Tebipenem Pivoxil

CAMBRIDGE, Mass., Dec. 19, 2025 (GLOBE NEWSWIRE) -- Spero Therapeutics , Inc. (Nasdaq: SPRO), a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and multi-drug resistant (MDR) bacterial infections, today announced that its development partner, GSK, filed a New Drug Application (NDA) resubmission to the U.S. Food and Drug Administration (FDA) for tebipenem HBr, an investigational oral carbapenem antibiotic being developed for the treatment of complicated urinary tract infections (cUTI), including pyelonephritis. The NDA submission triggers a $25 million milestone payment to Spero, expected to be received in Q1 2026. The NDA resubmission is supported by results from the successful Phase 3 PIVOT-PO trial (NCT number – NCT06059846). The trial was stopped early for efficacy in May, 2025 following a planned interim analysis. Trial results were presented as a late breaker at the IDWeek conference in October 2025. Spero has granted GSK an exclusive license to commercialize tebipenem HBr in all territories except for certain Asian territories, where Meiji retains development and commercialization rights. Tebipenem HBr Research Support Select tebipenem HBr studies have been funded in part with federal funds from the Department of Health and Human Services; Administration for Strategic Preparedness and Response; and Biomedical Advanced Research and Development Authority, under contract number HHSO100201800015C. About Spero Therapeutics Spero Therapeutics, headquartered in Cambridge, Massachusetts, is a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and MDR bacterial infections with high unmet need. For more information, visit . Forward Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding the timing of a $25 million milestone payment expected to be received by Spero in Q1 2026. In some cases, forward-looking statements may be identified by terms such as "may," "will," "should," "expect," "plan," "aim," "anticipate," "could," "intent," "target," "project," "contemplate," "believe," "estimate," "predict," "potential" or "continue," the negative of these terms or other similar expressions; however, the absence of these words does not mean that statement is not forward looking . Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of important risks, uncertainties and other factors that may cause actual results to differ materially from those indicated by such forward looking statements, including whether the results of any of Spero’s clinical trials will warrant submission for approval from the FDA or equivalent foreign regulatory agencies; whether the FDA will ultimately approve tebipenem HBr and, if so, the timing of any such approval, taking into account the effects of possible regulatory delays; whether the FDA will require any additional clinical data or place labeling restrictions on the use of tebipenem HBr that would delay approval and/or reduce the commercial prospects of tebipenem HBr; whether a successful commercial launch can be achieved and market acceptance of tebipenem HBr can be established; Spero's reliance on third parties to manufacture, develop, and commercialize its product candidates, if approved; Spero’s reliance on GSK pursuant to the exclusive GSK License Agreement to develop tebipenem HBr and GSK’s right thereunder to determine, in its sole discretion, whether to further develop tebipenem HBr; Spero's need for additional funding; Spero's ability to retain key personnel; whether Spero's cash resources will be sufficient to fund its continuing operations for the periods anticipated; and other factors discussed in the "Risk Factors" set forth in filings that Spero periodically makes with the Securities Exchange Commission. The forward-looking statements included in this press release represent Spero's views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Except as required by law, Spero explicitly disclaims any obligation to update any forward-looking statements. Investor Relations Contact: Shai Biran, PhD Spero Therapeutics IR@Sperotherapeutics.com Media Inquiries: media@sperotherapeutics.com

GSK is betting there is untapped demand for an oral option. \n GSK and Spero Therapeutics have shared phase 3 results on their antibiotic candidate, revealing that the oral therapy closely matched the intravenous incumbent in a trial that could support filings for approval.The partners stopped the study in hospitalized adults with complicated urinary tract infections (cUTIs) early for efficacy in May. At an interim analysis, GSK and Spero’s oral tebipenem HBr was non-inferior to intravenous imipenem-cilastatin on a primary endpoint that looked at clinical cure and microbiological eradication.GSK and Spero used ID Week 2025 in Atlanta to share the data behind the primary endpoint success. The partners saw a 58.5% overall success rate in patients who took 600 mg of tebipenem HBr, compared to 60.2% in a cohort that received 500 mg of imipenem-cilastatin. The difference was within the trial’s 10% margin for non-inferiority, achieving the primary endpoint of the study.Data on secondary endpoints add to the evidence that tebipenem HBr is as effective as the intravenous treatment. The partners said 93.5% of patients on tebipenem HBr were symptom-free, versus 95.2% of their counterparts on imipenem-cilastatin. Microbiological response rates were 60.3% in the tebipenem HBr group and 61.3% in the imipenem-cilastatin cohort.  GSK and Spero said clinical and microbiological response rates in patients with antimicrobial-resistant Enterobacterales were consistent with data from the broader primary analysis population. The efficacy of tebipenem HBr against ESBL-producing Enterobacterales—which break down some antibiotics—and pathogens that have limited susceptibility to levofloxacin could influence the use of the drug candidate. Under the terms of a deal that rescued the once-rejected tebipenem HBr, GSK will file for approval of the oral antibiotic. Back in 2022, after the FDA requested another phase 3 trial and denied Spero\'s approval application, the Big Pharma scooped up rights to the drug for $66 million upfront.Now, GSK\'s regulatory submission is expected this year. One question is how the FDA, which has talked up the importance of including data from U.S. patients in filings, will respond to a study that relied heavily on sites in Eastern Europe. Spero’s earlier phase 3 also featured many sites in Eastern Europe.If approved, tebipenem HBr could enable physicians to treat more cUTIs outside of hospitals. The current reliance on intravenous therapies means some patients are hospitalized for treatment. An effective oral option could free healthcare providers from the costs of treating patients in hospitals.GSK is betting there is untapped demand for an oral option. Basilea Pharmaceutica has reached a similar conclusion, licensing an oral beta-lactam/beta-lactamase inhibitor for up to $325 million in August. The deal with Venatorx Pharmaceuticals gave the Swiss biotech rights to a phase 3-ready drug candidate. While GSK and Spero have a head start, Basilea sees potential advantages to its molecule. On an earnings call in August, Marc Engelhardt, M.D., chief medical officer at Basilea, named physicians’ concerns about the resistance potential of carbapenems and the pill burden of tebipenem HBr as areas where the biotech can differentiate its asset. Basilea’s candidate is given two to three times a day, versus four times a day for tebipenem HBr.While GSK is handling the next steps for tebipenem HBr, the program\'s fate still has implications for Spero. The biotech could receive up to $351 million in milestones tied to the oral antibiotic, starting with a $25 million payment when GSK files for approval in the U.S. Spero has forecast that milestones could fund its operations into 2028.