Drug development for rare diseases is challenging, especially when these orphan drugs (OD) are intended for children. In 2007 the EU Paediatric Drug Regulation was enacted to improve the development of high quality and ethically researched medicines for children through the establishment of Paediatric Investigation Plans (PIPs). The effect of the EU Paediatric Drug Regulation on the marketing authorisation (MA) of drugs for children with rare diseases was studied. Data on all designated orphan drugs, their indication, MA, PIPs and indication group (adult or child) were obtained from the European Medicines Agency (EMA). The outcome and duration of the process from orphan drug designation (ODD) to MA, was compared, per indication, by age group. The effect of the Paediatric Drug Regulation, implemented in 2007, on the application process was assessed with survival analysis. Eighty-one orphan drugs obtained MA since 2000 and half are authorised for (a subgroup of) children; another 34 are currently undergoing further investigations in children through agreed PIPs. The Paediatric Drug Regulation did not significantly increase the number of ODDs with potential paediatric indications (58% before vs 64% after 2007 of ODDs, p = 0.1) and did not lead to more MAs for ODs with paediatric indications (60% vs 43%, p = 0.22). ODs authorised after 2007 had a longer time to MA than those authorised before 2007 (Hazard ratio (95% CI) 2.80 (1.84-4.28), p < 0.001); potential paediatric use did not influence the time to MA (Hazard ratio (95% CI) 1.14 (0.77-1.70), p = 0.52). The EU Paediatric Drug Regulation had a minor impact on development and availability of ODs for children, was associated with a longer time to MA, but ensured the further paediatric development of drugs still off-label to children. The impact of the Paediatric Drug Regulation on research quantity and quality in children through PIPs is not yet clear.
Intravenous (IV) artesunate is the treatment of choice for severe malaria. In Europe, however, no GMP-manufactured product is available and treatment data in European travellers are scarce. Fortunately, artesunate became available in the Netherlands and Belgium through a named patient programme. This is the largest case series of artesunate treated patients with severe malaria in Europe.Hospitalized patients treated with IV artesunate between November 2007 and December 2010 in the Netherlands and Belgium were retrospectively evaluated. Patient characteristics, treatment and clinical outcome were recorded on a standardized form and mortality, parasite clearance times and the occurrence of adverse events were evaluated.Of the 68 treated patients, including 55 with severe malaria, two patients died (2/55 = 3.6%). The mean time to 50% parasite clearance (PCT50), 90% and 99% were 4.4 hours (3.9 - 5.2), 14.8 hours (13.0 - 17.2), and 29.5 hours (25.9 - 34.4) respectively. Artesunate was well tolerated. However, an unusual form of haemolytic anaemia was observed in seven patients. The relationship with artesunate remains uncertain.Data from the named patient programme demonstrate that IV artesunate is effective and well-tolerated in European travellers lacking immunity. However, increased attention needs to be paid to the possible development of haemolytic anaemia 2-3 weeks after start of treatment.Treatment of IV artesunate should be limited to the period that IV treatment is required and should be followed by a full oral course of an appropriate anti-malarial drug.
Orphan drugs are drugs used in the treatment of life-threatening or chronic diseases that affect fewer than 1 out of 2000 persons in the European Union. Since the implementation of the European Regulation on Orphan Medicinal Products in 2000, 61 orphan drugs have been brought to market. One-third of these were granted their marketing authorisations based on non-comparative clinical research. Certain orphan drugs for extramural use will be transferred to the performance-based hospital financing system within the next few years. Unapproved orphan drugs are generally not reimbursed. In so-called compassionate use programmes, unauthorised orphan drugs can still become available to patients who do not participate in clinical trials. Compassionate use drugs are made available by the manufacturer.
