Lurasidone and Olanzapine in Patients with Schizophrenia

Cincinnati—An indirect treatment comparison of 6 atypical antipsychotic (AAP) medications for schizophrenia found that patient discontinuation rates were lowest for lurasidone and olanzapine. The findings from the comparison were presented during a poster session at the AMCP meeting. The poster was titled Discontinuation Rates among Atypical Antipsychotics for Schizophrenia: An Indirect Treatment Comparison.

According to the poster, discontinuing treatment or having poor adherence to AAPs has been associated with poor clinical and economic outcomes for those patients with schizophrenia. Adherence rates have been investigated in the past as part of the CATIE (Clinical Antipsychotic Trials of Effectiveness) Study conducted by the National Institute of Mental Health; however, several new medications were not included in the 2005 study.

In this indirect comparison, researchers used data from 3 parallel-group comparison studies to estimate the rates of all-cause discontinuations, discontinuations due to a lack of efficacy, and hospitalizations for 6 AAPs including aripiprazole, lurasidone, olanzapine, quetiapine XR, risperidone, and ziprasidone.

Researchers used data from CATIE, a randomized double-blind study that looked at 5 different treatments including olanzapine, quetiapine, risperidone, and ziprasidone, to determine discontinuation and hospitalization rates for the 4 AAPs. Researchers took the discontinuation and hospitalization rates seen in CATIE at 18-months and converted the figures into annualized discontinuation rates.

The second study included in the comparison was a 52-week open-label extension to a 26-week comparison of aripiprazole with olanzapine in patients with chronic schizophrenia. Researchers used this study to estimate annual discontinuation rates for aripiprazole that would be compared with the figures derived from the CATIE data. Although no hospitalization data were available in this study, researchers estimated this rate based on the relative risk of lack of efficacy for aripiprazole found in this study and the hospitalization rate for olanzapine found in the CATIE trial.

Finally, to estimate the annual discontinuation rate of lurasidone, researchers used Study 234, a randomized, double-blind study that evaluated safety and maintenance of efficacy for lurasidone compared to quetiapine XR. They compared their annual discontinuation rates of lurasidone to the estimated discontinuation rates of the CATIE AAPs.

Using the 3 previous research studies, the poster's authors conducted the indirect treatment comparison and found that olanzapine had the lowest rate of all-cause discontinuation (49.1%), followed by lurasidone (53.4%). The AAP with the highest rate of all-cause discontinuation was quetiapine XR (67.8%).

When discontinuation was examined due to a lack of efficacy, the authors of the poster found that, once again, olanzapine and lurasidone had the lowest discontinuation rates (9.9% and 14.3%, respectively). The highest discontinuation rates were in patients taking quetiapine XR (19.6%) and those taking risperidone (19.2%).

Lurasidone and olanzapine also had the lowest total annual all-cause hospitalization rates (5.7% and 7.8%, respectively), while aripiprazole (14.4%) and quetiapine XR (14.0%) had the highest.

This study was supported by Sunovion Pharmaceuticals Inc.