The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F COVER PAGE
OMB APPROVAL
OMB Number: 3235-0006
Expires: July 31, 2015
Estimated average burden
hours per response: 23.8
Report for the Calendar Year or Quarter Ended: 06-30-2018
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: ORBIMED ADVISORS LLC
Address: 601 Lexington Avenue
54th Floor
New York , NY10022
Form 13F File Number: 028-06774

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 form.

Person Signing this Report on Behalf of Reporting Manager:
Name: Sven H. Borho
Title: Member
Phone: 212-739-6400
Signature, Place, and Date of Signing:
/s/ Sven H. Borho New York , NY 08-14-2018
[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).)
Form 13F Summary Page
Report Summary:
Number of Other Included Managers: 1
Form 13F Information Table Entry Total: 147
Form 13F Information Table Value Total: 8,384,406
(thousands)
List of Other Managers Reporting for this Manager:
[If there are no entries in this list, omit this section.]
Form 13F File Number Name
028-10410 ORBIMED CAPITAL LLC

List of Other Included Managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.
[If there are no entries in this list, state “NONE” and omit the column headings and list entries.]
No. Form 13F File Number Name
1 028-10410 ORBIMED CAPITAL LLC
SEC FORM 13F-HR

The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Expires: July 31, 2015
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
ABBOTT LABS COM 002824100 24,036 394,100 SH DFND 1 250,000 0 144,100
ACADIA PHARMACEUTICALS INC COM 004225108 65,392 4,282,400 SH DFND 1 764,300 0 3,518,100
ADAMAS PHARMACEUTICALS INC COM 00548A106 2,583 100,000 SH Call DFND 1 23,500 0 76,500
ADAPTIMMUNE THERAPEUTICS PLC SPONDS ADR 00653A107 7,912 666,593 SH SOLE 666,593 0 0
AEGERION PHARMACEUTICALS INC NOTE 2.000% 8/1 00767EAB8 9,718 15,000,000 PRN DFND 1 3,098,000 0 11,902,000
AEGLEA BIOTHERAPEUTICS INC COM 00773J103 19,737 1,865,524 SH SOLE 1,865,524 0 0
AERIE PHARMACEUTICALS INC COM 00771V108 127,271 1,884,100 SH DFND 1 303,200 0 1,580,900
AERPIO PHARMACEUTICALS INC COM 00810B105 21,555 5,193,946 SH SOLE 5,193,946 0 0
AFFIMED N V COM N01045108 539 326,650 SH SOLE 326,650 0 0
AGILENT TECHNOLOGIES INC COM 00846U101 116,575 1,885,100 SH DFND 1 322,400 0 1,562,700
AKORN INC COM 009728106 3,318 200,000 SH Call DFND 1 47,000 0 153,000
ALEXION PHARMACEUTICALS INC COM 015351109 387,919 3,124,603 SH DFND 1 584,700 0 2,539,903
ALEXION PHARMACEUTICALS INC COM 015351109 8,691 70,000 SH Call DFND 1 16,500 0 53,500
