Sensory neuropathy as a manifestation of multiple acyl-coenzyme A dehydrogenase deficiency

Multiple acyl-coenzyme A dehydrogenase deficiency (MADD) is a rare metabolic disorder which typically manifests with muscle weakness. However, despite late-onset MADD being treatable, it is often misdiagnosed, due in part to the heterogeneity of presentations. We report a case of late-onset MADD manifesting first as a sensory neuropathy before progressing to myopathic symptoms and acute metabolic decompensation. Early diagnostic workup with acylcarnitine profiling and organic acid analysis was critical in patient outcome; metabolic decompensation and myopathic symptoms were completely reversed with riboflavin supplementation and dietary modification, although sensory neuropathy persisted. Clinical consideration of MADD as part of the differential diagnosis of neuropathy with myopathy is crucial for a timely diagnosis and treatment of MADD.

A systematic review of real-world evidence (RWE) supportive of new drug and biologic license application approvals in rare diseases

BACKGROUND

Real-world evidence (RWE) generated using real-world data (RWD) presents the potential to contextualize and/or supplement traditional clinical trials for regulatory approval of rare diseases (RDs). This systematic review evaluated the use of RWD for non-oncologic RD therapies with orphan drug designation (ODD) to support efficacy outcomes in regulatory application packages to the US Food and Drug Administration (FDA). New drug applications (NDAs) and biologic license applications (BLAs) submitted between January 2017 and October 2022 were obtained from publicly available FDA drug approval websites. NDAs and BLAs of non-oncologic RD therapies were screened, and manually reviewed using RWE-related keywords. Quantitative summary of number/proportion of study types was provided, whereas qualitative synthesis focused on key categories of output assessing the use of RWD in overall drug approval process, including agency's feedback on its strengths and key challenges.

RESULTS

A total of 868 NDAs and BLAs were identified, of which 243 were screened for non-oncologic RDs with ODD, and 151 were subsequently reviewed for the RWD used to support efficacy outcomes. Twenty (12 NDAs, 8 BLAs) applications met the review inclusion criteria. Most (19; 95%) applications used only retrospective RWD, while one (5%) collected RWD both retrospectively and prospectively. RWD studies included natural history including registry-based/retrospective historical controls (14; 70%), retrospective medical chart-reviews (4; 20%), and external RWD controls from other studies (2; 10%). The FDA generally accepted RWD studies demonstrating a large effect size despite the noted concerns and criticisms. However, the agency expressed concerns about overall quality and comparability of RWD with trial data for some applications, including RWD study designs with respect to differences in patients' baseline characteristics, missing information, and potential bias and measurement errors.

CONCLUSIONS

This systematic review highlights potential benefits of appropriately conducted RWE studies in RD, which can strengthen the clinical evidence for efficacy comparison and contextualization to support product approval efforts, particularly when a large magnitude of effect is observed for the new intervention. Nonetheless, quality and completeness of RWD and its comparability with trial data remain areas of concern that can serve as valuable learnings for advancing future science and regulatory approvals.

Analysis of caregiver perspectives on patients with mucopolysaccharidosis II treated with pabinafusp alfa: results of qualitative interviews in Japan

BACKGROUND

Mucopolysaccharidosis type II (MPS II), or Hunter syndrome, is a rare X-linked metabolic disorder predominantly affecting males. Pabinafusp alfa, an iduronate-2-sulfatase enzyme designed to cross the blood-brain barrier, was approved in Japan in 2021 as the first enzyme replacement therapy targeting both the neuropathic and somatic signs and symptoms of MPS II. This study reports caregivers' experiences of MPS II patients receiving pabinafusp alfa through qualitative interviews.

METHODS

Semi-structured, qualitative interviews were conducted with caregivers at seven clinical sites in Japan using a semi-structured moderation guide (Voice of the Caregiver guide). Thematic analysis was applied to the interview transcripts to identify symptoms and health-related quality of life impacts at baseline, changes during treatment, and overall treatment experience.

