SEC Form 3 
FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940 	  
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1. Name and Address of Reporting Person*
ORBIMED ADVISORS LLC	

(Last)	(First)	(Middle)	
601 LEXINGTON AVENUE, 54TH FLOOR	

(Street) 
NEW YORK	NY	10022	

(City)	(State)	(Zip)	
	2. Date of Event Requiring Statement (Month/Day/Year)
11/08/2019 	3. Issuer Name and Ticker or Trading Symbol 
89bio, Inc. [ ETNB ] 		
		4. Relationship of Reporting Person(s) to Issuer 
(Check all applicable) 
X	Director	X	10% Owner	
	Officer (give title below)		Other (specify below)	
	
	5. If Amendment, Date of Original Filed (Month/Day/Year)				
			6. Individual or Joint/Group Filing (Check Applicable Line) 
	Form filed by One Reporting Person	
X	Form filed by More than One Reporting Person	
	
Table I - Non-Derivative Securities Beneficially Owned	
1. Title of Security (Instr. 4) 	2. Amount of Securities Beneficially Owned (Instr. 4) 	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 	4. Nature of Indirect Beneficial Ownership (Instr. 5) 	
Common Stock, par value $0.001 per share	305,613	I	See footnote(2) 	
Common Stock, par value $0.001 per share	305,613	I	See footnote(3) 	
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities) 	
1. Title of Derivative Security (Instr. 4) 	2. Date Exercisable and Expiration Date (Month/Day/Year)	3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 	4. Conversion or Exercise Price of Derivative Security 	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 	6. Nature of Indirect Beneficial Ownership (Instr. 5) 	
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares				
Series A Preferred Stock	(1) 	(1) 	Common Stock	1,277,858(1) 	(1)	I	See footnote(2) 	
Series A Preferred Stock	(1) 	(1) 	Common Stock	1,277,858(1) 	(1)	I	See footnote(3) 	
1. Name and Address of Reporting Person*
ORBIMED ADVISORS LLC	

(Last)	(First)	(Middle)	
601 LEXINGTON AVENUE, 54TH FLOOR	

(Street) 
NEW YORK	NY	10022	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
OrbiMed Capital GP VI LLC	

(Last)	(First)	(Middle)	
601 LEXINGTON AVENUE, 54TH FLOOR	

(Street) 
NEW YORK	NY	10022	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
OrbiMed Advisors Israel II Ltd	

(Last)	(First)	(Middle)	
601 LEXINGTON AVENUE, 54TH FLOOR	

(Street) 
NEW YORK	NY	10022	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
OrbiMed Israel GP II, L.P.	

(Last)	(First)	(Middle)	
601 LEXINGTON AVENUE, 54TH FLOOR	

(Street) 
NEW YORK	NY	10022	

(City)	(State)	(Zip)	
	
Explanation of Responses:	
1. Each share of Series A Preferred Stock is convertible into common stock on a one-for-6.217 basis into the number of shares of common stock shown in column 3 at any time at the holder's election and automatically immediately prior to the closing of the Issuer's initial public offering. The Series A Preferred Stock has no expiration date.	
2. These securities are held of record by OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("OrbiMed GP VI") is the general partner of OPI VI and OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisors Act of 1940, as amended, is the managing member of OrbiMed GP VI. By virtue of such relationships, OrbiMed GP VI and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OPI VI and as a result may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein. Each of OrbiMed GP VI, OrbiMed Advisors, Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein disclaims beneficial ownership of the shares held by OPI VI, except to the extent of its or his pecuniary interest therein if any.	
3. These securities are held of record by OrbiMed Israel Partners II, L.P. ("OIP II"). OrbiMed Israel GP II, L.P. ("Israel GP II") is the general partner of OIP II, and OrbiMed Advisors Israel II Limited ("Advisors Israel II") is the general partner of Israel GP II. Advisors Israel II and Israel GP II may be deemed to have shared voting and investment power over all of the shares of common stock held by OIP II, and both Advisors Israel II and Israel GP II may be deemed directly or indirectly, including by reason of their mutual affiliation, to be the beneficial owners of the shares held by OIP II. Advisors Israel II exercises this investment power through an investment committee comprised of Carl L. Gordon, Jonathan T. Silverstein, Nissim Darvish, Anat Naschitz, and Erez Chimovits, each of whom disclaims beneficial ownership of the shares held by OIP II.	
Remarks:	
	
	OrbiMed Advisors LLC; By /s/ Douglas Coon, Chief Compliance Officer	11/08/2019	
	OrbiMed Capital GP VI LLC; By /s/ Douglas Coon, Chief Compliance Officer	11/08/2019	
	OrbiMed Advisors Israel II Limited; By /s/ Douglas Coon, Chief Compliance Officer	11/08/2019	
	OrbiMed Israel GP II, L.P.; By /s/ Douglas Coon, Chief Compliance Officer	11/08/2019	
	** Signature of Reporting Person	Date	
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.	
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).	
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