13D Filing: OrbiMed Advisors and Synlogic Inc. (SYBX)

CUSIP No.  87166L100

Page 2 of 13 Pages

1	NAME OF REPORTING PERSON OrbiMed Advisors LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) ☐ (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER   1,314,996
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER   1,314,996
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,314,996
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 8.08%*
14	TYPE OF REPORTING PERSON (See Instructions) IA

---

* This percentage is calculated based upon 16,282,496 shares of common stock outstanding of Synlogic, Inc. (the “Issuer”), as set forth in the Issuer’s Current Report on Form 8-K filed with the Securities and Exchange Commission on August 28, 2017.