TISBE: A Public Web Platform for the Consensus-Based Explainable Prediction of Developmental Toxicity.

Despite being extremely relevant for the protection of prenatal and neonatal health, the developmental toxicity (Dev Tox) is a highly complex endpoint whose molecular rationale is still largely unknown. The lack of availability of high-quality data as well as robust nontesting methods makes its understanding even more difficult. Thus, the application of new explainable alternative methods is of utmost importance, with Dev Tox being one of the most animal-intensive research themes of regulatory toxicology. Descending from TIRESIA (Toxicology Intelligence and Regulatory Evaluations for Scientific and Industry Applications), the present work describes TISBE (TIRESIA Improved on Structure-Based Explainability), a new public web platform implementing four fundamental advancements for in silico analyses: a three times larger dataset, a transparent XAI (explainable artificial intelligence) framework employing a fragment-based fingerprint coding, a novel consensus classifier based on five independent machine learning models, and a new applicability domain (AD) method based on a double top-down approach for better estimating the prediction reliability. The training set (TS) includes as many as 1008 chemicals annotated with experimental toxicity values. Based on a 5-fold cross-validation, a median value of 0.410 for the Matthews correlation coefficient was calculated; TISBE was very effective, with a median value of sensitivity and specificity equal to 0.984 and 0.274, respectively. TISBE was applied on two external pools made of 1484 bioactive compounds and 85 pediatric drugs taken from ChEMBL (Chemical European Molecular Biology Laboratory) and TEDDY (Task-Force in Europe for Drug Development in the Young) repositories, respectively. Notably, TISBE gives users the option to clearly spot the molecular fragments responsible for the toxicity or the safety of a given chemical query and is available for free at https://prometheus.farmacia.uniba.it/tisbe.

Optimizing the World Health Organization algorithm for HIV vertical transmission risk assessment by adding maternal self-reported antiretroviral therapy adherence.

BACKGROUND: The World Health Organization (WHO) risk assessment algorithm for vertical transmission of HIV (VT) assumes the availability of maternal viral load (VL) result at delivery and early viral control 4 weeks after initiating antiretroviral treatment (ART). However, in many low-and-middle-income countries, VL is often unavailable and mothers' ART adherence may be suboptimal. We evaluate the inclusion of the mothers' self-reported adherence into the established WHO-algorithm to identify infants eligible for enhanced post-natal prophylaxis when mothers' VL result is not available at delivery. METHODS: We used data from infants with perinatal HIV infection and their mothers enrolled from May-2018 to May-2020 in Mozambique, South Africa, and Mali. We retrospectively compared the performance of the WHO-algorithm with a modified algorithm which included mothers' adherence as an additional factor. Infants were considered at high risk if born from mothers without a VL result in the 4 weeks before delivery and with adherence <90%. RESULTS: At delivery, 143/184(78%) women with HIV knew their status and were on ART. Only 17(12%) obtained a VL result within 4 weeks before delivery, and 13/17(76%) of them had VL ≥1000 copies/ml. From 126 women on ART without a recent VL result, 99(79%) had been on ART for over 4 weeks. 45/99(45%) women reported suboptimal (< 90%) adherence. A total of 81/184(44%) infants were classified as high risk of VT as per the WHO-algorithm. The modified algorithm including self-adherence disclosure identified 126/184(68%) high risk infants. CONCLUSIONS: In the absence of a VL result, mothers' self-reported adherence at delivery increases the number of identified infants eligible to receive enhanced post-natal prophylaxis.

Ethical and procedural issues for applying researcher-driven multi-national paediatric clinical trials in and outside the European Union: the challenging experience of the DEEP project.

BACKGROUND: We describe our experience from a multi-national application of a European Union-funded research-driven paediatric trial (DEEP-2, EudraCT 2012-000353-31; NCT01825512). This paper aims to evaluate the impact of the local and national rules on the trial authorisation process in European and non-European countries. National/local provisions and procedures, number of Ethics Committees and Competent Authorities to be addressed, documentation required, special provisions for the paediatric population, timelines for completing the authorisation process and queries received were collected; compliance with the European provisions were evaluated. Descriptive analysis, Wilcoxon Rank-Sum test and General Linear Model analysis were used to determine factors potentially influencing the timelines. The Cluster Analysis procedure was used to identify homogenous groups of cases. RESULT: The authorisation process was completed in 7.7 to 53.8 months in European countries and in 17.1 to 27.1 months in non-European countries. The main factors influencing these timelines were the requests for changes/clarifications in European countries and the different national legislations in non-European countries. CONCLUSION: This work confirms that the procedures and requirements for the clinical trial application of a paediatric trial are different. In the European Union, the timeframes for submission were generally harmonised but longer. In non-European countries, delays were caused by national dispositions but the entire authorisation process resulted faster with less requests from ECs/CAs. The upcoming application of Regulation (EU) 536/2014 is expected to harmonise practices in Europe and possibly outside. Networks on paediatric research acting at international level will be crucial in this effort.

