San Diego-based Receptos, which made known its plans to go public weeks ago, has proposed a price range of $14 to $16 in the sale of 4.7 million shares, according to an SEC filing on Thursday. The company is conducting the midstage portion of a Phase II/III trial of its lead oral candidate, RPC1063, for treating multiple sclerosis. As Renaissance Capital reports, the midrange of the proposed IPO price would value venture-backed Receptos at $257 million. Yet keep in mind that most biotech IPOs last year priced below the proposed range. SEC filing | Renaissance item