RESULTS

Seven caregivers from 16 trial sites participated, representing seven children aged 8-18 years who had received pabinafusp alfa for 3.3-3.5 years at the time of the interviews. Data suggest a general trend toward improvement in multiple aspects, although not all caregivers observed discernible changes. Reported cognitive improvements included language skills, concentration, self-control, eye contact, mental clarity, concept understanding, following instructions, and expressing personal needs. Further changes were reported that included musculoskeletal improvements and such somatic changes as motor function, mobility, organ involvement, joint mobility, sleep patterns, and fatigue. Four caregivers reported improvements in family quality of life, five expressed treatment satisfaction, and all seven indicated a strong willingness to continue treatment of their children with pabinafusp alfa.

CONCLUSION

Caregivers' perspectives in this study demonstrate treatment satisfaction and improvement in various aspects of quality of life following therapy with pabinafusp alfa. These findings enhance understanding of pabinafusp alfa's potential benefits in treating MPS II and contribute to defining MPS II-specific outcome measures for future clinical trials.

Potential of Artificial Intelligence to Accelerate Drug Development for Rare Diseases

The growth in breadth and depth of artificial intelligence (AI) applications has been fast, running hand in hand with the increasing amount of digital data available. Here, we comment on the application of AI in the field of drug development, with a strong focus on the specific achievements and challenges posed by rare diseases. Data paucity and high costs make drug development for rare diseases especially hard. AI can enable otherwise inaccessible approaches based on the large-scale integration of heterogeneous datasets and knowledge bases, guided by expert biological understanding. Obstacles still exist for the routine use of AI in the usually conservative pharmaceutical domain, which can easily become disillusioned. It is crucial to acknowledge that AI is a powerful, supportive tool that can assist but not replace human expertise in the various phases and aspects of drug discovery and development.

Mucopolysaccharidosis type VII (Sly syndrome) - What do we know?

Mucopolysaccharidosis type VII (MPS VII) is an ultra-rare, life-threatening, progressive disease caused by genetic mutations that affect lysosomal storage/function. MPS VII has an estimated prevalence of <1:1,000,000 and accounts for <3% of all MPS diagnoses. Given the rarity of MPS VII, comprehensive information on the disease is limited and we present a review of the current understanding. In MPS VII, intracellular glycosaminoglycans accumulate due to a deficiency in the lysosomal enzyme that is responsible for their degradation, β-glucuronidase, which is encoded by the GUSB gene. MPS VII has a heterogeneous presentation. Features can manifest across multiple systems and can vary in severity, age of onset and progression. The single most distinguishing clinical feature of MPS VII is non-immune hydrops fetalis (NIHF), which presents during pregnancy. MPS VII usually presents within one month of life and become more prominent at 3 to 4 years of age; key features are skeletal deformities, hepatosplenomegaly, coarse facies, and cognitive impairment, although phenotypic variation is a hallmark. Current treatments include hematopoietic stem cell transplantation and enzyme replacement therapy with vestronidase alfa. Care should be individualized for each patient. Development of consensus guidelines for MPS VII management and treatment is needed, as consolidation of expert knowledge and experience (for example, through the MPS VII Disease Monitoring Program) may provide a significant positive impact to patients.

Whipple's disease: A rare disease that can be spotted by many doctors

Whipple's disease, an extremely rare, chronic infection caused by Tropheryma whipplei, an actinobacterium ubiquitously present in the environment, is a multisystemic condition that can affect several organs. Therefore, Whipple's disease should always be considered by physicians working across various branches of medicine, including internal medicine, rheumatology, infectious diseases, gastroenterology, haematology, and neurology. Initially, Whipple's disease is challenging to diagnose due to both its rarity and non-specific clinical features, almost indistinguishable from rheumatological conditions. A few years later, the onset of gastrointestinal symptoms increases the specificity of its clinical picture and helps in reaching the correct diagnosis. Diagnosis is typically made by finding PAS-positive macrophages in the lamina propria at duodenal biopsy. PCR for Tropheryma whipplei is nowadays also increasingly available, and represents an undeniable help in diagnosing this condition. However, it may also be misleading as false positives can occur. If not promptly recognized and treated, central nervous system involvement may develop, which can be fatal. The therapeutic gold standard has not yet been fully established, particularly in cases of recurrent disease, neurological involvement, and an immune reconstitution inflammatory syndrome that may arise following the initiation of antibiotic therapy.