ALIMERA SCIENCES INC COM 016259103 245 250,000 SH DFND 1 25,000 0 225,000
ALKERMES PLC SHS G01767105 5,968 145,000 SH SOLE 0 0 145,000
ALLERGAN PLC SHS G0177J108 214,436 1,286,205 SH DFND 1 347,431 0 938,774
ALNYLAM PHARMACEUTICALS INC COM 02043Q107 124,685 1,265,966 SH DFND 1 237,300 0 1,028,666
ALPINE IMMUNE SCIENCES INC COM 02083G100 24,970 3,298,516 SH SOLE 3,298,516 0 0
AMEDISYS INC COM 023436108 14,622 171,100 SH SOLE 0 0 171,100
AMGEN INC COM 031162100 22,908 124,100 SH SOLE 0 0 124,100
AMICUS THERAPEUTICS INC COM 03152W109 110,472 7,072,500 SH DFND 1 1,320,215 0 5,752,285
ANTHEM INC COM 036752103 126,584 531,800 SH DFND 1 127,000 0 404,800
ARGENX SE SPONSORED ADR 04016X101 49,658 599,300 SH SOLE 0 0 599,300
ARRAY BIOPHARMA INC COM 04269X105 82,237 4,900,900 SH DFND 1 871,600 0 4,029,300
ARSANIS INC COM 042873109 6,784 1,868,966 SH SOLE 1,868,966 0 0
ASCENDIS PHARMA A S SPONSORED ADR 04351P101 293,572 4,413,291 SH DFND 1 3,763,291 0 650,000
ASSEMBLY BIOSCIENCES INC COM 045396108 28,277 721,166 SH SOLE 0 0 721,166
ATHENEX INC COM 04685N103 8,024 430,000 SH SOLE 0 0 430,000
AUDENTES THERAPEUTICS INC COM 05070R104 99,919 2,615,000 SH SOLE 2,615,000 0 0
AURINIA PHARMACEUTICALS INC COM 05156V102 943 167,419 SH SOLE 0 0 167,419
AVROBIO INC COM 05455M100 7,140 250,000 SH SOLE 0 0 250,000
BEIGENE LTD SPONSORED ADR 07725L102 40,185 261,400 SH DFND 1 55,200 0 206,200
BIOGEN INC COM 09062X103 338,971 1,167,900 SH DFND 1 209,800 0 958,100
BIOLINERX LTD SPONSORED ADR 09071M106 924 1,038,600 SH SOLE 1,038,600 0 0
BIOMARIN PHARMACEUTICAL INC COM 09061G101 6,594 70,000 SH Call DFND 1 16,500 0 53,500
BIOMARIN PHARMACEUTICAL INC COM 09061G101 7,206 76,500 SH SOLE 0 0 76,500
BIOMARIN PHARMACEUTICAL INC NOTE 0.750%10/1 09061GAE1 532 500,000 PRN SOLE 0 0 500,000
BIOMARIN PHARMACEUTICAL INC NOTE 1.500%10/1 09061GAF8 592 500,000 PRN SOLE 0 0 500,000
BLUEBIRD BIO INC COM 09609G100 76,623 488,200 SH DFND 1 88,400 0 399,800
BOSTON SCIENTIFIC CORP COM 101137107 313,093 9,574,695 SH DFND 1 1,864,500 0 7,710,195
BRISTOL MYERS SQUIBB CO COM 110122108 131,726 2,380,300 SH DFND 1 505,300 0 1,875,000
CELGENE CORP COM 151020104 204,161 2,570,650 SH DFND 1 446,800 0 2,123,850
CIGNA CORPORATION COM 125509109 36,505 214,800 SH DFND 1 82,200 0 132,600
CLEMENTIA PHARMACEUTICALS IN COM 185575107 137,196 10,425,225 SH SOLE 10,425,225 0 0
CLOVIS ONCOLOGY INC COM 189464100 105,985 2,330,870 SH DFND 1 514,800 0 1,816,070
CLOVIS ONCOLOGY INC COM 189464100 4,547 100,000 SH Call DFND 1 23,500 0 76,500
COHERUS BIOSCIENCES INC COM 19249H103 20,727 1,480,482 SH SOLE 0 0 1,480,482
