(C-006) Characterizing treatment and burden of disease in adolescents with schizophrenia

Background: Schizophrenia is a severe and disabling disorder that significantly impacts daily functioning and quality of life. Current clinical guidelines recommend second-generation antipsychotic medication as first-line treatment. While seven oral second-generation antipsychotics have been approved for adolescents, no long-acting injectable (LAI) formulations have been approved for individuals under 18. As LAI formulations have shown to significantly improve adherence and reduce relapses compared to oral antipsychotics among adults, adolescents with schizophrenia are lacking this option.

Objectives: To characterize the burden of schizophrenia among adolescents by describing the prevalence of, and persistence and adherence to, treatment with antipsychotics.

Methods: This was a retrospective cohort study using the United States (US) Merative MarketScan Multi-State Medicaid database between 2017-2023. Patients newly initiating an oral or LAI antipsychotic between the ages 12-17, with a previous schizophrenia diagnosis, and with 365 days of prior observation were identified. Persistence was calculated as the proportion of patients with continuous medication use from initiation through one year allowing for 60 day gaps and adherence was calculated as the proportion of days (PDC) covered within the first year after initiation.

Results: Diagnosed schizophrenia in adolescents aged 12-17 was rare, with 0.22% receiving a diagnosis between 2017-2023. Among those diagnosed with schizophrenia (n=5,640), 78% had ≥1 dispensing of an oral antipsychotic and 6% had ≥1 dispensing of a LAI antipsychotic. However, persistence and adherence to both oral and LAI antipsychotics were limited, with only 29% and 30% treating through one continuous year and the average PDC being 0.48 and 0.46, respectively. Among adolescents with schizophrenia and ≥1 dispensing of a LAI (n=332), many treatment trials preceded it: 76% received ≥2 oral antipsychotic ingredients in the year prior and the average time from initial oral antipsychotic to LAI receipt was 1.1 years. Finally, among all adolescents with ≥1 dispensing of a LAI antipsychotic (n=2,188), other psychiatric conditions were more frequently diagnosed than schizophrenia: 67% had attention-deficit/ hyperactivity disorder, 53% had bipolar disorder, 39% had psychotic disorder, and 24% had major depression compared with 16% with schizophrenia.

Conclusions: These findings suggest a potential unmet medical need for adolescent patients with schizophrenia in the US as evidenced by gaps in treatment, varied treatment regimens over time, and off-label receipt of LAI antipsychotics.