X0306 4 2014-02-18 0 0001125345 MACROGENICS INC MGNX 0001207833 ORONSKY ARNOLD L C/O MACROGENICS, INC. 9640 MEDICAL CENTER DRIVE ROCKVILLE MD 20850 1 0 0 0 Common Stock 2014-02-18 4 S 0 200000 36.50 D 1708716 I See Footnote These securities were sold as follows: 192,940 by InterWest Partners VIII, LP ("IW8"), 1,540 by InterWest Investors VIII, LP ("II8") and 5,520 by InterWest Investors Q VIII, LP ("IIQ8"). InterWest Management Partners VIII, LLC ("IMP8") is the General Partner of IW8, II8 and IIQ8 and has sole voting and investment control over the shares owned by IW8, II8 and IIQ8. Arnold Oronsky is a Managing Directors of IMP8. The shares are held as follows: 1,648,219 by IW8; 13,262 by II8; and 47,235 by IIQ8. Arnold Oronsky disclaims beneficial ownership of these securities except to the extent of any pecuniary interest therein. /s/ Lynn Cilinski, attorney-in-fact 2014-02-18