Cartesian Therapeutics, Inc. — Director's Dealing 2016

Jun 30, 2016

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: SELECTA BIOSCIENCES INC (SELB)
CIK: 0001453687
Period of Report: 2016-06-27

Reporting Person: ORBIMED ADVISORS LLC (Director, 10% Owner)
Reporting Person: OrbiMed Capital GP III LLC (Director, 10% Owner)
Reporting Person: ISALY SAMUEL D (Director, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2016-06-27	Common Stock	C	11111	—	Acquired	12193	Indirect
2016-06-27	Common Stock	C	1166884	—	Acquired	1280604	Indirect
2016-06-27	Common Stock	P	5189	$14.00	Acquired	17382	Indirect
2016-06-27	Common Stock	P	544811	$14.00	Acquired	1825415	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2016-06-27	Series C Convertible Preferred Stock	$	C	3628	Disposed		Common Stock (3628)	Indirect
2016-06-27	Series C Convertible Preferred Stock	$	C	380986	Disposed		Common Stock (380986)	Indirect
2016-06-27	Series D Convertible Preferred Stock	$	C	739	Disposed		Common Stock (739)	Indirect
2016-06-27	Series D Convertible Preferred Stock	$	C	77697	Disposed		Common Stock (77697)	Indirect
2016-06-27	Series E Convertible Preferred Stock	$	C	4351	Disposed		Common Stock (6744)	Indirect
2016-06-27	Series E Convertible Preferred Stock	$	C	456870	Disposed		Common Stock (708201)	Indirect

Footnotes

F1: The reportable securities are owned directly by OrbiMed Associates III, LP ("Associates III"). OrbiMed Advisors LLC ("Advisors") is the general partner of Associates III. Samuel D. Isaly ("Isaly"), a natural person, is the managing member of and owner of a controlling interest in Advisors. By virtue of such relationships, Advisors and Isaly may be deemed to have voting and investment power over the securities held by Associates III and as a result may be deemed to have beneficial ownership over such securities.

F2: The reportable securities are owned directly by OrbiMed Private Investments III, LP ("OPI III"). OrbiMed Capital GP III LLC ("GP III") is the general partner of OPI III, and Advisors is the managing member of GP III. Isaly is the managing member of and owner of a controlling interest in Advisors. By virtue of such relationships, GP III, Advisors and Isaly may be deemed to have voting and investment power over the securities held by OPI III and as a result may be deemed to have beneficial ownership over such securities.

F3: The preferred stock is convertible at any time, at the holder's election and has no expiration date. The preferred stock automatically converted into common stock on a 1-for-1 basis upon the closing of the Issuer's initial public offering.

F4: The Series E Convertible Preferred Stock is convertible at any time, at the holder's election and has no expiration date. The Series E Convertible Preferred Stock automatically converted into common stock on an approximately 1-for-1.550115 basis upon the closing of the Issuer's initial public offering.

F5: This report on Form 4 is jointly filed by GP III, Advisors, and Isaly. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its or his pecuniary interest therein, if any. The Reporting Persons have designated Dr. Carl Gordon, a member of Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of the Reporting Persons is a beneficial owner for the purpose of Section 16 of the Exchange Act, or for any other purpose.