Basilea announces in-licensing of a novel clinical phase 3-ready oral antibiotic

Ad hoc announcement pursuant to Art. 53 LR

Allschwil, Switzerland, August 14, 2025

Basilea Pharmaceutica Ltd, Allschwil (SIX: BSLN), a commercial-stage biopharmaceutical company committed to meeting the needs of patients with severe bacterial and fungal infections, announced today that it has entered into an exclusive license agreement with Venatorx Pharmaceuticals, Inc., to acquire the global rights to ceftibuten-ledaborbactam etzadroxil, a clinical phase 3-ready oral beta-lactam/beta-lactamase inhibitor (BL/BLI) combination for the potential treatment of complicated urinary tract infections (cUTI), including pyelonephritis.

Ceftibuten-ledaborbactam etzadroxil is the combination of ceftibuten, an orally bioavailable cephalosporin antibiotic, and ledaborbactam etzadroxil, the orally bioavailable prodrug of the novel beta-lactamase inhibitor ledaborbactam. The combination demonstrates bactericidal activity against Enterobacterales, including multidrug-resistant pathogens, the major cause of cUTI.[1] In the USA, cUTI account for more than 600,000 hospital admissions each year.[2] This underscores the significant clinical burden and need for effective oral treatment options, which may shorten or entirely avoid hospitalization. In preclinical and clinical phase 1 studies, ceftibuten and ledaborbactam etzadroxil were shown to be safe and well tolerated.[3]

David Veitch, Chief Executive Officer of Basilea, said: “This agreement allows us to strengthen our late-stage clinical pipeline and supports our strategy of ensuring that we have a continuous stream of potential new product launches in the near-term future, positioning us for sustainable substantial revenue growth. Ceftibuten-ledaborbactam etzadroxil holds strong promise in addressing the critical unmet need for the oral treatment of cUTI caused by multidrug-resistant Gram-negative bacteria and represents a compelling global commercial opportunity. We expect starting a registrational phase 3 program in cUTI in about 18 months.”

Under the terms of the agreement, Basilea will make an upfront payment and potential milestone payments in 2025. Following the successful completion of the phase 3 clinical development program and after the grant of regulatory approval and start of commercialization, Venatorx is eligible to receive tiered mid-single-digit royalties and additional potential milestone payments of up to USD 325 million in total, if all agreed commercial milestone events are triggered over the term of the contract.

The transaction is expected to result in approximately CHF 15 million of additional research and development expenses in 2025, including the full upfront payment, all potential pre-commercial milestone payments and expected R&D expenses in 2025. Basilea will provide updated financial guidance for the full-year 2025, reflecting this transaction, with the half-year earnings report on August 19, 2025.

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