Forecasting the commercial potential of rare disease assets is high stakes. Small differences in assumptions have an outsized impact on forecasted revenues due to small patient populations. Unique rare disease forecasting challenges include: 

• Limited Published Epidemiology: Existing estimates are often outdated and subject to sample bias, which can over- or under-represent patient segments.
• Evolving Diagnosis & Treatment Dynamics: Diagnosis and treatment rates can shift rapidly, complicating forecasting and requiring constant assumption validation. 
• Influence of Access Dynamics: Changes in the access environment can materially accelerate or constrain uptake, altering the realized patient population. 

These challenges make it difficult to develop a credible picture of today’s diagnosed and treated populations and tomorrow’s addressable opportunity. Forecasts must not only interpret and reconcile fragmented literature and claims data but also anticipate how patient awareness, diagnostic pathways, and activation strategies will evolve. 

Three Archetype Approaches

Approaching rare disease forecasting using archetypes allows us to focus assumptions and sensitivities on the core levers relevant to the target indications. 

Diagnosis-Limited Archetype

This archetype covers the misdiagnosed or undiagnosed rare diseases. When diagnosed, patients often have to educate their care team. Diseases may be genetically driven or later-onset and less severe in presentation. Symptomatic patients use generics or intensive self-care routines. 

Core Challenge: Estimating the latent patient pool and modeling how awareness campaigns, diagnostic tools, and referral pathway improvements can expand the market. 

Illustrative Analogs: Transthyretin Amyloidosis (ATTR), Alpha-1 Antitrypsin Deficiency (AATD), and Lysosomal Storage Disorders (e.g., Fabry, Pompe).

Constrained Growth Archetype 

This archetype features an established diagnosed population based on genetic testing or clear diagnostic criteria. Uptake is constrained by lack of screening, utilization in subsets, or access restraints. There may be health system capacity constraints related to gene therapy adoption.

Core Challenge: Developing high impact strategies to counter constraining forces and modeling impact on adoption.

Illustrative Analogs: Duchenne Muscular Dystrophy (DMD), Spinal Muscular Atrophy (SMA), and Sickle-Cell Disease (SCD).

Mature Market Archetype 

This archetype has high diagnosis and treatment rates driven by longstanding awareness, established diagnostic pathways, and multiple available therapies. Market growth is driven primarily by differentiation among late entrants rather than expansion of the patient pool. Rebate walls and formulary entrenchment can create payer challenges for late entrants attempting to define differentiation.

Core Challenge: Identifying credible levers for differentiation to capture share in a well-defined market.

Illustrative Analogs: Pulmonary Arterial Hypertension (PAH), Hemophilia A/B, and Paroxysmal Nocturnal Hemoglobinuria (PNH).

A Defensible, Insights-Driven View of Rare Disease Opportunity 

At Triangle Insights Group, we blend quantitative rigor, analog-driven benchmarks, and strategic commercial insight to build a credible, investor-ready view and a roadmap for commercial opportunity. Our approach includes: 

Patient Journey & Diagnostic Pathway Mapping: Granular analysis of where patients fall out of the journey, who influences progression, and what interventions can accelerate diagnosis and treatment.

Commercial Opportunity Assessment and Forecasting: Robust models that synthesize published epidemiology, real-world claims, and registry insights.

Market Access Landscape: Our proprietary Policy Reporter database provides a detailed review of access policies and/or analogs to understand the relationship between clinical data package, label, pricing, and influential utilization management that influences product positioning.

Commercial Lever Prioritization & Launch Roadmap: A quantified view of which levers matter most and when. Our roadmaps focus commercial resources properly to unlock full market value. 

Triangle Insights helps clients see that ecosystem clearly, forecast credibly, and invest intelligently. Reach out to learn how Triangle Insights can offer customized support for strategic needs in rare disease and adjacent therapeutic areas.