Summary of ACELRX PHARMACEUTICALS INC

Item 8.01 Other Events.

Public Offering

On December 6, 2012, AcelRx Pharmaceuticals, Inc. ("AcelRx," "we," "our" or "us") entered into an underwriting agreement (the "Underwriting Agreement") with Jefferies & Company, Inc. and Cowen and Company, LLC, as representatives of the several underwriters named therein (collectively, the "Underwriters"), relating to the issuance and sale of 12,500,000 shares of our common stock, par value $0.001 per share. The price to the public in this offering is $3.31 per share and the Underwriters have agreed to purchase the shares from us pursuant to the Underwriting Agreement at a price of $3.1114 per share. The net proceeds to us from this offering are expected to be approximately $38.3 million, after deducting the underwriting discounts and commissions and other estimated offering expenses payable by us. The closing of the offering is expected to take place on or about December 12, 2012, subject to customary closing conditions. In addition, under the terms of the Underwriting Agreement, we have granted the Underwriters an option, exercisable for 30 days, to purchase up to an additional 1,875,000 shares of our common stock.

The Underwriting Agreement contains customary representations, warranties and agreements by us, customary conditions to closing, indemnification obligations of AcelRx and the Underwriters, including for liabilities under the Securities Act of 1933, as amended, other obligations of the parties and termination provisions. The representations, warranties and covenants contained in the Underwriting Agreement were made only for purposes of such agreement and as of specific dates, were solely for the benefit of the parties to such agreement, and may be subject to limitations agreed upon by the contracting parties.

The offering was made pursuant to written prospectus dated December 6, 2012 forming a part of the registration statement on Form S-1 (File No. 333-185067) (the "Registration Statement") previously filed with and declared effective by the Securities and Exchange Commission (the "SEC"). The foregoing description of the Underwriting Agreement does not purport to be complete and is qualified in its entirety by reference to the form of Underwriting Agreement previously filed as Exhibit 1.1 to the Registration Statement.

Updated Company Disclosure

AcelRx is filing information for the purpose of supplementing and updating its description of certain risks and uncertainties that could materially adversely affect its business, financial condition or results of operations from the description included under the heading, "Item 1A. Risk Factors" in its Quarterly Report on Form 10-Q for the quarter ended September 30, 2012, filed with the SEC on August 10, 2012. The updated risk factors are filed herewith as Exhibit 99.1 and are incorporated herein by reference.

Forward-Looking Statements

This report contains "forward-looking" statements, including, without limitation, all statements related to the completion, timing and size of the public offering. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include, without limitation, risks and uncertainties related to market conditions and the satisfaction of customary closing conditions related to the public offering. There can be no assurance that AcelRx will be able to complete the proposed public offering on the anticipated terms, or at all. AcelRx will need to raise additional capital to fund its operations and may be unable to raise capital when needed, which would force AcelRx to delay, reduce or eliminate its product development programs or commercialization efforts. Additional risks and uncertainties relating to AcelRx and its business can be found in the updated risk factors filed herewith as Exhibit 99.1. AcelRx expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in its expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.