Achillion Pharmaceuticals, which is developing treatments for infectious diseases, including HIV and Hepatitis C, announced the terms for its IPO on Friday. The Connecticut-based company plans to offer 4.5 million shares at a range of $14-$16, giving the deal a proposed market cap of $236 million. Cowen & Company, CIBC World Markets and JMP Securities are set to manage the deal. Timing has yet to be announced.