Response and remission on esketamine nasal spray in patients with treatment-resistant depression overall and among transcranial magnetic stimulation-naïve subgroup

BACKGROUND: Both esketamine nasal spray and transcranial magnetic stimulation (TMS) are indicated for treatment-resistant depression (TRD), but there are no guidelines on the sequence of use of these treatments. This analysis described response and remission on esketamine depending on previous TMS experience to inform decision making in treatment choice.
METHODS: Adults with TRD, including a subgroup without previous TMS experience, initiated esketamine (first session=index date) at Mindful Health Solutions clinics during 03/2019-01/2024. Clinical outcomes were defined using Patient Health Questionnaire (PHQ-9) scores. Baseline PHQ-9 score was measured before or on the index date; follow-up scores were observed after the index date until the end of patient clinical activity or data. Outcomes included response (≥50% decrease from baseline) and remission (PHQ-9 score < 5). Time to outcomes was described with Kaplan-Meier survival analysis; patients without an outcome were censored at the last PHQ-9 score.
RESULTS: 911 patients were identified (baseline PHQ-9 score: 16.3) of which 512 were TMS-naïve (baseline PHQ-9 score: 15.6). At 12 months after the index date, overall and among the TMS-naïve subgroup respectively, probabilities of achieving response were 69.6% and 75.4% and of achieving remission 37.3% and 44.3%. Median time to response was 3.6 months overall and 2.5 months in TMS-naïve subgroup. Median time to remission was not reached overall and was 15.1 months in TMS-naïve subgroup.
CONCLUSIONS: This descriptive analysis suggests that TMS experience does not preclude response to esketamine, however, there is a trend of TMS-naïve patients responding and reaching remission faster.