Background: There remains the need for well-tolerated agents to treat dermatophytoses. BAL4815 is the active component of the antifungal agent BAL8557 (the water-soluble prodrug) entering phase III clinical development as an oral and IV formulation. We report the minimum inhibitory and fungicidal concentrations (MICs and MFCs) of BAL4815 against common dermatophytes.
Methods: Organisms tested included ten strains each of Trichophyton rubrum (including strains with elevated terbinafine MICs), T. mentagrophytes, T. tonsurans, Epidermophyton floccosum, and Microsporum canis. MIC testing was performed using a microdilution method. MFC testing was performed by subculturing all wells from the MIC determinations that exhibited no visible growth.
Results: The MIC ranges of BAL4815 and terbinafine against all dermatophyte strains were 0.06– 0.25 and 0.002 –16 μg/ml, respectively. The mean MIC of BAL4815 was 0.09 μg/ml against all strains, including the T. rubrum strains with elevated terbinafine MICs. The mean MIC of terbinafine against all dermatophyte strains was 0.013 μg/ml, excluding the T. rubrum strains with elevated terbinafine strains, which had a mean MIC of 5.38 μg/ml. Neither BAL4815 nor terbinafine showed cidal activity against the majority of the strains tested.
Conclusion: The new azole BAL4815 showed potent activity against all the dermatophytes tested, including the T. rubrum isolates with elevated terbinafine MICs.
- TIMM 2nd (2010)