The Orphan Drug Act at 40: Legislative Triumph and the Challenges of Success

Policy Points The Orphan Drug Act (ODA) was the result of patient advocacy and by many measures has been strikingly successful. However, approximately 95% of the more than 7,000 known rare diseases still have no US Food and Drug Administration-approved treatment. The ODA's success led to sustained criticism of high drug prices, often for products that have orphan drug indications. Critics misconstrue the ODA's intent and propose reducing its incentives instead of pursuing policies focused on addressing broader prescription drug price challenges that exist in both the orphan and nonorphan drug market. Patients and their families will continue to defend the purpose and integrity of the ODA and to drive investments into rare disease research and clinical development.

Trends in orphan medicinal products approvals in the European Union between 2010-2022

BACKGROUND

Over the last twenty years of orphan drug regulation in Europe, the regulatory framework has increased its complexity, with different regulatory paths and tools engineered to facilitate the innovation and accelerate approvals. Recently, the proposal of the new Pharmaceutical Legislation for the European Union, which will replace at least three Regulations and one Directive, was released and its new framework is raising many questions. The aim of this study was to present a characterisation of the Orphan Medicinal Products (OMPs) authorised by the European Commission (EC), between 2010 and 2022, looking into eighteen variables, contributing to the ongoing discussion on the proposal and implementation of the new Pharmaceutical Legislation proposed.

METHODS

Data of the OMPs identified and approved between 2010 and 2022 were extracted from the European Public Assessment Reports (EPARs) produced by the European Medicines Agency. Information regarding legal basis of the application, applicant, protocol assistance received, type of authorization, registration status, type of molecule, ATC code, therapeutic area, target age, disease prevalence, number of pivotal clinical trials supporting the application, clinical trial designs, respective efficacy endpoints and number of patients enrolled in the pivotal clinical trials were extracted. A descriptive statistical analysis was applied.

RESULTS

We identified 192 OMPs approved in the period between 2010 and 2022. 89% of the OMPs have legal basis of "full application". 86% of the sponsors received protocol assistance whereas 64% of the MAA benefited from the accelerated assessment. 53% of the active substances are small molecules; about 1 in 5 molecules are repurposed. 40% of the OMPs have oncological therapeutic indications and 56% of the OMPs are intended to treat only adults. 71% of the products were approved based on a single pivotal trial.

CONCLUSIONS

This analysis of OMPs approved between 2010 and 2022 shows that a shift has occurred in the rare disease medicine development space. Through the period studied we observe an increase of non-small molecules approved, accelerated assessment received and non-standard MA's granted.

Analysis of the first ten years of FDA's rare pediatric disease priority review voucher program: designations, diseases, and drug development

BACKGROUND

The Rare Pediatric Disease (RPD) Priority Review Voucher (PRV) Program was enacted in 2012 to support the development of new products for children. Prior to requesting a voucher, applicants can request RPD designation, which confirms their product treats or prevents a rare disease in which the serious manifestations primarily affect children. This study describes the trends and characteristics of these designations. Details of RPD designations are not publicly disclosable; this research represents the first analysis of the RPD designation component of the program.

RESULTS

We used an internal US Food and Drug Administration database to analyze all RPD designations between 2013 and 2022. Multiple characteristics were analyzed, including the diseases targeted by RPD designation, whether the product targeted a neonatal disease, product type (drug/biologic), and the level of evidence (preclinical/clinical) to support designation. There were 569 RPD designations during the study period. The top therapeutic areas were neurology (26%, n = 149), metabolism (23%, n = 131), oncology (18%, n = 105). The top diseases targeted by RPD designation were Duchenne muscular dystrophy, neuroblastoma, and sickle cell disease. Neonatology products represented 6% (n = 33), over half were for drug products and 38% were supported by clinical data.

