A phase 2, randomized, double-blind, multicenter trial to evaluate the safety and efficacy of three dosing regimens of isavuconazole compared with fluconazole in patients with uncomplicated esophageal candidiasis

Abstract

Esophageal candidiasis is a frequent cause of morbidity in immunocompromised patients. Isavuconazole is a novel, broad-spectrum antifungal developed for the treatment of opportunistic fungal infections. This phase 2 trial compared the efficacy and safety of three oral dosing regimens of isavuconazole with an oral fluconazole regimen in the primary treatment of uncomplicated esophageal candidiasis. The isavuconazole regimens were as follows: 200 mg on day 1 and then 50 mg once daily (arm A), 400 mg on day 1 and then 400 mg once-weekly (arm B), and 400 mg on day 1 and then 100 mg once daily (arm C). Patients in arm D received fluconazole at 200 mg on day 1 and then 100 mg once daily. The minimum treatment duration was 14 days. The primary endpoint was the rate of endoscopically confirmed clinical response at end of therapy. Safety and tolerability were also assessed. Efficacy was evaluated in 153 of 160 enrolled patients. Overall, 146 (95.4%) achieved endoscopically confirmed clinical success. Each of the isavuconazole regimens was shown to be not inferior to fluconazole, i.e., arm A versus D, -0.5% (95% confidence interval [CI] -10.0 to 9.4), arm B versus D, 3.5% (95% CI, -5.6 to 12.7), and arm C versus D, -0.2% (95% CI, -9.8 to 9.4). The frequency of adverse events was similar in arm A (n = 22; 55%), arm B (n = 18; 45%), and arm D (n = 22; 58%), but higher in arm C (n = 29; 71%). In summary, efficacy and safety of once-daily and once-weekly isavuconazole were comparable with once-daily fluconazole in the primary treatment of uncomplicated esophageal candidiasis.