CORVUS PHARMACEUTICALS INC COM 221015100 65,524 5,967,584 SH SOLE 5,967,584 0 0
CRISPR THERAPEUTICS AG NAMEN AKT H17182108 29,157 496,200 SH DFND 1 106,100 0 390,100
CTI BIOPHARMA CORP COM NEW 12648L601 24,900 5,000,000 SH SOLE 5,000,000 0 0
DAVITA INC COM 23918K108 117,312 1,689,400 SH DFND 1 375,000 0 1,314,400
DBV TECHNOLOGIES S A SPONSORED ADR 23306J101 7,922 410,700 SH SOLE 0 0 410,700
DECIPHERA PHARMACEUTICALS IN COM 24344T101 78,924 2,005,700 SH DFND 1 287,000 0 1,718,700
DENTSPLY SIRONA INC COM 24906P109 104,763 2,393,500 SH DFND 1 590,200 0 1,803,300
DERMIRA INC COM 24983L104 9,491 1,031,596 SH SOLE 0 0 1,031,596
EDWARDS LIFESCIENCES CORP COM 28176E108 126,777 870,900 SH DFND 1 170,500 0 700,400
EHEALTH INC COM 28238P109 40,547 1,834,700 SH SOLE 0 0 1,834,700
ELECTROCORE INC COM 28531P103 6,568 397,826 SH DFND 1 198,913 0 198,913
EXELIXIS INC COM 30161Q104 36,179 1,681,200 SH DFND 1 329,400 0 1,351,800
FLUIDIGM CORP DEL COM 34385P108 9,439 1,583,700 SH DFND 1 59,600 0 1,524,100
FLUIDIGM CORP DEL NOTE 2.750% 2/0 34385PAA6 8,093 10,000,000 PRN SOLE 0 0 10,000,000
FOAMIX PHARMACEUTICALS LTD SHS M46135105 20,240 4,040,000 SH SOLE 0 0 4,040,000
GALAPAGOS NV SPON ADR 36315X101 44,891 486,990 SH DFND 1 68,500 0 418,490
GILEAD SCIENCES INC COM 375558103 25,828 364,600 SH SOLE 0 0 364,600
GLOBAL BLOOD THERAPEUTICS IN COM 37890U108 20,217 447,275 SH DFND 1 60,300 0 386,975
GW PHARMACEUTICALS PLC ADS 36197T103 2,930 21,000 SH SOLE 0 0 21,000
HCA HEALTHCARE INC COM 40412C101 24,347 237,300 SH DFND 1 76,000 0 161,300
HERON THERAPEUTICS INC COM 427746102 51,092 1,315,100 SH SOLE 0 0 1,315,100
HUMANA INC COM 444859102 21,608 72,600 SH DFND 1 31,300 0 41,300
ILLUMINA INC COM 452327109 79,458 284,500 SH DFND 1 70,600 0 213,900
IMMUNOGEN INC COM 45253H101 28,259 2,904,270 SH DFND 1 424,000 0 2,480,270
IMMUNOMEDICS INC COM 452907108 117,038 4,944,573 SH DFND 1 1,184,203 0 3,760,370
INCYTE CORP COM 45337C102 29,346 438,000 SH DFND 1 93,400 0 344,600
INOTEK PHARMACEUTICALS CORP NOTE 5.750% 8/0 45780VAB8 7,214 7,000,000 PRN SOLE 0 0 7,000,000
INSMED INC COM PAR $.01 457669307 69,245 2,927,891 SH DFND 1 494,900 0 2,432,991
INSMED INC NOTE 1.750% 1/1 457669AA7 24,253 26,500,000 PRN DFND 1 7,456,000 0 19,044,000
INSPIRE MED SYS INC COM 457730109 87,161 2,444,221 SH SOLE 2,444,221 0 0
INSYS THERAPEUTICS INC NEW COM NEW 45824V209 25,424 3,511,544 SH DFND 1 708,500 0 2,803,044
INTELLIA THERAPEUTICS INC COM 45826J105 23,967 876,000 SH SOLE 876,000 0 0
INTUITIVE SURGICAL INC COM NEW 46120E602 52,872 110,500 SH DFND 1 48,000 0 62,500
