Viozan (
sibenadet HCl,
AR-C68397AA) is a novel dual D2
dopamine receptor, beta2-adrenoceptor agonist that has been investigated for efficacy in alleviating the symptoms of
chronic obstructive pulmonary disease (
COPD). The slowly progressive nature of this disease means that patients will require ongoing therapeutic management for many years, or even decades. With such long-term treatment, the safety profile of new agents will be of paramount importance. As part of the large-scale assessment of
sibenadet, a 12-month safety study has been conducted. Following completion of a 2-week baseline period, 435 adults with stable, symptomatic, smoking-related
COPD were randomized to receive either 500 microg
sibenadet or placebo delivered via pressurized
metered dose inhaler (pMDI), three times daily for 52 weeks.
Sibenadet therapy was generally well tolerated, with the only notable differences seen in the incidence of
tremor and taste of treatment (16.9% vs. 4.1% and 14.5% vs. 4.1% in the
sibenadet and placebo groups respectively). There were a total of 79 patients with serious adverse events (SAEs), 43 (14.8%) in the
sibenadet pMDI group and 36 (24.8%) in the placebo group. No clinically significant abnormal laboratory values or overall differences between treatment groups were noted. Similarly, there were no clinically significant differences between the two treatment groups for cardiac variables, or in vital signs. The secondary variables showed no notable differences with respect to lung function, exacerbations or health-related quality of life. Due to the effective beta2-agonist properties, patients in the
sibenadet group did, however, report reduced rescue medication usage at all timepoints. While the results of this study show that, overall,
sibenadet therapy was well tolerated, the lack of sustained benefit reported in large-scale clinical efficacy studies means that
sibenadet development will not be continued.