Tebipenem HBr

Oral Carbapenem in Development for Treatment of Complicated Urinary Tract Infections

Antibiotic resistance is a growing global health threat, and one especially troubling concern is the rise in resistant strains of E. coli, the bacteria that cause the majority of urinary tract infections (UTIs).

The Center for Disease Dynamics, Economics & Policy (CDDEP) reports that in 2014, the most commonly used oral class of antibiotics for UTI, fluoroquinolones, were experiencing resistance at up to 35% in E. coli. The resistance had more than doubled in the last decade. Spero Therapeutics is developing a novel oral agent to treat these resistant bacteria.

On April 6, 2022, the results from the Phase 3 ADAPT-PO clinical trial for its investigational oral carbapenem antibiotic, tebipenem HBr, were published in the New England Journal of Medicine (NEJM).


Chemical Formula: C22H32BrN3O36S2
Molecular Weight: 578.54g/mol

Tebipenem HBr

We are developing Tebipenem HBr (tebipenem pivoxil hydrobromide; formerly SPR994) as an oral antibiotic for the treatment of complicated urinary tract infection (cUTI) and acute pyelonephritis (AP) to help patients avoid hospitalizations (stay at home) and/or transition patients home after IV therapy (get home).

Carbapenems are an important subclass of antibiotics because they have been observed to be safe and effective in the treatment of drug-resistant Gram-negative bacterial infections. Carbapenems have emerged as the standard-of-care for many multidrug-resistant (MDR) Gram-negative bacterial infections, but today they are only available as intravenous therapeutics for such indications.

The Latest

On April 6, 2022, Spero Therapeutics announced publication in the New England Journal of Medicine (NEJM) the results from the Phase 3 ADAPT-PO clinical trial for its investigational oral carbapenem antibiotic, tebipenem pivoxil hydrobromide (tebipenem HBr).

In June 2022, the FDA communicated that it had completed its review of the NDA and determined that the NDA could not be approved in its present form. In late June 2022, the FDA issued a Complete Response Letter for the tebipenem HBr NDA, where the FDA concluded that Spero’s Phase 3 cUTI clinical trial of tebipenem HBr (ADAPT-PO) was insufficient to support approval and that additional clinical study would be required. Spero has since requested and recently completed a Type A meeting with the FDA, discussing the regulatory pathway forward for potential approval of tebipenem HBr. Spero has received the Type A meeting minutes and proposed regulatory guidance regarding additional clinical study.  Spero plans to advance additional Phase 3 clinical development, and eventual commercialization through external partnership.

“Our commitment to the development of effective new agents to address unmet medical needs remains strong, as we seek to identify the optimal path forward for tebipenem’s regulatory approval, commercialization, and value creation, potentially through external partnerships. Tebipenem HBr remains an important part of the Spero pipeline and a complement to our SPR720 and SPR206 programs, which we continue to advance towards key clinical and regulatory milestones.”

Ankit Mahadevia, M.D.,
Chief Executive Officer of Spero Therapeutics

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NTM Info & Research is a 501(c)(3) non-profit organization formed for patient support, medical education and to help accelerate research.


Patients can follow the progress of SPR720 as the candidate moves through clinical trials. ClinicalTrials.gov is a database of clinical studies conducted worldwide.

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