(274) Treatment patterns and healthcare resource utilization in patients with schizophrenia or bipolar I disorder in the 6 months following initiation of olanzapine/samidorphan versus other atypical antipsychotics

Background: : Combination olanzapine and samidorphan (OLZ/SAM) is approved for the treatment of adults with schizophrenia (SZ) or bipolar I disorder (BD-I). In prior real-world studies, initiating OLZ/SAM was associated with significant reductions in hospitalizations and emergency department (ED) visits, which are proxies for relapse.

Objective: : Assess 6-month acute care events and treatment patterns in patients with SZ or BD-I after initiating OLZ/SAM vs comparator oral atypical antipsychotics.

Methods: : This retrospective (4/19/21-12/31/22) claims analysis used data from Komodo Healthcare Map. Eligible adults had 1 or more claims for OLZ/SAM or aripiprazole, cariprazine, olanzapine, risperidone (SZ and BD-I cohorts), brexpiprazole, lumateperone, or lurasidone (SZ cohort only). Continuous enrollment for at least 6 months before and after the index claim was required. Follow-up acute care events (inpatient [IP] admissions, ED visits) and treatment patterns (persistence, adherence, discontinuation) were compared for OLZ/SAM and comparator antipsychotics. Outcomes were stratified by disease cohort and adjusted with inverse probability weighting (P < 0.05 considered statistically significant).

Results: : There were 51,921 patients in the SZ cohort (OLZ/SAM, n=848; comparators, n=51,073) and 39,698 in the BD-I cohort (OLZ/SAM, n=685; comparators, n=39,013). In the SZ cohort, likelihoods of all-cause IP admissions and ED visits were significantly lower with OLZ/SAM vs all comparators (IP admission odds ratio [OR] range 0.59-0.73; ED visit OR range 0.67-0.74) except brexpiprazole (IP admission OR 0.80; ED visit OR 0.79). OLZ/SAM was associated with significantly better adherence, longer persistence, and lower likelihood of discontinuation vs all comparators in the SZ cohort. In the BD-I cohort, likelihoods of all-cause IP admissions and ED visits were significantly lower with OLZ/SAM vs olanzapine (IP admission OR 0.71; ED visit OR 0.79); likelihoods of all-cause IP admissions were significantly lower with OLZ/SAM vs risperidone (OR 0.80) and not significantly different from those with cariprazine or aripiprazole. OLZ/SAM initiation was associated with significantly better adherence, longer persistence, and lower likelihood of discontinuation vs all comparators except cariprazine for those with BD-I.

Conclusions: : Real-world treatment with OLZ/SAM resulted in lower use of acute inpatient care than most comparators and better adherence, persistence, and discontinuation vs all comparators in the SZ cohort and most comparators in the BD-I cohort.

Sponsorship:: Alkermes, Inc.