Machine Learning Systems Applied to Health Data and System.

The use of machine learning (ML) in medicine is becoming increasingly fundamental to analyse complex problems by discovering associations among different types of information and to generate knowledge for medical decision support. Many regulatory and ethical issues should be considered. Some relevant EU provisions, such as the General Data Protection Regulation, are applicable. However, the regulatory framework for developing and marketing a new health technology implementing ML may be quite complex. Other issues include the legal liability and the attribution of negligence in case of errors. Some of the above-mentioned concerns could be, at least partially, resolved in case the ML software is classified as a 'medical device', a category covered by EU/national provisions. Concluding, the challenge is to understand how sustainable is the regulatory system in relation to the ML innovation and how legal procedures should be revised in order to adapt them to the current regulatory framework.

Ethical, Legal and Regulatory Issues of Paediatric Translational Research. Call for an Adequate Model of Governance.

The lack of paediatric medicines, including innovative and advanced ones, is a long-lasting and well-known problem at European and international levels. Despite the existing legal frameworks and incentives, children remain deprived of many kinds of therapy because of challenges faced in appropriately study and tailoring medicinal and other products for them. In this context, the necessity to foster paediatric research addressing unsolved and uncovered issues within a 'translational approach' has appeared. This article, after having clarified the concept of translational research in the perspective of the establishment of a European paediatric research infrastructure (RI), will identify and point out ethical, legal and regulatory issues particularly relevant in a children's rights perspective. It concludes asking for the setting up of an adequate model of governance within a future RI, including adequate and independent ethical oversight and a pluridisciplinary common service dealing with ethical, legal and societal issues relevant for children.

The ethical framework for performing research with rare inherited neurometabolic disease patients.

The need for performing clinical trials to develop well-studied and appropriate medicines for inherited neurometabolic disease patients faces ethical concerns mainly raising from four aspects: the diseases are rare; include young and very young patients; the neurological impairment may compromise the capability to provide 'consent'; and the genetic nature of the disease leads to further ethical implications. This work is intended to identify the ethical provisions applicable to clinical research involving these patients and to evaluate if these cover the ethical issues. Three searches have been performed on the European regulatory/legal framework, the literature and European Union-funded projects. The European legal framework offers a number of ethical provisions ruling the clinical research on paediatric, rare, inherited diseases with neurological symptoms. In the literature, relevant publications deal with informed consent, newborn genetic screenings, gene therapy and rights/interests of research participants. Additional information raised from European projects on sharing patients' data from different countries, the need to fill the gap of the regulatory framework and to improve information to stakeholders and patients/families. CONCLUSION: Several recommendations and guidelines on ethical aspects are applicable to the inherited neurometabolic disease research in Europe, even though they suffer from the lack of a common ethical approach. What is Known: • When planning and conducting clinical trials, sponsors and researchers know that clinical trials are to be performed according to well-established ethical rules, and patients should be aware about their rights. • In the cases of paediatric patients, vulnerable patients unable to provide consent, genetic diseases' further rules apply. What is New: • This work discusses which ethical rules apply to ensure protection of patient's rights if all the above-mentioned features coexist. • This work shows available data and information on how these rules have been applied.

Clinical Trial Application in Europe: What Will Change with the New Regulation?

The European framework surrounding clinical trials on medicinal products for human use is going to change as demonstrated by the large debate at European institutional level. One of the major challenges is to overcome the lack of harmonisation of clinical trial procedures among countries. This aspect is gaining more and more importance, considering the increasing number of multicentre and multinational studies. In this work, the actual European rules governing the Clinical Trial Application have been analysed throughout the different steps including the registration of the trial in the European database; the preparation of documents to be submitted and their contents; the preparation of documents related to the information and consent process; the submission to competent bodies. Specific issues related to paediatric research and trials involving non EU/EEA countries have been addressed as well. Results reveal that the European legislation offers a well defined set of European rules covering different aspects of a Clinical Trial Application. However, these are not suitable to meet the challenges from multicentre and multinational clinical studies. A stronger set of rules, such as is available in a composite European Regulation has been adopted and is expected to harmonise practices and enable sponsors to carry out well conducted trials. But will the new regulation overcome the existing criticisms of Directive 2001/20/EC?

