ADARx Pharmaceuticals surges in Nasdaq debut after upsized $446.3 million IPO
** Late-stage drug developer ADARx Pharmaceuticals' ADRX.O shares surge as much as 36.5% in Nasdaq debut after upsized $446.3 million US IPO
** Stock opened at $22.10 apiece vs $17 IPO price
** San Diego-based ADRX, which is developing RNA-based drugs for rare diseases, sold about 26.3 million shares in upsized IPO after initially marketing roughly 21.9 million shares priced between $15 and $17 apiece
** Separately, drugmaker AbbVie ABBV.N had indicated interest in buying $100 million worth of shares in concurrent private placement
** J.P. Morgan, Morgan Stanley, TD Cowen and UBS Investment Bank were lead book-running managers for offering
** ADRX rival City Therapeutics also filed for US IPO on Thursday, reinforcing biotech pipeline for fall window
** "If ADARx does well, I expect City would have no problem finding buyers," said Matt Kennedy, senior strategist at Renaissance Capital, a provider of IPO-focused research and ETFs