13G Filing: Adage Capital Management and Stemline Therapeutics Inc (STML)

Stemline Therapeutics Inc (NASDAQ:STML): Phill Gross And Robert Atchinson’s Adage Capital Management filed an amended 13D.

You can check out Adage Capital Management’s latest holdings and filings here.

Please follow Adage Capital Management (if you aren’t already doing so) to get real-time email alerts whenever we publish an article about Adage Capital Management or update its stock holdings.

Follow Phill Gross's Adage Capital Management

You can access the original SEC filing by clicking here.

Ownership Summary Table

Name Sole Voting Power Shared Voting Power Sole Dispositive Power Shared Dispositive Power Aggregate Amount Owned Power Percent of Class
Adage Capital Partners 0 1,460,014 0 1,460,014 1,460,014 5.78%
Adage Capital Partners GP 0 1,460,014 0 1,460,014 1,460,014 5.78%
Adage Capital Advisors 0 1,460,014 0 1,460,014 1,460,014 5.78%
Robert Atchinson 0 1,460,014 0 1,460,014 1,460,014 5.78%
Phillip Gross 0 1,460,014 0 1,460,014 1,460,014 5.78%

Follow Phill Gross's Adage Capital Management

Page 1 of 12 – SEC Filing

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. )*

Stemline
Therapeutics, Inc.

(Name of Issuer)

Common Stock,
par value $0.0001 per share

(Title of Class of Securities)

85858C107

(CUSIP Number)

October 31,
2017

(Date of Event Which Requires Filing of This Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
¨ Rule 13d-1(b)
ý Rule 13d-1(c)
¨ Rule 13d-1(d)
(Page 1 of 12 Pages)

______________________________

*The remainder of this cover page shall
be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any
subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder
of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of
1934 (“Act“) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other
provisions of the Act (however, see the Notes).

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 2 of 12 – SEC Filing

1

NAME OF REPORTING PERSON

Adage Capital Partners, L.P.

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

1,460,014

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

1,460,014

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,460,014

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.78%

12

TYPE OF REPORTING PERSON

PN

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 3 of 12 – SEC Filing

1

NAME OF REPORTING PERSON

Adage Capital Partners GP, L.L.C.

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

1,460,014

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

1,460,014

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,460,014

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.78%

12

TYPE OF REPORTING PERSON

OO

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 4 of 12 – SEC Filing

 

1

NAME OF REPORTING PERSON

Adage Capital Advisors, L.L.C.

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

1,460,014

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

1,460,014

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,460,014

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.78%

12

TYPE OF REPORTING PERSON

OO

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 5 of 12 – SEC Filing

 

1

NAME OF REPORTING PERSON

Robert Atchinson

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

United States

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

1,460,014

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

1,460,014

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,460,014

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.78%

12

TYPE OF REPORTING PERSON

IN

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 6 of 12 – SEC Filing

 

1

NAME OF REPORTING PERSON

Phillip Gross

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

United States

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

1,460,014

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

1,460,014

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,460,014

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.78%

12

TYPE OF REPORTING PERSON

IN

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 7 of 12 – SEC Filing

 

Item 1(a). NAME OF ISSUER
The name of the issuer is Stemline Therapeutics, Inc. (the “Company“).
Item 1(b). ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES
The Company’s principal executive offices are located at 750 Lexington Avenue, Eleventh Floor, New York, New York 10022.
Item 2(a). NAME OF PERSON FILING
This statement is filed by:
(i) Adage Capital Partners, L.P., a Delaware limited partnership (“ACP“) with respect to the shares of Common Stock directly owned by it;
(ii) Adage Capital Partners GP, L.L.C., a limited liability company organized under the laws of the State of Delaware (“ACPGP“), as general partner of ACP with respect to the shares of Common Stock directly owned by ACP;
(iii) Adage Capital Advisors, L.L.C., a limited liability company organized under the laws of the State of Delaware (“ACA“), as managing member of ACPGP, general partner of ACP, with respect to the shares of Common Stock directly owned by ACP;
(iv) Robert Atchinson (“Mr. Atchinson“), as managing member of ACA, managing member of ACPGP, general partner of ACP with respect to the shares of Common Stock directly owned by ACP; and
(v) Phillip Gross (“Mr. Gross“), as managing member of ACA, managing member of ACPGP, general partner of ACP with respect to the shares of Common Stock directly owned by ACP.
The foregoing persons are hereinafter sometimes collectively referred to as the “Reporting Persons.”  Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party.
The filing of this statement should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of the securities reported herein.
Item 2(b). ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE
The address of the business office of each of the Reporting Persons is 200 Clarendon Street, 52nd floor, Boston, Massachusetts 02116.
Item 2(c). CITIZENSHIP
ACP is a limited partnership organized under the laws of the State of Delaware.  ACPGP and ACA are limited liability companies organized under the laws of the State of Delaware.  Messrs. Gross and Atchinson are citizens of the United States.

