Spero Therapeutics, Inc. is a clinical-stage biopharmaceutical company. The Company is focused on focused on identifying and developing novel treatments for rare diseases and multi-drug resistant (MDR) bacterial infections with unmet need. Its lead product candidate, SPR720, is an oral antimicrobial agent in development for the treatment of nontuberculous mycobacterial (NTM) pulmonary disease, a rare orphan disease. Its partnership-directed programs consist of tebipenem HBr and SPR206. The tebipenem HBr is designed to be the oral carbapenem-class antibiotic for use to treat certain bacterial infections that cause complicated urinary tract infections (cUTIs), including pyelonephritis, caused by certain microorganisms, in adult patients who have limited oral treatment options. SPR206 is a direct acting intravenous (IV)-administered product candidate being developed as an option to treat MDR Gram-negative bacterial infections in the hospital setting.