From Molecule to Patient: The Complex Journey of Orphan Drugs

The development and access to orphan drugs represent one of the most complex scientific, regulatory, and financial challenges in global healthcare systems. Unlike traditional medicines, orphan drugs face a fundamental paradox: high scientific complexity and extremely small patient populations. In Mexico, this challenge is further amplified by structural barriers in diagnosis, regulation, and institutional access. This article explores the full life cycle of these products, from early research to real-world availability in hospitals, highlighting key bottlenecks and strategic opportunities to improve patient access.

The Starting Point: Complex Science for Small Populations

Rare diseases affect approximately 6–8% of the global population, representing more than 300 million people worldwide. In Mexico, it is estimated that between 6 and 8 million individuals live with a rare disease [1]. However, over 7,000 rare diseases have been identified, and fewer than 5% have an approved treatment [2].

This imbalance defines the central challenge: developing highly specialized therapies for very small patient populations. Unlike other therapeutic areas, the orphan drug pipeline is heavily driven by advanced biotechnologies, gene therapies, and RNA-based platforms, increasing technical complexity and early-stage costs.

Research and Development: High Risk, High Investment

The development of a new drug, including orphan drugs, takes on average 10 to 12 years, with total costs exceeding USD 2 billion when accounting for failed compounds [3]. However, in rare diseases, additional challenges arise:

• Limited patient recruitment, extending clinical trial timelines

• Adaptive trial designs or limited evidence, requiring more complex regulatory validation

• High cost per patient, due to small cohorts

The probability of success from clinical development to approval is below 12% on average [4], forcing companies to prioritize projects with high unmet need and strong scientific rationale.

The Clinical Challenge: Evidence with Small Populations

One of the greatest challenges in orphan drug development is generating robust clinical evidence. Unlike common diseases, where trials may enroll thousands of patients, rare disease studies typically involve:

• Dozens or hundreds of patients

• Lack of standard comparators

• Use of surrogate endpoints or biomarkers

This creates a constant tension between the need for early access and the requirement for sufficient clinical evidence.

Regulatory Pathway: COFEPRIS as the Entry Gate

Once clinical development is completed, the drug must be submitted for evaluation to COFEPRIS.

In Mexico, this process includes:

• Evaluation of quality, safety, and efficacy

• Validation of clinical trial data

• Review of manufacturing processes

While improvements such as digitalization have been implemented in recent years, regulatory timelines still range from six to 12 months, depending on the complexity of the submission [5].

For orphan drugs, this process can be more complex due to limited clinical evidence.

The Critical Filter: General Health Council (CSG)

The next key step is inclusion in the National Formulary through the Consejo de Salubridad General.

This process determines whether a medicine becomes eligible for use within public healthcare institutions. It requires:

• Cost-effectiveness evaluation

• Budget impact analysis

• Comparative clinical assessment

This stage represents one of the most significant bottlenecks because:

• Orphan drugs often have high per-patient costs

• Traditional health economic models are not well suited for rare diseases

As a result, only a limited number of approved drugs successfully obtain formulary inclusion.

Institutional Access: From Approval to Real Availability

Even after formulary inclusion, real access depends on adoption by institutions such as:

• IMSS

• ISSSTE

• IMSS Bienestar

Each institution operates under its own evaluation processes, budgets, and priorities, leading to variability in access.

In many cases, access may take several additional years after regulatory approval, extending what is often referred to as the “access gap.”

The Final Mile: Procurement and Treatment Continuity

The journey does not end with institutional inclusion. For a drug to be truly available, the following are required:

• Public procurement processes (tenders or direct awards)

• Efficient distribution systems

• Timely patient diagnosis

In rare diseases, diagnosis is a critical barrier. The average diagnostic delay ranges between five and eight years, further delaying treatment access [6].

Additionally, treatment continuity is essential. Unlike high-volume drugs, orphan therapies depend on:

• Accurate demand planning

• Active patient identification

• Diagnostic support programs

Financial Impact: High Cost, High Value

The annual cost of an orphan drug can exceed US$150,000 per patient [7]. However, this cost must be assessed in context:

• Reduction in hospitalizations

• Improved quality of life

• Decrease in indirect costs

The challenge for healthcare systems is to shift from cost-based models to value-based frameworks.

The Innovation–Access Gap

Globally, the number of orphan therapies has grown significantly. However, in Mexico:

• Only a fraction of these therapies are available

• Even fewer achieve full institutional access

This creates a substantial gap between scientific innovation and real patient access.

Strategic Opportunities for Mexico

Mexico has a unique opportunity to position itself as a leader in rare diseases within Latin America. To achieve this, several strategic actions are needed:

1. Strengthen early diagnosis
Reduce the diagnostic odyssey through AI, genetics, and medical education.

2. Adapt regulatory frameworks
Introduce flexible pathways for rare disease evidence.

3. Modernize health economic evaluations
Develop value-based models tailored to orphan drugs.

4. Foster public-private partnerships
Expand access to diagnostic tools and innovative therapies.

5. Leverage technology and innovation
Integrate AI and genomic medicine to accelerate diagnosis and treatment.

Conclusion

The journey of an orphan drug from the laboratory to the patient is long, complex, and filled with challenges. However, it also represents one of the greatest opportunities to transform healthcare systems.

In Mexico, the challenge is not only to generate innovation but to ensure that innovation reaches those who need it most. Bridging the gap between science and access is not only a healthcare priority—it is an ethical imperative.

The future of rare diseases will depend on the ability of healthcare systems to adapt to a new reality: highly specialized therapies for small populations, with profoundly transformative impact.

Sources:

1. Secretaría de Salud. Rare disease epidemiology in Mexico.

2. Orphanet Report Series. Rare diseases epidemiology (2024).

3. DiMasi JA et al. Cost of drug development. Journal of Health Economics.

4. IQVIA. Global Trends in R&D 2024.

5. COFEPRIS. Regulatory report 2024.

6. Global Genes. Rare Disease Diagnostic Journey Report.

7. Evaluate Pharma. Orphan Drug Report 2024.