Orphan drugs are set to generate more than $400bn in annual sales by 2032, representing more than 21% of the entire global prescription pharmaceutical market, according to the 2026 Orphan Drug Report published by Evaluate.
The report underscores the enduring commercial strength of rare disease therapies, even as the wider industry contends with pricing pressures, patent cliffs and a growing appetite for high-volume treatments such as GLP-1 obesity drugs.
In 2022, orphan drugs accounted for 15% of prescription sales; by 2032, that share is projected to rise sharply, with rare disease revenues approaching the total size of the entire prescription market just two decades ago.
Policy developments on both sides of the Atlantic are playing a supporting role.
In the US, the current administration's One Big Beautiful Bill Act has extended Inflation Reduction Act exemptions from price negotiation to multi-indication orphan drugs—an expansion on previous rules that only protected single-indication products.
The Rare Pediatric Disease Priority Review Voucher programme was also reauthorised in early 2026, offering accelerated FDA review times for products targeting rare childhood conditions.
Despite these tailwinds, the report notes that orphan drugs' share of overall prescription sales is expected to slip during the coming seven years, as Big Pharma increasingly redirects R&D investment towards large-population indications to address a $300bn loss-of-exclusivity gap.
At the product level, Johnson & Johnson's multiple myeloma therapy Darzalex is forecast to become the world's top-selling orphan drug by 2032, with J&J projected to lead all sponsors with nearly $31bn in orphan drug revenues.
The top eight orphan drugs are each expected to exceed $6bn in annual sales, while the collective 2032 sales of today's orphan pipeline candidates are forecast to surpass $100bn.
"We continue to see drugs for rare diseases cement their place as major players in the overall drug market," said Andreas Hadjivasiliou, Manager, Content Strategy at Evaluate.
Their capacity to navigate a changing industry, policy and regulatory changes while maintaining momentum is something to be noted by developers in this space and in the mainstream drug markets as well.
The full report is available via the Evaluate website and includes detailed forecasts for leading companies, pipeline assets and therapy area trends shaping the rare disease landscape through 2032.