Rare Disease Clinical Trials: How to Find Them

For the roughly 30 million Americans living with a rare disease, clinical trials are often the most promising path to treatment. The gene therapy revolution has opened unprecedented possibilities. In the past three years alone, the FDA has approved gene therapies for sickle cell disease, hemophilia, and spinal muscular atrophy — and dozens more are in the pipeline.

Important: This is not medical advice. Talk to your doctor about whether a clinical trial is right for you.

The Gene Therapy Era

Gene therapy has gone from theoretical to transformative for rare diseases. These one-time treatments aim to correct the underlying genetic cause of disease rather than managing symptoms:

• Sickle cell disease: CRISPR-based gene editing (Casgevy) and gene addition therapy (Lyfgenia) were approved in 2023, marking the first CRISPR therapies. Newer trials are testing improved delivery methods and in-vivo gene editing that avoids stem cell transplant.
• Hemophilia: Hemgenix (hemophilia B) was approved in 2022. Trials for hemophilia A gene therapy continue, with several candidates showing durable factor production lasting years.
• Duchenne muscular dystrophy: Gene therapies delivering micro-dystrophin are in late-stage trials. Exon-skipping therapies that restore partial dystrophin function are also expanding.
• Cystic fibrosis: While CFTR modulators (Trikafta) help most CF patients, gene therapy and mRNA-based treatments are being developed for the 10% with mutations not responsive to modulators.

Orphan Drug Incentives Drive Trial Activity

The Orphan Drug Act provides tax credits, market exclusivity, and FDA assistance to companies developing rare disease treatments. This has led to a significant increase in rare disease trials:

• Over 600 orphan drugs approved since the Act passed in 1983
• Roughly half of all new FDA drug approvals in recent years have been for rare diseases
• Small biotech companies often focus exclusively on rare diseases, running lean trials with high per-patient investment

Recruiting Rare Disease Trials

How to Search Effectively

Finding rare disease trials requires a different approach than searching for common conditions:

• Use multiple search terms: Rare diseases often have multiple names. Search by both the common name and the medical term (e.g., "PKU" and "phenylketonuria").
• Contact patient organizations: Groups like NORD (National Organization for Rare Disorders) maintain trial listings and can connect you with researchers.
• Ask your specialist: Physicians at academic medical centers who specialize in your condition often know about upcoming trials before they are publicly listed.
• Consider natural history studies: Even if no treatment trial exists, natural history studies (which track disease progression) help build the foundation for future therapies and often give participants access to expert care.

Frequently Asked Questions