CONCLUSIONS

The RPD PRV program was created to encourage development of new products for children. The results of this study establish that a wide range of diseases have seen development-from rare pediatric cancers to rare genetic disorders. Continued support of product development for children with rare diseases is needed to find treatments for all children with unmet needs.

Institutional Priority-Setting for Novel Drugs and Therapeutics: A Qualitative Systematic Review

BACKGROUND

There is a lack of guidance on approaches to formulary management and funding for high-cost drugs and therapeutics by individual healthcare institutions. The objective of this review was to assess institutional approaches to resource allocation for such therapeutics, with a particular focus on paediatric and rare disease populations.

METHODS

A search of Embase and MEDLINE was conducted for studies relevant to decision-making for off-formulary, high-cost drugs and therapeutics. Abstracts were evaluated for inclusion based on the Simple Multiple-Attribute Rating Techniques (SMART) criteria. A framework of 30 topics across 4 categories was used to guide data extraction and was based on findings from the initial abstract review and previous health technology assessment (HTA) publications. Reflexive thematic analysis was conducted using QSR NVivo 12 software.

RESULTS

A total of 168 studies were included for analysis. Only 4 (2%) focused on paediatrics, while 21 (12%) centred on adults and the remainder (85%) did not specify. Thirty-two (19%) studies discussed the importance of high-cost therapeutics and 34 (23%) focused on rare/orphan drugs. Five themes were identified as being relevant to institutional decision-making for high-cost therapeutics: institutional strategy, substantive criteria, procedural considerations, guiding principles and frameworks, and operational activities. Each of these themes encompassed several sub-themes and was complemented by a sixth category specific to paediatrics and rare diseases.

CONCLUSION

The rising cost of novel drugs and therapeutics underscores the need for robust, evidence-based, and ethically defensible decision-making processes for health technology funding, particularly at the hospital level. Our study highlights practices and themes to aid decision-makers in thinking critically about institutional, substantive, procedural, and operational considerations in support of legitimate decisions about institutional funding of high-cost drugs and therapeutics, as well as opportunities and challenges that exist for paediatric and rare disease populations.

Creating a Roadmap to Quantitative Systems Pharmacology-Informed Rare Disease Drug Development: A Workshop Report

One of the goals of the Accelerating Rare Disease Cures (ARC) program in the Center for Drug Evaluation and Research (CDER) at the US Food and Drug Administration (FDA) is the development and use of regulatory and scientific tools, including drug/disease modeling, dose selection, and translational medicine tools. To facilitate achieving this goal, the FDA in collaboration with the University of Maryland Center of Excellence in Regulatory Science and Innovation (M-CERSI) hosted a virtual public workshop on May 11, 2023, entitled "Creating a Roadmap to Quantitative Systems Pharmacology-Informed Rare Disease Drug Development." This workshop engaged scientists from pharmaceutical companies, academic institutes, and the FDA to discuss the potential utility of quantitative systems pharmacology (QSP) in rare disease drug development and identify potential challenges and solutions to facilitate its use. Here, we report the main findings from this workshop, highlight the key takeaways, and propose a roadmap to facilitate the use of QSP in rare disease drug development.

