Esketamine versus placebo on time to remission in major depressive disorder with acute suicidality.

BACKGROUND: Esketamine (ESK) nasal spray, taken with oral antidepressant therapy, is approved for the treatment of depressive symptoms in adults with major depressive disorder (MDD) with acute suicidal ideation or behavior. In pooled analyses of two pivotal phase 3 studies, ASPIRE I and II, remission rates were consistently higher among patients with MDD with active suicidality who were treated with ESK + standard of care (SOC) versus placebo (PBO) + SOC at all time points in the double-blind and most time points in the follow-up phases. The current analysis of the ASPIRE data sets assessed the effect of ESK + SOC versus PBO + SOC on additional remission-related endpoints: time to achieving remission and consistent remission, proportion of patients in remission and consistent remission, and days in remission. METHODS: Post hoc analysis of pooled data from ASPIRE I and II (N = 451). Remission and consistent remission were defined as Montgomery-Åsberg Depression Rating Scale (MADRS) total score ≤ 12 at any given visit or two consecutive visits, respectively. Combined endpoints utilizing Clinical Global Impression-Severity of Suicidality-revised version [CGI-SS-r] ≤ 1 (i.e., not suicidal/questionably suicidal) along with the remission and consistent remission definitions (i.e., MADRS total score ≤ 12) were also examined. RESULTS: The median times to remission and consistent remission of MDD were significantly shorter in ESK + SOC versus PBO + SOC (15 versus 23 [p = 0.005] and 23 versus 50 days [p = 0.007], respectively) and a greater proportion of patients in ESK + SOC achieved remission and consistent remission by Day 25 (65.2% versus 55.5% and 54.2% versus 39.8%, respectively). Similar results were obtained using the combined endpoint for both remission definitions. The median percent of days in remission during the double-blind treatment phase was significantly greater in ESK + SOC (27.1% or 5 days) versus PBO + SOC (8.3% or 2 days; p = 0.006), and the significant difference was maintained during follow-up. CONCLUSION: Treatment with ESK + SOC versus PBO + SOC resulted in significantly shorter time to remission, greater proportion of patients in remission, and greater percent of days in remission using increasingly rigorous definitions of remission. These findings underscore the clinical benefits of ESK for adults with MDD with suicidality. TRIAL REGISTRATION: ClinicalTrials.gov registry NCT03039192 (registered February 1, 2017) and NCT03097133 (registered March 31, 2017).

Efficacy and Safety of Esketamine Nasal Spray in Patients with Treatment-Resistant Depression Who Completed a Second Induction Period: Analysis of the Ongoing SUSTAIN-3 Study.

BACKGROUND: Treatment-resistant depression (TRD) is a chronic illness requiring long-term treatment. Esketamine nasal spray (ESK) has been studied in several long-term trials of patients with TRD, including SUSTAIN-1 (NCT02493868) and SUSTAIN-3 (NCT02782104). This subgroup analysis of SUSTAIN-3 evaluated patients with TRD who received a second induction (IND) and maintenance treatment with ESK plus oral antidepressant (AD) after a relapse in SUSTAIN-1. METHODS: Patients aged 18-64 years who achieved stable remission or response with ESK and subsequently relapsed after randomization to continue ESK or switch to placebo nasal spray (PBO) in SUSTAIN-1 and entered the IND phase of SUSTAIN-3 were included in this interim analysis. Response (≥50% improvement in total score from baseline for Montgomery-Åsberg Depression Rating Scale [MADRS] and Patient Health Questionnaire 9-item [PHQ-9]), remission (MADRS score ≤12; PHQ-9 total score <5), changes in depression rating scores (measured as mean change from baseline), and safety were evaluated (incidence of treatment-emergent and serious adverse events [AE]). RESULTS: Of the 96 eligible patients who entered IND in SUSTAIN-3, 32 (33.3%) were taking ESK+AD at the time of relapse in SUSTAIN-1 and 64 (66.7%) were taking AD+PBO. Substantial improvements in depressive symptoms were observed over the second IND phase in both groups and were maintained over the optimization/maintenance (OP/M) phase. MADRS response rates following a second IND were 71.9% and 73.4% for previously relapsed (PR) ESK+AD and PR-AD+PBO, respectively; remission rates were 62.5% and 60.9%, respectively. During the IND and OP/M phases, 58.3% and 83.3% of patients experienced a treatment-emergent AE, respectively. No patients discontinued due to an AE during the second IND. CONCLUSIONS: Patients with TRD benefitted from receiving a second IND and maintenance treatment with ESK and no new safety signals were identified.

