X0306 4 2017-03-07 0 0001505512 Regulus Therapeutics Inc. RGLS 0001205903 RASTETTER WILLIAM H C/O REGULUS THERAPEUTICS INC. 10614 SCIENCE CENTER DRIVE SAN DIEGO CA 92121 1 0 0 0 Common Stock 2017-03-07 4 P 0 250000 1.15 A 350000 I WILLIAM H RASTETTER TTEE INVESTMENT TRUST 2002 TRUST BOARDS U/A DATED 11/11/2002 The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $1.15 to $1.20 inclusive. The reporting person undertakes to provide to RGLS, any security holder of RGLS, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote to this Form 4. Christopher Aker, Attorney in Fact 2017-03-07