Characteristics of Real-world Commercially Insured Patients With Treatment-resistant Depression Initiated on Esketamine Nasal Spray or Conventional Therapies in the United States.

Purpose: This study aimed to characterize patients with treatment-resistant depression (TRD) initiating esketamine or conventional therapies.

Methods: Adults with major depressive disorder (MDD) were selected from the IBM MarketScan Databases. A claims-based algorithm identified patients with evidence of TRD, defined as initiation of a new antidepressant therapy after 2 different antidepressant trials of adequate dose and duration during the most recent major depressive episode. Patients receiving treatment on/after March 5, 2019 (esketamine approval date for TRD), were classified to the esketamine cohort if they newly initiated esketamine (index date) or to the TRD conventional therapies cohorts if they newly initiated electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), or pharmacologic therapies (index date was the therapy initiation date, prioritizing ECT, then TMS, then pharmacologic antidepressant therapies). Patient characteristics in the 6 months before therapy initiation were described.

Findings: The esketamine cohort included 246 patients (mean age, 46.5 years; 63.0% female), and the TRD conventional therapies cohorts included 104,164 patients (mean age, 46.9 years; 74.8% female; 0.4% initiated ECT, 1.2% initiated TMS). During the 6 months preindex, in the esketamine and TRD conventional therapies cohorts, 77.6% and 41.4% received psychotherapy and 82.9% and 34.2% had a psychiatrist visit, respectively. Most patients had outpatient care for MDD in the esketamine (91.9%) and TRD conventional therapies (63.6%) cohorts; 57.3% and 21.0% received care at specialized mental health care settings. MDD was classified as "severe" among 81.3% and 35.1% of patients in the esketamine and TRD conventional therapies cohorts . Preindex mental health-related (MHR) inpatient admissions and emergency department visits were identified in 12.2% and 16.3% of the esketamine cohort and in 8.2% and 10.3% of the TRD conventional therapies cohort. Before therapy initiation, 34.6% and 17.6% of the esketamine and TRD conventional therapies cohorts received ≥3 unique antidepressants. Suicidal ideation or behavior was observed in 8.5% and 3.6% of the esketamine and TRD conventional therapies cohorts pretherapy initiation. Mean monthly all-cause health care costs in the esketamine cohort were $2532 (58.2% MHR); in the TRD conventional therapies cohorts, costs were $1873 (32.4% MHR).

Implications: Among patients with TRD, those initiating esketamine relative to conventional therapies displayed higher MDD severity, used more MHR inpatient/emergency department services and antidepressant treatments, and incurred higher health care costs 6 months pretherapy initiation. These findings suggest potential benefits of identifying and treating patients with TRD earlier with more effective treatments and should inform payers in consideration of esketamine coverage.