Spero Therapeutics Announces Closing of Rights Offering

Cambridge, Massachusetts, UNITED STATES

CAMBRIDGE, Mass., March 05, 2020 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq:SPRO), a multi-asset clinical-stage biopharmaceutical company focused on identifying, developing and commercializing treatments in high unmet need areas involving multi-drug resistant bacterial infections and rare diseases, today announced the closing of its previously announced rights offering (the “Rights Offering”).  At the closing, Spero sold and issued an aggregate of 1,046,249 shares of its common stock (the “Common Stock”) and an aggregate of 2,287 shares of its Series C convertible preferred stock (“Series C Preferred Stock”) pursuant to the exercise of subscription rights and oversubscription rights in the Rights Offering by existing holders of its Common Stock, Series A convertible preferred stock and Series B convertible preferred stock.  Certain affiliates of BVF Partners L.P., a Spero stockholder, were the sole purchasers of the shares of Series C Preferred Stock sold in the Rights Offering pursuant to the exercise of their subscription and oversubscription rights.  Spero raised aggregate gross proceeds of approximately $30.0 million in the Rights Offering.

The Rights Offering was made pursuant to Spero’s effective shelf registration statement on file with the Securities and Exchange Commission (the “SEC”) (File No. 333-228661) and a prospectus supplement and accompanying prospectus filed with the SEC on February 11, 2020. 

About Spero
Spero Therapeutics, Inc. is a multi-asset, clinical-stage biopharmaceutical company focused on identifying, developing and commercializing novel treatments for multidrug-resistant (MDR) bacterial infections and rare diseases. 

Spero’s lead product candidate, tebipenem HBr (tebipenem pivoxil hydrobromide; formerly SPR994), is designed to be the first oral carbapenem-class antibiotic for use in adults to treat MDR Gram-negative infections. 

Spero is also advancing SPR720, its novel oral therapy product candidate designed for the treatment of rare, orphan disease caused by pulmonary non-tuberculous mycobacterial (NTM) infections. 

Spero also has a platform technology known as its Potentiator Platform that includes an IV-administered product candidate, SPR206, being developed to treat MDR Gram-negative infections in the hospital setting. 

For more information, visit https://sperotherapeutics.com

Forward Looking Statement
Investors are cautioned that statements in this press release regarding the rights offering constitute forward-looking statements that involve risks and uncertainties.   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 prospectus supplement and accompanying prospectus relating to the rights offering 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 and Media Contact: 
Sharon Klahre 
Senior Director, Investor Relations