Predictors of response and remission in patients with treatment-resistant depression: A post hoc pooled analysis of two acute trials of esketamine nasal spray.

This exploratory post hoc analysis of two pooled 4-week, phase 3, double-blind, placebo- and active-controlled studies that compared esketamine nasal spray plus a newly initiated oral antidepressant (ESK+AD; n = 310) with a newly initiated oral AD plus placebo nasal spray (AD+PBO; n = 208) in patients with treatment-resistant depression (TRD) examined baseline patient demographic and psychiatric characteristics as potential predictors of response (≥50% reduction from baseline in Montgomery-Åsberg Depression Rating Scale [MADRS] total score) and remission (MADRS total score ≤12) at day 28. Overall, younger age, any employment, fewer failed ADs in the current depressive episode, and reduction in Clinical Global Impression-Severity (CGI-S) score at day 8 were significant positive predictors of response and remission at day 28. Treatment assignment was an important predictor of both response and remission. Patients treated with ESK+AD had 68% and 55% increased odds of achieving response and remission, respectively, versus those treated with AD+PBO. In the ESK+AD group, attainment of response and remission was more likely in patients who were employed, without significant anxiety at baseline, and who experienced a reduction in CGI-S score at day 8. Identification of predictors of response and remission may facilitate identification of those patients with TRD most likely to benefit from ESK+AD. Trial Registration: ClinicalTrials.gov: NCT02417064 (clinicaltrials.gov/ct2/show/NCT02417064) and NCT02418585 (clinicaltrials.gov/ct2/show/NCT02418585).

Adverse Events and Measurement of Dissociation After the First Dose of Esketamine in Patients With TRD.

BACKGROUND: "Dissociation" comprises distinct phenomena, some of which are associated with esketamine treatment and some may overlap with positive symptoms of psychosis. Relationships between dissociation and psychotic symptoms assessed by -clinician report vs conventional rating scales were investigated in a post hoc analysis of data from the initial treatment session in an -open-label, -long-term safety, phase 3 study of esketamine plus a newly initiated oral antidepressant in patients with treatment-resistant depression. METHODS: Adverse events of dissociation or psychosis were examined via investigator report and the Clinician Administered Dissociative States Scale (CADSS) and Brief Psychiatric Rating Scale-Plus, respectively, 40 minutes post first esketamine dose. The range of CADSS total scores associated with investigator-reported severity of dissociation was determined by equipercentile linking. Logistic regression models and receiver operating curve analysis explored the CADSS cutoff point for determining presence/absence of dissociation. Frequency of response to specific CADSS items was examined to investigate qualitative differences in the pattern of symptoms reported across investigator-reported levels of adverse event severity. RESULTS: Dissociation was reported as an adverse event in 14.3% (109/764) of patients. Severity of most CADSS items increased with the severity of investigator-reported dissociation. No CADSS cutoff point discriminated well between the presence and absence of dissociation events. Hallucinations were reported as adverse events in 5 patients; none reported delusions. CONCLUSIONS: CADSS scores and severity of dissociation adverse events move generally in the same direction; however, there is substantial variability in this relationship. No signature profile of dissociative experiences was revealed, and psychotic symptoms were uncommon. TRIAL REGISTRATION: Clinical Trials.gov identifier: NCT02497287.

Commentary on Cochrane review: "Ketamine and other glutamate receptor modulators for depression in adults with unipolar major depressive disorder".

BACKGROUND: Cochrane recently published a review of esketamine and other glutamate receptor modulators in depression. AIM: To address the limitations of the review, analyses of esketamine data were conducted to provide additional perspective to the reviewers' interpretation of their findings. METHODS: Response rate, remission rate, and change from baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) total score were determined using data from all esketamine phase 2/3 registration studies of treatment-resistant depression (TRD) and, separately, all esketamine phase 2/3 registration studies of major depressive disorder (MDD) and active suicidal ideation with intent. Outcomes were assessed at all timepoints (i.e., 24 h, 72 h (MDD with active suicidal intent only), and 1, 2, and 4 weeks). Enrollment criteria of the TRD studies were different than those of the studies of MDD and active suicidal ideation with intent, resulting in differences in patients' clinical characteristics and depression severity between the cohorts. Thus, we did not compare results between these cohorts (as was done in the Cochrane review). RESULTS/OUTCOMES: In the combined TRD studies, a statistically significant between-group difference favored esketamine plus antidepressant over antidepressant plus placebo at 24 h (based on response, remission, and change in MADRS score), 1 week (change in MADRS score), 2 weeks (response and change in MADRS score), and 4 weeks (response, remission, and change in MADRS score). In the combined studies of MDD and active suicidal ideation with intent, the between-group difference was statistically different, favoring esketamine plus standard-of-care over placebo plus standard-of-care, at 24 h (response, remission, and change in MADRS score), 72 h and 1 week (change in MADRS score), 2 weeks (response), and 4 weeks (response, remission, and change in MADRS score). For both study types, the between-group difference in outcomes was not statistically significant at the other timepoints. CONCLUSIONS/INTERPRETATION: Esketamine improves response, remission, and depressive symptoms as early as 24 h post-first dose among patients with TRD and among patients with MDD and active suicidal ideation with intent.

