A trial evaluating gradual- or immediate-switch strategies from risperidone, olanzapine, or aripiprazole to iloperidone in patients with schizophrenia

Abstract In a 12-week randomized open-label trial, adults diagnosed with schizophrenia experiencing inadequate efficacy and/or poor tolerability on risperidone, olanzapine, or aripiprazole were randomized to switch to iloperidone either gradually (ie, down-titration of current therapy over the first 2 weeks [to 50% on Day 1, 25% by Week 1, 0% by Week 2]) or immediately. All patients were titrated on iloperidone to 6 mg BID by Day 4, then flexibly dosing between 6 and 12 mg BID, as needed. The primary variable was the Integrated Clinical Global Impression of Change (I-CGI-C) and the primary analysis time point was Week 12. A total of 500 patients were randomized and received iloperidone (gradual switch, 240; immediate switch, 260), with 175, 155, and 170 patients switched from risperidone, olanzapine, and aripiprazole, respectively. I-CGI-C Results confirmed improved outcomes at Week 12, with scores that were similar between the gradual- and immediate-switch groups, respectively, for risperidone, 2.82 and 2.67 (95% CI: − 0.229, 0.511); olanzapine, 2.87 and 3.03 (95% CI: − 0.548, 0.235); and aripiprazole, 2.79 and 2.81 (95% CI: − 0.405, 0.368). Incidence of adverse events (AEs) was similar in both switch groups, with the most frequently reported (≥ 10%) being dizziness, dry mouth, somnolence, and weight increase. In conclusion, switching to iloperidone by either a gradual or an immediate method did not reveal any clinically significant differences in ratings of overall efficacy and safety/tolerability outcomes, based on the I-CGI-C at 12 weeks. Similar overall safety/AE profiles were observed regardless of the specific agent from which patients were switched.