Baker Bros. Advisors 13F-HR Quarterly holdings report by institutional manager

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:	Oct 31, 2018
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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
Acadia Pharmaceuticals Inc.	COM	004225108	650,286	20,481,442	SH		SOLE		20,481,442	0	0
Acceleron Pharma Inc.	COM	00434H108	1,121	28,765	SH		SOLE		28,765	0	0
Achaogen Inc.	COM	004449104	1,305	100,000	SH		SOLE		100,000	0	0
Achillion	COM	00448Q201	5,370	438,337	SH		SOLE		438,337	0	0
Acorda Therapeutics, Inc.	COM	00484M106	30,879	755,534	SH		SOLE		755,534	0	0
Aerie Pharmaceuticals	COM	00771V108	8,738	299,356	SH		SOLE		299,356	0	0
Affimed Therapeutics B.V.	COM	N01045108	2,480	400,000	SH		SOLE		400,000	0	0
Agios Pharmaceuticals	COM	00847X104	18,307	163,393	SH		SOLE		163,393	0	0
Alcobra Ltd.	SHS	M2239P109	1,081	289,871	SH		SOLE		289,871	0	0
Alder Biopharmaceutical Inc.	COM	014339105	4,461	153,350	SH		SOLE		153,350	0	0
Alnylam Pharmaceuticals, Inc.	COM	02043Q107	1,125	11,600	SH		SOLE		11,600	0	0
Amicus Therapeutics	COM	03152W109	4,008	481,697	SH		SOLE		481,697	0	0
Anacor Pharmaceuticals	COM	032420101	135,602	4,204,702	SH		SOLE		4,204,702	0	0
Aptose Biosciences, Inc.	COM	03835T200	2,833	479,164	SH		SOLE		479,164	0	0
Aquinox Pharmaceuticals, Inc.	COM	03842B101	9,078	1,210,350	SH		SOLE		1,210,350	0	0
Array Biopharma Inc.	COM	04269X105	6,782	1,433,797	SH		SOLE		1,433,797	0	0
Arrowhead Research Corp.	COM	042797209	9,083	1,230,802	SH		SOLE		1,230,802	0	0
Asterias Biotherapeutics, Inc.	COM SER A	04624N107	54	16,775	SH		SOLE		16,775	0	0
Aurinia Pharmaceuticals, Inc.	COM	05156V102	2,599	727,669	SH		SOLE		727,669	0	0
Avanir Pharmaceuticals	COM	05348P401	652,807	38,513,713	SH		SOLE		38,513,713	0	0
Bellicum Pharmaceuticals, Inc.	COM	079481107	98,697	4,283,732	SH		SOLE		4,283,732	0	0
Biocryst Pharmaceuticals Inc.	COM	09058V103	130,278	10,713,686	SH		SOLE		10,713,686	0	0
BioDelivery Sciences Intl. Inc.	COM	09060J106	2,524	210,021	SH		SOLE		210,021	0	0
Biomarin Pharmaceuticals	COM	09061G101	335,741	3,713,950	SH		SOLE		3,713,950	0	0
Biota Pharmaceuticals	COM	090694100	2,479	1,106,910	SH		SOLE		1,106,910	0	0
Biotime Inc. Rights	COM	09066L162	22	20,525	SH		SOLE		20,525	0	0
Bluebird Bio Inc.	COM	09609G100	13,758	150,000	SH		SOLE		150,000	0	0
Catalyst Pharmaceuticals, Inc.	COM	14888U101	19,945	6,715,462	SH		SOLE		6,715,462	0	0
Celsus Therapeutics	SPONSORED ADR NE	15119A202	3,235	673,887	SH		SOLE		673,887	0	0
Cerus	COM	157085101	73,025	11,702,727	SH		SOLE		11,702,727	0	0
Chemocentryx Inc.	COM	16383L106	342	50,000	SH		SOLE		50,000	0	0
Chimerix	COM	16934W106	6,941	172,414	SH		SOLE		172,414	0	0
Clovis Oncology	COM	189464100	11,347	202,630	SH		SOLE		202,630	0	0
Concert Pharmaceuticals, Inc.	COM	206022105	6,732	505,418	SH		SOLE		505,418	0	0
Cyclacel Pharmaceuticals Pfd. Conv. Ex 6%	PFD CONV EX 6%	23254L207	82	13,253	SH		SOLE		13,253	0	0
Cytrx Corp.	COM	232828509	3,699	1,350,000	SH		SOLE		1,350,000	0	0
DBV Technologies Inc.	SPONSORED ADR	23306J101	41,201	1,519,229	SH		SOLE		1,519,229	0	0
Derma Sciences	COM	249827502	32,931	3,537,137	SH		SOLE		3,537,137	0	0
Dermira	COM	24983L104	1,811	100,000	SH		SOLE		100,000	0	0
