The FDA has lifted the clinical hold on Spero Therapeutics Inc's (NASDAQ:SPRO) Phase 2 trial of SPR720 for nontuberculous mycobacterial (NTM) disease.

• The SPR720 program was placed on a clinical hold by the FDA following a review of data from a non-human primate (NHP) toxicology study in which mortalities with inconclusive causality to treatment were observed. 
• The FDA's decision to lift the hold follows Spero's submission of a comprehensive study report with detailed analyses from the NHP toxicology study. 
• Related: Spero Therapeutics Stock Surges On $40M Equity Funding, SPR206 Licensing Pact With Pfizer.
• NTM lung disease is a general term for disorders characterized by exposure to specific bacterial germs known as mycobacteria. 
• Spero plans on engaging with the FDA in Q1 of 2022 to discuss the re-initiation of the SPR720 Phase 2 trial, with an expected study start date commencing in 2H of 2022.
• SPR720 represents a novel antibacterial agent class that targets enzymes essential for bacterial DNA replication. 
• Price Action: SPRO shares are down 0.86% at $15.02 during the market session on the last check Tuesday.