Blackstone LP : Initial Statement of Beneficial Ownership

UNITED STATES SECURITIES AND EXCHANGE COMMISSION	OMB APPROVAL
Washington, D.C. 20549	OMB Number: 3235-0104
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INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF	hours per response... 0.5
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

1. Name and Address of Reporting Person *	2. Date of Event Requiring	3. Issuer Name and Ticker or Trading Symbol
Statement (MM/DD/YYYY)
Blackstone Holdings II L.P.	1/4/2019	Forty Seven, Inc. [FTSV]

C/O THE BLACKSTONE GROUP	_____ Director	___ X ___ 10% Owner
L.P., 345 PARK AVENUE	_____ Officer (give title below)	_____ Other (specify below)
(Street)	5. If Amendment, Date	6. Individual or Joint/Group Filing (Check Applicable Line)
Original Filed (MM/DD/YYYY)
NEW YORK, NY 10154	___ Form filed by One Reporting Person
_ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned

(1) (2) (3)

Common Stock

3816951

ISee Footnotes

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)

Explanation of Responses:

• (1) These securities are held directly by Clarus Lifesciences III, L.P. ("Clarus III"). Clarus Ventures III GP, L.P. ("Clarus III GP") is the sole general partner of Clarus III. Blackstone Clarus III L.L.C. is the sole general partner of Clarus GP. The sole member of Blackstone Clarus III L.L.C. is Blackstone Holdings II L.P. The sole general partner of Blackstone Holdings II L.P. is Blackstone Holdings I/II GP Inc. The controlling shareholder of Blackstone Holdings I/II GP Inc. is The Blackstone Group L.P. The sole general partner of The Blackstone Group L.P. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly-owned by Blackstone's senior managing directors and controlled by its founder, Stephen A. Schwarzman.

• (2) Information with respect to each of the Reporting Persons is given solely by such Reporting Person, and no Reporting Person has responsibility for the accuracy or completeness of information supplied by another Reporting Person.

• (3) Each of such Reporting Persons may be deemed to beneficially own the shares beneficially owned by Clarus III, but each disclaims beneficial ownership of such shares, except to the extent of such Reporting Person's pecuniary interest therein. The filing of this statement shall not be deemed to be an admission that, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the Reporting Persons are the beneficial owners of any securities reported herein.

Remarks:

This Form 3 is being filed in connection with the acquisition by The Blackstone Group L.P. and certain of its affiliates ("Blackstone") of Clarus Ventures, LLC and certain of its affiliates (collectively, "Clarus"). On January 4, 2019, Blackstone integrated the Clarus business into Blackstone (the "Clarus Integration"). As a result of such integration, Blackstone may be deemed to have become the beneficial owner of the securities beneficially owned by Clarus, including the securities of the Issuer.

Reporting Owners

Reporting Owner Name / Address

Director 10% Owner Officer Other

Blackstone Holdings II L.P.

C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE

NEW YORK, NY 10154

X

Blackstone Clarus III L.L.C. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK, NY 10154	X
Blackstone Holdings I/II GP Inc C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK, NY 10154	X
Blackstone Group L.P. 345 PARK AVENUE NEW YORK, NY 10154	X
Blackstone Group Management L.L.C. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK, NY 10154	X
SCHWARZMAN STEPHEN A C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK, NY 10154	X

Signatures

BLACKSTONE CLARUS III L.L.C., By: Blackstone Holdings II L.P., its managing member, By: Blackstone Holdings I/II GP Inc., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer

** Signature of Reporting Person

1/10/2019

Date

BLACKSTONE HOLDINGS II L.P., By: Blackstone Holdings I/II GP Inc., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer

** Signature of Reporting Person

1/10/2019

Date

BLACKSTONE HOLDINGS I/II GP INC., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer

** Signature of Reporting Person

1/10/2019

Date

THE BLACKSTONE GROUP L.P., By: Blackstone Group Management L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer

** Signature of Reporting Person

1/10/2019

Date

BLACKSTONE GROUP MANAGEMENT L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer

** Signature of Reporting Person

1/10/2019

Date

/s/ Stephen A. Schwarzman

** Signature of Reporting Person

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). Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

1/10/2019

Date

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