Feasibility-First · Global · IRB-Ready
Finding patients and specialists when prevalence is in the thousands
When a condition affects fewer than one person in 100,000, every assumption that underlies standard market research breaks down. The panel is too small. The specialists are too dispersed. The patients are too hard to find — and, once found, too important to waste on a poorly designed study.
MedPanel’s ultra-rare disease research recruitment capability was built specifically for this environment: global reach, verified specialist networks, advocacy organization partnerships, and a feasibility-first approach that tells you what is achievable before you commit a budget.
Ultra-rare vs. rare — a clinical and regulatory distinction that changes everything
“Rare disease” and “ultra-rare disease” are often used interchangeably. They should not be.
Rare
Rare disease
US patients (Orphan Drug Act)
EMA prevalence threshold
- Already restrictive — but workable with standard rare disease research infrastructure.
- Larger specialist communities and more accessible patient pools.
- Sample sizes of 50–200 are often achievable for quantitative work.
Ultra-rare
Ultra-rare disease
Most commonly cited threshold
Global patient population — or lower
- Treating physician communities may number 150 globally.
- FDA Accelerated Approval and Breakthrough Therapy pathways heavily used here.
- Sample sizes of 10–75 are typical — and often the realistic ceiling.
In regulatory terms, a rare disease in the United States is one affecting fewer than 200,000 people — the threshold that triggers Orphan Drug Act designation. The European Medicines Agency uses a prevalence of fewer than 5 in 10,000. These definitions are already restrictive. Ultra-rare disease goes further: the threshold most commonly cited in clinical and health policy literature is a prevalence below 1 in 100,000, which in practical terms means a global patient population that may be counted in the tens of thousands — or lower.
That distinction is not academic. It has direct consequences for drug development timelines, regulatory flexibility (the FDA’s Accelerated Approval and Breakthrough Therapy pathways are heavily used in ultra-rare programs), and for the feasibility of any research designed to generate evidence along the way. A survey that requires 200 patients is not viable in a condition with 3,000 diagnosed cases worldwide. A physician panel study that needs 50 specialists is a significant undertaking when the treating physician community numbers 150 globally.
Understanding where your program sits on this spectrum is the first conversation MedPanel has with every new client in ultra-rare disease.
Standard research panels were never built for ultra-rare conditions
General-purpose research panels — and even most specialty panels — are built on self-reported professional credentials and consumer-facing recruitment. That model has structural problems in any rare disease context. In ultra-rare disease, it fails completely.
Where standard panels break down
The structural challenges are specific – and they compound over time.
Self-reported credentials.
Panels may not always confirm whether a physician actively manages the target condition beyond limited exposure or academic familiarity.
Consumer recruitment pools.
Generic recruitment databases often have limited reach into communities affected by highly specialized rare diseases.
No disease-specific infrastructure.
Standard panels may struggle to address diagnostic complexity, delayed identification, and evolving classification pathways commonly associated with rare conditions.
How MedPanel builds the network
We do not rely on general panels. Our network is developed through three specialized sources.
Verified rare disease specialist network.
Healthcare professionals are validated through trusted professional and institutional sources rather than self-reported profiles.
Advocacy and community partnerships.
Long-term collaborations with rare disease organizations help support outreach across multiple specialized condition areas.
Professional referral networks.
Specialist-to-specialist referrals help identify experienced professionals actively involved in complex and rare disease care.
Advocacy partnerships and specialist referral networks
These are not generic claims about our “network.” They are the operational infrastructure that makes ultra-rare recruitment achievable rather than aspirational.
- 01
Condition-specific registries maintained by advocacy organizations. - 02
Patient conferences and convenings that gather the community in person. - 03
Newsletters reaching a meaningful proportion of the diagnosed population. - 04
Facebook & Slack groups active in the patient community. - 05
Centers of excellence that concentrate patient volume and specialist expertise. - 06
Physician-to-physician referral chains initiated by high-volume treaters.
For many ultra-rare conditions, the patient advocacy organization is the most reliable pathway to the patient community. These organizations often maintain condition-specific registries, run patient conferences, and have communication channels — newsletters, Facebook groups, Slack communities — that reach a meaningful proportion of the diagnosed population. MedPanel has established working relationships with advocacy organizations across dozens of ultra-rare conditions and engages them as recruitment partners under IRB-approved protocols that protect participant welfare.
Specialist referral networks operate on a parallel track. In ultra-rare disease, centers of excellence concentrate both specialist expertise and patient volume. A small number of academic medical centers and specialized clinics often see the majority of diagnosed patients for a given condition globally. MedPanel identifies these centers, engages the relevant specialists, and uses physician-to-physician referral to expand recruitment reach beyond what any panel alone can provide.
Timeline expectations and minimum feasible sample sizes
One of the most damaging things a research vendor can do in ultra-rare disease is promise a sample size or timeline that the underlying patient population cannot support. It delays programs, wastes budget, and — when the study arrives with a sample of eight instead of thirty — produces data that cannot be presented with confidence.
MedPanel’s feasibility process is designed to prevent this. Before a project enters design or budgeting, our recruitment team conducts a structured feasibility assessment that maps the known diagnosed population, the accessible specialist community, the advocacy organization landscape, and the competing research burden on that community — other studies, registries, and natural history programs that are drawing on the same finite pool of eligible participants.
The output of that assessment is a realistic picture: a defensible sample size range, a field timeline with milestone checkpoints, and — where necessary — a recommendation to consider alternative study designs such as expert elicitation, case-based surveys, or physician retrospective chart reviews that can generate usable evidence without requiring patient-level recruitment at scale.
10 – 30 patients
30 – 75 patients
15 – 50 experts
These numbers are smaller than pharma research teams are accustomed to working with. They are also, in many ultra-rare conditions, the realistic ceiling. MedPanel’s job is to design studies that generate confident, actionable findings within those constraints — and to tell you clearly when a proposed design is not achievable.
Our patient and caregiver research services and rare disease market research capabilities provide additional context on how we approach recruitment across the broader rare disease spectrum.
Map the diagnosed population
We start with a structured estimate of the global diagnosed population for your specific ultra-rare condition.
Identify the accessible specialist community
We map treating physicians, centers of excellence, and referring clinicians who actually see the patient volume.
Survey the advocacy landscape
We catalog existing patient advocacy organizations, their reach, and their willingness to partner.
Account for competing research burden
We check for active studies, registries, and natural-history programs drawing on the same finite pool.
Return a plain-language summary
Defensible sample size, realistic field timeline, alternative designs if needed — within five business days.
Free feasibility check
Request a free feasibility check for your ultra-rare study
If you are designing a research program in an ultra-rare condition, the most valuable conversation you can have before committing to a methodology is a feasibility conversation. MedPanel offers a complimentary feasibility check for ultra-rare disease recruitment inquiries.
Accessible population size assessment
Likely field timelines & sample size constraints
Advocacy organization availability
Plain-language summary in five business days
No obligation to proceed to a full study design — the feasibility output is yours to use however it is most useful to your program. Prefer email? Send your brief to info@medpanel.com with the subject line “Ultra-Rare Feasibility Request” and include your therapeutic area, condition name, target respondent type (physician, patient, caregiver, or payer), and approximate timeline.