The creation of an adaptable informed consent form for research purposes to overcome national and institutional bottlenecks in ethics review: experience from rare disease registries.

Background: The lack of harmonization of evaluation criteria by Ethics Committees in the European Union (EU) has led to inconsistent ethics reviews received by research sites participating in multicenter non-interventional studies. The European General Data Protection Regulation (GDPR) appears to be implemented at national level with a substantial degree of variance in interpretation. The European Reference Networks (ERNs) were struggling in setting an Informed Consent Form (ICF) for registries, allowing reuse of data for research purposes. The aim of this work is to develop an adaptable ICF for research purposes to be used in ERN registries. Methods: To work on this challenge, a team was established within the European Joint Programme on Rare Diseases (EJP RD) to develop a patients' registry ICF template allowing easy adaptation to ERNs, country, and site-level specificities. ERN and patients' representatives validated the choice of developing a GDPR-compliant template for research purposes. The feedback received from 34 Ethics Committees on the Clinical Patient Management System ICF, including the submission of patients' data to the ERN registries and the EU consent regulatory framework were analyzed along with existing ontologies for data access and reuse. An adaptable ICF was developed following iterative cycles of consultation and review by clinicians, research experts, ethics and regulatory advisors, and patients' representatives. The development of pediatric material for minor participants was also undertaken. Results and Conclusion: Research oriented ICF templates for adults and for parents/legal representatives of patients were released in 26 national languages. This adaptable ICF aims to foster, according to patients' preferences, the reuse of registries data for research purposes in compliance with the applicable laws and standards. Pediatric material is being finalized to collect minors' assent. ICF machine-readability is also progressing to enhance data discovery and facilitate its access and reuse conditions.

Innovative research methodologies in the EU regulatory framework: an analysis of EMA qualification procedures from a pediatric perspective.

Introduction: The European Medicines Agency (EMA) offers scientific advice to support the qualification procedure of novel methodologies, such as preclinical and in vitro models, biomarkers, and pharmacometric methods, thereby endorsing their acceptability in medicine research and development (R&D). This aspect is particularly relevant to overcome the scarcity of data and the lack of validated endpoints and biomarkers in research fields characterized by small samples, such as pediatrics. Aim: This study aimed to analyze the potential pediatric interest in methodologies qualified as "novel methodologies for medicine development" by the EMA. Methods: The positive qualification opinions of novel methodologies for medicine development published on the EMA website between 2008 and 2023 were identified. Multi-level analyses were conducted to investigate data with a hierarchical structure and the effects of cluster-level variables and cluster-level variances and to evaluate their potential pediatric interest, defined as the possibility of using the novel methodology in pediatric R&D and the availability of pediatric data. The duration of the procedure, the type of methodology, the specific disease or disease area addressed, the type of applicant, and the availability of pediatric data at the time of the opinion release were also investigated. Results: Most of the 27 qualifications for novel methodologies issued by the EMA (70%) were potentially of interest to pediatric patients, but only six of them reported pediatric data. The overall duration of qualification procedures with pediatric interest was longer than that of procedures without any pediatric interest (median time: 7 months vs. 3.5 months, respectively; p = 0.082). In parallel, qualification procedures that included pediatric data lasted for a longer period (median time: 8 months vs. 6 months, respectively; p = 0.150). Nephrology and neurology represented the main disease areas (21% and 16%, respectively), while endpoints, biomarkers, and registries represented the main types of innovative methodologies (32%, 26%, and 16%, respectively). Discussion: Our results underscore the importance of implementing innovative methodologies in regulatory-compliant pediatric research activities. Pediatric-dedicated research infrastructures providing regulatory support and strategic advice during research activities could be crucial to the design of ad hoc pediatric methodologies or to extend and validate them for pediatrics.

Target therapy for high-risk neuroblastoma treatment: integration of regulatory and scientific tools is needed.

