CAMBRIDGE, Mass., July 12, 2018 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO ), a multi-asset clinical-stage biopharmaceutical company focused on identifying, developing and commercializing novel treatments for multidrug-resistant bacterial infections, today announced the pricing of an underwritten public offering of 3,780,000 shares of its common stock and 2,220 shares of its non-voting Series A Convertible Preferred Stock.  The public offering price of each share of common stock is $12.50 and the public offering price of each share of Series A Preferred Stock is $12,500.00.

The gross proceeds to Spero from this offering are $75,000,000, before deducting underwriting discounts and commissions, and other estimated offering expenses payable by Spero. All of the shares in the offering will be sold by Spero.  In addition, Spero has granted the underwriters a 30-day option to purchase up to an additional 567,000 shares of common stock at the public offering price, less the underwriting discount.  The offering is expected to close on July 17, 2018, subject to customary closing conditions.

Each share of Series A Preferred Stock is convertible into 1,000 shares of common stock, provided that conversion will be prohibited if, as a result, the holder of the Series A Preferred Stock and its affiliates would own more than 9.99% of the total number of shares of common stock then outstanding.

Cowen and Company, LLC, Stifel, Nicolaus & Company, Incorporated and Cantor Fitzgerald & Co. are serving as joint book-running managers for the offering.  Oppenheimer & Co. Inc. is acting as lead manager for the offering, and H.C. Wainwright & Co., LLC is acting as co-manager for the offering.

A registration statement relating to the offering has been filed with the Securities and Exchange Commission (SEC) and was declared effective on July 12, 2018.  The offering is being made only by means of a prospectus. Copies of the final prospectus relating to the offering may be obtained, when available, from Cowen and Company, LLC, c/o Broadridge Financial Solutions, Attention: Prospectus Department, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at (631) 274-2806; from Stifel, Nicolaus & Company, Incorporated, Attention: Syndicate, One Montgomery Street, Suite 3700, San Francisco, CA 94104, or by telephone at (415) 364-2720, or by email at syndprospectus@stifel.com; or from Cantor Fitzgerald & Co., Attention: Capital Markets, 499 Park Ave., 6th Floor, New York, NY 10022, or by email at prospectus@cantor.com.

This press release shall not constitute an offer to sell or a solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Spero

Spero is a multi-asset clinical-stage biopharmaceutical company focused on identifying, developing and commercializing novel treatments for multidrug-resistant bacterial infections.

Forward-Looking Statements

Investors are cautioned that statements in this press release regarding the intention, completion, timing and option relating to the proposed public offering constitute forward-looking statements that involve risks and uncertainties, including, without limitation, risks and uncertainties related to market conditions and the satisfaction of customary closing conditions related to the proposed public offering. There can be no assurance that Spero will be able to complete the proposed public offering. Additional information on risks facing Spero can be found under the heading “Risk Factors” in Spero’s periodic reports, including its annual report on Form 10-K and quarterly reports on Form 10-Q, and in the preliminary prospectus related to this offering filed with the SEC, and the final prospectus related to this offering to be filed with the SEC, each available on the SEC's web site at www.sec.gov. Spero 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.

Spero Investor Contact:
Sharon Klahre
Director, Investor Relations
857-242-1547
IR@sperotherapeutics.com