner. Supernatants from these cultures were able to induce angiogenesis in vitro, significantly inhibited by a neutralizing anti-VEGF antibody. When bronchial cells were exposed to supernatants of rhinovirus-infected mononuclear cells from normal subjects or atopic patients with asthma, VEGF induction was significantly higher under the influence of the atopic environment. VEGF was elevated during rhinovirus-associated asthma exacerbations. CONCLUSION: Rhinovirus infection, a frequent event, induces VEGF production in bronchial epithelial cells and human airways, an effect enhanced in an atopic environment. Rhinovirus-associated, VEGF-mediated angiogenesis may contribute to airway remodeling in asthma.

Angiopoietin-2 causes inflammation in vivo by promoting vascular leakage.

Angiopoietins (Angs) are endothelium-selective ligands that exert most of their actions through the Tie-2 receptor. It is widely accepted that Ang-1 promotes the structural integrity of blood vessels and exhibits anti-inflammatory properties. In contrast, the role of Ang-2 remains less clear because it has been shown to behave as a Tie-2 agonist or antagonist under different experimental conditions. To define the role of Ang-2 in acute inflammation, we studied the effects of recombinant Ang-2 administration in vivo. We show herein that Ang-2, but not Ang-1, induces edema formation in the mouse paw in a dose-dependent manner; the edema seems to be fast-peaking (maximum at 30 min) and resolves within 4 h. The effect of Ang-2 is blocked by the coadministration with a soluble form of the Tie-2 receptor or Ang-1. NO and prostaglandin E(2) levels in mouse paw following the injection of Ang-2 remained unaltered, suggesting that the action of Ang-2 does not involve these mediators. In addition, Ang-2 exerted a weak stimulatory effect on leukocyte migration in the mouse paw. Similarly, Ang-2 injected into the mouse air pouch produced only a modest effect on cell extravasation that peaked at 30 min. However, when cell migration was elicited using zymosan, Ang-2 significantly inhibited leukocyte migration. We conclude that Ang-2 by itself stimulates the extravasation of cell-poor fluid, but in the presence of ongoing inflammation it reduces cellular infiltration in tissues.

Angiopoietins in angiogenesis and beyond.

The angiopoietin (Ang) family of growth factors includes four members, all of which bind to the endothelial receptor tyrosine kinase Tie2. Two of the Angs, Ang-1 and Ang-4, activate the Tie2 receptor, whereas Ang-2 and Ang-3 inhibit Ang-1-induced Tie2 phosphorylation. While genetic models have underscored the importance of Angs in the developing cardiovascular system, other studies have demonstrated that Ang-1 promotes endothelial cell survival, sprouting and tube formation. More recently, a new aspect of the biology of this class of growth factors has emerged, namely the ability of Ang-1 to reduce inflammation. This review presents an outline of Angs and their receptors, examining their structure, expression, signalling, regulation and biological significance and comments on the role and potential usefulness of Angs in medicine.