Use of Clinical Global Impressions-Severity (CGI-S) to Assess Response to Antidepressant Treatment in Patients with Treatment-Resistant Depression.

Background: This post-hoc analysis evaluated the agreement between Clinical Global Impressions-Severity (CGI-S) score- and Montgomery-Åsberg Depression Rating Scale (MADRS) total score-based assessment of response in patients with treatment-resistant depression (TRD) treated with esketamine nasal spray plus a newly initiated oral antidepressant (ESK-NS + AD). Methods: Data were analyzed from a phase 3, randomized, double-blind study (TRANSFORM-2) of flexibly dosed esketamine or placebo nasal spray plus a newly initiated oral-AD in adults with moderate-to-severe TRD. Patients with ≥50% reduction in MADRS from baseline at the end of the 4-week acute treatment phase were defined as responders. For the CGI-S-based assessment of response, patients with ≥2 points decrease from baseline or a CGI-S score of ≤3 (mildly depressed to normal) were considered responders. Cohen's kappa coefficient was calculated to assess level of agreement between MADRS and CGI-S-based assessments. Results: At the end of 4-week treatment, the proportion of responders among all study patients (n=201) was similar when assessed using the MADRS (61%) and CGI-S (62%) methods, with substantial agreement (Cohen's kappa=0.76; sensitivity=92%; specificity=84%) between both methods. When restricting analysis to ESK-NS + AD-treated patients (n=101) who had a higher response rate (on MADRS: 69%; on CGI-S: 68%), the agreement remained substantial (Cohen's kappa=0.75; sensitivity=91%; specificity=84%). Conclusion: The CGI-S may be a practical and reliable alternative to the MADRS to assess response to ESK-NS + AD in patients with TRD and can be used in real-world practice to support informed treatment decisions.

Montgomery-Åsberg Depression Rating Scale factors in treatment-resistant depression at onset of treatment: Derivation, replication, and change over time during treatment with esketamine.

OBJECTIVE: Derive and confirm factor structure of the Montgomery-Åsberg Depression Rating Scale (MADRS) in patients with treatment-resistant depression (TRD) and evaluate how the factors evident at baseline change over 4 weeks of esketamine treatment. METHODS: Two similarly-designed, short-term TRANSFORM trials randomized adults to esketamine or matching placebo nasal spray, each with a newly-initiated oral antidepressant, for 4 weeks (TRANSFORM-1: N = 342 patients; TRANSFORM-2: N = 223 patients). The factor structure of MADRS item scores at baseline was determined by exploratory factor analysis in TRANSFORM-2 and corroborated by confirmatory factor analysis in TRANSFORM-1. Change in MADRS factor scores from baseline (day 1) to the end of the 28-day double-blind treatment phase of TRANSFORM-2 was analyzed using a mixed-effects model for repeated measures (MMRM). RESULTS: Three factors were identified based on analysis of MADRS items: Factor 1 labeled affective and anhedonic symptoms (apparent sadness, reported sadness, lassitude, inability to feel), Factor 2 labeled anxiety and vegetative symptoms (inner tension, reduced sleep, reduced appetite, concentration difficulties), and Factor 3 labeled hopelessness (pessimistic thoughts, suicidal thoughts). The three-factor structure observed in TRANSFORM-2 was verified in TRANSFORM-1. Treatment benefit at 24 h with esketamine versus placebo was observed on all 3 factors and continued throughout the 4-week double-blind treatment period. CONCLUSIONS: A three-factor structure for MADRS appears to generalize to TRD. All three factors improved over 4 weeks of treatment with esketamine nasal spray.

Treatment patterns and decision drivers to discharge patients with depression hospitalised for acute suicidal ideation in Europe.