Introduction: Several new active substances (ASs) targeting neuroblastoma (NBL) are under study. We aim to describe the developmental and regulatory status of a sample of ASs targeting NBL to underline the existing regulatory gaps in product development and to discuss possible improvements. Methods: The developmental and regulatory statuses of the identified ASs targeting NBL were investigated by searching for preclinical studies, clinical trials (CTs), marketing authorizations, pediatric investigation plans (PIPs), waivers, orphan designations, and other regulatory procedures. Results: A total of 188 ASs were identified. Of these, 55 were considered 'not under development' without preclinical or clinical studies. Preclinical studies were found for 115 ASs, of which 54 were associated with a medicinal product. A total of 283 CTs (as monotherapy or in combination) were identified for 70 ASs. Of these, 52% were at phases 1, 1/2, and 2 aimed at PK/PD/dosing activity. The remaining ones also included efficacy. Phase 3 studies were limited. Studies were completed for 14 ASs and suspended for 11. The highest rate of ASs involved in CTs was observed in the RAS-MAPK-MEK and VEGF groups. A total of 37 ASs were granted with a PIP, of which 14 involved NBL, 41 ASs with a waiver, and 18 ASs with both PIPs and waivers, with the PIP covering pediatric indications different from the adult ones. In almost all the PIPs, preclinical studies were required, together with early-phase CTs often including efficacy evaluation. Two PIPs were terminated because of negative study results, and eight PIPs are in progress. Variations in the SmPC were made for larotrectinib sulfate/Vitrakvi® and entrectinib/Rozlytrek® with the inclusion of a new indication. For both, the related PIPs are still ongoing. The orphan designation has been largely adopted, while PRIME designation has been less implemented. Discussion: Several ASs entered early phase CTs but less than one out of four were included in a regulatory process, and only two were granted a pediatric indication extension. Our results confirm that it is necessary to identify a more efficient, less costly, and time-consuming "pediatric developmental model" integrating predictive preclinical study and innovative clinical study designs. Furthermore, stricter integration between scientific and regulatory efforts should be promoted.

PedCRIN tool for the biosamples management in pediatric clinical trials.

In pediatric clinical research, it is essential to implement ethical and regulatory requirements, training, and facilities to grant the proper management of specimens, considering that blood sampling may be difficult, the number of specimens is usually limited, and all efforts should be made to minimize sample volumes. In the context of the Pediatric Clinical Research Infrastructure Network (PedCRIN) project, an easy-to-use tool has been developed to guide investigators and sponsors in managing specimens and associated data in compliance with the applicable European rules in the context of pediatric clinical trials. Key topics and research questions to properly manage biosamples and related data in the context of pediatric trials were identified by PedCRIN partners; the current European regulatory/ethical and legal resources were searched for and analyzed; the items/measures/procedures to ensure regulatory compliance of a pediatric trial with regards to biosamples were defined. A checklist of the key items to be considered for the management of biological samples in pediatric clinical trials in compliance with the European applicable rules and legislation, was prepared. It is publicly available on the PedCRIN website https://ecrin.org/projects/pedcrin. Five different topics were covered: consent and assent; minimizing harm and maximizing welfare; sampling volume; skills, training and facilities required for sampling; and long-term storage of biological material. This exercise addressed a specific need in the field of pediatric research to implement ad hoc procedures for specimen handling. In fact, specific guidance on the management of biosamples in pediatrics is not available.

Informed consent and assent guide for paediatric clinical trials in Europe.

OBJECTIVE: Clinical trial sponsors spend considerable resources preparing informed consent (IC) and assent documentation for multinational paediatric clinical trial applications in Europe due to the limited and dispersed patient populations, the variation of national legal and ethical requirements, and the lack of detailed guidance. The aim of this study was to design new easy-to-use guide publicly available on European Medicines Agency's, Enpr-EMA website for all stakeholders. METHODS: Current EU legal, ethical and regulatory guidance for paediatric clinical trials were collated, analysed and divided into 30 subject elements in two tables. The European Network of Young Person's Advisory Group reviewed the data and provided specific comments. A three-level recommendation using 'traffic light' symbols was designed for four age groups of children, according to relevance and the requirements. RESULTS: A single guide document includes two tables: (1) general information and (2) trial-specific information. In the age group of 6-9 years old, 92% of the trial-specific subject elements can be or should be included in the IC discussion. Even in the youngest possible age group (2-5 years old children), the number of elements considered was, on average, 52%. CONCLUSION: The EU Clinical Trial Regulation (2014) does not contain specific requirements exclusively for paediatric clinical trials. This work is the first to extensively collate all the current legal, regulatory and ethical documentation on the IC process, together with input from adolescents. This guide may increase the ethical standards in paediatric clinical trials.

