Executives of Spero Therapeutics Inc. evaded analysts’ attempts to clarify “deficiencies” noted by the U.S. FDA in its ongoing review of the company’s NDA seeking approval of oral carbapenem antibiotic tebipenem HBr for complicated urinary tract infections (cUTIs), emphasizing instead that they have three months to work with the regulator ahead of a June 27 PDUFA date assigned to the application.