UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report

(Date of earliest event reported)

March 30, 2015

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (609) 243-0123

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On March 30, 2015, we drew down the remaining $5 million of our term loan with Hercules Technology Growth Capital (“Hercules”), pursuant to the terms and conditions of the loan and security agreement dated as of May 9, 2014 (the “Loan Agreement”), so that the total principal amount of the term loan outstanding under the Loan Agreement is $15 million. We incorporate by reference the description of the Loan Agreement included in our Form 8-K current report filed with the Securities and Exchange Commission (the “SEC”) on May 12, 2014 and Note 8 to our Consolidated Financial Statements included in our Form 10-K annual report for the year ended December 31, 2014, filed with the SEC on March 17, 2015, as if fully set forth in this Form 8-K.

Pursuant to the Loan Agreement, we issued Hercules a warrant (the “Warrant”) to purchase 158,006 shares of our common stock at an exercise price of $2.67 per share. As we have drawn down the remaining $5 million of the term loan, the Warrant is now exercisable for an additional 52,669 shares of our common stock, or an aggregate of 210,675 shares of our common stock. The Warrant is exercisable beginning on the date of issuance and expires May 9, 2019. Until the shares of common stock issuable upon exercise of the Warrant may be resold pursuant to Rule 144 under the Securities Act of 1933 (the “Securities Act”), the holder of the Warrant has “piggyback” registration rights, which permit the holder of the warrant to have the “resale” of the shares of common stock issued upon exercise of the Warrant included on any registration statement we file after the issuance date under which we register for resale any shares of common stock held by any person.

The descriptions of the Loan Agreement and the Warrant contained or incorporated by reference in this Form 8-K report do not purport to be compete and are qualified in their entirety to the complete text of the Loan Agreement and the Warrant, including exhibits, which we filed with the SEC as exhibits to our Form 10-Q current report for the quarter ending June 30, 2014, filed on August 7, 2014.

The information provide in Item 1.01 of this Form 8-K report is incorporated by reference into this Item 2.03.

The information provided in Item 1.01 of this Form 8-K report is incorporated by reference into this Item 3.02.

We issued the Warrant to Hercules in reliance on the exemption from registration provided under Section 4(2) of the Securities Act. We relied on the exemption from registration provided under Section 4(2) based in part on the representations made by Hercules that it is an accredited investor, as such term is defined in Rule 501(a) under the Securities Act, and that the securities acquired by Hercules were being acquired for investment purposes and not with a view to the sale or distribution of any part thereof.

SIGNATURE

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 hereunto duly authorized.

Date: March 31, 2015