By Chris Wack

Spero Therapeutics Inc. said the U.S. Food and Drug Administration has lifted the clinical hold on the Phase 2 trial of SPR720, its investigational oral product candidate being developed for nontuberculous mycobacterial disease.

The SPR720 program was placed on a clinical hold by the FDA following a review of data from a non-human primate toxicology study in which mortalities with inconclusive causality to treatment were observed.

The company said 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.

Spero plans on engaging with the FDA in the first quarter of 2022 to discuss the re-initiation of the SPR720 Phase 2 trial for NTM-pulmonary disease patients, with an expected study start date commencing in the second half of 2022.

Spero Therapeutics shares were up 6% to $16 in premarket trading.

Write to Chris Wack at chris.wack@wsj.com

(END) Dow Jones Newswires

01-04-22 0842ET