Objective: To monitor long-term symptomatic tolerability and remission in patients with stable but suboptimally treated psychoses after switching to risperidone long-acting injectable (RLAI).
Method: This subgroup analysis of the Switch to Risperidone Microspheres (StoRMi) open-label trial followed up patients with psychoses who were converted to RLAI for a period of 18 months or until RLAI became commercially available in their country of residence. It included patients from seven European countries. Dosage adjustments were performed as clinically necessary. The efficacy endpoint was achieving and maintaining remission, defined as absent to mild core schizophrenia symptoms for > or = 6 months. A schizophrenia assessment was also completed and patients were monitored for the development of adverse events (AEs). Discontinuation rates were calculated based on Kaplan-Meier estimates where patients switching to commercial RLAI were used as censored observations.
Results: A total of 529 patients were followed for up to 18 months. At 18 months, the discontinuation rate was 55.7% based on Kaplan-Meier estimates. The median time to discontinuation was 15.7 months (95% CI (14.0; 17.5)). RLAI was generally well tolerated with most AEs mild-to-moderate in severity. 13% of patients discontinued treatment because of an AE. Body weight of patients increased by a mean A+/- SD of 1.0 A+/- 6.1 kg from treatment initiation to endpoint (p = 0.0001). Glucose-related AEs occurred in four patients (0.8%). Among those patients not meeting severity remission criteria at baseline, 44.8% were in remission at endpoint. Among those patients meeting severity criteria for remission at baseline, 84.2% were in remission at endpoint. A total of 93.7% of the patients who achieved or maintained remission at 6 months were in remission at endpoint.
Conclusions: RLAI is safe during long-term treatment up to 18 months in adults requiring antipsychotics. Conversion to RLAI resulted in improved symptom control. Most patients achieved and maintained a sustained remission (> or = 6 months) after conversion to RLAI.