Exhibit 1

JOINT FILING AGREEMENT

 The undersigned hereby agree that the Statement on Schedule 13D, dated November 25, 2019, with respect to the ordinary shares of 89bio, Inc. is filed on behalf of each of us pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. Each of the undersigned agrees to be responsible for the timely filing of this Statement, and for the completeness and accuracy of the information concerning itself contained therein. This Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument.

IN WITNESS WHEREOF, the undersigned have executed this Agreement as of the 25th day of November 2019.

ORBIMED ADVISORS LLC
By:	/s/ Carl L. Gordon
	Name: Carl L. Gordon
	Title: Member of OrbiMed Advisors LLC
ORBIMED ADVISORS ISRAEL II LIMITED
By:	/s/ Carl L. Gordon
	Name: Carl L. Gordon
	Title: Director
ORBIMED ISRAEL GP II, L.P.
By:	ORBIMED ADVISORS ISRAEL II LIMITED, its general partner
By:	/s/ Carl L. Gordon
	Name: Carl L. Gordon
	Title: Director
ORBIMED CAPITAL GP VI LLC
By:	ORBIMED ADVISORS LLC, its managing member
By:	/s/ Carl L. Gordon
	Carl L. Gordon
	Member of OrbiMed Advisors LLC