{"id":3275,"date":"2024-06-10T11:22:40","date_gmt":"2024-06-10T15:22:40","guid":{"rendered":"https:\/\/cytel.agencyukdev.com\/perspectives\/strategies-to-overcome-limited-patient-population-challenges-in-rare-disease-studies\/"},"modified":"2024-08-22T06:15:57","modified_gmt":"2024-08-22T10:15:57","slug":"strategies-to-overcome-limited-patient-population-challenges-in-rare-disease-studies","status":"publish","type":"perspectives","link":"https:\/\/cytel.agencyukdev.com\/fr\/perspectives\/strategies-to-overcome-limited-patient-population-challenges-in-rare-disease-studies\/","title":{"rendered":"Strategies to Overcome Limited Patient Population Challenges in Rare Disease Studies"},"content":{"rendered":"

Written by Boaz N. Adler, MPA, Director, Global Product Engagement, and Valeria Mazzanti, MPH, Associate Director, Customer Success<\/p>\n

Rare disease studies come with their own unique challenges, particularly limited patient populations. However, there are a number of adaptive clinical trial design strategies that can be used to mitigate the challenge of hard-to-recruit patient populations and associated trial risks. Here, we delve into four: sample size optimization, sample size re-estimation, phase II\/III seamless designs, and Exact Statistical methodologies, and how each of these can help trial sponsors working with limited rare disease patient populations.<\/p>\n

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What are rare diseases? <\/strong><\/p>\n

In the United States, a disease is considered rare if it affects fewer than 200,000 people (that is, about 60 per 100,000 people). The European Union defines it as those with a prevalence of less than 5 patients in 10,000. There are over 7,000 known rare diseases to date, such as Sickle Cell Disease, Duchenne Muscular Dystrophy, and Sjogren’s Disease. As medical technology develops, specifically in the areas of gene-mapping, more diseases join this list each year. With the identification and mapping of these diseases, there is also increasing interest in gene-editing and personalized medicines to address these diseases and provide treatments and cures. However, unique challenges persist.<\/p>\n

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What makes the area of rare disease unique as a field of study?<\/strong><\/p>\n

The most significant challenge in the area of rare diseases<\/a> is the limited number of patients available for study. This can be exacerbated by the fact that those impacted by rare diseases are often misdiagnosed in the first stages of their disease, complicating their treatment paths and adding to their anxiety and suffering. Another significant challenge in drug development for rare disease is the ability to measure and demonstrate treatment effect. Treatments that are not cures often rely on disease activity scales or quality of life measures, which may require a larger number of study subjects. Cures, on the other hand, may require very long-term follow-up to establish the success of the therapy, thus increasing the costs and administration of such studies.<\/p>\n

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How can limited population numbers be addressed in clinical trial design and execution?<\/strong><\/p>\n

Limited population size <\/a>can lead to increasing timelines for patient recruitment, sometimes to untenable lengths; or in cases where the patient population is very rare, there may simply not be enough patients for the application of the typical statistical methodologies, or even fully comparable trials. In the first instance, applying designs that seek to minimize the required sample size can help mitigate both overall study duration and study cost. Such designs may include sample size re-estimation or seamless phase II\/III studies. For the latter example, where the number of patients is exceedingly rare, applying Exact Statistical methods, designed to account for missing or sparse data, or using single-arm non-comparative designs may be useful. In cases of non-comparative study designs, external comparison methods relying on real-world evidence such as historical controls or external control arms can be used to augment evidence.<\/p>\n

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How are some of these challenges mitigated or addressed in clinical trial design?<\/strong><\/p>\n

There are a number of ways trial sponsors can use adaptive clinical trial designs<\/a> and strategies to account for limited or hard-to-recruit patient populations. Below, we delve into four: Sample-Size Optimization; Sample-Size Reassessment; Phase II\/III Seamless Designs; and Exact designs.<\/p>\n

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