Innovative design and analysis for rare disease drug development.

One of the most challenges for rare diseases drug development is probably the availability of subjects with the diseases under a small patient population. It is then a great concern how to conduct clinical trials with the limited number of subjects available for obtaining substantial evidence regarding effectiveness and safety for approval of the drug product under investigation. For rare diseases drug development, FDA indicated that the Agency does not have the intention to create a statutory standard for approval of orphan drugs that is different from the standard for approval of drugs in common conditions. In this case, innovative thinking and approach for obtaining substantial evidence for approval of rare diseases drug products are necessarily applied. In this article, basic considerations for rare disease drug development are discussed. The innovative thinking of demonstrating not-ineffectiveness rather than effectiveness with a limited number of subjects available is outlined. In addition, an innovative approach utilizing a two-stage adaptive seamless trial design in conjunction with the concept of real-world data and real-world evidence is proposed not only to obtain substantial evidence for approval of rare diseases drug products, but also to meet the same standard as those drug products in common conditions. Under the two-stage adaptive seamless trial design, sample size calculation for rare diseases clinical trials based on the innovative probability monitoring procedure is also discussed.

Feasibility Study for Bedside Production of Recombinant Human Acid α-Glucosidase: Technical and Financial Considerations.

OBJECTIVE: The high cost of orphan drugs limits their access by many patients, especially in low- and middle-income countries. Many orphan drugs are off-patent without alternative generic or biosimilar versions available. Production of these drugs at the point-of-care, when feasible, could be a cost-effective alternative. METHODS: The financial feasibility of this approach was estimated by setting up a small-scale production of recombinant human acid alpha-glucosidase (rhGAA). The commercial version of rhGAA is Myozyme™, and Lumizyme™ in the United States, which is used to treat Pompe disease. The rhGAA was produced in CHO-K1 mammalian cells and purified using multiple purification steps to obtain a protein profile comparable to Myozyme™. RESULTS: The established small-scale production of rhGAA was used to obtain a realistic cost estimation for the magistral production of this biological drug. The treatment cost of rhGAA using bedside production was estimated at $3,484/gram, which is 71% lower than the commercial price of Myozyme ™. CONCLUSION: This study shows that bedside production might be a cost-effective approach to increase the access of patients to particular life-saving drugs.

Availability, accessibility and delivery to patients of the 28 orphan medicines approved by the European Medicine Agency for hereditary metabolic diseases in the MetabERN network.

BACKGROUND: The European Medicine Agency granted marketing approval to 164 orphan medicinal products for rare diseases, among which 28 products intended for the treatment of hereditary metabolic diseases. Taking advantage of its privileged connection with 69 healthcare centres of excellence in this field, MetabERN, the European Reference Network for hereditary metabolic diseases, performed a survey asking health care providers from 18 European countries whether these products are available on the market, reimbursed and therefore accessible for prescription, and actually delivered in their centre. RESULTS: Responses received from 52 centres (75%) concerned the design of treatment plans, the access to marketed products, and the barriers to delivery. Treatment options are always discussed with patients, who are often involved in their treatment plan. Most products (26/28) are available in most countries (15/18). Among the 15 broadly accessible products (88.5% of the centres), 9 are delivered to most patients (mean 70.1%), and the others to only few (16.5%). Among the 10 less accessible products (40.2% of the centres), 6 are delivered to many patients (66.7%), and 4 are rarely used (6.3%). Information was missing for 3 products. Delay between prescription and delivery is on average one month. Beside the lack of availability or accessibility, the most frequent reasons for not prescribing a treatment are patients' clinical status, characteristic, and personal choice. CONCLUSIONS: Data collected from health care providers in the MetabERN network indicate that two-third of the orphan medicines approved by EMA for the treatment of hereditary metabolic diseases are accessible to treating patients, although often less than one-half of the patients with the relevant conditions actually received the approved product to treat their disease. Thus, in spite of the remarkable achievement of many products, patients concerned by EMA-approved orphan medicinal products have persistent unmet needs, which deserve consideration. The enormous investments made by the companies to develop products, and the high financial burden for the Member States to purchase these products emphasize the importance of a scrupulous appreciation of treatment value involving all stakeholders at early stage of development, before marketing authorization, and during follow up.

Statistical considerations for rare diseases drug development.

One of the most challenges for rare disease clinical trials is probably the availability of a small patient population. It is then a great concern on how to conduct clinical trials with a small number of subjects available for obtaining substantial evidence regarding safety and effectiveness for approval of the rare disease drug product under investigation. FDA, however, does not have the intention to create a statutory standard for approval of orphan drugs that are different from the standard for approval of drugs in common conditions. Thus, it is suggested that innovative trial designs such as a complete n-of-1 trial design or an adaptive design should be used for an accurate and reliable assessment of rare disease drug products under investigation. In this article, basic considerations, innovative trial designs, and statistical methods for data analysis are discussed. In addition, some innovative thinking for the evaluation of rare disease drug products is proposed.

