- Post-Effective Amendment to Registration Statement (POS AM)

As filed with the Securities and Exchange Commission on May 1, 2009

Registration No. 333-152660

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

____________________________

POST-EFFECTIVE AMENDMENT NO. 1 TO

FORM S-1

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

____________________________

ARNO THERAPEUTICS, INC .

( Exact name of registrant as specified in its charter)

Delaware	2834	52-2286452
(State or other jurisdiction of incorporation or organization)	(Primary Standard Industrial Classification Code Number)	(I.R.S. Employer Identification No.)

_______________________________

4 Campus Drive, 2 nd Floor

Parsippany, New Jersey, 07054

(862) 703-7170

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

____________________________

Brian Lenz

Chief Financial Officer

Arno Therapeutics, Inc.

4 Campus Drive, 2 nd Floor

Parsippany, New Jersey, 07054

(862) 703-7175

(Name, address, including zip code, and telephone number,

including area code, of agent for service)

Copies to:

Christopher J. Melsha, Esq.

Fredrikson & Byron, P.A.

200 South Sixth Street, Suite 4000

Minneapolis, MN 55402-1425

Telephone: (612) 492-7000

Facsimile: (612) 492-7077

_____________________________

Approximate date of commencement of proposed sale to the public: This post-effective amendment de-registers all shares of common stock registered hereunder and remaining unsold as of the date hereof.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended, check the following box. 

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration number of the earlier effective registration statement for the same offering. 

If this Form is a post effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. 

If this Form is a post effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. 

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.


	Large accelerated filer o	Accelerated filer o
	Non-accelerated filer o (Do not check if a smaller reporting company)	Smaller reporting company þ

DEREGISTRATION OF UNSOLD SECURITIES

On July 31, 2008, Arno Therapeutics, Inc. (the “Company”) filed a registration statement on Form S-1, as amended October 1, 2008 (File No. 333-152660) (the “Registration Statement”), which was declared effective on October 3, 2008. The Registration Statement registered the sale by the selling stockholders identified therein of a total of 10,562,921 shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”). The purpose of this Post-Effective Amendment to the Registration Statement is to withdraw and remove from registration the unissued and unsold shares of Common Stock previously registered under the Registration Statement. Consequently, in accordance with an undertaking made by the Company in the Registration Statement to remove from registration, by means of a post-effective amendment, any of the securities that remain unsold at the termination of the offering, the Company hereby removes from registration the securities of the Company that are registered but unsold under the Registration Statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant has duly caused this Post-Effective Amendment No. 1 to its Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Parsippany, State of New Jersey, on May 1, 2009.



	ARNO THERAPEUTICS, INC.

	By:	/s/ Brian Lenz
		Brian Lenz Chief Financial Officer

Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment No. 1 to the Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.

Signature		Title	Date

/s/ Roger G. Berlin		Chief Executive Officer and Director	May 1, 2009
Roger G. Berlin, M.D.		(Principal Executive Officer)

/s/ Brian Lenz		Chief Financial Officer	May 1, 2009
Brian Lenz		(Principal Financial and Accounting Officer)

*		Non-Executive Chairman and Director	May 1, 2009
Arie S. Belldegrun, M.D.

*		Director	May 1, 2009
Robert I. Falk

		Director	May __, 2009
William F. Hamilton, Ph.D.

*		Director	May 1, 2009
Peter M. Kash

*		Director	May 1, 2009
Joshua A. Kazam

/s/ David M. Tanen		Director	May 1, 2009
David M. Tanen

*	/s/ David M. Tanen
	David M. Tanen Attorney-in-fact