Paediatric Medicines in Europe: The Paediatric Regulation-Is It Time for Reform?

Objectives: In this paper, we investigated the effects of the European Paediatric Regulation (EC) N° 1901/2006 with respect to satisfying the paediatric therapeutic needs, assessed in terms of the increased number of paediatric medicinal products, new therapeutic indications in specific high-need conditions (neonates, oncology, rare disease, etc.) and increased number of paediatric clinical studies supporting the marketing authorisation. Methods: We analysed the paediatric medicinal products approved by the European Medicines Agency in the period January 2007-December 2019, by collecting the following data: year of approval, active substance, legal basis for the marketing authorisation, type of medicinal product (i.e., chemical, biological, or ATMP), orphan drug status, paediatric indication, Anatomical Therapeutic Chemical code (first-level), number and type of paediatric studies. Data were compared with similar data collected in the period 1996-2006. Results: In the period January 1996-December 2019, in a total of 1,190 medicinal products and 843 active substances, 34 and 38%, respectively, were paediatric. In the two periods, before and after the Paediatric Regulation implementation, the paediatric/total medicinal products ratio was constant while the paediatric/total active substances ratio decreased. Moreover, excluding generics and biosimilars, a total of 106 and 175 paediatric medicines were granted a new paediatric indication, dosage or age group in the two periods; out of 175, 128 paediatric medicines had an approved Paediatric Investigational Plan. The remaining 47 were approved without an approved Paediatric Investigational Plan, following the provisions of Directive 2001/83/EC and repurposing an off-patent drug. The analysis of the clinical studies revealed that drugs with a Paediatric Investigational Plan were supported by 3.5 studies/drug while drugs without a Paediatric Investigational Plan were supported by only 1.6 studies/drug. Discussion: This report confirms that the expectations of the European Paediatric Regulation (EC) N° 1901/2006 have been mainly satisfied. However, the reasons for the limited development of paediatric medicines in Europe, should be further discussed, taking advantage of recent initiatives in the regulatory field, such as the Action Plan on Paediatrics, and the open consultation on EU Pharmaceutical Strategy.

Antioxidant treatment of hindlimb-unloaded mouse counteracts fiber type transition but not atrophy of disused muscles.

Oxidative stress was proposed as a trigger of muscle impairment in various muscle diseases. The hindlimb-unloaded (HU) rodent is a model of disuse inducing atrophy and slow-to-fast transition of postural muscles. Here, mice unloaded for 14 days were chronically treated with the selective antioxidant trolox. After HU, atrophy was more pronounced in the slow-twitch soleus muscle (Sol) than in the fast-twitch gastrocnemius and tibialis anterior muscles, and was absent in extensor digitorum longus muscle. In accord with the phenotype transition, HU Sol showed a reduced expression of myosin heavy chain type 2A (MHC-2A) and increase in MHC-2X and MHC-2B isoforms. In parallel, HU Sol displayed an increased sarcolemma chloride conductance related to an increased expression of ClC-1 channels, changes in excitability parameters, a positive shift of the mechanical threshold, and a decrease of the resting cytosolic calcium concentration. Moreover, the level of lipoperoxidation increased proportionally to the degree of atrophy of each muscle type. As expected, trolox treatment fully prevented oxidative stress in HU mice. Atrophy was not prevented but the drug significantly attenuated Sol phenotypic transition and excitability changes. Trolox treatment had no effect on control mice. These results suggest possible benefits of antioxidants in protecting muscle against disuse.

Multiple pathological events in exercised dystrophic mdx mice are targeted by pentoxifylline: outcome of a large array of in vivo and ex vivo tests.

