Under the Securities Exchange Act of 1934	
(Amendment No.___)*	
 	
Lantheus Holdings, Inc.	
(Name of Issuer)	
 	
Common Stock, par value $0.01 per share	
(Title of Class of Securities)	
 	
516544103	
(CUSIP Number)	
 	
December 12, 2016	
(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 8 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).

CUSIP No. 516544103	13G	Page  2 of 8 Pages	

1	NAME OF REPORTING PERSON
Numeric Investors LLC	 	
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP	(a) ¨
(b) ¨	 	
3	SEC USE ONLY	 	
4	CITIZENSHIP OR PLACE OF ORGANIZATION
State of Delaware	 	
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:	5	SOLE VOTING POWER
0	 	
 	6	SHARED VOTING POWER
2,094,575 shares of Common Stock	 	 	
 	7	SOLE DISPOSITIVE POWER
0	 	 	 	
 	8	SHARED DISPOSITIVE POWER
2,094,575 shares of Common Stock	 	 	 	
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
2,094,575 shares of Common Stock	 	 	 	
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES	¨	 	 	 	
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
5.70%	 	 	 	
12	TYPE OF REPORTING PERSON
OO	 	 	 	

CUSIP No. 516544103	13G	Page  3 of 8 Pages	

1	NAME OF REPORTING PERSON
Man Group plc	 	
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP	(a) ¨
(b) ¨	 	
3	SEC USE ONLY	 	
4	CITIZENSHIP OR PLACE OF ORGANIZATION
United Kingdom	 	
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:	5	SOLE VOTING POWER
0	 	
 	6	SHARED VOTING POWER
2,094,575 shares of Common Stock	 	 	
 	7	SOLE DISPOSITIVE POWER
0	 	 	 	
 	8	SHARED DISPOSITIVE POWER
2,094,575 shares of Common Stock	 	 	 	
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
2,094,575 shares of Common Stock	 	 	 	
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES	¨	 	 	 	
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
5.70%	 	 	 	
12	TYPE OF REPORTING PERSON
OO, HC	 	 	 	

 

CUSIP No. 516544103	13G	Page  4 of 8 Pages	

Item 1(a).	NAME OF ISSUER:	
 	 	
 	The name of the issuer is Lantheus Holdings, Inc., a Delaware corporation (the "Company").	
 
Item 1(b).	ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:	
 	 	
 	The Company's principal executive offices are located at 331 Treble Cove Road, North Billerica, MA 01862.	
 
Item 2(a).	NAME OF PERSON FILING:	
 	 	
 	This statement is filed by the entities and persons listed below, who are collectively referred to herein as the " Reporting Persons " with respect to the Common Stock (as defined in Item 2(d) below):	
 	 	
 	Investment Manager:	
 	 	
 	(i)	Numeric Investors LLC (the "Investment Manager"), with respect to the Common Stock held by certain funds and/or managed accounts to which the Investment Manager serves as investment manager (collectively, the " Numeric Funds ").	
 	 	
 	Parent Company:	
 	 	
 	(ii)	Man Group plc (the "Parent Company"), which indirectly, through various intermediate entities, controls the Investment Manager, with respect to the Common Stock held by each of the Numeric Funds.	
 
Item 2(b).	ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:	
 	 	
Item 2(c).	CITIZENSHIP:	
 	 	
 	This statement is filed by:	
 	 	
 	(i)	Numeric Investors LLC
470 Atlantic Avenue,6th Floor
Boston, MA 02210
Citizenship: State of Delaware	
 	 	
 	(ii)	Man Group Plc
Riverbank House
2 Swan Lane
London EC4R 3AD
United Kingdom
Citizenship: United Kingdom	
 
Item 2(d).	TITLE OF CLASS OF SECURITIES:	
 	 	
 	Common Stock, par value $0.01 per share (the "Common Stock").	

CUSIP No. 516544103	13G	Page  5 of 8 Pages	
 
Item 2(e).	CUSIP NUMBER:	
 	 	
 	516544103	
 
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)	¨	Employee Benefit Plan or Endowment Fund in accordance with Rule 13d-1(b)(1)(ii)(F),	

 	(g)	¨	Parent Holding Company or control person in accordance with Rule 13d-1(b)(1)(ii)(G),	
 	(h)	¨	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:____________________________	
 
Item 4.	OWNERSHIP	
 	 	
 	The information required by Items 4(a) - (c)  is set forth in Rows (5) - (11) of the cover page for each Reporting Person hereto and is incorporated herein by reference for each such Reporting Person.  The percentage set forth in Row (11) of the cover page for each Reporting Person is based on the 36,756,106 shares of Common Stock outstanding as of November 30, 2016, as reported in the Company's Registration Statement on Form S-3 filed with the Securities and Exchange Commission on December 12, 2016.	
 	 	
 	The Investment Manager, which serves as the investment manager to each of the Numeric Funds, may be deemed to be the beneficial owner of all of the Common Stock owned by the Numeric Funds.  The Parent Company, which indirectly, through various intermediate entities, controls the Investment Manager, may be deemed to be the beneficial owner of all the Common Stock owned by the Numeric Funds. The Parent Company hereby disclaims any beneficial ownership of any such Common Stock.	

CUSIP No. 516544103	13G	Page  6 of 8 Pages	

 
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.	
 	 	
 	See Item 2.	
 
Item 7.	IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.	
 	 	
 	Not applicable.	
 
Item 8.	IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.	
 	 	
 	Not applicable.	
 
Item 9.	NOTICE OF DISSOLUTION OF GROUP.	
 	 	
 	Not applicable.	
 
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 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.	

CUSIP No. 516544103	13G	Page  7 of 8 Pages	

SIGNATURES
After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.
DATE: December 20, 2016
 
NUMERIC INVESTORS LLC	 	 	

By:  /s/ Nadine Le Gall	 	 	
Name:	/s/ Nadine Le Gall	 	 	
Title:	Chief Compliance Officer	 	 	
 	 	 	
MAN GROUP PLC	 	 	

By:  /s/ Michelle Robyn Grew	 	 	
Name:	Michelle Robyn Grew	 	 	
Title:	Chief Administrative Officer	 	 	

 

CUSIP No. 516544103	13G	Page  8 of 8 Pages	
 
EXHIBIT I
 
JOINT FILING AGREEMENT
 
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.
 
DATED as of December 20, 2016
 
NUMERIC INVESTORS LLC	 	 	

By:  /s/ Nadine Le Gall	 	 	
Name:	/s/ Nadine Le Gall	 	 	
Title:	Chief Compliance Officer	 	 	
 	 	 	
MAN GROUP PLC	 	 	

By:  /s/ Michelle Robyn Grew	 	 	
Name:	Michelle Robyn Grew	 	 	
Title:	Chief Administrative Officer