QOLP-23. PHASE II RANDOMISED PLACEBO-CONTROLLED DOUBLE-BLIND STUDY OF ACETAZOLAMIDE VERSUS PLACEBO FOR CEREBRAL OEDEMA IN RECURRENT AND/OR PROGRESSIVE HIGH-GRADE GLIOMA REQUIRING TREATMENT WITH DEXAMETHASONE

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>INTRODUCTION</jats:title> <jats:p>Symptoms of raised intracranial pressure (ICP) in recurrent or progressive high-grade glioma (HGG) generally require corticosteroid treatment, often causing toxicity with variable effects on reversing ICP symptoms. Acetazolamide reduces ICP in other clinical settings including case series in glioma.</jats:p> </jats:sec> <jats:sec> <jats:title>AIM</jats:title> <jats:p>To explore whether addition of oral acetazolamide enables safe dexamethasone dose reduction in management of raised ICP in recurrent and/or progressive HGG.</jats:p> </jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>Participants had recurrent, progressive and/or persistent residual HGG requiring recommencement of dexamethasone, dose increase or dexamethasone dependency; prior/current bevacizumab was an exclusion. Eligible participants were randomised 1:1 to acetazolamide 250mg twice daily or placebo for 8 weeks. Standardised protocols were used for dexamethasone dose changes in both arms, with planned dose decrease from day 5 once ICP symptoms were stable. The primary endpoint was a composite of dexamethasone dose reduction and stability of performance status. Secondary endpoints included toxicity and feasibility (accrual and compliance).</jats:p> </jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Thirty participants of a planned sample of 84 were enrolled (mean age 58 y (32-89)) from 7 Australian sites. The mean baseline dexamethasone dose was 6.2mg (4-16mg). Mean duration on treatment was 38 days (4-57) in placebo group and 31 days (3-60) in acetazolamide group, with 9 participants (30%) completing all study treatment (6 placebo, 3 acetazolamide). Study withdrawal was due to adverse events (n=6 (1 placebo, 5 acetazolamide)) and disease progression (n=6 (3 per arm)). Four participants (13%) (2 per arm) were stable responders meeting the primary endpoint criteria (≥50% corticosteroid dos