A rare disease company can have compelling science, encouraging clinical data and a clearly defined patient population—and still substantially overestimate its commercial opportunity.
The problem often begins with prevalence.
A company identifies the number of people believed to have a disease, applies assumptions about diagnosis and treatment, and begins building a commercial forecast.
But prevalence is not the market.
The more important question is:
How many patients can actually be identified, reached, treated and reimbursed?
That number can be very different.
Start With the Patient, Not the Epidemiology
In rare disease, patients do not move neatly from diagnosis to treatment.
Some remain undiagnosed for years. Others have an incorrect diagnosis. Genetic testing may be required but inconsistently used. Patients may live far from the centers with disease expertise.
Even after diagnosis, another series of filters begins.
Does the patient meet the clinical criteria used in the pivotal trial? Is the disease too advanced? Are there age restrictions? Will the physician recommend treatment? Will the family accept it? Can the patient reach the treatment center? Will the payer authorize therapy?
Each question reduces the commercially reachable population.
That matters enormously when a company is developing a high-cost therapy for a small population.
Clinical Development Can Determine the Future Market
These commercial questions should not wait until launch planning.
The design of a clinical program can determine which patients ultimately become treatable.
Inclusion criteria, age ranges, disease severity, endpoints and the characteristics of responders can eventually influence the label, physician confidence and payer requirements.
A trial may demonstrate statistical significance across a population. But commercialization requires another question:
Which patient is most likely to experience a meaningful benefit?
If a company can identify that patient early, it may improve clinical development, regulatory discussions, payer evidence and ultimately physician adoption.
If it cannot, the company may reach approval with a much less differentiated product than expected.
Centers of Excellence Change the Equation
Rare disease populations are often concentrated around relatively few specialists and Centers of Excellence.
That can be an advantage.
A company may not need thousands of prescribers. A relatively small number of experienced physicians may manage a significant portion of the identifiable population.
But concentration also creates dependencies.
Referral pathways matter. Diagnostic practices matter. Treatment capacity matters. Travel burden matters. And for therapies requiring specialized administration or monitoring, the ability of the center to treat patients may become a commercial constraint.
A patient who exists epidemiologically but cannot realistically enter the treatment pathway is not the same as a reachable patient.
Reimbursement Further Narrows the Population
Approval does not automatically produce access.
For expensive rare disease therapies, payers may require genetic confirmation, disease-severity criteria, previous treatment failures, specialist prescribing or documentation that mirrors—or even narrows—the clinical trial population.
That is why health economics, outcomes research and payer evidence should be considered during development rather than after approval.
The evidence required to satisfy a regulator and the evidence required to convince a payer are not always the same.
Build the Commercial Model Backward
Before committing substantial capital to late-stage development, a biotechnology company should be able to move beyond the prevalence estimate and answer several practical questions:
- Who is the patient?
- Where is that patient?
- Who treats the patient?
- How is the patient diagnosed?
- What would cause the physician to choose this therapy?
- What evidence will the payer require?
- And how many patients remain after all of those filters are applied?
That is the population on which the commercial strategy should be built.
In rare disease commercialization, the largest epidemiological estimate is rarely the most useful number.
The number that matters is the number of patients the company can actually reach, treat and obtain reimbursement for.
About PharmaKonsult
PharmaKonsult advises biotechnology leaders on the clinical-development and commercialization decisions that shape an asset’s future commercial value. Learn more about our biotech commercialization consulting services.
