EXPRESS ZIP REGISTRATION CODE FREE SERIES

Each pre-funded warrant will be exercisable for one share of our common stock and will be exercisable at any time after its original issuance until exercised in full. We are also offering to certain purchasers whose purchase of shares of common stock in this offering would otherwise result in the purchaser, together with its affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock immediately following the consummation of this offering, the opportunity to purchase, if such purchasers so choose, pre-funded warrants in lieu of shares of common stock that would otherwise result in any such purchaser’s beneficial ownership exceeding 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock. The common warrants will be exercisable beginning on the date of issuance (the “Series 1 Common Warrants”) or, as applicable (as further described herein), the date on which we (a) receive approval from our stockholders (the “Stockholder Approval”) to increase the number of shares of common stock we are authorized to issue (a “Capital Event”) and (b) effect such Capital Event by filing with the Secretary of State of the State of Delaware a certificate of amendment to our amended and restated certificate of incorporation (each such date, an “Initial Exercise Date”) (the “Series 2 Common Warrants”), at an exercise price of $ per share and will expire on the five-year anniversary of the Initial Exercise Date. The combined purchase price for each share of common stock and accompanying common warrant is $0.7905. The common warrants will be issued separately but must be purchased together with the common stock and/or the pre-funded warrants (as described below).

EXPRESS ZIP REGISTRATION CODE FREE SERIES

We are offering 25,300,442 shares of our common stock together with common warrants to purchase shares of our common stock (and the shares of common stock that are issuable from time to time upon exercise of the Series 1 Common Warrants (as defined below)). If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.

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

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 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 statement number of the earlier effective registration statement for the same offering. 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, check the following box. Approximate date of commencement of proposed sale to public: As soon as practicable after this Registration Statement is declared effective.

Express zip registration code free