Budget impact of introducing once-every-6-months paliperidone palmitate in US health care plans

BACKGROUND: In the United States, most patients with schizophrenia have Medicaid coverage. Antipsychotic treatments are the cornerstone of schizophrenia management; most patients are treated with daily oral antipsychotics but struggle with medication adherence. Evidence suggests that medica-tion adherence is inversely correlated with dosing frequency. Once-monthly paliperi-done palmitate (PP) has been demonstrated to improve adherence compared with oral antipsychotics; transitioning to once-every-3-months PP (PP3M) further improved adherence. In 2021, once-every-6-months PP (PP6M) was approved by the US Food and Drug Administration to provide even longer between-dose intervals. Public health stakeholders who aim to improve medication adherence are interested in understanding how introducing PP6M to the formulary will impact the budget. OBJECTIVE: To evaluate the budget impact of introducing PP6M to the formulary from the perspectives of a hypothetical US multistate health care payer and state Medicaid pro-grams using California, Georgia, and Ohio as examples.METHODS: The budget impact model was developed from a payer perspective, com-paring the reference scenario (without PP6M in the market) with a new scenario (with PP6M). The study population included patients with schizophrenia who were eli-gible to receive PP6M. Market shares were assigned to the reference and new market scenarios. Efficacy was measured by the rela-tive risk of relapse while receiving treatment. Adherence effects were included in the model and affected costs of treatment and relapse rates. A deterministic 1-way sensitiv -ity analysis was performed.RESULTS: Base-case results for a multistate payer with 1 million members demonstrate that adding PP6M to the market results in total incremental plan-level costs ranging from $7,747 in year 1 to $11,501 in year 5. Increased drug costs were offset by admin-istration and relapse cost savings ($105 and $881 in year 5, respectively). The average incremental cost per treated patient per year was stable at $180.06 for each year, and the incremental cost per member per month stayed below $0.01 for each year. The results of the model from the state-level Medicaid scenarios are broadly similar to those of the multistate base-case perspective. The 1-way sensitivity analysis demonstrated the model is most sensitive to the per-package costs of PP6M and PP3M, along with the proportion of patients fully adherent with PP3M.CONCLUSIONS: The budget impact of introducing PP6M as a treat-ment option is minimal. With the expected cost offsets from reduced administration and relapse costs due to adherence benefits, these results suggest that PP6M can be a viable treatment option from a clinical and a budgetary perspective.