Despite the focus on high drug prices, orphan drugs are expected to grow at double the rate of the rest of the pharmaceutical industry over the next six years.

Orphan drug sales are set to grow 11% each year between now and 2024, compared with 6.4% growth for the overall pharma market in the same period, according to a report from EvaluatePharma.
By 2024, orphan drugs are expected to account for a fifth of all prescription sales and generate $262 billion worldwide. Oncology drugs will make up half of orphan drug sales by 2024, followed by blood disorder treatments, at about 12% of the market.
Analysts don’t expect the recent pressure on curbing drug prices to put much of a dent on orphan drugs, despite the fact that they are some of the most expensive drugs on the market. The median cost of orphan drugs was about $147,000 per patient per year in 2017, compared to $30,708 for non-orphan drugs, according to the report. 
In 2017, the most expensive drug in the U.S. was Soliris, a rare disease treatment from Alexion, that cost more than $500,000 per patient annually, the report said. That top spot is expected to be taken in 2018 by either Biogen’s spinal muscular atrophy drug Spinraza, which costs $750,000, or BioMarin’s Brineura for Batten disease, with an annual cost of $702,000.
While Novartis currently leads in worldwide orphan drug sales, the report predicted that Celgene’s two multiple myeloma treatments, Revlimid and Pomalyst, will push Celgene to the worldwide leader in orphan drug sales by 2024.
Blockbuster oncology drugs such as Merck’s Keytruda and Bristol-Myers Squibb’s Opdivo will also sit at the top of the list in 2024. The report forecasted that both drugs will see a double digit annual growth in sales over the next six years.
In the U.S., rare diseases are defined as occurring in less than 200,000 patients. In 2017, the FDA set out to modernize its orphan drug designation process. The agency aimed to address the backlog of orphan drug designation requests and streamline the process for future requests, making it easier for drug manufacturers to address these rare disease.