The Ashburn, Va.-based specialty pharmaceutical company, which develops therapeutic products for rare and orphan diseases, said the offering would put up for sale 24.8 million ordinary shares represented by 5 million American Depositary Shares at a purchase price of $1.00 per ADS, as well as pre-funded warrants to purchase 10.3 million ordinary shares represented by 2.1 million ADSs at a pre-funded warrant price of $0.9999 per ADS.