High-cost drugs for rare diseases: their expenditure and value based on a regional area-based study

Background: in the field of rare diseases (RDs) most of the European studies on budget impact analysis of drugs that have been conducted often lay on theoretical assumptions and focus only on Orphan drugs (ODs). Objectives: we aimed to estimate the budget impact of specific drugs for non-oncological RDs, both ODs and non-ODs, using real-world data about patients residing in Veneto Region (Italy) and to describe its expenditure structure and dynamics. Methods: a population-based multi-source observational study was conducted using data from Regional administrative databases; an ad-hoc drugs' list specific for RDs including both ODs and non-ODs and classifying them by ATC codes has been created. Results: In 2019, the total expenditure for drugs specific for RDs was EUR 97.2 million (6.6% of the total Regional budget). The RD drug list included 58 ATC codes, of which 15 ATC had an annual budget impact over EUR 1 million ("blockbuster drugs"). The most expensive treatment was a non-OD drug (Coagulation factor VIII). The two most represented therapeutical areas were the metabolic and the hematological ones. Conclusions: Cost analyses on RD high-cost drugs expenditure should consider any specific RD drug, not only ODs. Expenditure dynamics for RD drugs are peculiar showing "blockbuster drugs". Some therapeutical areas seem to be lacking in the drug research field.

TLDA: A transfer learning based dual-augmentation strategy for traditional Chinese Medicine syndrome differentiation in rare disease

The Traditional Chinese Medicine (TCM) has demonstrated its significant medical value over the decades, particularly during the COVID-19 pandemic. TCM-AI interdisciplinary models have been proposed to model TCM knowledge, diagnosis, and treatment experiments in clinical practice. Among them, numerous models have been developed to simulate the syndrome differentiation process of human TCM doctors for automatic syndrome diagnosis. However, these models are designed for normal scenarios and trained using a supervised learning paradigm which needs tens of thousands of training samples. They fail to effectively differentiate syndromes in rare disease scenarios where the available TCM electronic medical records (EMRs) are very limited for each unique syndrome. To address the challenge of rare diseases, this study proposes a simple yet effective method called Transfer Learning based Dual-Augmentation (TLDA). TLDA aims to augment the limited EMRs at both the sample-level and feature-level, enriching the pathological and medical information during training. Extended experiments involving 11 comparison models, including the state-of-the-art model, demonstrate the effectiveness of TLDA. TLDA outperforms all comparison models by a significant margin. Furthermore, TLDA can also be extended to other medical tasks when the EMRs for diagnosis are limited in samples.

Expansion of Anticomplement Therapy Indications from Rare Genetic Disorders to Common Kidney Diseases

Complement constitutes a major part of the innate immune system. The study of complement in human health has historically focused on infection risks associated with complement protein deficiencies; however, recent interest in the field has focused on overactivation of complement as a cause of immune injury and the development of anticomplement therapies to treat human diseases. The kidneys are particularly sensitive to complement injury, and anticomplement therapies for several kidney diseases have been investigated. Overactivation of complement can result from loss-of-function mutations in complement regulators; gain-of-function mutations in key complement proteins such as C3 and factor B; or autoantibody production, infection, or tissue stresses, such as ischemia and reperfusion, that perturb the balance of complement activation and regulation. Here, we provide a high-level review of the status of anticomplement therapies, with an emphasis on the transition from rare diseases to more common kidney diseases.

User Centered Rare Disease Clinical Trial Knowledge Graph (RCTKG)

Drug development in rare diseases is challenging due to the limited availability of subjects with the diseases and recruiting from a small patient population. The high cost and low success rate of clinical trials motivate deliberate analysis of existing clinical trials to understand status of clinical development of orphan drugs and discover new insight for new trial. In this project, we aim to develop a user centered Rare disease based Clinical Trial Knowledge Graph (RCTKG) to integrate publicly available clinical trial data with rare diseases from the Genetic and Rare Disease (GARD) program in a semantic and standardized form for public use. To better serve and represent the interests of rare disease users, user stories were defined for three types of users, patients, healthcare providers and informaticians, to guide the RCTKG design in supporting the GARD program at NCATS/NIH and the broad clinical/research community in rare diseases.

Applying the win ratio method in clinical trials of orphan drugs: an analysis of data from the COMET trial of avalglucosidase alfa in patients with late-onset Pompe disease

BACKGROUND

Clinical trials for rare diseases often include multiple endpoints that capture the effects of treatment on different disease domains. In many rare diseases, the primary endpoint is not standardized across trials. The win ratio approach was designed to analyze multiple endpoints of interest in clinical trials and has mostly been applied in cardiovascular trials. Here, we applied the win ratio approach to data from COMET, a phase 3 trial in late-onset Pompe disease, to illustrate how this approach can be used to analyze multiple endpoints in the orphan drug context.

