Purpose: OASIS (NCT03919994) was a prospective, observational study designed to provide insights on real-world outcomes associated with atypical long-acting injectable (LAI) antipsychotic medications.
Patients and methods: OASIS (March 2019-January 2023) was conducted across 63 US sites. Adults (≥18 years) with schizophrenia who newly initiated one of four atypical LAI antipsychotics (aripiprazole lauroxil, aripiprazole monohydrate, paliperidone palmitate, or risperidone long-acting injection [microsphere formulation]) were enrolled and followed for up to 12 months in routine care. Treatment patterns (reasons for treatment initiation, duration of use, rates of switching/discontinuation) were assessed. Outcomes included Clinical Global Impression-Severity (CGI-S), Clinician-Rated Dimensions of Psychosis Symptom Severity (CRDPSS) scale, and patient-reported Glasgow Antipsychotic Side-Effect Scale (GASS) scores. Results are summarized descriptively.
Results: Overall, 277 patients with schizophrenia enrolled and received ≥1 injection. Most common reasons for initiating atypical LAI antipsychotics at baseline were the presence of persistent psychotic symptoms (50%) and adherence challenges with oral antipsychotics (44%). Mean (SD) time on index treatment was 210.0 (145.3) days. Overall, 130 (47%) patients completed 12 months of follow-up; 74% of them remained on the treatment initiated until the end of study participation. Most study visits were conducted in person and were planned/scheduled versus crisis visits. Mean (SD) baseline CGI-S score was 4.2 (1.1), indicating moderate illness severity; individual CRDPSS symptom scores were mild (mean [SD] delusions score, 2.0 [1.4]; hallucinations, 1.9 [1.4]; negative symptoms, 1.6 [1.3]) at baseline and remained stable after treatment initiation. Antipsychotic side effects were generally absent or mild at baseline (mean [SD] GASS total score, 10.7 [10.3]) and over follow-up.
Conclusion: Treatment patterns in this observational study reinforced the real-world utility of atypical LAI antipsychotics in the treatment of schizophrenia. Results suggest that patients initiating treatment remained clinically stable with mostly absent or mild side effects for up to 12 months of follow-up.
Keywords: antipsychotic; aripiprazole; paliperidone palmitate; patient-reported outcome measures; risperidone.
Atypical long-acting injectable (LAI) antipsychotic medications may be underused in the treatment of schizophrenia. In the Observational Study of Long-Acting Injectables in Schizophrenia (OASIS) study, we wanted to better understand the benefits of these medications in the real world. We followed patients with schizophrenia who started taking one of four atypical LAI antipsychotics: aripiprazole lauroxil, aripiprazole monohydrate, paliperidone palmitate, or risperidone. We looked at patterns of how clinicians and patients used these medications and how patients benefited from treatment for up to 1 year. All patients were treated according to their clinician’s practice of routine care; the recommendation to start treatment and the medication chosen were up to the patients and their clinician. Most patients in the study were treated at a community mental health clinic or private practice, not a hospital. Illness severity was moderate and symptoms were mild at the start of the study. After they started taking an atypical LAI antipsychotic, most patients stayed on the medication that they started. Only a few patients switched to a different medication or stopped taking medication altogether. Despite the COVID-19 pandemic, most healthcare visits were in person and were planned rather than crisis visits. Over the course of up to 1 year of follow-up, illness severity and symptoms were stable, and most patients experienced no or mild side effects from the medication they were taking. These results show the utility of atypical LAI antipsychotic medications for the treatment of patients with schizophrenia in a real-world setting.
© 2025 Weiden et al.