750. Isavuconazole Cerebrospinal Fluid Concentration in Refractory Coccidioidal Meningitis - A Three-Patient Case Series

Background Coccidioidal meningitis (CM) causes life-threatening infection with limited treatment options. Small series have reported variable treatment success with isavuconazole. An absence of published data exists on cerebrospinal fluid (CSF) penetration of this agent. Methods Paired serum and CSF levels were measured on three patients with refractory CM treated on salvage isavuconazole therapy. Results 11 CSF levels were sent on 3 patients; 7 from ventricular sources (Ommaya reservoir or external ventricular drain) and 4 from lumbar punctures at 6-44 days after treatment initiation, 2-24.6 hours after oral or intravenous dose. All levels sent from ventricular sources were undetectable < 25µg/mL despite adequate paired serum levels (mean 2.45 µg/mL, range 1.25-6.38 µg/mL; n = 7 levels). Mean lumbar CSF levels were 1.00 µg/mL (range 0.45-1.72 µg/mL; n = 4 levels) with adequate serum levels (mean 3.57 µg/mL, range 1.78-5.63 µg/mL; n = 4 levels). Table 1. Isavuconazole serum and cerebrospinal fluid concentration measurements Conclusion Isavuconazole was detected in lumbar, but not ventricular CSF in three patients treated for CM. Disclosures All Authors: No reported disclosures