GSK and Spero Therapeutics have inked a licensing agreement over Spero’s investigational antibiotic tebipenem HBr, also known as tebipenem pivoxil hydrobromide.

The oral antibiotic could potentially treat complicated urinary tract infections, including pyelonephritis, caused by certain bacteria, the companies said.

Spero expects to begin a phase 3 clinical trial of the drug candidate in 2023.

Under the licensing deal, GSK will pay Spero $66 million upfront, plus potential milestone payments. The transaction is expected to close in the fourth quarter of this year.