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.

Relationship Between Dissociation and Antidepressant Effects of Esketamine Nasal Spray in Patients With Treatment-Resistant Depression.

BACKGROUND: In this post-hoc analysis, data from 2 positive, pivotal, phase 3 trials of esketamine nasal spray (ESK) in treatment-resistant depression (TRD)-short-term study (TRANSFORM-2) and maintenance study (SUSTAIN-1)-were analyzed to evaluate the relationship between dissociation and antidepressant effects of ESK. METHODS: Analysis by responder status, correlation analysis, and mediation analysis were performed to assess the relationships between peak Clinician Administered Dissociative States Scale (CADSS) scores after first (day 1) and last (day 25) ESK dose and change in Montgomery-Åsberg Depression Rating Scale (MADRS) total scores at the first (day 2) and last assessments (day 28) in TRANSFORM-2 and peak CADSS after first maintenance ESK dose and time to relapse in SUSTAIN-1 (only for mediation analysis). RESULTS: In TRANSFORM-2, the percentage of responders (>50% reduction in MADRS) at day 2 and day 28 did not significantly differ between patients who did vs did not manifest significant dissociation (peak CADSS scores >4 or ≤4, respectively) following the first ESK dose. Spearman correlation coefficients between dissociation and depression improvement were nonsignificant and close to zero. CADSS scores did not significantly mediate the reduction in MADRS at day 2 or 28 in TRANSFORM-2 or the time to depression relapse in SUSTAIN-1. The mean difference in MADRS between ESK and active-control arms persisted beyond day 2 without significant change across time, although the mean peak CADSS scores significantly decreased across consecutive doses and fewer patients experienced significant dissociation after the last ESK dose compared with the first. CONCLUSION: Within the dose range tested, the dissociative and antidepressant effects of ESK were not significantly correlated. TRIAL REGISTRATION: NCT02417064 (TRANSFORM-1); NCT02418585(TRANSFORM-2); NCT02493868 (SUSTAIN-1).

Comparison of Long-Term Efficacy and Safety of Esketamine Nasal Spray Plus Oral Antidepressant in Younger Versus Older Patients With Treatment-Resistant Depression: Post-Hoc Analysis of SUSTAIN-2, a Long-Term Open-Label Phase 3 Safety and Efficacy Study.

BACKGROUND: Older, compared with younger, patients with treatment-resistant depression (TRD) typically have lower response and remission rates with poorer tolerability to antidepressant treatment. This post-hoc analysis compared outcomes following treatment with esketamine nasal spray (ESK) between younger (18-64 years) and older (≥65 years) patients with TRD. METHODS: SUSTAIN-2, an up to 1-year open-label safety and efficacy study of ESK plus an oral antidepressant, included patients with TRD either directly enrolled (≥18-year) or transferred from a phase 3 double-blind study, TRANSFORM-3 (≥65-year). Patients were treated in two phases: 4-week induction and 48-week optimization/maintenance. RESULTS: Younger (n = 624) and older (n = 178) patients had similar baseline characteristics except for hypertension history (21.5% versus 48.3%, respectively). Patients (younger versus older) had similar mean baseline Montgomery-Åsberg Depression Rating Scale (MADRS) total scores and mean (SD) reductions in MADRS total scores for induction (-18.0 [7.19] versus -18.1 [9.37]; p = 0.492 [t = 0.69, df = 701]) and optimization/maintenance (week 12) (-19.9 [7.03] versus -22.2 [9.50]; p = 0.265 [t = -1.12, df = 3470]) phases. Treatment-emergent adverse events (TEAEs) reported in younger versus older patients, respectively, were: induction, 86.1% versus 74.8%; optimization/maintenance, 86.8% versus 81.0%; serious TEAEs: induction, 2.2% versus 1.9%; optimization/maintenance, 6.7% versus 4.8%; TEAEs of increased blood pressure: induction, 6.9% versus 6.5%; optimization/maintenance, 7.1% versus 9.5%; and falls: induction, 0.3% versus 0.6%; optimization/maintenance, 0.2% versus 0.8%. Cognitive tests did not show clinically meaningful differences between the age groups. CONCLUSIONS: Although limited by the open-label design of SUSTAIN-2, this post-hoc analysis showed generally comparable improvement in depression between ESK-treated younger and older adult patients with TRD, with consistent safety outcomes.

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.

