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

88 Positions as of 12/31/2013

Company ▲ Class Value of Shares ($1,000s) Change in Value ($1,000s) Change (%) Shares Held
ACADIA PHARMACEUTICALS COM 387,928 New 19,955,126
ACCELERON PHARMA INC COM 1,152 1,152 New 30,000
ACHILLION PHARMACEUTICALS INC COM 1,288 New 455,000
AEGERION PHARMACEUTICALS INC COM 21,715 -13,910 (39.05) 500,000
AERIE PHARMACEUTICALS INC COM 4,482 4,482 New 300,000
AGIOS PHARMACEUTICALS INC COM 8,368 234 2.88 205,750
AMBIT BIOSCIENCES CORP COM 5,191 (0) 747,954
AMICUS THERAPEUTICS INC COM 948 New 515,072
ANACOR PHARMACEUTICALS INC COM 38,775 25,181 185.24 2,500,000
ARIAD PHARMACEUTICALS INC COM -9,603 Sold Out 0
ARRAY BIOPHARMA INC COM 5,685 New 1,500,000
ARROWHEAD RESH CORP COM NEW 39,459 -639 (1.59) 3,090,000
AVANIR PHARMACEUTICALS INC CL A NEW 18,783 3,460 22.58 5,428,591
BIOCRYST PHARMACEUTICALS COM 55,878 New 6,699,979
BIODELIVERY SCIENCES INTL INC COM 6,277 New 846,005
BIOMARIN PHARMACEUTICAL INC COM 118,206 70,510 147.83 1,941,304
BIOTA PHARMACEUTIALS INC COM 6,182 6,182 New 1,130,113
BLUEBIRD BIO INC COM 2,278 59 2.64 114,461
CERUS CORP COM 38,049 New 8,455,306
CHELSEA THERAPEUTICS INTL LTD COM 27,409 New 5,794,753