Orphan drugs are drugs used in the treatment of life-threatening or chronic diseases that affect fewer than 1 out of 2000 persons in the European Union. Since the implementation of the European Regulation on Orphan Medicinal Products in 2000, 61 orphan drugs have been brought to market. One-third of these were granted their marketing authorisations based on non-comparative clinical research. Certain orphan drugs for extramural use will be transferred to the performance-based hospital financing system within the next few years. Unapproved orphan drugs are generally not reimbursed. In so-called compassionate use programmes, unauthorised orphan drugs can still become available to patients who do not participate in clinical trials. Compassionate use drugs are made available by the manufacturer
Rare diseases are characterised by a low prevalence. There are so many different rare diseases, that millions of people are affected.The vast majority of these diseases suffer from a lack of approved treatment options and orphan drugs (ODs) therefore represent a huge unmet medical need. ODs face regulatory and operational challenges during their development , i.e. few and heterogeneous patients for study, complicated diagnostics, ethical issues, limited clinical expertise, lack of validated biomarkers and more importantly, lack of return of investment in the small target population. Several incentives have been put in place in Europe, to stimulate orphan drug development. Nonetheless, many obstacles may still frustrate research and product development for rare diseases. This thesis focusses on the clinical development process of ODs in general, paediatric ODs and two specific ODs, artesunate for the treatment of severe malaria and levamisole for nephrotic syndrome in children. Formulation issues and pharmacology in children have been addressed for levamisole. We were able to develop small tablets for children aged 2 - 18 years that were found to be suitable in terms of palatability, acceptability, dosing flexibility and stability without compromising dissolution. The pharmacokinetic profile was established in the same patient population, revealing PK estimates comparable to those in adults, but with a greater interindividual variability. A dose effect relationship still has to be established. For IV artesunate, a named patient program (NPP) was set up to collect clinical data of European malaria patients. The results from this program support several European guidelines that replaced IV quinine by IV artesunate as the drug of first choice for severe malaria. Furthermore, it was also found that manual exchange transfusion does not contribute to parasite clearance with artesunate treatment and is therefore no longer recommended. A hitherto unknown adverse effect, late haemolytic anaemia 2-3 weeks after start of treatment, was found that requires attention during the follow up after treatment. The European regulatory framework has been used as an overlapping theme to discuss differences in availability and accessibility of (paediatric) ODs. Considerable differences exist across Europe regarding patient access. It is important to reduce inequalities between countries, for both unauthorised and authorised ODs. Firstly by harmonisation of NPPs at European level, to ensure equal availability of unauthorised ODs without compromising patient safety. NPPs provide a unique opportunity to study both the benefits and risks of unregistered products for rare diseases, provided that the patients are actively registered and monitored in a central and strictly controlled (electronic) database, managed by an independent authority (eg. EMA). Secondly, accessibility of registered ODs should be equal across Europe. This could be achieved by instalment of a European pricing and reimbursement procedure as proposed by Eurordis. Lastly, collaboration between all stakeholders is the key to success in ODs. Especially academia-industry collaborations with clear and transparent agreementsare essential to the continued development of ODs.
Objectives: To develop an oral solid dosage form of levamisole suitable for the paediatric population in terms of dose accuracy, palatability, stability and ease of administration. Methods: Small undividable tablets (Ø5 – 8 mm) in four different strengths were manufactured to allow for flexible and accurate dosing. In vitro dissolution testing was used to determine drug release in different media. The bitter taste of levamisole was masked using a film-coat and assessed in healthy volunteers. Suitability and acceptability of the tablets were evaluated in 100 patients with nephrotic syndrome aged 2 – 18 years participating in a double blind, placebo-controlled, randomised trial. Results: All tablet strengths showed good taste-masking characteristics and similar, pH independent, dissolution profiles. Successful taste masking was achieved without affecting the dissolution rate. In a total of 100 paediatric patients, more than 20,000 levamisole tablets were swallowed without any difficulties, choking or aspiration. Conclusion: The formulated tablets were found to be suitable for children aged 2 – 18 years and to provide good dose accuracy.
