Centrexion Therapeutics Corp., of Boston, which filed to sell up to 5 million shares in the price range of $14 to $16 in an IPO has postponed the offering. It is developing a pipeline of non-opioid therapies, with the most advanced, CNTX-4975, in pivotal phase III development for the treatment of patients with moderate to severe pain due to knee osteoarthritis. The company had planned to list on Nasdaq under the symbol CNTX.