Top Clinical Research Organizations for Rare Diseases in 2025

Individual rare diseases affect small populations, but their collective impact is significant

There are more than 7,000 known rare diseases which impact ~300 million people globally.¹ Today, 95% of rare diseases still lack approved treatments, but research and development in this area is experiencing significant growth as advancements in technology and genomics allow for more targeted therapies and personalized medicine.¹

• The rare disease clinical trials market was valued at $12.6 billion in 2023 and is expected to reach nearly $32 billion by 2033, with a compound annual growth rate (CAGR) of 9.7%.² 

Successfully conducting studies involving small populations requires a practiced hand. Sponsors turn to rare disease clinical research organizations (CROs) to manage critical aspects of study design and execution. This can range from clinical development planning, regulatory strategy, protocol design, and site selection to startup, recruitment, trial operations, sample and data management, and logistics.

What makes a rare disease clinical trial different?

Small populations, limited natural history data, and lack of standardized endpoints increase complexity on many levels. Patient-centric study designs and novel recruitment strategies are key to protecting the scarcity and fragility of these populations. Ensuring your CRO partner has global reach will better position you to enroll sufficient participants for statistical significance.

Regulatory pathways for rare diseases may also differ, particularly with designations such as orphan drug status or expedited review and approval processes. An experienced rare disease CRO should provides you with:

• Expertise in the nuances of designing and conducting rare disease clinical trials
• Familiarity with the global regulatory landscape and accelerated approval pathways
• Innovative approaches to patient identification, engagement, recruitment, and retention
• Global access to key opinion leaders (KOLs) and site relationships to broaden patient reach

Top 10 rare disease clinical and contract research organizations for 2025

Medpace

• Founded in 1992, Medpace is a mid-sized CRO that provides end-to-end clinical development services with a focus on rare diseases in a spectrum of therapeutic areas, including neuroscience, metabolic, cardiology, and ophthalmology. They have supported 479 rare disease studies in 69 countries, enrolling 43,700 patients across 14,300 sites.³ Medpace has also built a Rare Disease Consortium comprised of physicians, project managers, and regulatory consultants with orphan drug development experience.

Precision for Medicine

• 200+ rare disease clinical trials across 100+ rare indications helped Precision for Medicine develop an integrated approach, called Rarefied Thinking, that sets new standards for efficiency in complex early-phase development. The company's established networks of specialized phase I/II research sites accelerate study startup in complex populations. A seamless infrastructure connects clinical operations and laboratory services to execute sophisticated protocols, including biomarker-driven trials, basket trials and umbrella studies. Precision manufacturing solutions provides strategic consultancy on the development of cell and gene therapies, while a deep roster of regulatory experts ensures confidence and compliance at every milestone.⁴ 

IQVIA

• IQVIA offers vast data resources and analytical capabilities to provide insight into rare disease populations. This rare disease CRO has participated in more than 300 rare disease studies, including over 60 for ultra-rare indications. IQVIA leverages the Bespoke Gene Therapy Consortium (BGTC) regulatory playbook and is collaborating with industry and nonprofit partners to develop standardized platform-based approaches and streamline the regulatory pathway for advanced therapies.⁵

PPD (Part of Thermo Fisher Scientific)

• PPD provides comprehensive clinical development services with a strong emphasis on rare diseases, including neurological, metabolic, and neuromuscular disorders. Their capabilities are bolstered by the advanced laboratory services and diagnostic tools of Thermo Fisher Scientific. Over the past five years, PPD has supported more than 600 rare disease studies involving 17,800 sites across 101 countries. PPD also offers a Rare Disease and Pediatric Center of Excellence focused on patient-centric trial designs and innovative recruitment strategies.⁶

Parexel

• Parexel offers a full spectrum of clinical research services with specialized teams dedicated to rare diseases. In the past five years, they have been involved in over 520 rare disease projects, enrolling nearly 75,000 patients across more than 18,700 sites. Through their Center of Excellence for Rare Diseases, Parexel brings together cross-functional expertise to meet timelines, minimize patient burden, and incorporate patient feedback throughout each trial.⁷