A human-on-a-chip approach to tackling rare diseases.

Drug development for rare diseases, classified as diseases with a prevalence of < 200 000 patients, is limited by the high cost of research and low target population. Owing to a lack of representative disease models, research has been challenging for orphan drugs. Human-on-a-chip (HoaC) technology, which models human tissues in interconnected in vitro microfluidic devices, has the potential to lower the cost of preclinical studies and increase the rate of drug approval by introducing human phenotypic models early in the drug discovery process. Advances in HoaC technology can drive a new approach to rare disease research and orphan drug development.

Orphan drug development: the increasing role of clinical pharmacology.

Over the last few decades there has been a paradigm shift in orphan drug research and development. The development of the regulatory framework, establishment of rare disease global networks that support drug developments, and advances in technology, has resulted in tremendous growth in orphan drug development. Nevertheless, several challenges during orphan drug development such as economic constraints; insufficient clinical information; fewer patients and thus inadequate power; etc. still exist. While the standard regulatory requirements for drug approval stays the same, applications of scientific judgment and regulatory flexibility is significantly important to help meeting some of the immense unmet medical need in rare diseases. Clinical pharmacology presents a vital role in accelerating orphan drug development and overcoming some of these challenges. This review highlights the critical contributions of clinical pharmacology in orphan drug development; for example, dose finding, optimizing clinical trial design, indication expansion, and population extrapolation. Examples of such applications are reviewed in this article.

Implementing reflective multicriteria decision analysis (MCDA) to assess orphan drugs value in the Catalan Health Service (CatSalut).

BACKGROUND: Orphan medicines show some characteristics that hinder the evaluation of their clinical added value. The often low level of evidence available for orphan drugs, together with a high budget impact and an incremental cost-effectiveness ratio many times higher than drugs used for non-orphan diseases, represent challenges in their appraisal and effective access to clinical use. In order to explore how to handle these hurdles, the Catalan Health Service (CatSalut) began an initiative on a multidimensional assessment of drugs value during the appraisal process. Reflective multicriteria decision analysis (MCDA) using analytical methods was chosen, since it may help to standardise and contextualize all the relevant data related with the drug that could contribute to a decision. The aim of the study was to determine whether the implementation of reflective MCDA methodology could support the decision-making process about orphan medicines in the context of CatSalut. METHODS: The assessment and decision-making process for orphan drugs in the Programa d'Harmonització Farmacoterapeutica (PHF) of CatSalut was prioritized to test the implementation of the reflective MCDA both a qualitative and quantitatively. A staged approach was used with the following main steps: selection and structuration of quantitative criteria (Core Model) and qualitative criteria (Contextual Tool), framework scoring and assessment of three orphan drug case studies. This proof-of-concept would grant a continued refinement of the methodology and, if and when validated, its potential integration to other therapeutic areas of the PHF. RESULTS: The final framework was composed by 10 quantitative criteria (Core Model) and 4 qualitative criteria (Contextual Tool) according to the PHF goals being the most important criteria "disease severity", "unmet need", "comparative effectiveness" and "comparative safety /tolerability". The matrix developed for the case studies served as a guide for the selection of the essential information that the decision-makers were expected to include in a framework. The reflective discussion was considered the most relevant phase of the approach to support inputs for health decision-making processes reflecting both drug value and place in therapy. CONCLUSIONS: The study showed that reflective MCDA methodology could be implemented to complement the decision-making process in CatSalut, as an aid to determine the clinical added value for orphan medicines. MCDA provided transparency and a structured discussion during the committee meetings, thus increasing transparency and predictability of the relevant items supporting the agreements adopted on orphan drugs access.

International experiences in multicriteria decision analysis (MCDA) for evaluating orphan drugs: a scoping review.

Introduction: Orphan diseases are low-prevalence conditions with chronically debilitating or life-threatening consequences. Their treatments are generally called orphan drugs (OD). Health-technology assessment processes have traditionally considered cost-effectiveness analysis (CEA), when making reimbursement and pricing decisions for health-care plans. Valuing OD with standard CEA raises important issues due to uncertain evidence, inability to meet cost-effectiveness thresholds for reimbursement and high budget impact, among others. Multi-criteria decision analysis (MCDA) allows to overcome these issues and improve the technical and ethical quality of decisions regarding prioritization, coverage, and reimbursement of OD. Areas covered: A scoping review was conducted in order to characterize MCDA frameworks for assessing OD and implementation experiences. We reviewed electronic databases (Medline, Embase, Cochrane Library, EBSCO, CINAHL, EconLit, Web of Science, LILACS, Google Scholar) key journals (Orphanet Journal of Rare Diseases and Value in Health) and organization repositories. Expert opinion: The theoretical framework for MCDA considers areas related to characteristics of orphan diseases and their technologies' clinical and economic impact. Participation processes are critical in incorporating societal values in weighting different dimensions and constructing decision rules. Local implementation pilots considering different stakeholders are necessary in order to pinpoint specific barriers and opportunities.