BACKGROUND: There is limited published information about the management of patients with major depressive disorder (MDD) hospitalised for acute suicidal ideation (SI). This study aimed to identify treatment patterns and unmet needs in the management of these patients and the decision drivers for hospital discharge. METHODS: Cross-sectional survey-based study enrolling hospital-based European psychiatrists. The study had a qualitative and a quantitative stage, including a conjoint exercise. RESULTS: Each respondent (N = 413) managed, on average, 62 MDD patients with acute SI per typical three-month period; 76% of these patients required hospitalisation. Severity of SI and severity of MDD were considered the most important factors for hospital admission and discharge. In the conjoint analysis, these attributes accounted for 54% of the discharge decision. Key treatment goals included improving depressive symptoms and achieving MDD remission. Antidepressants were a standard treatment for 98% of respondents but 63% defined rapid onset of action as a critical unmet need, followed by a good tolerability profile (34%). LIMITATIONS: The study has a cross-sectional design representing respondents' behaviour and attitudes at a particular point in time. In the conjoint analysis, the results represent stated behaviour and not observed clinical behaviour. CONCLUSIONS: Physicians' decisions to admit and discharge patients with MDD hospitalised for acute SI are mostly driven by the severity of SI and depression. Antidepressants with rapid onset of action, which can quickly improve depressive symptoms, represent a key unmet need for these patients and may contribute to a higher likelihood of early discharge.

Patient profiles, initial hospital encounter characteristics, and hospital re-encounters of patients with a hospital emergency department visit or inpatient admission for major depressive disorder.

OBJECTIVES: To gain a better understanding of the characteristics of patients with a hospital encounter for major depressive disorder (MDD) and evaluate associated hospital resource utilization, hospital charges and costs, and hospital re-encounters. METHODS: Adult patients with a hospital encounter (i.e. emergency department [ED] visit only or inpatient admission) with MDD as the primary discharge diagnosis (index event) during July 2018‒March 2019 were selected from the Premier Healthcare Database. Patient characteristics, hospital resource utilization, and hospital charges and costs were evaluated during index events. During a 12-month follow-up, hospital re-encounters (MDD-related and all-cause ED visit only or inpatient readmissions) were examined. RESULTS: The study population included 77,178 patients with an index hospital encounter (ED visit only: 49.9%; inpatient admission: 50.1%) for MDD. The most common secondary mental health-related diagnosis was suicidal ideation/behavior, which was recorded in 51.8% of patients. The mean age was 38.2 years, 53.0% were female, and 72.1% were Caucasian. Among patients with an ED visit only, the mean index hospital charges and costs were $3,608 and $639, respectively. Among those with inpatient admissions, the mean length of stay was 4.9 days, and the mean index hospital charges and costs were $17,107 and $6,095, respectively. During the 12-month follow-up, 13.3% of patients in the overall study population had an MDD-related hospital re-encounter (primary or secondary discharge diagnosis code indicating MDD); nearly one-third (31.3%) occurred within 30 days post-discharge. During the follow-up, 28.1% had an all-cause hospital re-encounter with 29.7% having occurred within 30 days post-discharge. LIMITATIONS: Due to constraints of the Premier Healthcare Database, healthcare resource utilization and costs outside of the hospital could not be evaluated. CONCLUSIONS: Patients with a hospital encounter for MDD are relatively young, commonly have suicidal ideation/behavior, utilize substantial hospital resources, and have a high risk for a hospital re-encounter in the 30 days post-discharge.

Effect of Sleep Disturbance on Efficacy of Esketamine in Treatment-Resistant Depression: Findings from Randomized Controlled Trials.

