Oral Carbapenem Poised to Reshape UTI Treatment Landscape

NEW YORK, NY – November 13, 2025

Spero Therapeutics Advances Promising UTI Therapy

Spero Therapeutics announced positive Phase 3 trial results for tebipenem HBr, an oral carbapenem antibiotic aimed at treating complicated urinary tract infections (cUTI). The data, unveiled earlier this week, demonstrate non-inferiority to intravenous imipenem-cilastatin, a standard treatment for cUTI, signaling a potential shift in how these infections are managed. This advancement arrives as antibiotic resistance continues to climb, making effective treatment options increasingly scarce. The company has projected a cash runway extending into 2028, bolstered by a licensing agreement with GSK, who is slated to submit a New Drug Application (NDA) to the FDA in the coming months.

A New Approach to Combating Resistant Infections

Currently, many cUTIs, particularly those caused by multi-drug resistant pathogens like ESBL-producing bacteria, require hospitalization for intravenous antibiotic administration. This presents a significant burden on healthcare resources and poses challenges for patients. Tebipenem HBr offers a potential solution: an oral formulation of a carbapenem, a class of antibiotics often reserved as a last resort due to resistance concerns. The PIVOT-PO trial, which enrolled over 900 patients, demonstrated that the oral drug achieved comparable efficacy to its intravenous counterpart in treating cUTI, including pyelonephritis.

“The need for new antibiotics, particularly those effective against resistant strains, is critical,” stated one infectious disease specialist. “An oral carbapenem could dramatically alter treatment paradigms, reducing hospitalization rates and improving patient outcomes.”

The trial results showed an overall success rate of 58.5% for tebipenem HBr, compared to 60.2% for intravenous imipenem-cilastatin, with a non-inferiority margin. Importantly, the safety profile of the oral drug appeared consistent with that of other carbapenems, with most adverse events being mild or moderate.

Financials and Partnership Dynamics

Spero’s advancement isn't happening in a vacuum. The company has a strategic partnership with GSK, which holds exclusive commercialization rights for tebipenem HBr in most global markets. This collaboration is crucial for Spero, which lacks the resources to bring the drug to market independently. GSK is expected to submit the NDA to the FDA in the fourth quarter of 2025, with a potential regulatory decision in the second half of 2026.

The financial implications for Spero are significant. The company reported a reduced net loss of $7.38 million in the most recent quarter, aided by cost-cutting measures and the licensing agreement with GSK. This extension of their cash runway into 2028 provides them with the financial stability to focus on regulatory submissions and potential future development programs. However, the success of tebipenem HBr hinges on GSK's ability to successfully commercialize the drug. One analyst commented, “GSK's track record in bringing new antibiotics to market is somewhat mixed. Their commitment to tebipenem HBr will be crucial to its ultimate success.”

Beyond the financial benefits, Spero recently discontinued a separate program for SPR720, a drug aimed at treating non-tuberculous mycobacterial pulmonary disease (NTM-PD), after failing to meet its primary endpoint in a Phase 2a trial. This decision allowed Spero to streamline its focus and resources towards advancing tebipenem HBr, underscoring the company’s strategic prioritization of this promising asset.

The Broader Impact on Antibiotic Stewardship

The introduction of an oral carbapenem raises important considerations regarding antibiotic stewardship. While carbapenems are effective against a wide range of bacteria, their widespread use can contribute to the development of resistance. Experts emphasize the need for responsible prescribing practices and robust antimicrobial stewardship programs to mitigate this risk. “We need to ensure that tebipenem HBr is used appropriately, only when other antibiotics are not effective,” explained a public health advocate. “This requires careful monitoring of resistance patterns and adherence to evidence-based guidelines.”

The potential for an oral carbapenem to reduce hospitalization rates could also have a positive impact on healthcare costs and resource utilization. By allowing patients to receive treatment at home, it could free up hospital beds and reduce the burden on healthcare facilities. This is particularly important in the face of increasing healthcare costs and a growing aging population. While the long-term impact of tebipenem HBr on antibiotic resistance remains to be seen, its potential to address a critical unmet need in the treatment of cUTIs is undeniable. The next 12-18 months will be crucial as GSK prepares to submit the NDA and navigate the regulatory process.