Effects of Mu-Opiate Receptor Gene Polymorphism rs1799971 (A118G) on the Antidepressant and Dissociation Responses in Esketamine Nasal Spray Clinical Trials.

BACKGROUND: At ketamine and esketamine doses at which antidepressant doses are achieved, these agents are relatively selective, noncompetitive, N-methyl-D-aspartate receptor antagonists. However, at substantially higher doses, ketamine has shown mu-opioid receptor (MOR-gene symbol: OPRM1) agonist effects. Preliminary clinical studies showed conflicting results on whether naltrexone, a MOR antagonist, blocks the antidepressant action of ketamine. We examined drug-induced or endogenous MOR involvement in the antidepressant and dissociative responses to esketamine by assessing the effects of a functional single nucleotide polymorphism rs1799971 (A118G) of OPRM1, which is known to alter MOR agonist-mediated responses. METHODS: Participants with treatment-resistant depression from 2 phase III, double-blind, controlled trials of esketamine (or placebo) nasal spray plus an oral antidepressant were genotyped for rs1799971. Participants received the experimental agents twice weekly for 4 weeks. Antidepressant responses were rated using the change in Montgomery-Åsberg Depression Rating Scale (MADRS) score on days 2 and 28 post-dose initiation, and dissociative side effects were assessed using the Clinician-Administered Dissociative-States Scale at 40 minutes post-dose on days 1 and 25. RESULTS: In the esketamine + antidepressant arm, no significant genotype effect of single nucleotide polymorphism rs1799971 (A118G) on MADRS score reductions was detected on either day 2 or 28. By contrast, in the antidepressant + placebo arm, there was a significant genotype effect on MADRS score reductions on day 2 and a nonsignificant trend on day 28 towards an improvement in depression symptoms in G-allele carriers. No significant genotype effects on dissociative responses were detected. CONCLUSIONS: Variation in rs1799971 (A118G) did not affect the antidepressant response to esketamine + antidepressant. Antidepressant response to antidepressant + placebo was increased in G-allele carriers, compatible with previous reports that release of endorphins/enkephalins may play a role in mediating placebo effect. TRIAL REGISTRATION: NCT02417064 and NCT02418585; www.clinicaltrials.gov.

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.

Efficacy and Safety of Esketamine Nasal Spray Plus an Oral Antidepressant in Elderly Patients With Treatment-Resistant Depression-TRANSFORM-3.

BACKGROUND: Elderly patients with major depression have a poorer prognosis, are less responsive to treatment, and show greater functional decline compared with younger patients, highlighting the need for effective treatment. METHODS: This phase 3 double-blind study randomized patients with treatment-resistant depression (TRD) ≥65 years (1:1) to flexibly dosed esketamine nasal spray and new oral antidepressant (esketamine/antidepressant) or new oral antidepressant and placebo nasal spray (antidepressant/placebo). The primary endpoint was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to day 28. Analyses included a preplanned analysis by age (65-74 versus ≥75 years) and post-hoc analyses including age at depression onset. RESULTS: For the primary endpoint, the median-unbiased estimate of the treatment difference (95% CI) was -3.6 (-7.20, 0.07); weighted combination test using MMRM analyses z = 1.89, two-sided p = 0.059. Adjusted mean (95% CI) difference for change in MADRS score between treatment groups was -4.9 (-8.96, -0.89; t = -2.4, df = 127; two-sided nominal p = 0.017) for patients 65 to 74 years versus -0.4 (-10.38, 9.50; t = -0.09, two-sided nominal p = 0.930) for those ≥75 years, and -6.1 (-10.33, -1.81; t = -2.8, df = 127; two-sided nominal p = 0.006) for patients with depression onset <55 years and 3.1 (-4.51, 10.80; t = 0.8, two-sided nominal p = 0.407) for those ≥55 years. Patients who rolled over into the long-term open-label study showed continued improvement with esketamine following 4 additional treatment weeks. CONCLUSIONS: Esketamine/antidepressant did not achieve statistical significance for the primary endpoint. Greater differences between treatment arms were seen for younger patients (65-74 years) and patients with earlier onset of depression (<55 years).

Efficacy and Safety of Fixed-Dose Esketamine Nasal Spray Combined With a New Oral Antidepressant in Treatment-Resistant Depression: Results of a Randomized, Double-Blind, Active-Controlled Study (TRANSFORM-1).

