Ironwood Pharmaceuticals, which develops innovative medicines targeting therapeutic needs, announced terms for its IPO on Wednesday. The Cambridge, MA-based company plans to raise $250 million by offering 16.7 million class A shares at a price range of $14-$16. At the mid-point of the proposed range, Ironwood will command a market value of $1.6 billion. Ironwood Pharmaceuticals, which was founded in 1998 and booked $32 million in revenue (collaborative arrangements and services) over the last 12 months, plans to list on the NASDAQ under the symbol IRWD. Though the early stage company currently has no commercial products, its candidates include one Phase 3 drug called linaclotide, which treats irritable bowel syndrome, one Phase 1 pain drug, and various preclinical programs. Ironwood's collaborators include Forest Laboratories, Almirall and Astellas Pharma. J.P. Morgan, Morgan Stanley, and Credit Suisse are the lead underwriters on the deal, which is expected to price during the week of Feb. 1.