Discovery Laboratories Inc.	COM	254668403	4,236	3,652,117	SH		SOLE		3,652,117	0	0
Dyax Corp.	COM	26746E103	86,579	6,157,789	SH		SOLE		6,157,789	0	0
Enanta Pharmaceuticals	COM	29251M106	3,832	75,357	SH		SOLE		75,357	0	0
Epizyme Inc.	COM	29428V104	3,811	201,963	SH		SOLE		201,963	0	0
Five Prime Therapeutics Inc.	COM	33830X104	535	19,823	SH		SOLE		19,823	0	0
Foamix Pharmaceuticals Ltd.	SHS	M46135105	7,161	1,021,600	SH		SOLE		1,021,600	0	0
Foundation Medicine Inc.	COM	350465100	2,803	126,147	SH		SOLE		126,147	0	0
Genomic Health Inc.	COM	37244C101	436,592	13,656,318	SH		SOLE		13,656,318	0	0
Geron Corp.	COM	374163103	1,309	402,629	SH		SOLE		402,629	0	0
Gilead Sciences Inc.	COM	375558103	24,141	256,108	SH		SOLE		256,108	0	0
Halozyme Therapeutics Inc.	COM	40637H109	26,790	2,776,143	SH		SOLE		2,776,143	0	0
Heron Therapeutics, Inc.	COM	427746102	26,234	2,607,784	SH		SOLE		2,607,784	0	0
Idera Pharmaceuticals Inc.	COM	45168K306	7,181	1,628,172	SH		SOLE		1,628,172	0	0
Ignyta	COM	451731103	3,911	571,000	SH		SOLE		571,000	0	0
Incyte Corp.	COM	45337C102	1,085,359	14,845,559	SH		SOLE		14,845,559	0	0
Infinity Pharmaceuticals Inc.	COM	45665G303	5,270	312,025	SH		SOLE		312,025	0	0
Insmed Inc.	COM	457669307	17,138	1,107,850	SH		SOLE		1,107,850	0	0
Ironwood Pharmaceuticals	COM	46333X108	5,303	346,160	SH		SOLE		346,160	0	0
Isis Pharmaceuticals, Inc.	COM	464330109	5,946	96,303	SH		SOLE		96,303	0	0
Juno Therapeutics Inc.	COM	48205A109	5,222	100,000	SH		SOLE		100,000	0	0
Karyopharm Therapeutics	COM	48576U106	3,522	94,095	SH		SOLE		94,095	0	0
Kythera Biopharmaceuticals	COM	501570105	9,927	286,255	SH		SOLE		286,255	0	0
La Jolla Pharmaceuticals, Inc.	COM	503459604	7,779	421,631	SH		SOLE		421,631	0	0
Ligand Pharmaceuticals	COM	53220K504	3,906	73,400	SH		SOLE		73,400	0	0
Lipocine Inc.	COM	53630X104	2,630	500,000	SH		SOLE		500,000	0	0
Loxo Oncology Inc.	COM	548862101	1,175	100,000	SH		SOLE		100,000	0	0
Macrogenics, Inc.	COM	556099109	10,938	311,891	SH		SOLE		311,891	0	0
Marinus Pharmaceuticals Inc.	COM	56854Q101	2,161	204,476	SH		SOLE		204,476	0	0
Mast Therapeutics, Inc.	COM	576314108	2,674	4,774,434	SH		SOLE		4,774,434	0	0
Mediwound Ltd.	ORD SHS	M68830104	1,499	225,000	SH		SOLE		225,000	0	0
Mirati Therapeutics Inc.	COM	60468T105	44,079	2,380,074	SH		SOLE		2,380,074	0	0
Neurocrine Biosciences, Inc.	COM	64125C109	12,390	554,590	SH		SOLE		554,590	0	0
Neuroderm Ltd.	ORD SHS	M74231107	3,510	250,000	SH		SOLE		250,000	0	0
Novavax Inc.	COM	670002104	7,255	1,223,362	SH		SOLE		1,223,362	0	0
Omeros Corp.	COM	682143102	16,060	648,101	SH		SOLE		648,101	0	0
Ophthotech Corp.	COM	683745103	1,650	36,776	SH		SOLE		36,776	0	0
Orasure Technologies Inc.	COM	68554V108	2,379	234,664	SH		SOLE		234,664	0	0
Osiris Therapeutics Inc.	COM	68827R108	8,165	510,606	SH		SOLE		510,606	0	0
Palatin Technologies Inc.	COM	696077403	1,497	2,050,000	SH		SOLE		2,050,000	0	0
Pharmacyclics Inc.	COM	716933106	1,116,140	9,129,231	SH		SOLE		9,129,231	0	0
Progenics Pharmaceuticals, Inc.	COM	743187106	33,640	4,449,797	SH		SOLE		4,449,797	0	0
ProQR Therapeutics NV	SHS	N71542109	8,668	400,000	SH		SOLE		400,000	0	0
Proteon Therapeutics, Inc.	COM	74371L109	1,798	172,917	SH		SOLE		172,917	0	0