METHODS

All possible participant pairings from both arms of COMET were compared sequentially on changes at week 49 in upright forced vital capacity (FVC) % predicted and six-minute walk test (6MWT). Each participant's response for the two endpoints was first classified as a meaningful improvement, no meaningful change, or a meaningful decline using thresholds based on published minimal clinically important differences (FVC ± 4% predicted, 6MWT ± 39 m). Each comparison assessed whether the outcome with avalglucosidase alfa (AVA) was better than (win), worse than (loss), or equivalent to (tie) the outcome with alglucosidase alfa (ALG). If tied on FVC, 6MWT was compared. In this approach, the treatment effect is the ratio of wins to losses ("win ratio"), with ties excluded.

RESULTS

In the 2499 possible pairings (51 receiving AVA × 49 receiving ALG), the win ratio was 2.37 (95% confidence interval [CI], 1.30-4.29, p = 0.005) when FVC was compared before 6MWT. When the order was reversed, the win ratio was 2.02 (95% CI, 1.13-3.62, p = 0.018).

CONCLUSION

The win ratio approach can be used in clinical trials of rare diseases to provide meaningful insight on treatment benefits from multiple endpoints and across disease domains.

Using automated text classification to explore uncertainty in NICE appraisals for drugs for rare diseases

OBJECTIVE

This study examined the application, feasibility, and validity of supervised learning models for text classification in appraisals for rare disease treatments (RDTs) in relation to uncertainty, and analyzed differences between appraisals based on the classification results.

METHODS

We analyzed appraisals for RDTs (n = 94) published by the National Institute for Health and Care Excellence (NICE) between January 2011 and May 2023. We used Naïve Bayes, Lasso, and Support Vector Machine models in a binary text classification task (classifying paragraphs as either referencing uncertainty in the evidence base or not). To illustrate the results, we tested hypotheses in relation to the appraisal guidance, advanced therapy medicinal product (ATMP) status, disease area, and age group.

RESULTS

The best performing (Lasso) model achieved 83.6 percent classification accuracy (sensitivity = 74.4 percent, specificity = 92.6 percent). Paragraphs classified as referencing uncertainty were significantly more likely to arise in highly specialized technology (HST) appraisals compared to appraisals from the technology appraisal (TA) guidance (adjusted odds ratio = 1.44, 95 percent CI 1.09, 1.90, p = 0.004). There was no significant association between paragraphs classified as referencing uncertainty and appraisals for ATMPs, non-oncology RDTs, and RDTs indicated for children only or adults and children. These results were robust to the threshold value used for classifying paragraphs but were sensitive to the choice of classification model.

CONCLUSION

Using supervised learning models for text classification in NICE appraisals for RDTs is feasible, but the results of downstream analyses may be sensitive to the choice of classification model.

Knowledge and Attitudes of Clinical Trials among Patients with Rare Diseases and the Guardians in China

BACKGROUND

Conducting of clinical trials for rare diseases faces multiple challenges. Patients' cognition and attitude toward clinical trials are crucial, which may affect their participation and compliance, and affect the schedule of clinical trials eventually.

OBJECTIVE AND METHOD

This study aims to explore the knowledge and attitudes of clinical trials of patients with rare diseases or patients' guardians. An anonymous cross-sectional survey was conducted from November 1, 2021, to November 30, 2021. A total of 1131 valid questionnaires were included. Among them, 417 were filled in by the patients themselves, and 714 were answered by the patients' guardians.