PURPOSE: To evaluate the relationship of sleep disturbance to the antidepressant effects of esketamine. MATERIALS AND METHODS: Two double-blind, 4-week studies randomized adults with treatment-resistant depression (TRD) to placebo or esketamine nasal spray, each with newly initiated antidepressant. Sleep was assessed using Montgomery-Åsberg Depression Rating Scale (MADRS) item 4. Change in response (≥50% decrease in MADRS total score) and remission (total MADRS score ≤12) at day 28 was examined by presence/absence of baseline sleep disturbance using logistic regression models. Impact on reported sleep disturbance (MADRS item 4 score) was examined using ANCOVA models. RESULTS: At baseline, most patients reported disturbed sleep - moderate/severe (65.3%, 369/565), mild (25.3%, 143/565), or none/slightly (9.4%, 53/565) - with similar distribution between treatment groups. A higher proportion of esketamine-treated patients achieved response (OR = 2.05; 95% CI: 1.40-3.02; P < 0.001) and remission (OR = 1.81; 95% CI: 1.23-2.66; P = 0.003) at day 28 compared to antidepressant plus placebo, regardless of presence/severity of sleep disturbance. Consistent with this, sleep (MADRS item 4 score) improved in both groups after the first dose, more so with esketamine by day 8 (between-group difference: P ≤ 0.02 at all time points). Across both treatment groups, 1-point improvement in sleep at day 8 increased the probability of antidepressant response on day 28 by 26% (OR = 1.26, 95% CI: 1.12-1.42; P < 0.001), and remission by 28% (OR = 1.28, 95% CI: 1.14-1.43; P < 0.001). CONCLUSION: Antidepressant efficacy of esketamine was demonstrated in patients with TRD, regardless of the presence of sleep disturbance. After 8 days of treatment and thereafter, significantly more esketamine-treated patients reported improvement in sleep versus antidepressant plus placebo.

Effect of Concomitant Benzodiazepine Use on Efficacy and Safety of Esketamine Nasal Spray in Patients with Major Depressive Disorder and Acute Suicidal Ideation or Behavior: Pooled Randomized, Controlled Trials.

PURPOSE: The impact of benzodiazepines on the efficacy and safety of esketamine as a rapid-acting antidepressant remains unclear. MATERIALS AND METHODS: Data from two identically designed, randomized double-blind studies were pooled and analyzed on a post-hoc basis. In both studies, adults with major depressive disorder with acute suicidal ideation or behavior were randomized to placebo or esketamine 84 mg nasal spray twice-weekly for 4 weeks, each with comprehensive standard-of-care (initial hospitalization and newly initiated or optimized oral antidepressant[s]). Efficacy and safety were analyzed in two groups based on whether patients used concomitant benzodiazepines, which were prohibited within 8 hours before and 4 hours after the first dose of esketamine and within 8 hours of the primary efficacy assessment at 24 hours. The primary efficacy endpoint - change from baseline to 24 hours post-first dose in Montgomery-Asberg Depression Rating Scale (MADRS) total score - was analyzed using ANCOVA. RESULTS: Most patients (309/451, 68.5%) used concomitant benzodiazepines. Greater decrease in MADRS total score was observed with esketamine (mean [SD]: -16.1 [11.73]) versus placebo (-12.6 [10.56]) at 24 hours (least-squares mean difference: -3.7, 95% CI: -5.76, -1.59). The differences between the esketamine and placebo groups were clinically meaningful, irrespective of benzodiazepine use (benzodiazepine: -4.3 [-6.63, -1.89]; no benzodiazepine: -3.1 [-6.62, 0.45]). Among patients taking esketamine, change in MADRS total score was not significantly different between patients taking benzodiazepines (-15.8 [11.27]) versus those not taking benzodiazepines (-16.8 [12.82]) (least-squares mean difference: 1.1, [-2.24, 4.45]). Among esketamine-treated patients, the incidence of sedation was higher with benzodiazepine use, whereas dissociation was similar. CONCLUSION: Benzodiazepines do not meaningfully affect the rapid-acting antidepressant effect of esketamine at 24 hours post-first dose among patients with MDD and acute suicidal ideation or behavior.

The effect of esketamine in patients with treatment-resistant depression with and without comorbid anxiety symptoms or disorder.

BACKGROUND: Comorbid anxiety is generally associated with poorer response to antidepressant treatment. This post hoc analysis explored the efficacy of esketamine plus an antidepressant in patients with treatment-resistant depression (TRD) with or without comorbid anxiety. METHODS: TRANSFORM-2, a double-blind, flexible-dose, 4-week study (NCT02418585), randomized adults with TRD to placebo or esketamine nasal spray, each with a newly-initiated oral antidepressant. Comorbid anxiety was defined as clinically noteworthy anxiety symptoms (7-item Generalized Anxiety Disorder scale [GAD-7] score ≥10) at screening and baseline or comorbid anxiety disorder diagnosis at screening. Treatment effect based on change in Montgomery-Åsberg Depression Rating Scale (MADRS) total score, and response and remission were examined by presence/absence of comorbid anxiety using analysis of covariance and logistic regression models. RESULTS: Approximately 72% (162/223) of patients had baseline comorbid anxiety. Esketamine-treated patients with and without anxiety demonstrated significant reductions in MADRS (mean [SD] change from baseline at day 28: -21.0 [12.51] and -22.7 [11.98], respectively). Higher rates of response and remission, and a significantly greater decrease in MADRS score at day 28 were observed compared to antidepressant/placebo, regardless of comorbid anxiety (with anxiety: difference in LS means [95% CI] -4.2 [-8.1, -0.3]; without anxiety: -7.5 [-13.7, -1.3]). There was no significant interaction of treatment and comorbid anxiety (p = .371). Notably, in the antidepressant/placebo group improvement was similar in those with and without comorbid anxiety. CONCLUSION: Post hoc data support efficacy of esketamine plus an oral antidepressant in patients with TRD, regardless of comorbid anxiety.

