BAKER BROS. ADVISORS LP Information

667 MADISON AVE, NEW YORK, New York, 10065, (212) 339-5600

Report Date: 12/31/2013

Position Statistics

Total Positions 88
New Positions 14
Increased Positions 31
Decreased Positions 21
Positions with Activity 52
Sold Out Positions 4
Total Mkt Value (in $ millions) 5,021

Institutional Holdings information is filed by major institutions on form 13-F with the Securities and Exchange Commission.

Sector Weighting

Basic Materials
Capital Goods
Conglomerates 1.33%
Consumer Cyclical
Consumer/Non-Cyclical
Energy
Financial
Healthcare 97.78%
Services
Technology
Transportation
Utilities

52 Activity Positions as of 12/31/2013

Company Class Value of Shares ($1,000s) ▼ Change in Value ($1,000s) Change (%) Shares Held
SEATTLE GENETICS INC COM 805,383 54,880 7.31 20,735,926
PHARMACYCLICS INC COM 782,550 -26,117 (3.23) 8,719,218
BIOMARIN PHARMACEUTICAL INC COM 118,206 70,510 147.83 1,941,304
QUESTCOR PHARMACEUTICALS INC COM 59,703 17,700 42.14 775,864
HALOZYME THERAPEUTICS INC COM 47,668 -5,455 (10.27) 6,297,026
MIRATI THERAPEUTICS INC COM 45,459 7,640 20.20 2,380,074
ARROWHEAD RESH CORP COM NEW 39,459 -639 (1.59) 3,090,000
GILEAD SCIENCES INC COM 38,928 -48,278 (55.36) 556,108
ANACOR PHARMACEUTICALS INC COM 38,775 25,181 185.24 2,500,000
CLOVIS ONCOLOGY INC COM 29,111 12,560 75.89 530,738
AEGERION PHARMACEUTICALS INC COM 21,715 -13,910 (39.05) 500,000
AVANIR PHARMACEUTICALS INC CL A NEW 18,783 3,460 22.58 5,428,591
DYAX CORP COM 13,639 13,639 New 2,026,537
TG THERAPEUTICS INC COM 11,592 8,430 266.61 2,199,656
KYTHERA BIOPHARMACEUTICALS INC COM 11,278 1,735 18.19 313,191
INSMED INC COM PAR $.01 10,679 -2,004 (15.8) 796,378
STEMLINE THERAPEUTICS INC COM 10,585 -1,966 (15.66) 675,042
PROTHENA CORP PLC SHS 10,293 -1,000 (8.86) 336,918
IDERA PHARMACEUTICALS INC COM NEW 8,786 -7,460 (45.92) 3,171,765
AGIOS PHARMACEUTICALS INC COM 8,368 234 2.88 205,750