 CAMBRIDGE, Mass., March 17, 2022 GLOBE NEWSWIRE -- Spero Therapeutics, Inc. Nasdaq: SPRO, today announced that it will host a conference call and live audio webcast on Thursday, March 31, 2022, at 4:30 p.m. ET to report its fourth quarter and full-year 2021 financial results and provide an update on its business and pipeline. 