Factors associated with positive and negative recommendations for cancer and non-cancer drugs for rare diseases in Canada.

BACKGROUND: In Canada, reimbursement recommendations on drugs for common and rare diseases are overseen by the Canadian Agency for Drugs and Technologies in Health (CADTH) and made through the pan-Canadian Oncology Drug Review (pCODR) and the Common Drug Review (CDR). While the agency specifies information requirements for the review of drug submissions, how that information is used by each process to formulate final reimbursement recommendations, particularly on drugs for rare diseases (DRDs) in which per patient treatment costs are often high, is unclear. The purpose of this study was to determine which factors contribute to recommendation type for DRDs. METHODS: Information was extracted from CDR and pCODR recommendations on drugs for diseases with a prevalence < 1 in 2000 from January 2012 to April 2018. Data were tabulated and multiple logistic regression was applied to explore the association between recommendation type and the following factors: condition/review process (cancer vs non-cancer), year, prevalence, clinical effectiveness (improvements in surrogate, clinical and patient reported outcomes), safety, quality of evidence (availability of comparative data, consistency between population in trial and indication, and bias), clinical need, treatment cost, and incremental cost-effective ratio (ICER). Two-way interactions were also explored. RESULTS: A total of 103 recommendations were included. Eleven were resubmissions, all of which received a positive recommendation. Among new submissions (n = 92), DRDs that were safe or offered improvements in clinical or patient reported outcomes were more likely to receive positive reimbursement recommendations. No associations between recommendation type and daily treatment cost, cost-effectiveness, or condition (cancer or non-cancer) were found. CONCLUSIONS: Clinical effectiveness, as opposed to economic considerations or whether the drug is indicated for cancer or non-cancer, determine the type of reimbursement recommendation.

Towards regulatory endorsement of drug development tools to promote the application of model-informed drug development in Duchenne muscular dystrophy.

Drug development for rare diseases is challenged by small populations and limited data. This makes development of clinical trial protocols difficult and contributes to the uncertainty around whether or not a potential therapy is efficacious. The use of data standards to aggregate data from multiple sources, and the use of such integrated databases to develop statistical models can inform protocol development and reduce the risks in developing new therapies. Achieving regulatory endorsement of such models through defined pathways at the US Food and Drug Administration and European Medicines Authority allows such tools to be used by the drug development community for defined contexts of use without further need for discussion of the underlying model(s). The Duchenne Regulatory Science Consortium (D-RSC) has brought together multiple stakeholders to develop a clinical trial simulation tool for Duchenne muscular dystrophy using such an approach. Here we describe the work of D-RSC as an example of how such an approach may be effective at reducing uncertainty in drug development for rare diseases, and thus bringing effective therapies to patients faster.

The impact of orphan drug policies in treating rare diseases.

This paper is based on Shalini Weerasooriya's Masters dissertation in Public Health at the University of Sheffield. A literature review was conducted to understand the role that orphan drug policies have played in the development of new treatments for rare diseases. The impacts of the policies were categorised as 'tangible' or 'intangible' and further synthesis identified 10 main themes such as incentives for investment, criteria for eligibility and assessment of drug applications and further guidance to industry during the drug development cycle. The review concludes that whilst policies have contributed positively towards improving the research and development of orphan drugs it has not exhausted its uses and must now shift its focus to facilitating greater accessibility and affordability of the treatments and that stakeholders are essential to the success of this process. Implications for practice are identified, for example the need to further update and refine the policy with changing demographics and advancing technologies and, in particular, greater collaboration and involvement through, for example, evidence based training programmes is recommended. It is concluded that focus must shift to address the gap between having available drugs and being able to access and afford them. F.J.

Evaluating Canadians' Values for Drug Coverage Decision Making.

BACKGROUND: Decision makers are facing growing challenges in prioritizing drugs for reimbursement because of soaring drug costs and increasing pressures on financial resources. In addition to cost and effectiveness, payers are using other values to dictate which drugs are prioritized for funding, yet there are limited data on the Canadian public's priorities. OBJECTIVES: To measure the relative societal importance of values considered most relevant in informing drug reimbursement decisions in a representative sample of Canadians. METHODS: An online survey of 2539 Canadians aged 19 years and older was performed in which 13 values used in drug funding prioritization were ranked and then weighted using an analytic hierarchy process. RESULTS: Canadians value safe and efficacious drugs that have certainty of evidence. The values ranked in the top 5 by most of our subjects were potential effect on quality of life (65.4%), severity of the disease (62.6%), ability of drug to work (61.1%), safety (60.5%), and potential to extend life (49.4%). Values related to patient or disease characteristics such as rarity, socioeconomic status, and health and lifestyle choices held the lowest rankings and weights. CONCLUSIONS: Canadians value, above all, treatment-related factors (eg, efficacy and safety) and disease-related factors (eg, severity and equity). Decision makers are currently using additional justifications to prioritize drugs for reimbursement, such as rarity and unmet need, which were not found to be highly valued by Canadians. Decision makers should integrate the public's values into a Canadian reimbursement framework for prioritization of drugs competing for limited funds.

