Evaluation of the therapeutic efficacy and safety of the selective anxiolytic afobazole in generalized anxiety disorder and adjustment disorders: Results of a multicenter randomized comparative study of diazepam

AIM: to summarize the previously published results of a multicenter randomized clinical research phase III study trial of afobazole (INN: fabomotizole) versus diazepam in the treatment of patients with generalized anxiety disorder (GAD) and adjustment disorders (AD). SUBJECTS AND METHODS: Five investigating centers included 150 patients aged 18 to 60 years (60 patients with GAD and 90 with AD) a simple structure of anxiety disorders without concurrent mental, neurological or somatic disorders. Patients were randomized to take afobazole (30 mg/day; n=100) or diazepam (30 mg/day; n=50) for 30 days. Prior to drug administration, patients susceptible to placebo were excluded according to the results of its 7-day use. Withdrawal syndrome was evaluated within 10 days after completion of active therapy. The primary efficacy endpoint was the change of Hamilton Anxiety Rating Scale (HAMA) total score. The scores of the Clinical Global Impression (CGI) Scale and the Sheehan Scale as secondary efficacy endpoints were analyzed. Drug safety was evaluated by assessment of adverse events. RESULTS: Afobazole and diazepam caused a significant reduction of HAMA total score. In the afobazole group, the reduction of anxiety exceeded that in the diazepam group (the difference in the total score changes was 2.93 [0.67; 5.19]; p=0,01).The proportion of patients with reduction of disease severity was 72% in the afobazole group and 58% in the diazepam group. After therapy completion, the proportion of patients with no or mild disorder in the afobazole group was significantly higher than that in the diazepam group (69 and 44%, respectively; χ2=12.46; p=0,014). There was a trend toward a higher subjective patient-rated estimate of the afobazole effect using the Sheehan scale. There were a total of 15 and 199 adverse events in the afobazole and diazepam groups, respectively. No manifestations of afobazole withdrawal syndrome were found. Diazepam withdrawal syndrome was observed in 34 (68%) patients. CONCLUSION: Afobazole is an effective and safe drug to treat patients with GAD and AD and non-inferior than diazepam in the treatment of these disorders, however it is superior in terms of several variables, including the safety profile.