In 2015, the U.S. Food and Drug Administration (FDA) approved 21 new drugs to treat rare diseases, which was almost half (47%) of all novel drugs approved in 2014. [i] It was also the second consecutive year the FDA approved more rare disease drugs than any previous year in history, highlighting an important trend: After decades of neglecting rare diseases research, biopharma companies are increasingly identifying this category as an attractive development pathway.