Resources and expertise that help solve the unique challenges of rare disease research

Real World Evidence

Utilizing Evidence from Single-Arm Studies

In the absence of a suitable patient population typically required for large-scale RCTs, a single-arm study may be conducted to support accelerated regulatory approval for treatment effectiveness. Mapi has critically reviewed the strengths and limitations of a series of evidence synthesis methods that allow for comparisons of new treatments to best support care or existing therapies on the basis of single-arm studies. These reviews help identify methods that mitigate study factors and population-level differences associated with using single-arm studies to assess comparative effectiveness and incremental cost-effectiveness.


Registries are used to track patient treatments and outcomes, clinical effectiveness, and safety of a product, and are particularly useful when dealing with a rare disease, rare exposure, or special population. Investigators and sponsors periodically receive registry data reports. These reports provide them with qualitative feedback on the use of a pharmaceutical or biotech product, which may impact both practice patterns and product use. Similarly, implementation of a new protocol or process in the clinical setting—and its impact on providing quality healthcare—may be demonstrated and tracked in a registry for the purpose of continuous quality.

Mapi has a specific expertise in the design and conduct of the types of registries that are often used to:

  • Confirm correct product use
  • Identify and quantify SAE rates
  • Evaluate disease outcomes (e.g., survival rates, pregnancy)
  • Identify off-label use
  • Monitor adherence to treatment guidelines
  • Understand actual use
  • Obtain information to better inform patients and prescribers

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