INVITAE CORP COM 46185L103 11,159 1,518,197 SH SOLE 1,518,197 0 0
IOVANCE BIOTHERAPEUTICS INC COM 462260100 71,019 5,548,326 SH DFND 1 1,337,800 0 4,210,526
IRONWOOD PHARMACEUTICALS INC COM CL A 46333X108 56,007 2,929,250 SH DFND 1 667,500 0 2,261,750
IRONWOOD PHARMACEUTICALS INC COM CL A 46333X108 2,868 150,000 SH Call DFND 1 34,500 0 115,500
JAZZ PHARMACEUTICALS PLC SHS USD G50871105 179,209 1,040,100 SH DFND 1 234,300 0 805,800
JOHNSON & JOHNSON COM 478160104 91,733 756,000 SH DFND 1 551,000 0 205,000
K2M GROUP HLDGS INC COM 48273J107 18,972 843,205 SH DFND 1 195,700 0 647,505
KALA PHARMACEUTICALS INC COM 483119103 47,339 3,447,840 SH SOLE 3,447,840 0 0
LIFEPOINT HEALTH INC COM 53219L109 25,044 513,200 SH DFND 1 120,900 0 392,300
LOXO ONCOLOGY INC COM 548862101 93,332 538,000 SH SOLE 538,000 0 0
MAGELLAN HEALTH INC COM NEW 559079207 24,120 251,383 SH DFND 1 54,900 0 196,483
MARINUS PHARMACEUTICALS INC COM 56854Q101 4,013 567,600 SH SOLE 567,600 0 0
MEDIGUS LTD SPONSORD ADR NEW 58471G201 74 60,000 SH SOLE 60,000 0 0
MEDNAX INC COM 58502B106 37,333 862,600 SH DFND 1 295,300 0 567,300
MERCK & CO INC COM 58933Y105 284,076 4,680,000 SH DFND 1 1,157,800 0 3,522,200
MYLAN N V SHS EURO N59465109 133,819 3,702,800 SH DFND 1 739,400 0 2,963,400
NABRIVA THERAPEUTICS PLC SHS G63637105 13,640 3,919,600 SH SOLE 3,919,600 0 0
NATERA INC COM 632307104 18,520 984,086 SH SOLE 984,086 0 0
NEUROCRINE BIOSCIENCES INC COM 64125C109 13,537 137,800 SH SOLE 0 0 137,800
NEURONETICS INC COM 64131A105 3,992 150,000 SH DFND 1 51,400 0 98,600
NEVRO CORP COM 64157F103 100,618 1,260,091 SH DFND 1 267,900 0 992,191
NOVO-NORDISK A S ADR 670100205 15,220 330,000 SH SOLE 0 0 330,000
NOVUS THERAPEUTICS INC COM 67011N105 17,760 2,537,110 SH SOLE 2,537,110 0 0
OBSEVA SA COM H5861P103 39,448 2,605,531 SH SOLE 2,605,531 0 0
ORTHOPEDIATRICS CORP COM 68752L100 3,647 136,900 SH SOLE 0 0 136,900
PFIZER INC COM 717081103 35,627 982,000 SH SOLE 982,000 0 0
PIERIS PHARMACEUTICALS INC COM 720795103 15,920 3,140,000 SH SOLE 3,140,000 0 0
PROQR THRAPEUTICS N V SHS EURO N71542109 9,512 1,302,955 SH DFND 1 85,783 0 1,217,172
PUMA BIOTECHNOLOGY INC COM 74587V107 161,650 2,732,881 SH DFND 1 542,246 0 2,190,635
RADIUS HEALTH INC COM NEW 750469207 22,483 762,900 SH DFND 1 59,700 0 703,200
RECRO PHARMA INC COM 75629F109 539 107,357 SH SOLE 107,357 0 0
REDHILL BIOPHARMA LTD SPONSORED ADS 757468103 4,819 564,900 SH SOLE 564,900 0 0
REGENERON PHARMACEUTICALS COM 75886F107 128,509 372,500 SH DFND 1 73,200 0 299,300
RESTORBIO INC COM 76133L103 44,198 4,830,387 SH SOLE 4,830,387 0 0