The phosphodiesterases inhibitor pentoxifylline gained attention for Duchenne muscular dystrophy therapy for its claimed anti-inflammatory, antioxidant, and antifibrotic action. A recent finding also showed that pentoxifylline counteracts the abnormal overactivity of a voltage-independent calcium channel in myofibers of dystrophic mdx mice. The possible link between workload, altered calcium homeostasis, and oxidative stress pushed toward a more detailed investigation. Thus a 4- to 8-wk treatment with pentoxifylline (50 mg x kg(-1) x day(-1) ip) was performed in mdx mice, undergoing or not a chronic exercise on treadmill. In vivo, the treatment partially increased forelimb strength and enhanced resistance to treadmill running in exercised animals. Ex vivo, pentoxifylline restored the mechanical threshold, an electrophysiological index of calcium homeostasis, and reduced resting cytosolic calcium in extensor digitorum longus muscle fibers. Mn quenching and patch-clamp technique confirmed that this effect was paralleled by a drug-induced reduction of membrane permeability to calcium. The treatment also significantly enhanced isometric tetanic tension in mdx diaphragm. The plasma levels of creatine kinase and reactive oxygen species were both significantly reduced in treated-exercised animals. Dihydroethidium staining, used as an indicator of reactive oxygen species production, showed that pentoxifylline significantly reduced the exercise-induced increase in fluorescence in the mdx tibialis anterior muscle. A significant decrease in connective tissue area and profibrotic cytokine transforming growth factor-beta(1) was solely found in tibialis anterior muscle. In both diaphragm and gastrocnemius muscle, a significant increase in neural cell adhesion molecule-positive area was instead observed. This data supports the interest toward pentoxifylline and allows insight in the level of cross talk between pathogenetic events in workloaded dystrophic muscle.

Gentamicin treatment in exercised mdx mice: Identification of dystrophin-sensitive pathways and evaluation of efficacy in work-loaded dystrophic muscle.

Aminoglycosides force read through of premature stop codon mutations and introduce new mutation-specific gene-corrective strategies in Duchenne muscular dystrophy. A chronic treatment with gentamicin (32 mg/kg/daily i.p., 8-12 weeks) was performed in exercised mdx mice with the dual aim to clarify the dependence on dystrophin of the functional, biochemical and histological alterations present in dystrophic muscle and to verify the long term efficiency of small molecule gene-corrective strategies in work-loaded dystrophic muscle. The treatment counteracted the exercise-induced impairment of in vivo forelimb strength after 6-8 weeks. We observed an increase in dystrophin expression level in all the fibers, although lower than that observed in normal fibers, and found a concomitant recovery of aquaporin-4 at sarcolemma. A significant reduction in centronucleated fibers, in the area of necrosis and in the percentage of nuclear factor-kB-positive nuclei was observed in gastrocnemious muscle of treated animals. Plasma creatine kinase was reduced by 70%. Ex vivo, gentamicin restored membrane ionic conductance in mdx diaphragm and limb muscle fibers. No effects were observed on the altered calcium homeostasis and sarcolemmal calcium permeability, detected by electrophysiological and microspectrofluorimetric approaches. Thus, the maintenance of a partial level of dystrophin is sufficient to reinforce sarcolemmal stability, reducing leakiness, inflammation and fiber damage, while correction of altered calcium homeostasis needs greater expression of dystrophin or direct interventions on the channels involved.

Orphan medicinal products in Europe and United States to cover needs of patients with rare diseases: an increased common effort is to be foreseen.

BACKGROUND: In the European Union (EU) and United States (US), specific regulations have been released to provide incentives to develop and sell orphan medicinal products. We analysed the status of orphan drugs designated that not yet received a marketing authorisation or already marketed for patients affected by rare diseases in the EU and US up to December 2015. For each drug, the following data were extracted: designation date, active substance(s), orphan condition and indication, trade name, approved therapeutic indication, approved ages, genetic nature of disease and if affects children. RESULTS: In the EU, 1264 Orphan Drug Designations have been granted and 133 medicinal products were approved covering a total of 179 indications and 122 rare conditions. Among these, 79 were approved under Regulation (EC)141/2000 (65 still listed in the Orphan Medicinal Products Register and 14 lost the orphan designation but still authorised) and 23 were approved centrally by the European Agency before the Orphan Regulation entered into force. On the other hand, in the US 3082 designations and 415 orphan products, covering a total of 521 indications and 300 rare conditions, were granted. As a result, the mean of designations per year is 79 in the EU and 93.4 in the US, while the mean of approved indications per year is 8.5 in the EU and 15.8 in the US. No orphan product is marketed in the EU for bone and connective tissue, ophthalmic, poisoning/overdose, renal, urinary and reproductive rare diseases. Among the marketed medicinal products, only 46.6% in the EU and 35.2% in the US are approved for children. If all the existing market approvals were merged, 362 additional therapeutic indications in the EU and 72 in the US would be covered. CONCLUSIONS: Our data show that notwithstanding the incentives issued, the number of medicines for rare diseases is still limited, and this is more evident in certain therapeutic areas. However, by merging all the existing approvals, patients would benefit of substantial advantages in both geographic areas. Efforts and cooperation between EU and US seem the only way to speed up the development and marketing of drugs for rare diseases.