0000899243-18-017520.txt : 20180620 0000899243-18-017520.hdr.sgml : 20180620 20180620204354 ACCESSION NUMBER: 0000899243-18-017520 CONFORMED SUBMISSION TYPE: 3 PUBLIC DOCUMENT COUNT: 2 CONFORMED PERIOD OF REPORT: 20180620 FILED AS OF DATE: 20180620 DATE AS OF CHANGE: 20180620 REPORTING-OWNER: OWNER DATA: COMPANY CONFORMED NAME: Booth Bruce CENTRAL INDEX KEY: 0001451612 FILING VALUES: FORM TYPE: 3 SEC ACT: 1934 Act SEC FILE NUMBER: 001-38541 FILM NUMBER: 18910724 MAIL ADDRESS: STREET 1: 890 WINTER STREET STREET 2: SUITE 320 CITY: WALTHAM STATE: MA ZIP: 02451 ISSUER: COMPANY DATA: COMPANY CONFORMED NAME: Magenta Therapeutics, Inc. CENTRAL INDEX KEY: 0001690585 STANDARD INDUSTRIAL CLASSIFICATION: PHARMACEUTICAL PREPARATIONS [2834] IRS NUMBER: 000000000 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 BUSINESS ADDRESS: STREET 1: 245 FIRST STREET STREET 2: 4TH FLOOR CITY: CAMBRIDGE STATE: MA ZIP: 02142 BUSINESS PHONE: 857-201-2700 MAIL ADDRESS: STREET 1: 245 FIRST STREET STREET 2: 4TH FLOOR CITY: CAMBRIDGE STATE: MA ZIP: 02142 3 1 doc3.xml FORM 3 SUBMISSION X0206 3 2018-06-20 0 0001690585 Magenta Therapeutics, Inc. MGTA 0001451612 Booth Bruce C/O MAGENTA THERAPEUTICS, INC 50 HAMPSHIRE STREET CAMBRIDGE MA 02139 1 0 0 0 Common Stock 96749 I See Footnote Series A Preferred Stock Common Stock 4667797 I See Footnote Series B Preferred Stock Common Stock 79079 I See Footnote 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. 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. 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. Dr. Booth is a member of AVA X LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund X, except to the extent of his pecuniary interest therein, if any. Exhibit 24.1: Power of Attorney /s/ Ommer Chohan, Attorney-in-Fact for Bruce Booth 2018-06-20 EX-24.1 2 attachment1.htm EX-24.1 DOCUMENT

                                 POWER OF ATTORNEY

        Know all by these presents that the undersigned hereby constitutes and
appoints Ommer Chohan with full power of substitution, the undersigned's true
and lawful attorney-in-fact to:

        (1)   prepare, execute in the undersigned's name and on the
              undersigned's behalf, and submit to the U.S. Securities and
              Exchange Commission (the "SEC") a Form ID, including amendments
              thereto, and any other documents necessary or appropriate to
              obtain codes and passwords enabling the undersigned to make
              electronic filings with the SEC of reports required by Section
              16(a) of the Securities Exchange Act of 1934 or any rule or
              regulation of the SEC;

        (2)   execute for and on behalf of the undersigned, in the undersigned's
              capacity as an officer and/or director of Magenta Therapeutics,
              Inc. (the "Company"), Forms 3, 4, and 5 in accordance with Section
              16(a) of the Securities Exchange Act of 1934 and the rules
              thereunder;

        (3)   do and perform any and all acts for and on behalf of the
              undersigned which may be necessary or desirable to complete and
              execute any such Form 3, 4, or 5, complete and execute any
              amendment or amendments thereto, and timely file such form with
              the SEC and any stock exchange or similar authority; and

        (4)   take any other action of any type whatsoever in connection with
              the foregoing which, in the opinion of such attorney-in-fact, may
              be of benefit to, in the best interest of, or legally required by,
              the undersigned, it being understood that the documents executed
              by such attorney-in-fact on behalf of the undersigned pursuant to
              this Power of Attorney shall be in such form and shall contain
              such terms and conditions as such attorney-in-fact may approve in
              such attorney-in-fact's discretion.

        The undersigned hereby grants to such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be
done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934.

        This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in- fact.

        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of June 14, 2018.

                                        /s/ Bruce Booth
                                        -------------------------------
                                                  Signature

                                                            Bruce Booth
                                        -------------------------------
                                                     Name