Rare disease drug companies, what they make and what the FDA decides next

Which pharmaceutical companies focus on rare diseases?

Trial Friend profiles 125 companies that sponsor trials or sell medicines in the rare diseases we track, in 2 groups.

Rare disease specialists (72): companies built around orphan conditions, such as Alnylam Pharmaceuticals, BioMarin Pharmaceutical, Ultragenyx Pharmaceutical, Sarepta Therapeutics, argenx, Ascendis Pharma, PTC Therapeutics and Travere Therapeutics.

Diversified drugmakers (53): large companies with rare disease divisions, including Novartis, Roche and Genentech, Sanofi and Genzyme, Takeda, Pfizer and AstraZeneca, whose Alexion unit is one of the biggest rare disease businesses in the world.

On each profile: the company's live trials from ClinicalTrials.gov and its FDA-approved drugs.

Which companies have the most rare disease clinical trials?

Counted by how many of our tracked rare diseases a company has trials in, the big diversified companies have the widest footprints.

Top 8 by disease count: Roche / Genentech (72), Pfizer (69), Novartis (59), AstraZeneca (50), Eli Lilly and Company (43), Alexion Pharmaceuticals (35), AbbVie (28) and Sanofi / Genzyme (27).

Specialists: run deeper rather than wider pipelines, often 3 to 10 conditions each, so a specialist can still be the most important company for a single disease.

Note: the disease count on each profile updates as trials open and close.

Which companies are developing gene therapies and genetic medicines for rare diseases?

65 of the 460 drugs in our Drug Decoder are gene therapies, gene editing treatments or RNA medicines, from 23 companies with profiles here.

With genetic medicines in the Drug Decoder: Ionis Pharmaceuticals, Biogen, Alnylam Pharmaceuticals, AstraZeneca PLC, Orchard Therapeutics, Roche Holding AG / Genentech, bluebird bio and Krystal Biotech.

Gene editing specialists: CRISPR Therapeutics, Intellia Therapeutics, Beam Therapeutics and Editas Medicine.

AAV gene therapy companies: Regenxbio, Taysha Gene Therapies, Solid Biosciences, Tenaya Therapeutics and Lexeo Therapeutics.

RNA medicine companies: Dyne Therapeutics, Avidity Biosciences, now part of Novartis, and Stoke Therapeutics.

Cost: our gene therapy pricing guide explains why these treatments cost what they do.

Which rare diseases have the most companies working on them?

A handful of conditions draw 20 or more companies each, while others have few or none.

Most crowded: Acute myeloid leukemia (29 companies), Multiple myeloma (26 companies), Myelodysplastic syndromes (24 companies), Sickle cell disease (22 companies), Multiple sclerosis (21 companies), Myasthenia gravis (21 companies), Immune thrombocytopenia (18 companies) and Cystic fibrosis (17 companies).

Why they attract companies: a known biological target, a patient population large enough to enroll trials quickly, and a precedent that the FDA will approve on a measurable endpoint.

Least served: our 2026 trial census found 6 tracked diseases with no recruiting trial anywhere.

Which companies have won FDA approvals for rare disease drugs in 2026?

Our FDA calendar has recorded 23 rare disease approvals and label expansions so far in 2026.

Most approvals: Genentech (Roche), Ultragenyx and Takeda with 2 each.

Large companies on the list: Genentech (Roche), Takeda, Bristol Myers Squibb and Johnson & Johnson (Janssen).

First-time launchers: INOVIO, Egetis Therapeutics, Elevar Therapeutics, Scholar Rock, Priovant Therapeutics and Vera Therapeutics, each with its first FDA-approved drug.

Source: each decision on the FDA calendar links to the FDA or company announcement behind it.

Which companies have rare disease FDA decisions coming up?

58 applications on our FDA calendar are waiting on the FDA, most of them for rare diseases.

Most pending: Genentech (Roche) (4), BridgeBio Pharma (3), Cogent Biosciences (3), Novartis (2) and BioMarin (2).

Dates: the FDA calendar lists every target date with the trial behind each application.

Alerts: sign up on any disease page to be emailed on decision day.

What is the difference between a rare disease specialist and a diversified pharmaceutical company, and why does it matter to patients?

The difference is how much of the company rides on rare disease, and it changes what patients can expect from each.