RHYTHM PHARMACEUTICALS INC COM 76243J105 64,552 2,065,000 SH SOLE 2,065,000 0 0
ROCKET PHARMACEUTICALS INC COM 77313F106 15,213 775,000 SH SOLE 0 0 775,000
SAREPTA THERAPEUTICS INC COM 803607100 59,825 452,600 SH DFND 1 94,300 0 358,300
SCPHARMACEUTICALS INC COM 810648105 19,300 3,409,865 SH SOLE 3,409,865 0 0
SELECT MED HLDGS CORP COM 81619Q105 92,097 5,074,200 SH DFND 1 1,248,800 0 3,825,400
SELECTA BIOSCIENCES INC COM 816212104 24,417 1,842,797 SH SOLE 1,842,797 0 0
SHIRE PLC SPONSORED ADR 82481R106 60,195 356,608 SH DFND 1 102,600 0 254,008
SIERRA ONCOLOGY INC COM 82640U107 3,751 1,267,104 SH SOLE 1,267,104 0 0
SINOVAC BIOTECH LTD SHS P8696W104 21,183 2,839,500 SH SOLE 0 0 2,839,500
STEADYMED LTD SHS M84920103 19,108 4,246,196 SH SOLE 4,246,196 0 0
STRYKER CORP COM 863667101 24,215 143,400 SH DFND 1 62,400 0 81,000
SYNDAX PHARMACEUTICALS INC COM 87164F105 3,068 437,000 SH SOLE 437,000 0 0
SYNLOGIC INC COM 87166L100 19,955 2,029,996 SH SOLE 2,029,996 0 0
TANDEM DIABETES CARE INC COM NEW 875372203 37,192 1,689,000 SH DFND 1 286,000 0 1,403,000
TELEFLEX INC COM 879369106 51,067 190,400 SH DFND 1 35,700 0 154,700
TENET HEALTHCARE CORP COM NEW 88033G407 12,518 372,900 SH DFND 1 87,800 0 285,100
TESARO INC COM 881569107 2,992 67,281 SH DFND 1 17,934 0 49,347
THERMO FISHER SCIENTIFIC INC COM 883556102 120,866 583,500 SH DFND 1 102,500 0 481,000
TRICIDA INC COM 89610F101 325,589 10,889,280 SH SOLE 10,889,280 0 0
TRIPLE-S MGMT CORP CL B 896749108 11,359 290,800 SH SOLE 0 0 290,800
ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 5,197 67,605 SH DFND 1 11,700 0 55,905
UNITEDHEALTH GROUP INC COM 91324P102 30,250 123,300 SH DFND 1 53,100 0 70,200
UNIVERSAL HLTH SVCS INC CL B 913903100 51,630 463,300 SH DFND 1 103,900 0 359,400
VERONA PHARMA PLC SPONSORED ADS 925050106 17,080 1,250,396 SH SOLE 1,250,396 0 0
VERRICA PHARMACEUTICALS INC COM 92511W108 29,195 1,479,733 SH SOLE 1,479,733 0 0
VERTEX PHARMACEUTICALS INC COM 92532F100 304,670 1,792,600 SH DFND 1 276,700 0 1,515,900
VERTEX PHARMACEUTICALS INC COM 92532F100 29,743 175,000 SH Call DFND 1 41,500 0 133,500
VIEWRAY INC COM 92672L107 65,453 9,458,567 SH SOLE 9,458,567 0 0
WRIGHT MED GROUP N V ORD SHS 0.03 PAR N96617118 164,136 6,322,668 SH DFND 1 1,049,359 0 5,273,309
WRIGHT MED GROUP N V RIGHT 03/01/2019 N96617126 11,196 8,746,583 SH SOLE 0 0 8,746,583
XENON PHARMACEUTICALS INC COM 98420N105 5,840 634,812 SH SOLE 634,812 0 0
XTANT MED HLDGS INC COM NEW 98420P308 51,099 9,207,012 SH SOLE 9,207,012 0 0
ZAI LAB LTD ADR 98887Q104 37,456 1,611,000 SH SOLE 1,611,000 0 0