GSK has signed an exclusive licence agreement with Spero Therapeutics for the latter’s tebipenem pivoxil hydrobromide (tebipenem HBr).

Tebipenem HBr is a late-stage, oral carbapenem antibiotic intended to treat complicated urinary tract infections (cUTI), including acute pyelonephritis caused by certain bacteria.

It is an oral formulation of tebipenem pivoxil, a carbapenem antibiotic for paediatric infections limited to pneumonia, otitis media and sinusitis, sold by Meiji Seika Pharma in Japan.

Under the licence deal, GSK will obtain exclusive rights to develop and market Tebipenem HBr worldwide, excluding Japan and certain other Asian countries retained by Meiji Seika.

Spero is anticipated to receive an initial upfront payment of $66m, in addition to potential milestone-based payments in the future.

The US biotech company will execute and fund the remaining Phase 3 trial, and GSK will advance the further clinical development, including regulatory submission and marketing.

In addition, the British drugmaker will purchase shares of Spero’s common stock worth $9m, under a stock purchase agreement between the companies.

The transactions are expected to be completed in the fourth quarter of this year, subject to certain customary closing conditions.

GSK chief commercial officer Luke Miels said: “There is a high unmet medical need for a novel oral antibiotic as an alternative to intravenous hospital therapy for drug-resistant complicated urinary tract infections.

“Tebipenem HBr complements GSK’s infectious disease strategy and is consistent with our commitment to find value-enhancing opportunities to build a strong late-stage portfolio.

“Tebipenem HBr has a clear US FDA regulatory path to potential approval, which could significantly benefit patients with complicated urinary tract infections.”

Tebipenem HBr has received the US FDA Qualified Infectious Disease Product (QIDP) and Fast Track designations for the treatment of cUTI and acute pyelonephritis.

Upon receiving the FDA approval, tebipenem HBr would become the first oral carbapenem antimicrobial to get marketing approval in the US.

Spero is expected to conduct an additional Phase 3 trial in 2023, to support the regulatory submission, based on positive feedback from the US FDA.

Spero chief executive officer Ankit Mahadevia said: “Spero’s agreement with GSK provides a critical step towards fully realising the value tebipenem HBr can potentially provide to physicians, payors, and patients.

“We are thrilled to collaborate with GSK on developing tebipenem HBr for patients suffering from complicated urinary tract infections.”