BACKGROUND: About one-third of patients with depression fail to achieve remission despite treatment with multiple antidepressants and are considered to have treatment-resistant depression. METHODS: This Phase 3, double-blind, multicenter study enrolled adults with moderate-to-severe depression and nonresponse to ≥2 antidepressants in the current depression episode. Eligible patients (N = 346) were randomized (1:1:1) to twice-weekly nasal spray treatment (esketamine [56 or 84 mg] or placebo) plus a newly initiated, open-label, oral antidepressant taken daily for 4 weeks. The primary efficacy endpoint was change from baseline to day 28 in the Montgomery-Asberg Depression Rating Scale total score, performed by blinded, remote raters. Based on the predefined statistical testing sequence, esketamine 84 mg/antidepressant had to be significant for esketamine 56 mg/antidepressant to be formally tested. RESULTS: Statistical significance was not achieved with esketamine 84 mg/antidepressant compared with antidepressant/placebo (least squares [LS] means difference [95% CI]: -3.2 [-6.88, 0.45]; 2-sided P value = .088). Although esketamine 56 mg/antidepressant could not be formally tested, the LS means difference was -4.1 [-7.67, -0.49] (nominal 2-sided P value = .027). The most common (>20%) adverse events reported for esketamine/antidepressant were nausea, dissociation, dizziness, vertigo, and headache. CONCLUSIONS: Statistical significance was not achieved for the primary endpoint; nevertheless, the treatment effect (Montgomery-Asberg Depression Rating Scale) for both esketamine/antidepressant groups exceeded what has been considered clinically meaningful for approved antidepressants vs placebo. Safety was similar between esketamine/antidepressant groups and no new dose-related safety concerns were identified. This study provides supportive evidence for the safety and efficacy of esketamine nasal spray as a new, rapid-acting antidepressant for patients with treatment-resistant depression. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02417064.

Use of video-recordings of site-based interviews for quality assurance in a study of subjects with schizophrenia and persistent negative symptoms.

Site-independent ratings derived from audio-digital recordings of site-based interviews are often used for quality assurance monitoring to affirm ratings reliability in CNS clinical trials. The present study of subjects with schizophrenia and persistent negative symptoms used video instead of audio recordings of site-based interviews and thereby facilitated visual observation of the subject by the remote rater. "Paired" site-independent scores of the Positive and Negative Syndrome Scale (PANSS) and Brief Negative Symptom Scale (BNSS) were obtained from video-recordings of site-based interviews. The intraclass correlation between site-based and paired site-independent ratings was r = 0.839 for the total PANSS scores (n = 1006) and r = 0.871 for the total BNSS scores (n = 892); <5 % of paired scores deviated outside the acceptable confidence intervals. Ratings "outliers" were identified and remediated. We examined the pattern of paired scoring deviations for the BNSS, total PANSS, PANSS symptom subscales, and the Marder negative symptom factor. Each metric revealed a bidirectional pattern of scoring deviations such that mean site-based ratings were higher than site-independent ratings when symptom severity was high but lower than site-independent ratings when symptom severity was low. The pattern of bidirectional paired scoring deviations observed in this analysis has previously been noted in paired ratings analyses of subjects experiencing an acute exacerbation of psychosis in schizophrenia and major depressive disorder as well. The bidirectional pattern may reflect inherent differences between live ratings and remotely scored recorded ratings. This analysis affirms the utility of video-recordings of site-based ratings for surveillance in trials with subjects with schizophrenia and persistent negative symptoms.

Effects of the selective AMPA modulator NBI-1065845 on the pharmacokinetics of midazolam or ethinyl estradiol-levonorgestrel in healthy adults.

This parallel-arm, phase I study investigated the potential cytochrome P450 (CYP)3A induction effect of NBI-1065845 (TAK-653), an investigational α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor potentiator in phase II development for major depressive disorder. The midazolam treatment arm received the sensitive CYP3A substrate midazolam on Day 1, followed by NBI-1065845 alone on Days 5-13; on Day 14, NBI-1065845 was administered with midazolam, then NBI-1065845 alone on Day 15. The oral contraceptive treatment arm received ethinyl estradiol-levonorgestrel on Day 1, then NBI-1065845 alone on Days 5-13; on Day 14, NBI-1065845 was administered with ethinyl estradiol-levonorgestrel, then NBI-1065845 alone on Days 15-17. Blood samples were collected for pharmacokinetic analyses. The midazolam treatment arm comprised 14 men and 4 women, of whom 16 completed the study. Sixteen of the 17 healthy women completed the oral contraceptive treatment arm. After multiple daily doses of NBI-1065845, the geometric mean ratios (GMRs) (90% confidence interval) for maximum observed concentration were: midazolam, 0.94 (0.79-1.13); ethinyl estradiol, 1.00 (0.87-1.15); and levonorgestrel, 0.99 (0.87-1.13). For area under the plasma concentration-time curve (AUC) from time 0 to infinity, the GMRs were as follows: midazolam, 0.88 (0.78-0.98); and ethinyl estradiol, 1.01 (0.88-1.15). For levonorgestrel, the GMR for AUC from time 0 to the last quantifiable concentration was 0.87 (0.78-0.96). These findings indicate that NBI-1065845 is not a CYP3A inducer and support its administration with CYP3A substrates. NBI-1065845 was generally well tolerated, with no new safety signals observed after coadministration of midazolam, ethinyl estradiol, or levonorgestrel.

