Basilea Pharmaceutica Halts Development of MRSA Antibiotic, Citing Risk-Return Criteria

Swiss biopharmaceutical company Basilea Pharmaceutica has announced its decision not to pursue further development of tonabacase, a potential antibiotic treatment for methicillin-resistant Staphylococcus aureus (MRSA). The company cited "stringent risk-return criteria" as the primary reason for this strategic move, highlighting the ongoing challenges in antibiotic development within the pharmaceutical industry.

Tonabacase Development Timeline and Decision

Basilea secured a license option for tonabacase, an endolysin antibiotic, from South Korea's iNtRON Biotechnology in 2023. Throughout 2024, the company conducted a preclinical evaluation of the asset to determine whether to proceed with securing exclusive rights for human trials.

Initially, the outlook for tonabacase appeared promising. Basilea's Chief Medical Officer, Marc Engelhardt, M.D., had expressed optimism about the compound in 2023, stating, "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."

However, after completing its preclinical profiling, Basilea revealed in its full-year earnings report that it had "taken the decision not to pursue further development" of tonabacase. This decision effectively cancels plans for a potential phase 2 clinical study that had been tentatively scheduled for 2025.

Basilea's Strategic Focus and Industry Trends

The decision to halt tonabacase's development underscores Basilea's commitment to maintaining strict portfolio management practices. The company stated, "This decision demonstrates that we are focused on stringent risk-return criteria when making portfolio decisions."

Basilea's move reflects broader trends in the pharmaceutical industry, where many major companies have reduced their focus on developing new antibiotics and antifungals due to low returns on investment. However, Basilea has chosen a different path, pivoting away from cancer research to concentrate on anti-infectives.

The company currently markets two anti-infective products: Cresemba for invasive fungal infections and Zevtera for bacterial infections. Basilea's clinical pipeline is now led by fosmanogepix, an antifungal licensed from Amplyx Pharmaceuticals, which is slated to enter its second phase 3 study targeting mold infections.

Government Support and Future Prospects

Despite the setback with tonabacase, Basilea's efforts in developing new antifungals received a significant boost in September 2024. The U.S. Department of Health and Human Services approved up to $268 million in funding for the company over more than a decade, demonstrating continued government support for anti-infective research.

This substantial funding, coupled with Basilea's strategic focus on anti-infectives, positions the company to continue its work in addressing critical medical needs in the face of growing antimicrobial resistance challenges.