Securities Registration Statement (simplified Form) (s-3/a)

Large accelerated filer

Accelerated filer

Non-accelerated filer

¨ (Do not check if a smaller reporting company)

Smaller reporting company

As filed with the Securities and Exchange Commission on July 2, 2013

Registration No. 333-170495

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 1

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

MYREXIS, INC.

(Exact name of registrant as specified in its charter)


Delaware		26-3996918
(State or other jurisdiction of incorporation or organization)		(IRS Employer Identification No.)

c/o Xstelos Holdings, Inc.

630 Fifth Avenue, Suite 2260

New York, New York 10020

(801) 214-7800

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

Jonathan M. Couchman

President and Chief Executive Officer

Myrexis, Inc.

c/o Xstelos Holdings, Inc.

630 Fifth Avenue, Suite 2260

New York, New York 10020

(801) 214-7800

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Adam W. Finerman, Esq.

Olshan Frome Wolosky LLP

Park Avenue Tower

65 East 55th Street

New York, New York 10022

(212) 451-2300

Approximate date of commencement of proposed sale to the public: Not Applicable.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box: o

If any of the securities being offered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, please check the following box: o

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

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. o

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. o

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. o

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. (Check one):

DEREGISTRATION OF UNSOLD SECURITIES

This Post-Effective Amendment No. 1 to Form S-3 relates to the Registration Statement on Form S-3 (333-170495), filed with the Securities and Exchange Commission on November 9, 2010 (the “ Registration Statement ”) by Myrexis, Inc., a Delaware corporation (the “ Registrant ”). The Registration Statement registered the sale of up to $80,000,000 of the Registrant’s securities.

In accordance with an undertaking made by the Registrant in the Registration Statement to remove from registration, by means of a post-effective amendment, any of the securities that had been registered for issuance that remain unsold at the termination of the offering, the Registrant hereby removes from registration all of its securities registered but unsold under the Registration Statement as of the date hereof.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Post-Effective Amendment No. 1 on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of New York, State of New York, on the 2nd day of July, 2013.