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 [Image: see text] CONCLUSION: Isavuconazole was detected in lumbar, but not ventricular CSF in three patients treated for CM. DISCLOSURES: All Authors: No reported disclosures