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 8 of 12 – SEC Filing

Item 2(d). TITLE OF CLASS OF SECURITIES
Common Stock, par value $0.0001 per share (the “Common Stock“).
Item 2(e). CUSIP NUMBER
85858C107
Item 3. IF THIS STATEMENT IS FILED PURSUANT TO Rules 13d-1(b), OR 13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:
(a) ¨ Broker or dealer registered under Section 15 of the Act;
(b) ¨ Bank as defined in Section 3(a)(6) of the Act;
(c) ¨ Insurance company as defined in Section 3(a)(19) of the Act;
(d) ¨ Investment company registered under Section 8 of the Investment Company Act of 1940;
(e) ¨ An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);
(f) ¨

An employee benefit plan or endowment fund in
accordance with Rule 13d-1(b)(1)(ii)(F);

(g) ¨

A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

(h) ¨

A savings association as defined in Section 3(b)
of the Federal Deposit Insurance Act;

(i) ¨

A church plan that is excluded from the definition
of an investment company under Section 3(c)(14) of the Investment Company Act;

(j) ¨ A non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J);
(k) ¨ Group, in accordance with Rule 13d-1(b)(1)(ii)(K).
If filing as a non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J), please
specify the type of institution: Not applicable.
Item 4. OWNERSHIP
A. Adage Capital Partners, L.P., Adage Capital Partners GP, L.L.C. and Adage Capital Advisors, L.L.C.
(a) Amount beneficially owned:  1,460,014
(b) Percent of class: 5.78%.  The percentage set forth in this Schedule 13G is calculated based upon the 25,280,024 shares of Common Stock reported to be issued and outstanding as of August 8, 2017 as reflected in the Company’s Form 10-Q for the quarterly period ended June 30, 2017, filed with the Securities and Exchange Commission on August 8, 2017.

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 9 of 12 – SEC Filing

(c) (i) Sole power to vote or direct the vote:  0
(ii) Shared power to vote or direct the vote: 1,460,014
(iii) Sole power to dispose or direct the disposition:  0
(iv) Shared power to dispose or direct the disposition of:  1,460,014
ACP has the power to dispose of and the power to vote the shares of Common Stock beneficially owned by it, which power may be exercised by its general partner, ACPGP.  ACA, as managing member of ACPGP, directs ACPGP’s operations. Neither ACPGP nor ACA directly own any shares of Common Stock.  By reason of the provisions of Rule 13d-3 of the Securities Exchange Act of 1934 (the “Act“), ACPGP and ACA may be deemed to beneficially own the shares owned by ACP.
B. Robert Atchinson and Phillip Gross
(a) Amount beneficially owned:  1,460,014
(b) Percent of class:  5.78%
(c) (i) Sole power to vote or direct the vote:  0
(ii) Shared power to vote or direct the vote:  1,460,014
(iii) Sole power to dispose or direct the disposition:  0
(iv) Shared power to dispose or direct the disposition:  1,460,014
Messrs. Atchinson and Gross, as managing members of ACA, have shared power to vote the shares of Common Stock beneficially owned by ACP.  Neither Mr. Atchinson nor Mr. Gross directly own any shares of Common Stock.  By reason of the provisions of Rule 13d-3 of the Act, each may be deemed to beneficially own the shares beneficially owned by ACP.
Item 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS
Not applicable.
Item 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON
Not applicable.
Item 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON
Not applicable.
Item 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
Not applicable.
Item 9. NOTICE OF DISSOLUTION OF GROUP
Not applicable.

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 10 of 12 – SEC Filing

Item 10. CERTIFICATION
Each of the Reporting Persons hereby makes the following certification:
By signing below each Reporting Person certifies that, to the best of his or its knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 11 of 12 – SEC Filing

SIGNATURES

After reasonable
inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in
this statement is true, complete and correct.

DATE: November 9, 2017

ADAGE CAPITAL PARTNERS, L.P.
By:  Adage Capital Partners GP, L.L.C.,
its general partner
By:  Adage Capital Advisors, L.L.C.,
its managing member
/s/ Robert Atchinson
Name:  Robert Atchinson
Title: Managing Member
ADAGE CAPITAL PARTNERS GP, L.L.C.
By:  Adage Capital Advisors, L.L.C.,
its managing member
/s/ Robert Atchinson
Name:  Robert Atchinson
Title: Managing Member
ADAGE CAPITAL ADVISORS, L.L.C.
/s/ Robert Atchinson
Name:  Robert Atchinson
Title: Managing Member
ROBERT ATCHINSON
/s/ Robert Atchinson
ROBERT ATCHINSON, individually
PHILLIP GROSS
/s/ Phillip Gross
PHILLIP GROSS, individually

Follow Stemline Therapeutics Inc (NASDAQ:STML)

Page 12 of 12 – SEC Filing

EXHIBIT 1

JOINT FILING AGREEMENT
PURSUANT TO RULE 13d-1(k)

The undersigned acknowledge and agree that the foregoing statement
on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule
13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The
undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy
of the information concerning him or it contained herein and therein, but shall not be responsible for the completeness and accuracy
of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information
is inaccurate.

DATE: November 9, 2017

ADAGE CAPITAL PARTNERS, L.P.
By:  Adage Capital Partners GP, L.L.C.,
its general partner
By:  Adage Capital Advisors, L.L.C.,
its managing member
/s/ Robert Atchinson
Name:  Robert Atchinson
Title: Managing Member
ADAGE CAPITAL PARTNERS GP, L.L.C.
By:  Adage Capital Advisors, L.L.C.,
its managing member
/s/ Robert Atchinson
Name:  Robert Atchinson
Title: Managing Member
ADAGE CAPITAL ADVISORS, L.L.C.
/s/ Robert Atchinson
Name:  Robert Atchinson
Title: Managing Member
/s/ Robert Atchinson
ROBERT ATCHINSON, individually
/s/ Phillip Gross
PHILLIP GROSS, individually

Follow Stemline Therapeutics Inc (NASDAQ:STML)