Comments to Drs. Bahji, Vazquez, and Zarate.

In the absence of head-to-head studies directly comparing the efficacy of intranasal esketamine to that of intravenous ketamine, valid conclusions regarding comparative efficacy cannot be made based on the existing data from trials using markedly differing study designs and patient populations.

Patient-reported outcomes in major depressive disorder with suicidal ideation: a real-world data analysis using PatientsLikeMe platform.

BACKGROUND: The current analysis utilized data collected via an online patient community platform, PatientsLikeMe (PLM) to compare patient-reported experiences in patients with major depressive disorder (MDD) with suicidal ideation (MDSI) to those with MDD but without suicidal ideation. METHODS: PLM members who joined PLM between May-2007 and February-2018 and reported a diagnosis of MDD were included. The MDSI cohort included patients with MDD who reported at least one suicide-related symptom at a severity greater than "none". Demographics, comorbidities, symptoms, and side-effects were compared between MDSI and MDD cohorts. Factors correlated with suicidal ideation (SI) were determined by a random forest procedure. RESULTS: Patients in the MDSI cohort (n = 266) were younger (median age, 36 vs 44 years) with an earlier disease onset (before 30 years, 83% vs 71%), and a longer diagnosis latency (median, 4 vs 2 years) vs patients in the MDD cohort (n = 11,963). Majority of patients were women in both cohorts (73% vs 83%). Median number of psychiatric comorbidities was higher in the MDSI cohort (4 vs 3). Unprompted symptoms (e.g., loneliness, feeling of hopelessness, social anxiety, impulsivity, and self-hating thoughts) were more frequent in the MDSI cohort. Hopelessness, loneliness, anhedonia, social anxiety, and younger age were highly correlated with suicidal ideation. CONCLUSIONS: This analysis utilized patient-reported data to better understand symptoms, experiences, and characteristics of patients with MDSI compared to patients with MDD. The results identified various risk factors correlated with suicidal ideation that may help guide clinical judgement for patients with MDD who may not voluntarily report suicidal ideation.

Managing Esketamine Treatment Frequency Toward Successful Outcomes: Analysis of Phase 3 Data.

BACKGROUND: Esketamine nasal spray was recently approved for treatment-resistant depression. The current analysis evaluated the impact of symptom-based treatment frequency changes during esketamine treatment on clinical outcomes. METHODS: This is a post-hoc analysis of an open-label, long-term (up to 1 year) study of esketamine in patients with treatment-resistant depression (SUSTAIN 2). During a 4-week induction phase, 778 patients self-administered esketamine twice weekly plus a new oral antidepressant daily. In responders (≥50% reduction in Montgomery-Åsberg Depression Rating Scale total score from baseline), esketamine treatment frequency was thereafter decreased during an optimization/maintenance phase to weekly for 4 weeks and then adjusted to the lowest frequency (weekly or every other week) that maintained remission (Montgomery-Åsberg Depression Rating Scale ≤ 12) based on a study-defined algorithm. The relationship between treatment frequency and symptom response, based on clinically meaningful change in Clinical Global Impression-Severity score, was subsequently evaluated 4 weeks after treatment frequency adjustments in the optimization/maintenance phase. RESULTS: Among 580 responders treated with weekly esketamine for the first 4 weeks in the optimization/maintenance phase (per protocol), 26% continued to improve, 50% maintained clinical benefit, and 24% worsened. Thereafter, when treatment frequency could be reduced from weekly to every other week, 19% further improved, 49% maintained benefit, and 32% worsened. For patients no longer in remission after treatment frequency reduction, an increase (every other week to weekly) resulted in 47% improved, 43% remained unchanged, and 10% worsened. CONCLUSIONS: These findings support individualization of esketamine nasal spray treatment frequency to optimize treatment response in real-world clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02497287.