Antipsychotic Treatment Pathways, Real-World Adherence, Healthcare Resource Utilization, and Healthcare Costs Among Patients With Schizophrenia Treated With Once-Monthly, Once-Every-Three-Months, and Once-Every-Six-Months Paliperidone Palmitate in the United States
Clinical Therapeutics, 2026
Purpose
Patients with schizophrenia can initiate once-every-6-months paliperidone palmitate (PP6M), currently the longest dosing interval long-acting injectable (LAI) antipsychotic (AP), following adequate treatment with once-every-3-months paliperidone palmitate (PP3M) or once-monthly paliperidone palmitate (PP1M). However, limited real-world evidence exists describing the AP treatment pathways, adherence, healthcare resource utilization, and costs among patients with schizophrenia treated with PP1M, PP3M, or PP6M.
Methods
Descriptive retrospective analysis of 3 cohorts of adults with schizophrenia who had ≥4 PP1M, ≥1 PP3M, or ≥1 PP6M claim(s) were selected from Komodo Research Data closed US insurance claims (January 01, 2016 to December 31, 2023; index date: first PP1M/PP3M/PP6M claim on/after January 09, 2021). Patients included had ≥12 months of pre-index insurance eligibility and no bipolar/pregnancy diagnoses. AP treatment pathways were evaluated over the pre-index continuous insurance eligibility period. The 6- and 12-month adherence to the index treatment (proportion of days covered ≥80%), schizophrenia-related inpatient admissions, and direct all-cause costs (2023 US dollars; per-patient-per-year [PPPY]) were described from index to the earliest of end of data or eligibility.
Findings
The sample included 17,463 patients in the PP1M cohort, 5348 in the PP3M cohort, and 628 in the PP6M cohort, with mean follow-up of 16.0, 14.2, and 9.4 months, respectively (mean age 40.6-41.3 years; 24.8-28.2% females). Patients were observed for 4.6 years on average before initiating PP6M, during which 72.1% used oral APs, 83.3% used PP1M (average of 21.9 months), and 71.0% used PP3M (average of 27.8 months); 98.6% of patients transitioned to PP6M directly from PP1M (32.5%) or PP3M (67.5%). Two-thirds of patients (PP1M: 61.2%; PP3M: 64.6%) initiated PP6M at the higher dose strength of 1560 mg. Among patients in the PP1M, PP3M, and PP6M cohorts with sufficient follow-up, 59.4%, 75.8%, and 100% were adherent at 6 months and 51.4%, 59.1%, and 73.9% were adherent at 12 months. At 3 months post index, 5.1% of the PP1M cohort, 2.1% of the PP3M cohort, and 1.8% of the PP6M cohort had a schizophrenia-related inpatient admission. Mean all-cause medical costs PPPY numerically decreased with less frequent administration (PP1M: $22,116; PP3M: $16,030; PP6M: $14,217); PP6M had the lowest medical to total all-cause cost ratio (PP6M: 26.7%; PP3M: 35.5%; PP1M: 44.9%).
Implications
Patients with schizophrenia using PP3M or PP6M were numerically more adherent to treatment, incurred lower medical costs, and a lower proportion had a schizophrenia-related inpatient admission relative to patients using PP1M, suggesting LAIs with longer dosing intervals may improve clinical outcomes and decrease economic burden.
Authors
Morrison L, Pilon D, Voegel A, Diaz L, Yokoji K, Benson C