RESULTS

The average score of clinical trial knowledge of the patients (8.25) was lower than that of the guardians (8.85). The willingness of the patients to participate in clinical trials was high (4.28), and the willingness of the patients' guardians was also high for patients to participate in clinical trials (4.35). The main promoting factors of clinical trial participation were the possibility of curing the disease. The main hindering factors of participation in clinical trials were lack of access to clinical trial information and concern about the safety and effectiveness of the trial drug.

CONCLUSIONS

In conclusion, most respondents had some basic knowledge of clinical trials and high willingness to participate in clinical trials. But there were some cognitive deficiencies about clinical trials and many hindering factors to participate in clinical trials. Clinical trials of rare diseases should be patient-centered and truly meet the unmet clinical, psychological, and social needs of patients with rare diseases.

Non-viral delivery of nucleic acid for treatment of rare diseases of the muscle

Rare muscular disorders (RMDs) are disorders that affect a small percentage of the population. The disorders which are attributed to genetic mutations often manifest in the form of progressive weakness and atrophy of skeletal and heart muscles. RMDs includes disorders such as Duchenne muscular dystrophy (DMD), GNE myopathy, spinal muscular atrophy (SMA), limb girdle muscular dystrophy, and so on. Due to the infrequent occurrence of these disorders, development of therapeutic approaches elicits less attention compared with other more prevalent diseases. However, in recent times, improved understanding of pathogenesis has led to greater advances in developing therapeutic options to treat such diseases. Exon skipping, gene augmentation, and gene editing have taken the spotlight in drug development for rare neuromuscular disorders. The recent innovation in targeting and repairing mutations with the advent of CRISPR technology has in fact opened new possibilities in the development of gene therapy approaches for these disorders. Although these treatments show satisfactory therapeutic effects, the susceptibility to degradation, instability, and toxicity limits their application. So, an appropriate delivery vector is required for the delivery of these cargoes. Viral vectors are considered potential delivery systems for gene therapy; however, the associated concurrent immunogenic response and other limitations have paved the way for the applications of other non-viral systems like lipids, polymers, cellpenetrating peptides (CPPs), and other organic and inorganic materials. This review will focus on non-viral vectors for the delivery of therapeutic cargoes in order to treat muscular dystrophies.

Decisions on Non-oncology Breakthrough Therapy Designation Requests in 2017-2019

BACKGROUND

The US Food and Drug Administration's Breakthrough Therapy Designation (BTD) program is intended to facilitate and expedite development of investigational drugs to address unmet medical needs. The objective of this study is to provide an update on FDA's process for review of BTD requests.

METHODS

We reviewed Center for Drug Evaluation and Research (CDER) decisions to grant or deny breakthrough therapy designation requests for non-oncology drugs or biological products ("drugs") from January 1, 2017, through December 31, 2019. Data collection included characteristics of the corresponding drug and condition, reasons for granting or denying breakthrough therapy status, reasons for rescinding or withdrawing breakthrough therapy status after a request was granted (if applicable), and subsequent marketing approval status through 2022.

RESULTS

Among 240 requests, 93 (39%) requests were granted and 147 (61%) requests were denied. Granting of requests was more common for conditions where no therapy was available or for orphan diseases. Common reasons for denial included data-related issues, insufficient treatment effect, inadequate study design, endpoint attributes, safety issues, and reliance on post hoc analyses. Among 28 drugs receiving marketing approval as of the end of 2022 for the indication for which BTD was previously granted, 21 (75%) involved a first-in-class mechanism of action.

CONCLUSIONS

This analysis describes CDER's decision-making process related to review of requests for breakthrough therapy designations and enhances public awareness regarding efforts to expedite drug development.

Cost of Exempting Sole Orphan Drugs From Medicare Negotiation

Importance

The Inflation Reduction Act (IRA) requires Medicare to negotiate prices for some high-spending drugs but exempts drugs approved solely for the treatment of a single rare disease.

Objective

To estimate Medicare spending and global revenues for drugs that might have been exempt from negotiation from 2012 to 2021.

