SELLAS Life Sciences Group, Inc. — Major Shareholding Notification 2010

Jul 12, 2010

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13G

(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND

AMENDMENTS THERETO FILED PURSUANT TO RULE 13D-2

(Amendment No. )*

RXi Pharmaceuticals Corporation

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

74978T109

(CUSIP Number)

June 30, 2010

(Date of Event Which Requires Filing of This Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

o Rule 13d-1(b)

ý Rule 13d-1(c)

o Rule 13d-1(d)

*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. 74978T109 13G Page 2 of 8 Pages

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) TANG CAPITAL PARTNERS, LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*	(a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	SOLE VOTING POWER 0
6	SHARED VOTING POWER 952,369
7	SOLE DISPOSITIVE POWER 0
8	SHARED DISPOSITIVE POWER 952,369

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 952,369
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.18%
12	TYPE OF REPORTING PERSON PN

CUSIP No. 74978T109 13G Page 3 of 8 Pages

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) TANG CAPITAL MANAGEMENT, LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*	(a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	SOLE VOTING POWER 0
6	SHARED VOTING POWER 952,369
7	SOLE DISPOSITIVE POWER 0
8	SHARED DISPOSITIVE POWER 952,369

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 952,369
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.18%
12	TYPE OF REPORTING PERSON OO

CUSIP No. 74978T109 13G Page 4 of 8 Pages

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) KEVIN C. TANG
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*	(a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION UNITED STATES

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	SOLE VOTING POWER 0
6	SHARED VOTING POWER 952,369
7	SOLE DISPOSITIVE POWER 0
8	SHARED DISPOSITIVE POWER 952,369

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 952,369
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.18%
12	TYPE OF REPORTING PERSON IN

Item 1(a).	Name of Issuer:
	RXi Pharmaceuticals Corporation, a Delaware corporation (the “Issuer”)
Item 1(b).	Address of Issuer’s Principal Executive Offices:
	60 Prescott Street, Worcester, MA 01605
Item 2(a).	Name of Person Filing:
	This Statement on Schedule 13G (this “Statement”) is filed by Tang Capital Partners, LP (“Tang Capital Partners”); Tang Capital Management, LLC, the general partner of Tang Capital Partners (“Tang Capital Management”); and Kevin C. Tang, the manager of Tang Capital Management.
Item 2(b).	Address of Principal Business Office or, if none, Residence:
	4401 Eastgate Mall, San Diego, CA 92121
Item 2(c).	Citizenship:
	Tang Capital Partners is a Delaware limited partnership. Tang Capital Management is a Delaware limited liability company. Mr. Tang is a United States citizen.
Item 2(d).	Title of Class of Securities:
	Common Stock, $0.0001 par value per share (the “Common Stock”)
Item 2(e).	CUSIP Number: 74978T109

Item 3.	Not applicable.
Item 4.	Ownership.

(a)
Tang Capital Partners. Tang Capital Partners is the beneficial owner of 952,369 shares of Common Stock and shares voting and dispositive power over such securities with Tang Capital Management and Kevin C. Tang.
Tang Capital Management. Tang Capital Management, as the general partner of Tang Capital Partners, may be deemed to beneficially own the 952,369 shares beneficially owned by Tang Capital Partners and shares voting and dispositive power over such shares with Tang Capital Partners and Kevin C. Tang.
Kevin C. Tang. Kevin C. Tang may be deemed to beneficially own 952,369 shares beneficially owned by Tang Capital Partners. Mr. Tang shares voting and dispositive power over such shares with Tang Capital Partners and Tang Capital Management.

(b)
Tang Capital Partners	5.18%
Tang Capital Management	5.18%
Kevin C. Tang	5.18%

(c) — (i)	sole power to vote or to direct the vote:
	Tang Capital Partners	0 shares
	Tang Capital Management	0 shares
	Kevin C. Tang	0 shares
(ii)	shared power to vote or to direct the vote:
	Tang Capital Partners	952,369 shares
	Tang Capital Management	952,369 shares
	Kevin C. Tang	952,369 shares
(iii)	sole power to dispose or to direct the disposition of:
	Tang Capital Partners	0 shares
	Tang Capital Management	0 shares
	Kevin C. Tang	0 shares
(iv)	shared power to dispose or to direct the disposition of:
	Tang Capital Partners	952,369 shares
	Tang Capital Management	952,369 shares
	Kevin C. Tang	952,369 shares

Item 5.	Ownership of Five Percent or Less of a Class.
	If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following: o
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.
	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.
	By signing below I certify that, to the best of my 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.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date:	July 12, 2010
TANG CAPITAL PARTNERS, LP
By:	Tang Capital Management, LLC, its General Partner
By:	/s/ Kevin C. Tang
	Kevin C. Tang, Manager
TANG CAPITAL MANAGEMENT, LLC
By:	/s/ Kevin C. Tang
	Kevin C. Tang, Manager
/s/ Kevin C. Tang
Kevin C. Tang