Trial Outcomes & Findings for A Study of Oral Tebipenem Pivoxil Hydrobromide (TBP-PI-HBr) Compared to Intravenous Imipenem-cilastatin in Participants With Complicated Urinary Tract Infection (cUTI) or Acute Pyelonephritis (AP) (NCT NCT06059846)

The planned enrollment for the full study was 2648 participants. As specified in the protocol, a pre-planned interim analysis occurred when approximately 60% of participants reached the test-of-cure visit. The study met the primary endpoint for efficacy at the interim analysis and the study was stopped. Enrollment was paused during the interim analysis. Therefore, a total of 1690 participants were enrolled in the study at various investigative sites from 21 Dec 2023 to 06 Feb 2025.

Participants with a clinical diagnosis of complicated urinary tract infection/acute pyelonephritis (cUTI/AP) were randomized in a 1:1 ratio to receive either tebipenem pivoxil hydrobromide (TBP-PI-HBr) or imipenem-cilastatin.

A Study of Oral Tebipenem Pivoxil Hydrobromide (TBP-PI-HBr) Compared to Intravenous Imipenem-cilastatin in Participants With Complicated Urinary Tract Infection (cUTI) or Acute Pyelonephritis (AP)

Overall response includes combined clinical cure plus microbiological eradication. Clinical cure is defined as a complete resolution or significant improvement of signs and symptoms of cUTI or AP present at baseline and no new symptoms, such that no further antibacterial therapy is warranted, and participant is alive. Microbiological eradication (favorable microbiological response) is defined as a reduction of baseline uropathogens to \<10\^3 CFU/mL and negative repeated blood culture if blood culture was positive for uropathogen growth at baseline and participant is alive.

Overall response includes combined clinical cure plus microbiological eradication. Clinical cure is defined as a complete resolution or significant improvement of signs and symptoms of cUTI or AP present at baseline and no new symptoms, such that no further antibacterial therapy is warranted, and participant is alive. Microbiological eradication (favorable microbiological response) is defined as a reduction of baseline uropathogens to \<10\^3 CFU/mL and negative repeated blood culture if blood culture was positive for uropathogen growth at baseline and participant is alive.

Overall response includes combined clinical cure plus microbiological eradication. Clinical cure is defined as a complete resolution or significant improvement of signs and symptoms of cUTI or AP present at baseline and no new symptoms, such that no further antibacterial therapy is warranted, and participant is alive. Microbiological eradication (favorable microbiological response) is defined as a reduction of baseline uropathogens to \<10\^3 CFU/mL and negative repeated blood culture if blood culture was positive for uropathogen growth at baseline and participant is alive.

Overall response includes combined clinical cure plus microbiological eradication. Clinical cure is defined as a complete resolution or significant improvement of signs and symptoms of cUTI or AP present at baseline and no new symptoms, such that no further antibacterial therapy is warranted, and participant is alive. Microbiological eradication (favorable microbiological response) is defined as a reduction of baseline uropathogens to \<10\^3 CFU/mL and negative repeated blood culture if blood culture was positive for uropathogen growth at baseline and participant is alive.

Clinical response at EOT and TOC is based on the Investigator's assessment of changes in baseline cUTI/AP signs and symptoms. Clinical cure: complete resolution or marked improvement of baseline symptoms with no new symptoms and no need for additional antimicrobial therapy. Clinical failure: baseline symptoms not fully resolved, new symptoms occur requiring non-study antibiotics, or death. Clinical indeterminate: insufficient data to classify response (e.g., lost to follow-up or missing data). Clinical response at LFU is based on change from baseline. Cure, including sustained clinical cure: met cure criteria at TOC and remained free of new or recurrent cUTI/AP symptoms at LFU with no need for further antibiotics. Failure, including clinical relapse: met cure criteria at TOC but developed new cUTI/AP symptoms at LFU requiring antibiotics. Clinical indeterminate: insufficient data to classify as sustained cure or relapse.

Clinical response at EOT and TOC is based on the Investigator's assessment of changes in baseline cUTI/AP signs and symptoms. Clinical cure: complete resolution or marked improvement of baseline symptoms with no new symptoms and no need for additional antimicrobial therapy. Clinical failure: baseline symptoms not fully resolved, new symptoms occur requiring non-study antibiotics, or death. Clinical indeterminate: insufficient data to classify response (e.g., lost to follow-up or missing data). Clinical response at LFU is based on change from baseline. Cure, including sustained clinical cure: met cure criteria at TOC and remained free of new or recurrent cUTI/AP symptoms at LFU with no need for further antibiotics. Failure, including clinical relapse: met cure criteria at TOC but developed new cUTI/AP symptoms at LFU requiring antibiotics. Clinical indeterminate: insufficient data to classify as sustained cure or relapse.