Design, Setting, and Participants

This cross-sectional study analyzed drugs that met the IRA threshold for price negotiation (Medicare spending >$200 million/y) in any year from 2012 to 2021 and had an Orphan Drug Act designation. We stratified drugs into 4 mutually exclusive categories: approved for a single rare disease (sole orphan), approved for multiple rare diseases (multiorphan), initially approved for a rare disease and subsequently approved for a nonrare disease (orphan first), and initially approved for a nonrare disease and subsequently approved for a rare disease (non-orphan first).

Outcomes

The primary outcomes were the number of sole orphan drugs, estimated Medicare spending on those drugs from 2012 to 2021, and global revenue since launch.

Results

Among 282 drugs, 95 (34%) were approved to treat at least 1 rare disease, including 25 sole orphan drugs (26%), 20 multiorphan drugs (21%), 13 orphan first drugs (14%), and 37 non-orphan first drugs (39%). From 2012 to 2021, Medicare spending on sole orphan drugs increased from $3.4 billion to $10.0 billion. Each year, a median (IQR) of $2.5 ($1.9-$2.6) billion in Medicare spending would have been excluded from price negotiation because of the sole orphan exemption. The cumulative global revenue of the median (IQR) sole orphan drug was $11 ($6.6-$19.2) billion.

Conclusions and Relevance

The sole orphan exemption will exclude billions of dollars of Medicare drug spending from price negotiation. The high level of global revenues achieved by these drugs, however, suggests that special exemption is unnecessary for them to achieve financial success. Congress could consider removing the sole orphan exemption to obtain additional savings for patients and taxpayers and to eliminate any potential disincentive for developing additional indications for these drugs.

Uptake of orphan drugs in the WHO essential medicines lists

Objective

We evaluated the uptake of medicines licensed as orphan drugs by the United States Food and Drug Administration (FDA) or European Medicines Agency (EMA) into the WHO Model list of essential medicines and the WHO Model list of essential medicines for children from 1977 to 2021.

Methods

We collated and analysed data on drug characteristics, reasons for adding or rejecting medicines, and time between regulatory approval and inclusion in the lists. We compared trends in listing orphan drugs before and after revisions to the inclusion criteria of the essential medicines lists in 2001, as well as differences in trends for listing orphan and non-orphan drugs, respectively.

Findings

The proportion of orphan drugs in the essential medicines lists increased from 1.9% (4/208) in 1977 to 14.6% (70/478) in 2021. While orphan drugs for communicable diseases have remained stable over time, we observed a considerable shift towards more orphan drugs for noncommunicable diseases, particularly for cancer. The median period for inclusion in the essential medicines lists after either FDA or EMA first approval was 13.5 years (range: 1-28 years). Limited clinical evidence base and uncertainty about the magnitude of net benefit were the most frequent reasons to reject proposals to add new orphan drugs to the essential medicines lists.

Conclusion

Despite lack of a global definition of rare diseases, the essential medicines lists have broadened their scope to include medicines for rare conditions. However, the high costs of many listed orphan drugs pose accessibility and reimbursement challenges in resource-constrained settings.

ADRENOCORTICAL CARCINOMA: AN ORPHAN MALIGNANCY: FROM THE PATIENT TO THE BENCH AND BACK

Adrenocortical carcinoma (ACC) is an orphan cancer with 35% five-year survival that has been unchanged for last five decades. Patients often present with severe hypercortisolism or with mass effects. The only Food and Drug Administration (FDA)-approved drug for ACC is mitotane, an insecticide derivative, which provides only limited additional months of survival, but with toxicities. Little progress in the field has occurred due to a lack of preclinical models. We recently developed new human ACC in vitro and in vivo research models. We produced the first two new ACC cell lines for the field, CU-ACC1 and CU-ACC2, which we have distributed for global collaborations. In addition, we developed 10 ACC patient-derived xenograft (PDX) and two humanized ACC-PDX models to test new therapeutics and examine the mechanism of mitotane action in combination with immunotherapy. These new preclinical models allow us to identify novel targets and test new therapeutics for our patients with adrenal cancer.