Spero Therapeutics Announces Presentation of SPR719 (Active Moiety of SPR720) In Vitro Data Demonstrating Low Propensity for the Development of Resistance at IDWeek 2024

Core Insights - Spero Therapeutics presented data on SPR719, demonstrating its low propensity for resistance development in Nontuberculous Mycobacterium Pulmonary Disease (NTM-PD) Mycobacterium avium complex (MAC) strains when used alone or in combination with standard care agents [1][4][5] Group 1: SPR719 and Its Mechanism - SPR720 is an oral prodrug that converts to SPR719, which targets the ATPase site of DNA gyrase B in mycobacteria, offering a distinct mechanism compared to existing antibiotics for NTM-PD [2] - The study showed that SPR719 had a high potency with minimum inhibitory concentration (MIC) values of 2 µg/mL for both macrolide susceptible and resistant strains [5] Group 2: Study Findings - The in vitro study indicated that SPR719 suppressed the emergence of resistance against MAC isolates, with mutation frequencies approximately three orders of magnitude lower than standard care comparators [5] - No resistant colonies were found when SPR719 was combined with clarithromycin or ethambutol, indicating no antagonism and supporting its potential for prolonged combination regimens in NTM-PD treatment [5] Group 3: NTM-PD Overview - NTM-PD is caused by bacteria found in soil, dust, and water, with the Mycobacterium avium complex being the most common pathogen [6] - The incidence of NTM pulmonary disease is increasing globally, with approximately 130,000 patients affected in the U.S. and Europe, growing at a rate of 8% annually [6]