** Regenxbio's RGNX.O shares down 17.3% premarket on Fri to $9.26 after $100 mln follow-on prices

** Rockville, Maryland-based biotech announces ~11.1 mln shares, including ~1.1 mln prefunded warrants, at $9

** Offering, which represents roughly 21% of shares outstanding, priced at 19.6% discount to last close

** Morgan Stanley, JP Morgan, Leerink and Mizuho joint bookrunners

** RGNX intends to use net offering proceeds for clinical trials, capex, working capital, development of product candidate pipeline, pay down debt, among other purposes, per the prospectus

** Last month, RGNX said U.S. FDA reversed rejection of co's rare-disease gene therapy, Navsunli, backs accelerated approval bid, and co said to receive $100 mln milestone payment from partner AbbVie ABBV.N for its eye disease drug

** Through Thurs, RGNX shares rallied 62% over the past month, leaving them down 22% YTD

** 12 of 13 brokerages rate the stock "strong buy" or "buy", 1 "hold"; median PT $22.50, per LSEG data