Basilea Pharmaceutica has cited its “stringent risk-return criteria” as a reason for not taking up its option to bring a MRSA antibiotic into clinical development.
Basilea secured the license option for the endolysin antibiotic, called tonabacase, from Korea’s iNtRON Biotechnology in 2023. Basilea had been conducting a preclinical evaluation of the asset throughout 2024 ahead of a decision on whether to secure the exclusive rights to take tonabacase into human trials.
When it signed the agreement with iNtRON, Basilea pointed to preclinical evidence of tonabacase’s activity against methicillin-resistant and methicillin-susceptible Staphylococcus aureus (MRSA and MSSA) as well as coagulase-negative staphylococci.
“There continues to be a high medical need for new treatment options for patients with persistent infections caused by Gram-positive bacteria and tonabacase is an exciting and innovative asset for us to evaluate over the coming months,” Basilea Chief Medical Officer Marc Engelhardt, M.D., said back in 2023. “If the outcome of our evaluation is positive and we enter into a full license agreement, we may be able to start directly a phase 2 clinical study in 2025.”
That trial is now off the menu, as Basilea has completed its own preclinical profiling of the medicine and “taken the decision not to pursue further development,” the Swiss company said in its full-year earnings report.
“This decision demonstrates that we are focused on stringent risk-return criteria when making portfolio decisions,” the company added.
Basilea currently markets Cresemba for invasive fungal infections and Zevtera for bacterial infections. The low return on investment means many of the biggest biopharmas have given up working on new antifungals or antibiotics in recent years—although GSK in particular has continued to sign deals and post encouraging clinical results against infections like gonorrhea.
Meanwhile, Basilea has swum against the tide, pivoting away from cancer toward anti-infectives last year. The company’s clinical pipeline is headed up by fosmanogepix, an antifungal licensed from Amplyx Pharmaceuticals that Basilea is planning to enter into its second phase 3 study against mold infections.
Basilea’s work developing new antifungals received a significant boost last September from the U.S. Department of Health and Human Services, which signed off on up to $268 million of funding to the biopharma over more than a decade.