A Double-Blind, Randomized Study Comparing the Efficacy and Safety of Sertindole and Risperidone in Patients With Treatment-Resistant Schizophrenia

Objective: The comparative efficacy of second-generation antipsychotics has yet to be fully elucidated in patients with treatment-resistant schizophrenia. The objective of this study was to examine the efficacy and safety of sertindole, compared to risperidone, in this patient population. Method: In this multicenter, phase 3, randomized, double-blind, parallel-group study, only patients with DSM-IV schizophrenia who had failed an adequate antipsychotic treatment within the previous 6 months and who had not responded positively to haloperidol during screening were eligible for enrollment. The primary efficacy variable was change in Positive and Negative Syndrome Scale (PANSS) from baseline to final assessment. Weekly assessments included the PANSS, the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), and the Clinical Global Impressions (CGI) scale. The study was conducted between June 1996 and April 1998. Results: Of the 321 patients randomly assigned to double-blind treatment, 217 patients completed the study (sertindole, n/n = 142/216 [66%]; risperidone, n/n = 75/105 [71%]). The main reason for withdrawal in both groups was ineffective therapy. The between-group difference in PANSS total score was not statistically significant and both groups showed improvement, with mean changes of -18.6 in the sertindole group and -20.9 in the risperidone group based on observed cases and -12.0 and -19.0, respectively, based on the last-observation-carried-forward method for imputing missing data. There were no statistically significant differences between the groups in any of the secondary end points: PANSS positive and negative subscales, CGI scores, BPRS total scores and positive symptom sub-scale scores, and SANS total scores. Patients reported similar levels of adverse events and treatment-emergent adverse events (TEAEs), except for extrapyramidal syndrome-related TEAEs, which were more common in the risperidone-treated group. Prolongation of the QTc interval was observed significantly more frequently with sertindole treatment. Conclusions: Sertindole and risperidone are effective and well-tolerated in patients with treatment-resistant schizophrenia. Sertindole offers an alternative treatment option for refractory patients in Europe given its good EPS profile, favorable metabolic profile, and comparable efficacy to risperidone.