Specialist: earns most or all of its revenue from orphan conditions with a small number of programs, so a single trial readout or FDA decision can decide the company's future.

Diversified: runs rare disease programs alongside large franchises in cancer, diabetes or immunology, so one result rarely decides the company's direction.

In the directory: each company's row says which kind it is, and its profile lists any help-paying programs for its approved drugs.

Where are rare disease companies based?

92 of the 125 companies in the directory are headquartered in the United States.

US clusters: Boston and Cambridge, the San Francisco Bay Area, San Diego, and the Philadelphia and New Jersey corridor.

Outside the US: Switzerland (5), Japan (4), United Kingdom (3), Italy (3) and Sweden (3), plus a handful of other countries.

For patients: trial sites matter more than headquarters. Most of these companies run trials across North America and Europe, and our disease pages map every recruiting site.

Which rare disease drug companies offer patient assistance programs?

67 companies in this directory run a patient support program, such as copay help, free medicine or insurance help, that Trial Friend has checked on the company's own website, covering 227 FDA-approved rare disease medicines.

Most medicines covered: Bristol Myers Squibb (14), Sanofi / Genzyme (14), Novartis (12), Roche / Genentech (9), Takeda Pharmaceutical Company (9) and Janssen / Johnson & Johnson (8).

Copay cards are for private insurance; people on Medicare or Medicaid usually look to a free medicine program or a charity fund instead.

Each company profile lists its programs with phone numbers, and the help paying page sorts every program by insurance type.

How do I find which company is running a clinical trial for my disease?

Start from your disease page, where every recruiting trial names its sponsor.

Disease page: each trial card names the sponsor, and sponsors with a profile here are linked.

Company profile: shows every rare disease trial that company has open, pulled live from ClinicalTrials.gov, plus its approved drugs from the FDA's label database.

Good to know: academic hospitals sponsor more rare disease trials than companies do, so a trial run by a university is normal and not a lesser option.

What happened to Millennium, Ariad, Ganymed, Kolltan, Constellation, Progenics, Ra Pharmaceuticals and Sigma-Tau?

They were acquired or renamed, which is the usual fate of a successful rare disease biotech.

Millennium Pharmaceuticals: part of Takeda since 2008.

Ariad Pharmaceuticals: acquired by Takeda in 2017.

Ganymed Pharmaceuticals: bought by Astellas in 2016.

Kolltan Pharmaceuticals: bought by Celldex in 2016.

Constellation Pharmaceuticals: acquired by MorphoSys in 2021; MorphoSys itself was acquired by Novartis in 2024.

Progenics Pharmaceuticals: joined Lantheus in 2020.

Ra Pharmaceuticals: developer of the myasthenia gravis drug now sold as Zilbrysq, acquired by UCB in 2020.

Sigma-Tau Pharmaceuticals: its US business was renamed Leadiant Biosciences in 2017.

For patients: the programs usually continue under the new owner, so a trial you joined does not disappear when the company name does.

Why do investors and large pharmaceutical companies pursue rare diseases?

Because US law rewards it and the trials are smaller.

Orphan Drug Act: a drug the FDA designates as an orphan drug, for a disease affecting fewer than 200,000 people in the United States, can get 7 years of market exclusivity for that use after approval, a tax credit on clinical testing costs and a waiver of the FDA application fee for the designated use.

Smaller trials: a rare disease drug can succeed on a single well-designed study, and approvals can rest on biomarkers under the accelerated pathway.

Pricing: companies say prices are high because each patient population is small.

The trade-off: a specialist's value can rest on 1 or 2 readouts, which is why these companies are frequently acquired once their lead drug is approved.

Pediatric incentive: our priority review voucher guide covers one more incentive aimed at pediatric rare diseases.

How does Trial Friend choose which companies to list?

A company gets a profile when it sponsors trials or markets approved drugs in the rare diseases we cover, so the directory grows as we add diseases.

Mix: 93 of the 125 are publicly traded and 32 are private or subsidiaries.

Independence: under our editorial standards, sponsors cannot pay to have a drug listed or described more favorably, and we do not recruit patients on anyone's behalf.

Data: the trial and approval data on each profile come straight from ClinicalTrials.gov and openFDA and refresh automatically.