UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form 13F
Form 13F COVER PAGE
Report for the Calendar Year or Quarter Ended: 3/31/2013
Check here if Amendment []; Amendment Number:
-------
This Amendment (Check only one.): [] is a restatement.
[] adds new holdings entries.
Institutional Investment Manager Filing this Report:
Name: Palo Alto Investors, LLC
Address: 470 University Avenue
Palo Alto, CA 94301
Form 13F File Number: 28-10266
The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this submission.
Persons Signing this Report on Behalf of Reporting Manager:
Name: Scot Smith
Title: Chief Operating Officer
Phone: (650) 325-0772
Signature, Place, and Date of Signing:
/s/ Scot Smith Palo Alto, CA 5/8/2013
--------------------------------- --------------------------------- ----------
[Signature] [City, State] [Date]
Report Type (Check only one):
[X] 13F HOLDINGS REPORT. (Check here if all holdings of this reporting
manager are reported in this report.)
[ ] 13F NOTICE. (Check here if no holdings reported are in this report,
and all holdings are reported by other reporting manager(s).)
[ ] 13F COMBINATION REPORT. (Check here if a portion of the holdings for
this reporting manager are reported in this report and a portion are
reported by other reporting manager(s).)
List of Other Managers Reporting for this Manager:
Form 13F SUMMARY PAGE
Report Summary:
Number of Other Included Managers: 0
Form 13F Information Table Entry Total: 33
Form 13F Information Table Value Total: $ 844,098
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(In Thousands)
List of Other Included Managers:
Provide a numbered list of the name(s) and 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.
NONE
FORM 13F INFORMATION TABLE
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
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VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGERS SOLE SHARED NONE
------------------------------ -------------- --------- -------- ---------- --- ---- ---------- -------- ---------- ------ ----
AMAG Pharmaceuticals, Inc. COM 00163U106 40,109 1,681,710 1,681,710 0 0
AVEO Pharmaceuticals, Inc. COM 053588109 6,447 877,153 877,153 0 0
Abiomed Inc. COM 003654100 43,923 2,352,598 2,352,598 0 0
Aegerion Pharmaceuticals Inc. COM 00767E102 4,245 105,240 105,240 0 0
Alimera Sciences, Inc. COM 016259103 11,159 3,634,984 3,634,984 0 0
Amicus Therapeutics, Inc. COM 03152W109 15,155 4,780,670 4,780,670 0 0
Anacor Pharmaceuticals, Inc. COM 032420101 3,669 567,926 567,926 0 0
ArthroCare Corp. COM 043136100 9,559 274,994 274,994 0 0
Auxilium Pharmaceuticals, Inc. COM 05334D107 41,537 2,402,394 2,402,394 0 0
Biomarin Pharmaceuticals, Inc COM 09061G101 48,857 784,719 784,719 0 0
Conceptus Inc COM 206016107 10,851 449,300 449,300 0 0
Cubist Pharmaceuticals, Inc. COM 229678107 39,068 834,421 834,421 0 0
Cyberonics, Inc. COM 23251P102 90,390 1,931,418 1,931,418 0 0
Cytokinetics Inc. COM 23282W100 1,789 1,569,271 1,569,271 0 0
Dendreon Corp COM 24823Q107 1,957 413,400 413,400 0 0
Hyperion Therapeutics COM 44915N101 2,159 83,600 83,600 0 0
Insmed, Inc. COM 457669307 1,995 266,299 266,299 0 0
Intermune Inc. COM 45884X103 16,068 1,775,485 1,775,485 0 0
Momenta Pharmaceuticals, Inc. COM 60877T100 16,216 1,215,576 1,215,576 0 0
NxStage Medical, Inc. COM 67072V103 498 44,129 44,129 0 0
Onyx Pharmaceuticals, Inc. COM 683399109 131,150 1,475,915 1,475,915 0 0
QLT Inc. COM 746927102 17,466 1,975,820 1,975,820 0 0
Questcor Pharmaceuticals, Inc. COM 74835Y101 40,127 1,233,145 1,233,145 0 0
Rigel Pharmaceuticals Inc. COM 766559603 19,770 2,907,371 2,907,371 0 0
STAAR Surgical Company COM 852312305 19,386 3,443,330 3,443,330 0 0
Savient Pharmaceuticals, Inc. COM 80517Q100 8,980 11,224,495 11,224,495 0 0
Sequenom Inc. COM 817337405 35,486 8,550,730 8,550,730 0 0
Spectrum Pharmaceuticals Inc. COM 84763A108 2,954 395,985 395,985 0 0
United Therapeutics Corp COM 91307C102 54,581 896,678 896,678 0 0
Vanda Pharmaceutical Inc. COM 921659108 6,852 1,747,867 1,747,867 0 0
ViroPharma Incorporated COM 928241108 99,395 3,950,518 3,950,518 0 0
Xoma Ltd. COM 98419J107 629 180,235 180,235 0 0
pSivida Corporation COM 74440J101 1,671 729,548 729,548 0 0