QLT Inc.	COM	746927102	6,159	1,535,863	SH		SOLE		1,535,863	0	0
Receptos Inc.	COM	756207106	2,928	23,900	SH		SOLE		23,900	0	0
Repros Therapeutics	COM	76028H209	19,940	2,000,000	SH		SOLE		2,000,000	0	0
Rigel Pharmaceuticals	COM	766559603	1,094	481,972	SH		SOLE		481,972	0	0
Sage Therapeutics Inc.	COM	78667J108	2,745	75,000	SH		SOLE		75,000	0	0
Salix Pharmaceuticals	COM	795435106	73,024	635,321	SH		SOLE		635,321	0	0
Sangamo Biosciences, Inc.	COM	800677106	14,531	955,332	SH		SOLE		955,332	0	0
Seattle Genetics, Inc.	COM	812578102	895,197	27,861,720	SH		SOLE		27,861,720	0	0
Stemline Therapeutics Inc.	COM	85858C107	5,778	338,671	SH		SOLE		338,671	0	0
Sunesis Pharmaceuticals Inc.	COM	867328601	8,160	3,200,000	SH		SOLE		3,200,000	0	0
Synageva Biopharma Corp.	COM	87159A103	989,182	10,660,432	SH		SOLE		10,660,432	0	0
Synergy Pharmaceuticals	COM	871639308	2,968	973,245	SH		SOLE		973,245	0	0
Synta Pharmaceuticals	COM	87162T206	1,325	500,000	SH		SOLE		500,000	0	0
Tekmira Pharmaceuticals Corp.	COM	87911B209	7,335	484,156	SH		SOLE		484,156	0	0
Tesaro Inc.	COM	881569107	1,161	31,218	SH		SOLE		31,218	0	0
TG Therapeutics	COM	88322Q108	32,477	2,050,313	SH		SOLE		2,050,313	0	0
Threshold Pharma	COM	885807206	6,855	2,155,516	SH		SOLE		2,155,516	0	0
Ultragenyx Pharmaceuticals	COM	90400D108	6,582	150,000	SH		SOLE		150,000	0	0
UniQure B.V.	SHS	N90064101	454	30,672	SH		SOLE		30,672	0	0
Vanda Pharmaceuticals, Inc.	COM	921659108	64,041	4,472,153	SH		SOLE		4,472,153	0	0
Versartis Inc.	COM	92529L102	51,225	2,281,744	SH		SOLE		2,281,744	0	0
Xencor	COM	98401F105	9,486	591,371	SH		SOLE		591,371	0	0
Xenoport	COM	98411C100	60,545	6,903,628	SH		SOLE		6,903,628	0	0
Xoma Corp.	COM	98419J107	60,757	16,924,013	SH		SOLE		16,924,013	0	0
Ziopharm Oncology Inc.	COM	98973P101	982	193,640	SH		SOLE		193,640	0	0
Zogenix, Inc.	COM	98978L105	3,220	2,350,400	SH		SOLE		2,350,400	0	0
Celladon Corp	COM	15117E107	7,324	375,000	SH		SOLE		375,000	0	0
Mallinckrodt PUB LTD CO	SHS	G5785G107	4,621	46,666	SH		SOLE		46,666	0	0
Acorda Therapeutics Notes 1.75% 6/15/2021	CONV BONDS	00484MAA4	69,839	60,900,000	PRN		SOLE		60,900,000	0	0
Biomarin Pharmaceuticals Notes 1.875% 4/23/2017	CONV BONDS	09061GAD3	102,104	22,898,000	PRN		SOLE		22,898,000	0	0
Biomarin Pharmaceuticals Notes 0.75% 10/15/2018	CONV BONDS	09061GAE1	14,715	12,500,000	PRN		SOLE		12,500,000	0	0
Gilead 1.625% 5/1/16	CONV BONDS	375558AP8	88,977	21,500,000	PRN		SOLE		21,500,000	0	0
Incyte Corporation Notes 4.75% 10/1/2015 144A	CONV BONDS	45337CAJ1	336,182	40,446,000	PRN		SOLE		40,446,000	0	0
Incyte Corporation Notes 0.375% 11/15/2018 144A	CONV BONDS	45337CAK8	388,039	259,000,000	PRN		SOLE		259,000,000	0	0
Incyte Corporation Notes 1.25% 11/15/2020 144A	CONV BONDS	45337CAL6	421,613	274,500,000	PRN		SOLE		274,500,000	0	0
Medivation 2.625% 4/1/17	CONV BONDS	58501NAA9	67,334	34,720,000	PRN		SOLE		34,720,000	0	0
Protalix Biotherapeutics, Inc. Notes 4.5% 9/15/18	CONV BONDS	74365AAB7	2,645	3,500,000	PRN		SOLE		3,500,000	0	0
Salix 2.75% 5/15/15	CONV BONDS	795435AC0	542,741	219,440,000	PRN		SOLE		219,440,000	0	0
Salix 1.5% 3/15/19	CONV BONDS	795435AE6	27,339	15,000,000	PRN		SOLE		15,000,000	0	0