UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q/A

Amendment No. 1

x  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2012

OR

¨  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

For the transition period from                       to                      

Commission File Number 000-30929

TG THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

787 Seventh Avenue

New York, New York 10019

(Address including zip code of principal executive offices)

(212) 554-4484

(Registrant's telephone number, including area code)

MANHATTAN PHARMACEUTICALS, INC.

(Former name, former address and former fiscal year, if changed since last report)

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

x Yes ¨ No

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 definition of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by checkmark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes ¨ No x

There were 14,917,658 shares of the registrant’s common stock, $0.001 par value, outstanding as of May 10, 2012.

EXPLANATORY NOTE

TG THERAPEUTICS, INC. (the “Company”) is filing this amendment (the “Form 10-Q/A”) to our Quarterly Report on Form 10-Q for the quarter ended March 31, 2012 (the “Form 10-Q”), filed with the U.S. Securities and Exchange Commission on May 14, 2012, solely to correct an error to the exhibits. While the exhibit list of the Form 10-Q correctly included both the TG Therapeutics, Inc. Amended and Restated 2012 Incentive Plan, dated May 14, 2012, and Powers of Attorney for Laurence N. Charney, William J. Kennedy and Mark Schoenebaum, these four exhibits were inadvertently omitted from the filing. They are now being filed with the 10-Q/A.

This Form 10-Q/A should be read in conjunction with the original Form 10-Q, which continues to speak as of the date of the Form 10-Q. Except as specifically noted above, this Form 10-Q/A does not modify or update disclosures in the original Form 10-Q. Accordingly, this Form 10-Q/A does not reflect events occurring after the filing of the Form 10-Q or modify or update any related or other disclosures.

ITEM 6. EXHIBITS

The exhibits listed on the Exhibit Index are included with this report.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

EXHIBIT INDEX

The following exhibits are included as part of this Amendment No. 1 to the Quarterly Report on Form 10-Q: