SEC FORM 3

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^*

BYERS BLAKE

(Last)

(First)

(Middle)

C/O MAGENTA THERAPEUTICS, INC.

50 HAMPSHIRE STREET

(Street)

CAMBRIDGE

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)

X	Director	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)

X	Form filed by One Reporting Person
	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)

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)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	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)
Series A Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	51,626	⁽¹⁾	I⁽³⁾	See Footnote⁽³⁾
Series B Preferred Stock	⁽²⁾	⁽²⁾	Common Stock	3,287,511	⁽²⁾	I⁽³⁾	See Footnote⁽³⁾

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 at any time at the holder's election and will automatically convert immediately prior to the closing of the Issuer's initial public offering. 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 at the holder's election and will automatically convert immediately prior to the closing of the Issuer's initial public offering. The Series B Preferred Stock has no expiration date.

3. The reported securities are directly held by GV 2016, L.P. GV 2016 GP, L.P., the general partner of GV 2016, L.P., GV 2016 GP, L.L.C., the general partner of GV 2016 GP, L.P., Alphabet Holdings LLC, the sole member of GV 2016 GP, L.L.C., XXVI Holdings Inc., the managing member of Alphabet Holdings LLC, and Alphabet Inc., the sole stockholder of XXVI Holdings Inc., may each be deemed to have sole power to vote or dispose of these shares. Dr. Byers is an affiliate of GV 2016 GP, L.P. but does not have voting or dispositive power over the shares held by GV 2016, L.P. Dr. Byers disclaims beneficial ownership of the shares held by GV 2016, L.P. except to the extent of his pecuniary interest, if any, therein and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the reported securities for the purpose of Section 16 or for any other purpose.

Remarks:

Exhibit 24.1: Power of Attorney

	/s/ Zoran Zdraveski, Attorney-in-Fact for Blake Byers	06/20/2018
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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