Challenges in Orphan Drug Development: Identification of Effective Therapy for Thyroid-Associated Ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO), the ocular manifestation of Graves' disease, is a process in which orbital connective tissues and extraocular muscles undergo inflammation and remodeling. The condition seems to result from autoimmune responses to antigens shared by the thyroid and orbit. The thyrotropin receptor (TSHR), expressed at low levels in orbital tissues, is a leading candidate antigen. Recent evidence suggests that another protein, the insulin-like growth factor-I receptor (IGF-IR), is overexpressed in TAO, and antibodies against IGF-IR have been detected in patients with the disease. Furthermore, TSHR and IGF-IR form a physical and functional complex, and signaling initiated at TSHR requires IGF-IR activity. Identification of therapy for this rare disease has proven challenging and currently relies on nonspecific and inadequate agents, thus representing an important unmet need. A recently completed therapeutic trial suggests that inhibiting IGF-IR activity with a monoclonal antibody may be an effective and safe treatment for active TAO.

Generic Substitution of Orphan Drugs for the Treatment of Rare Diseases: Exploring the Potential Challenges.

Generic drugs are important components of measures introduced by healthcare regulatory authorities to reduce treatment costs. In most patients and conditions the switch from a branded drug to its generic counterpart is performed with no major complications. However, evidence from complex diseases suggests that generic substitution requires careful evaluation in some settings and that current bioequivalence criteria may not always be adequate for establishing the interchangeability of branded and generic products. Rare diseases, also called orphan diseases, are a group of heterogeneous diseases that share important characteristics: in addition to their scarcity, most are severe, chronic, highly debilitating, and often present in early childhood. Finding a treatment for a rare disease is challenging. Thanks to incentives that encourage research and development programs in rare diseases, several orphan drugs are currently available. The elevated cost of orphan drugs is a highly debated issue and a cause of limited access to treatment for many patients. As patent protection and the exclusivity period of several orphan drugs will expire soon, generic versions of orphan drugs should reach the market shortly, with great expectations about their impact on the economic burden of rare diseases. However, consistent with other complex diseases, generic substitution may require thoughtful considerations and may be even contraindicated in some rare conditions. This article provides an overview of rare disease characteristics, reviews reports of problematic generic substitution, and discusses why generic substitution of orphan drugs may be challenging and should be undertaken carefully in rare disease patients.

The possibility of obtaining marketing authorization of orphan pharmaceutical compounding preparations: 3,4-DAP for Lambert-Eaton Myasthenic Syndrome.

BACKGROUND: Pharmaceutical compounding preparations, produced by (hospital) pharmacies, usually do not have marketing authorization. As a consequence, some of these pharmaceutical compounding preparations can be picked-up by a pharmaceutical company to obtain marketing authorization, often leading to price increases. An example is the 3,4-diaminopyridine slow release (3,4-DAP SR) tablets for Lambert-Eaton Myasthenic Syndrome (LEMS). In 2009 marketing authorization was given for the commercial immediate release phosphate salt of the drug, including a fifty-fold price increase compared to the pharmaceutical compounding preparation. Obtaining marketing authorization for 3,4-DAP SR by academia might have been a solution to prevent this price increase. To determine whether the available data of a pharmaceutical compounding preparation with long-term experience in regular care are adequate to obtain marketing authorization, 3,4-DAP SR is used as a case study. METHODS: A retrospective qualitative case-study was performed. Initially, document analysis was executed by collecting the required data for marketing authorization in general and whether data of Firdapse® and 3,4-DAP SR met these requirements. Secondly, the (non-) available data of the two formulations were compared with each other to determine the differences in availability. RESULTS: At the time of approval, almost all data were available for both Firdapse® and 3,4-DAP SR. Conversely, much of the data used for the approval of Firdapse® originated from the 3,4-DAP immediate release (3,4-DAP IR) formulation. Only two bioequivalence studies and one pharmacology safety study was performed with Firdapse® before marketing authorization application. CONCLUSIONS: In conclusion, at time Firdapse® obtained approval, the data available did not differ substantially from 3,4-DAP SR, indicating that approval with 3,4-DAP SR would have been possible. We make a plea for approval of orphan medicinal products developed and manufactured by academic institutions as to keep utilization of these products affordable.