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. 3years; 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.
Morrison et al. (Sun,) studied this question.