Real-world adherence, healthcare resource utilization, and costs following a transition to aripiprazole once every 2 months among patients diagnosed with bipolar I disorder in the United States.

INTRODUCTION

Transitioning from oral to long-acting injectable (LAI) antipsychotics may improve adherence and reduce healthcare resource utilization (HCRU) in patients living with bipolar I disorder (BP-I), with potentially greater improvements with LAIs with dosing intervals longer than 1 month. Aripiprazole monohydrate is available as LAI formulations administered once-monthly [aripiprazole once-monthly (AOM)] or once every 2 months (aripiprazole 2-month ready-to-use [Ari 2MRTU]). This pre-post analysis described adherence, HCRU, and costs over 6 months in adults diagnosed with BP-I who transitioned from oral antipsychotics or AOM to Ari 2MRTU.

METHODS

This retrospective, noninterventional study used Kythera Labs United States closed claims to identify adults diagnosed with BP-I, commercially or Medicaid-insured, and who transitioned from oral antipsychotics or AOM to Ari 2MRTU from April 2023-September 2024 (index date = Ari 2MRTU transition). Continuous enrollment for 12 months pre- and 6 months post-index was required. Study outcomes were compared 6 months prior to and following the index date.

RESULTS

Among those who transitioned from oral antipsychotics to Ari 2MRTU (n = 371),mean proportion of days covered (PDC) increased from 0.60 to 0.76 (26.2% relative increase), mean medication possession ratio (MPR) increased from 0.67 to 0.85 (26.8% relative increase), and proportion of patients with MPR ≥ 0.8 increased from 41.2% to 72.0% (74.5% relative increase) (all P < 0.0001). Notable reductions in all-cause inpatient visits and length of stay (LOS) were observed, along with reductions in BP-I-related LOS and emergency department (ED) visits. All-cause inpatient, ED, and total medical (inpatient, outpatient, ED) costs declined. Among those who transitioned from AOM to Ari 2MRTU (n = 1,096), mean PDC increased from 0.56 to 0.81 (45.3% relative increase), mean MPR increased from 0.62 to 0.89 (43.7% relative increase), and proportion of patients with MPR ≥ 0.8 increased from 51.2% to 79.0%) (54.4% relative increase) (all P < 0.0001). Inpatient visits (all-cause, BP-I-related), and all-cause LOS decreased, along with all-cause ED and total medical costs.

DISCUSSION: Transitioning to Ari 2MRTU was associated with improved treatment adherence and reduced selected HCRU measures and total medical costs, supporting its value as a treatment option for BP-I.