Dianthus Therapeutics (DNTH) Form 3 Initial statement of insider ownership

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^*

Atlas Venture Fund X, L.P.

(Last) (First) (Middle)

400 TECHNOLOGY SQ., 10TH FLOOR

(Street)

CAMBRIDGE MA 02139

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
06/20/2018

3. Issuer Name and Ticker or Trading Symbol
Magenta Therapeutics, Inc. [ MGTA ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

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	96,749	D(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	4,667,797	(1)	D(3)
Series B Preferred Stock	(2)	(2)	Common Stock	79,079	(2)	D(3)

1. Name and Address of Reporting Person^*

Atlas Venture Fund X, L.P.

(Last) (First) (Middle)

400 TECHNOLOGY SQ., 10TH FLOOR

(Street)

CAMBRIDGE MA 02139

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ATLAS VENTURE ASSOCIATES X, L.P.

(Last) (First) (Middle)

400 TECHNOLOGY SQ., 10TH FL.

(Street)

CAMBRIDGE MA 02139

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Atlas Venture Associates X, LLC

(Last) (First) (Middle)

400 TECHNOLOGY SQ., 10TH FL.

(Street)

CAMBRIDGE MA 02139

(City) (State) (Zip)

Explanation of Responses:

1. Each share of Series A Preferred Stock is convertible into shares of the Issuer's common stock, $0.001 par value per share ("Common Stock") on a 2.58398:1 basis. Upon the closing of the Issuer's initial public offering, all shares of Series A Preferred Stock will convert into shares of Common Stock of the Issuer. The Series A Preferred Stock has no expiration date.

2. Each share of Series B Preferred Stock is convertible into shares of the Issuer's Common Stock on a 2.58398:1 basis. Upon the closing of the Issuer's initial public offering, all shares of Series B Preferred Stock will convert into shares of Common Stock of the Issuer. The Series B Preferred Stock has no expiration date.

3. The shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). The general partner of Atlas Venture Fund X is Atlas Venture Associates X, L.P. ("AVA X LP"). Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. Each of AVA X LP and AVA X LLC disclaims Section 16 beneficial ownership of the securities held by Atlas Venture Fund X, except to the extent of its pecuniary interest therein, if any.

Remarks:

	Atlas Venture Fund X, L.P., By: Atlas Venture Associates X, L.P., its general partner, by Atlas Associates X, LLC, its general partner, By: Ommer Chohan, Chief Financial Officer /s/ Ommer Chohan	06/20/2018
	Atlas Venture Associates X, LP, By: Atlas Venture Associates X, LLC, its general partner, By: Ommer Chohan, Chief Financial Officer /s/ Ommer Chohan	06/20/2018
	Atlas Venture Associates X, LLC, By: Ommer Chohan, Chief Financial Officer /s/ Ommer Chohan	06/20/2018
	** Signature of Reporting Person	Date
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