Flagship Ventures Fund V Form 3 Rubius Therapeutics / EDWIN M KANIA JR ownership change

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^*

Flagship Ventures Fund IV General Partner LLC

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
07/17/2018

3. Issuer Name and Ticker or Trading Symbol
Rubius Therapeutics, Inc. [ RUBY ]

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	5,000,000	I	See Footnote(1)

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	(2)	(2)	Common Stock	15,323,593	(2)	I	See Footnote(3)
Series A Preferred Stock	(2)	(2)	Common Stock	3,830,402	(2)	I	See Footnote(4)
Series A Preferred Stock	(2)	(2)	Common Stock	5,000,000	(2)	I	See Footnote(5)
Series A Preferred Stock	(2)	(2)	Common Stock	5,000,000	(2)	I	See Footnote(6)
Series B Preferred Stock	(2)	(2)	Common Stock	593,948	(2)	I	See Footnote(5)
Series B Preferred Stock	(2)	(2)	Common Stock	593,948	(2)	I	See Footnote(6)
Series B Preferred Stock	(2)	(2)	Common Stock	1,781,843	(2)	I	See Footnote(7)
Series C Preferred Stock	(2)	(2)	Common Stock	195,466	(2)	I	See Footnote(5)
Series C Preferred Stock	(2)	(2)	Common Stock	195,466	(2)	I	See Footnote(6)
Series C Preferred Stock	(2)	(2)	Common Stock	781,860	(2)	I	See Footnote(7)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund IV General Partner LLC

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship VentureLabs IV, LLC

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund IV, L.P.

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund IV-Rx, L.P.

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund V, L.P.

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship V VentureLabs Rx Fund, L.P.

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Opportunities Fund I, L.P.

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

AFEYAN NOUBAR

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

KANIA EDWIN M JR

(Last) (First) (Middle)

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

Explanation of Responses:

1. Shares held by Flagship VentureLabs IV LLC ("VentureLabs IV"). Flagship Ventures Fund IV, L.P. ("Flagship Fund IV") is a member of VentureLabs IV and also serves as its manager. Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP") is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by VentureLabs IV. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

2. The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock will automatically convert into common stock upon the closing of the Issuer's initial public offering.

3. Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

4. Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV-Rx. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

5. Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

6. Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

7. Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein

	Flagship Ventures Fund IV General Partner LLC By: /s/ Noubar B. Afeyan Name: Noubar B. Afeyan, Ph.D. Title: Manager	07/17/2018
	Flagship VentureLabs IV LLC By: Flagship Ventures Fund IV, L.P., its manager By: Flagship Ventures Fund IV General Partner LLC, its general partner By: /s/ Noubar B. Afeyan Name: Noubar B. Afeyan, Ph.D. Title: Manager	07/17/2018
	Flagship Ventures Fund IV, L.P. By: Flagship Ventures Fund IV General Partner LLC, its general partner By: /s/ Noubar B. Afeyan Name: Noubar B. Afeyan, Ph.D. Title: Manager	07/17/2018
	Flagship Ventures Fund V, L.P. By: Flagship Ventures Fund V General Partner LLC, its general partner By: /s/ Noubar B. Afeyan Name: Noubar B. Afeyan, Ph.D. Title: Manager	07/17/2018
	Flagship VentureLabs Rx Fund, L.P. By: Flagship Ventures Fund V General Partner LLC, its general partner By: /s/ Noubar B. Afeyan Name: Noubar B. Afeyan, Ph.D. Title: Manager	07/17/2018
	Flagship Ventures Opportunities Fund I, L.P. By: Flagship Ventures Opportunities Fund I General Partner LLC, its general partner By: /s/ Noubar B. Afeyan Name: Noubar B. Afeyan, Ph.D. Title: Manager	07/17/2018
	/s/ Edwin M. Kania Jr.	07/17/2018
	/s/ Noubar B. Afeyan Ph.D.	07/17/2018
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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