Clinical response at EOT and TOC is based on the Investigator's assessment of changes in baseline cUTI/AP signs and symptoms. Clinical cure: complete resolution or marked improvement of baseline symptoms with no new symptoms and no need for additional antimicrobial therapy. Clinical failure: baseline symptoms not fully resolved, new symptoms occur requiring non-study antibiotics, or death. Clinical indeterminate: insufficient data to classify response (e.g., lost to follow-up or missing data). Clinical response at LFU is based on change from baseline. Cure, including sustained clinical cure: met cure criteria at TOC and remained free of new or recurrent cUTI/AP symptoms at LFU with no need for further antibiotics. Failure, including clinical relapse: met cure criteria at TOC but developed new cUTI/AP symptoms at LFU requiring antibiotics. Clinical indeterminate: insufficient data to classify as sustained cure or relapse.

Participants were evaluated for microbiological response based on blood and urine cultures as: Eradication, defined as reduction of Baseline uropathogens to \<10\^3 CFU/mL on urine culture and negative repeated blood culture (if blood culture was positive at Baseline) ;Persistence, defined as Isolation from urine culture of ≥10\^3 CFU/mL or from blood of any of the Baseline uropathogen(s) identified at study entry; Indeterminate: no follow-up urine culture is available, or urine culture results are missing, or follow-up urine culture cannot be interpreted for any reason.

Participants were evaluated for microbiological response based on blood and urine cultures as: Eradication, defined as reduction of baseline uropathogens to \<10\^3 CFU/mL on urine culture and negative repeated blood culture (if blood culture was positive at Baseline); Persistence, defined as Isolation from urine culture of ≥10\^3 CFU/mL or from blood of any of the Baseline uropathogen(s) identified at study entry; Indeterminate: no follow-up urine culture is available, or urine culture results are missing, or follow-up urine culture cannot be interpreted for any reason.

Overall response includes combined clinical cure plus microbiological eradication. Clinical cure is defined as a complete resolution or significant improvement of signs and symptoms of cUTI or AP present at baseline and no new symptoms, such that no further antibacterial therapy is warranted, and participant is alive. Microbiological eradication (favorable microbiological response) is defined as a reduction of baseline uropathogens to \<10\^3 CFU/mL and negative repeated blood culture if blood culture was positive for uropathogen growth at baseline and participant is alive.

Overall response includes combined clinical cure plus microbiological eradication. Clinical cure is defined as a complete resolution or significant improvement of signs and symptoms of cUTI or AP present at baseline and no new symptoms, such that no further antibacterial therapy is warranted, and participant is alive. Microbiological eradication (favorable microbiological response) is defined as a reduction of baseline uropathogens to \<10\^3 CFU/mL and negative repeated blood culture if blood culture was positive for uropathogen growth at baseline and participant is alive.

Participants were evaluated for clinical response outcome based on assessment of signs and symptoms as: Cure, including sustained clinical cure (defined as met criteria for clinical cure at TOC, and remained free of new or recurrent signs and symptoms of cUTI or AP at LFU visit such that no further antibacterial therapy is warranted); Failure, including clinical relapse (defined as met criteria for clinical cure at TOC, but new signs and symptoms of cUTI or AP are present at LFU visit and participant requires antibacterial therapy for cUTI); or Clinical indeterminate: insufficient data are available to determine if participant is a sustained clinical cure or clinical relapse. If a participant is assessed as a clinical failure at EOT, participant is automatically considered a failure at TOC and LFU visits. If a participant is assessed as a clinical failure at TOC, participant is automatically considered a failure at LFU visit.

Participants were evaluated for clinical response outcome based on assessment of signs and symptoms as: Cure, including sustained clinical cure (defined as met criteria for clinical cure at TOC, and remained free of new or recurrent signs and symptoms of cUTI or AP at LFU visit such that no further antibacterial therapy is warranted); Failure, including clinical relapse (defined as met criteria for clinical cure at TOC, but new signs and symptoms of cUTI or AP are present at LFU visit and participant requires antibacterial therapy for cUTI); or Clinical indeterminate: insufficient data are available to determine if participant is a sustained clinical cure or clinical relapse. If a participant is assessed as a clinical failure at EOT, participant is automatically considered a failure at TOC and LFU visits. If a participant is assessed as a clinical failure at TOC, participant is automatically considered a failure at LFU visit.