ICON

• ICON is a global provider of drug and device development and commercialization services. With 97 locations across 55 countries, ICON offers an expansive network to facilitate multi-regional trials.  To date, ICON has supported 779 rare disease studies, enrolling over 24,000 patients across more than 6,200 sites worldwide.  Icon utilizes an evidence-based methodology and a core set of study-branded tools to help sponsors identify sites and to support sites in finding potential patients. To meet the unique regulatory, scientific, and operational considerations of rare disease trials, ICON has also established a Gene Therapy Working Group to provide guidance on all phases of advanced therapy studies.^8,9

Syneos Health

• Syneos Health offers a unique end-to-end service model that aligns clinical and commercial objectives, providing a seamless pathway from trial to market. They have created the Syneos Health Rare Disease Consortium to integrate their medical, operational, and commercial expertise, ensuring a holistic approach to clinical development. In the past five years, they have conducted more than 350 projects in rare disease indications.¹⁰

Fortrea

• With their focus on technological innovation and patient-centric methodologies, Fortrea is an emerging leader in rare disease clinical research. Their top therapeutic areas for rare disease include hematology, neuroscience, metabolic disease, and cardiovascular. Over the past five years, Fortrea has been involved in 877 rare disease studies, including 233 studies in pediatric indications.¹¹

Caidya

• Having run nearly 200 rare disease studies in over 22,000 patients, Caidya has developed expertise in regulatory strategy, patient finding, and site education and training. They have broad medical expertise spanning a wide range of rare diseases, including what type of information to incorporate from registries to support clinical trial design.¹²

Ergomed

• Ergomed provides a range of services tailored to the needs of rare disease clinical trials, including locating hard-to-find patients worldwide. Their experience includes more than 300 rare disease studies in over 125 unique indications, with greater than 20,000 patients recruited across 55 countries. Ergomed is recognized as an expert in rare disease research, with 70% of their project managers and 80% of their clinical research associates having rare disease experience.¹³

Selecting the right rare disease CRO

Focus your search first on their experience in the therapeutic area of interest, as understanding the nuances of the condition can lead to more effective trial design and execution. Next, examine your needs regarding flexibility, customization, and adaptability since each rare disease study requires an approach that is tailored to the condition, the drug, and the patient population under investigation.

Lastly, understand their global reach, regulatory expertise, technological capabilities, operational capabilities, and cultural fit. You're looking for a partner that not only meets your immediate needs, but can also contribute to the long-term success of your drug development program.

Explore the reasons Precision is an ideal rare disease CRO partner for Sponsors worldwide.

References

1. The Lancet Global Health. The landscape for rare diseases in 2024. Lancet Glob Health. 2024;12(3):e341.
2. Future Market Insights Inc. Rare Disease Clinical Trials Market. Available at https://www.futuremarketinsights.com/reports/rare-disease-clinical-trials-market.
3. Medpace. Rare disease & orphan indication CRO. Available at https://www.medpace.com/therapeutics/crossovers/rare-disease/. 
4. Precision for Medicine. Rare disease CRO services, deep lab experience and a passion to help patients in need. Available at https://www.precisionformedicine.com/therapeutic-research-expertise/rare-cro.
5. IQVIA. Small-sized trials, big impact. Available at https://www.iqvia.com/solutions/therapeutics/rare-diseases.
6. PPD. Rare disease CRO services. Available at https://www.ppd.com/therapeutic-expertise/rare-disease/.
7. Parexel. Rare disease CRO services. Available at https://www.parexel.com/therapeutic-expertise/rare-diseases-cro.
8. ICON. Facts and figures. Available at https://www.iconplc.com/news-events/mediakit/facts-and-figures.
9. ICON. Rare & orphan diseases. Available at https://www.iconplc.com/therapeutics/rare-orphan-diseases.
10. Syneos Health. Rare disease consortium. Available at https://www.syneoshealth.com/therapeutic-depth/rare-disease-consortium.
11. Fortrea. Rare diseases. Available at https://www.fortrea.com/scientific-expertise/specialty-areas/rare-diseases.html.
12. Caidya. Rare diseases. Available at https://www.caidya.com/what-we-do/therapeutic-areas/rare-diseases/.
13. Ergomed. Pioneering rare disease clinical research solutions. Available at https://ergomedcro.com/therapeutic-expertise/rare-disease/.