Intravenous (IV) artesunate is the treatment of choice for severe malaria. In Europe, this treatment is only available in a few countries via named patient programmes (NPPs). As a case study, the legal and organisational aspects and pharmacovigilance of these NPPs and possibilities for harmonisation within the EU were studied over time and space using IV artesunate (Malacef) in the Netherlands, Belgium and France. The legal base and organisation of NPPs in the Netherlands, Belgium and France were studied. The diffusion and cumulative availability of IV artesunate and the pharmacovigilance components were compared among the three countries using distribution data from the period 2007 through 2012. Artesunate has quickly gained acceptance for treating severe malaria in the Netherlands, whereas both Belgium and France have introduced this treatment more hesitantly. This difference in acceptance is due to differences in the implementation of NPP legislation among the countries. France currently has a proactive system in which treatment requires the permission for each patient and an intensive follow-up protocol. On the other hand, Belgium and Dutch NPPs are more dependent on the investigators' initiative and are therefore potentially faster and more flexible, facilitating the discovery of adverse effects that have not been reported by more formal comparative clinical trials. NPPs provide a unique opportunity to study both the benefits and risks of unregistered products for treating rare diseases, provided that the patients are actively vigilated. Thus, we recommend that NPPs should be harmonised throughout Europe in order to ensure equal availability of treatment and therapeutic benefit to all Europeans without compromising patient safety.
Abstract Background Exchange transfusion (ET) has remained a controversial adjunct therapy for the treatment of severe malaria. In order to assess the relative contribution of ET to parasite clearance in severe malaria, all patients receiving ET as an adjunct treatment to parenteral quinine or to artesunate were compared with patients treated with parenteral treatment with quinine or artesunate but who did not receive ET. ET was executed using a standardized manual isovolumetric exchange protocol. Methods All patients in the Rotterdam Malaria Cohort treated for severe P. falciparum malaria at the Institute for Tropical Diseases of the Harbour Hospital between 1999 and 2011 were included in this retrospective follow-up study. Both a two-stage approach and a log-linear mixed model approach were used to estimate parasite clearance times (PCTs) in patients with imported malaria. Severe malaria was defined according to WHO criteria. Results A total of 87 patients with severe malaria was included; 61 received intravenous quinine, whereas 26 patients received intravenous artesunate. Thirty-nine patients received ET as an adjunct treatment to either quinine (n = 23) or artesunate (n = 16). Data from 84 of 87 patients were suitable for estimation of parasite clearance rates. PCTs were significantly shorter after administration of artesunate as compared with quinine. In both models, ET did not contribute significantly to overall parasite clearance. Conclusion Manual exchange transfusion does not significantly contribute to parasite clearance in artesunate-treated individuals. There may be a small effect of ET on parasite clearance under quinine treatment. Institution of ET to promote parasite clearance in settings where artesunate is available is not recommended, at least not with manually executed exchange procedures.
The aim was to investigate the population pharmacokinetics of levamisole in children with steroid-sensitive nephrotic syndrome.Non-linear mixed effects modelling was performed on samples collected during a randomized controlled trial. Samples were collected from children who were receiving 2.5 mg kg(-1) levamisole (or placebo) orally once every other day. One hundred and thirty-six plasma samples were collected from 38 children from India and Europe and included in the analysis. A one compartment model described the data well.The apparent clearance rate (CL/F) and distribution volume (V/F) were 44 l h(-1) 70 kg(-1) and 236 l 70 kg(-1) , respectively; estimated interindividual variability was 32-42%. In addition to allometric scaling of CL/F and V/F to body weight, we identified a significant proportional effect of age on CL/F (-10.1% per year). The pharmacokinetics parameters were not affected by gender, tablet strength or study centre. The median (interquartile range) maximum plasma concentration of levamisole was 438.3 (316.5-621.8) ng ml(-1) , and the median area under the concentration-time curve was 2847 (2267-3761) ng ml(-1) h. Median tmax and t½ values were 1.65 (1.32-2.0) h and 2.60 (2.06-3.65) h, respectively.Here, we present the first pharmacokinetic data regarding levamisole in children with steroid-sensitive nephrotic syndrome. The pharmacokinetic profile of levamisole in children was similar to findings reported in adults, although the elimination rate was slightly higher in children.
'%3e%3cpath id='a' fill='%23FF0' d='M0 0v6h4' transform='rotate(18)'/%3e%3cuse xlink:href='%23a' transform='scale(-1 1)'/%3e%3c/g%3e%3cg id='c' transform='rotate(72)'%3e%3cuse xlink:href='%23b'/%3e%3cuse xlink:href='%23b' transform='rotate(72)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='scale(-1 1)'/%3e%3c/svg%3e)