Participants were evaluated for clinical response outcome based on assessment of signs and symptoms as: Cure, including sustained clinical cure: Sustained clinical cure is defined as met criteria for clinical cure at TOC, and remained free of new or recurrent signs and symptoms of cUTI or AP at LFU visit such that no further antibacterial therapy is warranted; Failure, including clinical relapse: Clinical relapse is defined as met criteria for clinical cure at TOC, but new signs and symptoms of cUTI or AP are present at LFU visit and participant requires antibacterial therapy for cUTI; Clinical indeterminate: insufficient data are available to determine if participant is a sustained clinical cure or clinical relapse. If a participant is assessed as a clinical failure at EOT, participant is automatically considered a failure at TOC and LFU visits. If a participant is assessed as a clinical failure at TOC, participant is automatically considered a failure at LFU visit.

Participants were evaluated for microbiological response based on blood and urine cultures as: Eradication, including sustained microbiologic eradication, i.e.,microbiologic eradication at TOC and no subsequent urine culture after TOC demonstrating recurrence of original Baseline uropathogen at ≥10\^3 CFU/mL;Persistence, including microbiologic recurrence, i.e.,isolation from urine culture at ≥10\^3 CFU/mL or blood culture of any of Baseline uropathogen(s) at any time after documented eradication at TOC visit up to and including LFU visit; Microbiologic indeterminate: no follow-up urine culture is available, or urine culture results are missing, or follow-up urine culture cannot be interpreted for any reason. If a participant is assessed as a microbiological persistence at EOT, participant is automatically considered persistent at TOC and LFU. If assessed as persistent at TOC, participant is automatically considered a persistent at LFU.

Participants were evaluated for clinical response outcome based on assessment of signs and symptoms as: Cure, including sustained clinical cure: Sustained clinical cure is defined as met criteria for clinical cure at TOC, and remained free of new or recurrent signs and symptoms of cUTI or AP at LFU visit such that no further antibacterial therapy is warranted; Failure, including clinical relapse: Clinical relapse is defined as met criteria for clinical cure at TOC, but new signs and symptoms of cUTI or AP are present at LFU visit and participant requires antibacterial therapy for cUTI; Clinical indeterminate: insufficient data are available to determine if participant is a sustained clinical cure or clinical relapse. If a participant is assessed as a clinical failure at EOT, participant is automatically considered a failure at TOC and LFU visits. If a participant is assessed as a clinical failure at TOC, participant is automatically considered a failure at LFU visit.

Participants were evaluated for microbiological response based on blood and urine cultures as: Eradication, including sustained microbiologic eradication, i.e.,microbiologic eradication at TOC and no subsequent urine culture after TOC demonstrating recurrence of original Baseline uropathogen at ≥10\^3 CFU/mL;Persistence, including microbiologic recurrence, i.e.,isolation from urine culture at ≥10\^3 CFU/mL or blood culture of any of Baseline uropathogen(s) at any time after documented eradication at TOC visit up to and including LFU visit; Microbiologic indeterminate: no follow-up urine culture is available, or urine culture results are missing, or follow-up urine culture cannot be interpreted for any reason. If a participant is assessed as a microbiological persistence at EOT, participant is automatically considered persistent at TOC and LFU. If assessed as persistent at TOC, participant is automatically considered a persistent at LFU.

Participants will be evaluated for microbiological response based on blood and urine cultures as :Eradication, including sustained microbiologic eradication, i.e., microbiologic eradication at TOC and no subsequent urine culture after TOC demonstrating recurrence of original Baseline uropathogen at ≥10\^3 CFU/mL;Persistence, including microbiologic recurrence, i.e.,isolation from urine culture at ≥10\^3 CFU/mL or blood culture of any of Baseline uropathogen(s) at any time after documented eradication at TOC visit up to and including LFU visit; Microbiologic indeterminate:no follow-up urine culture is available, or urine culture results are missing, or follow-up urine culture cannot be interpreted for any reason. If a participant is assessed as a microbiological persistence at EOT,participant is automatically considered persistent at TOC and LFU. If assessed as persistent at TOC, participant is automatically considered a persistent at LFU.

An Adverse Event (AE) was defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product, which does not necessarily have to have a causal relationship with the treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal investigational/experimental) product, whether or not related to this product. Serious Adverse Event (SAE) is any AE occurring at any dose and regardless of causality that results in death, is life threatening, requires immediate or prolongation of hospitalization, results in significant disability, congenital anomaly and is a medically important reaction. TEAEs are defined as events that are newly occurring or worsening from the time of the first dose of IP through LFU.