Ziprasidone vs clozapine in schizophrenia patients refractory to multiple antipsychotic treatments: the MOZART study

This 18-week, randomized, flexible-dose, double-blind, double-dummy trial evaluated ziprasidone as an alternative to clozapine in treatment-refractory schizophrenia patients. Patients had a DSM-IV diagnosis of schizophrenia, a history of resistance and/or intolerance to at least three acute cycles with different antipsychotics given at therapeutic doses, PANSS score ≥80, and CGI-S score ≥4. Patients were randomized to ziprasidone (80–160 mg/day, n=73) or clozapine (250–600 mg/day, n=74). On the primary ITT-LOCF analysis, baseline-to-endpoint decreases in PANSS total scores were similar in the ziprasidone (−25.0±22.0, 95% CI −30.2 to −19.8) and clozapine (−24.5±22.5, 95% CI −29.7 to −19.2) groups. A progressive and significant reduction from baseline in PANSS total score was observed from day 11 in both study arms. There were also significant improvements on PANSS subscales, CGI-S, CG-I, CDSS, and GAF, without between-drug differences. The two treatment groups had similar rates of early discontinuations due to AEs. AEs were mostly of similar mild-moderate severity in the two groups. There were also no detrimental effects on prolactin, renal and liver function, hematology, and cardiovascular parameters. However, ziprasidone but not clozapine showed a significant reduction of SAS and AIMS scores. Moreover, when compared with clozapine, ziprasidone also had a more favorable metabolic profile, with significant endpoint differences in weight, fasting glucose, total cholesterol, LDL cholesterol, and triglycerides. In conclusion, this trial indicates that both ziprasidone and clozapine, having comparable efficacy coupled with satisfactory general safety and tolerability, may be regarded as valuable options for the short-term treatment of difficult-to-treat schizophrenia patients with a history of multiple resistance and/or intolerance to antipsychotics. The more favorable metabolic profile of ziprasidone may represent an added value that could guide clinicians, at least in the presence of patients at high risk for metabolic disorders.