Risperidone ISM as a New Option in the Clinical Management of Schizophrenia: A Narrative Review

Extrapyramidal adverse events and anticholinergics use after the long-term treatment of patients with schizophrenia with the new long-acting antipsychotic Risperidone ISM®: results from matching-adjusted indirect comparisons versus once-monthly formulations of Paliperidone palmitate and Aripiprazole monohydrate in 52-week studies

BACKGROUND

Risperidone ISM® is a newly developed long-acting injectable (LAI) treatment for schizophrenia in adults. In the absence of head-to-head comparisons with other similar antipsychotics, the objective of this study was to generate indirect evidence of some aspects of the safety and tolerability of Risperidone ISM compared to other LAI antipsychotics for treatment of patients with schizophrenia in the maintenance treatment setting.

METHODS

A literature review was conducted systematically to identify maintenance treatment studies reporting safety and tolerability outcomes for LAI antipsychotic therapies. Following an assessment of between-trial heterogeneity, a matching-adjusted indirect comparison (MAIC) was performed to account for between-trial imbalances in patient characteristics and to generate comparative evidence for safety and tolerability endpoints.

RESULTS

The analysis showed that incidence of extrapyramidal symptoms (EPS) was found to be numerically, but not statistically significantly, lower in patients receiving Risperidone ISM than in those receiving Paliperidone palmitate (PP) (OR [95% CI] 0.63 [0.29, 1.38], p = 0.253) and statistically significantly lower than with Aripiprazole monohydrate once-monthly (AOM) (OR [95% CI] 0.25 [0.12, 0.53], p < 0.001). Use of anticholinergic agents for the alleviation of EPS was also shown to be significantly lower in Risperidone ISM patients than in those receiving PP (OR [95% CI] 0.29 [0.10, 0.83], p = 0.021) or AOM (OR [95% CI] 0.01 [0.003, 0.06], p < 0.001), suggesting a superior tolerability profile for clinically relevant EPS. Results from the sensitivity analyses comparing stabilized and stable patients receiving Risperidone ISM to those receiving AOM yielded similarly favorable conclusions in line with the base case analyses.

CONCLUSIONS

This MAIC is consistent with the safety and tolerability results obtained during the PRISMA-3 clinical trial in the long-term treatment of schizophrenia and suggests a favorable safety and tolerability profile in terms of EPS incidence and anticholinergic agent use, relative to other antipsychotic therapies used for treatment of patients with schizophrenia in the maintenance setting.

Personal and Social Functioning and Health-Related Quality of Life in Patients with Schizophrenia Treated with the Long-Acting Injectable Antipsychotic Risperidone ISM

OBJECTIVE

To analyze the effect of Risperidone ISM on social functioning and health-related quality of life (HR-QoL) in both short- and long-term treatment of patients with schizophrenia.

PATIENTS AND METHODS

This analysis was based on data from both phases of the PRISMA-3 study, including 433 relapsed patients from the double-blind (DB) phase of the PRISMA-3 trial who were treated for 12-weeks with once-monthly (every 28 days) intramuscular Risperidone ISM 75 mg or 100 mg (n = 288), or placebo (n = 145), as well as 174 patients transitioning from the DB to an open-label 52-week extension (OLE) phase, plus 41 de novo patients treated on a stable maintenance dose of oral risperidone. The clinician-administered Personal and Social Performance (PSP) scale and the patient-reported 20-item Subjective Well-being under Neuroleptics scale (SWN-20) were used to measure social functioning and HR-QoL outcomes, respectively.

RESULTS

Risperidone ISM significantly improved PSP total score from baseline to endpoint (Day 85) versus placebo in the DB phase with mean change total score (95% CI) of 10.7 (9; 12) compared to 4.8 (3; 7) for placebo (p < 0.0001). The statistically significant improvement was present from the first measurement time point (Day 29). SWN-20-measured HR-QoL increased on average in patients treated with Risperidone ISM in the DB phase. A significant improvement was also observed for PSP and SWN-20 scores from the OLE baseline to week 52 for patients transitioning from the DB phase. Stable de novo patients maintained similar PSP and SWN-20 scores during the whole OLE phase.

CONCLUSION

Risperidone ISM provided a rapid and sustained improvement in personal and social functioning, and HR-QOL without need of oral risperidone supplementation or loading doses. These findings, along with a fast onset of efficacy, could contribute to reinforcing the therapeutic alliance and possibly an earlier discharge. Moreover, patient functioning continued improving or was maintained with long-term treatment.