Spero Pharmaceuticals is a clinical-stage biopharmaceutical company focused on developing novel antibiotic treatments for rare infections with high unmet medical needs. The company's primary asset is tebipenem HBr, an oral carbapenem antibiotic in clinical development for complicated urinary tract infections caused by resistant bacteria, representing a potential first-in-class oral treatment option in a crowded antibiotic market where bacterial resistance to existing therapies is widespread. Spero has licensed tebipenem HBr to GlaxoSmithKline for global development and commercialization outside Japan, and generates revenue through milestone payments from GSK and government grants from agencies such as BARDA and CARB-X, with the company eligible to receive additional development and sales milestones plus tiered royalties on future product sales if the drug gains regulatory approval.