INTERACT: a randomized phase 2 study of the DAAO inhibitor luvadaxistat in adults with schizophrenia.

Deficits in N-methyl-d-aspartate receptor (NMDAR) signaling are implicated in the pathogenesis of schizophrenia. Luvadaxistat (TAK-831/NBI-1065844) is an investigational d-amino acid oxidase (DAAO) inhibitor that increases d-serine levels at NMDAR coagonist sites. INTERACT is a phase 2 randomized, placebo-controlled study that evaluated the efficacy and safety of three doses of luvadaxistat, covering a range of DAAO occupancy and d-serine levels, in patients with schizophrenia with persistent negative symptoms. The study included a 14-day, single-blinded placebo run-in period and a 12-week, double-blinded treatment period. The primary efficacy endpoint was the 12-week change from baseline in Positive and Negative Syndrome Scale-Negative Symptom Factor Score (PANSS NSFS). Secondary efficacy endpoints included the 12-week changes from baseline in Brief Assessment of Cognition in Schizophrenia (BACS) score and Schizophrenia Cognition Rating Scale (SCoRS) score. Safety endpoints included adverse event assessments. The full analysis set included all randomized patients (N = 256 [placebo, n = 87; luvadaxistat 50 mg, n = 58; 125 mg, n = 56; 500 mg, n = 55]); 228 patients completed the study. No significant improvements in PANSS NSFS were observed at any dose versus placebo at week 12. Improvements were observed with luvadaxistat 50 mg versus placebo in cognitive endpoints: BACS composite score (nominal one-sided p = 0.031) and SCoRS interviewer total score (nominal one-sided p = 0.011). Luvadaxistat did not significantly improve negative symptoms of schizophrenia. However, luvadaxistat 50 mg met the prespecified secondary endpoints for cognitive performance (BACS) and function (SCoRS), warranting further investigation in patients with cognitive impairment associated with schizophrenia. Luvadaxistat was well-tolerated in INTERACT, with no new safety signals observed. ClinicalTrials.gov: NCT03382639.

Neural mechanisms of antidepressant efficacy of the dopamine receptor agonist pramipexole in treatment of bipolar depression.

The D2/D3 receptor agonist pramipexole has clinical efficacy as an antidepressant, but its neural mechanisms are unknown. We used ¹8FDG-PET to investigate the cerebral metabolic effects of pramipexole augmentation of mood stabilizers in bipolar II depression. Fifteen bipolar II depressed patients on mood stabilizers were imaged at baseline and following 6 wk of pramipexole (n=7) or placebo (n=8) augmentation. Relative to placebo, pramipexole treatment was associated with reductions in normalized metabolism in bilateral orbitofrontal cortex, left ventrolateral prefrontal cortex (PFC), and right anteromedial PFC. Voxel-wise analyses additionally showed decreased normalized metabolism in the left inferior parietal cortex and medial frontopolar cortical (BA 10P) area of the anteromedial PFC following pramipexole treatment. These pramipexole-induced effects on regional metabolism suggest a mechanism of antidepressant action distinct from that previously reported under serotonin reuptake inhibitor treatment and appear compatible with evidence that the central dopaminergic system plays a role in the pathophysiology of bipolar depression.

Cardiac Safety of Esketamine Nasal Spray in Treatment-Resistant Depression: Results from the Clinical Development Program.

BACKGROUND: An intranasal formulation of esketamine, combined with an oral antidepressant, is approved in the USA and the European Union for adults with treatment-resistant depression (TRD). Transient cardiovascular stimulatory effects have been reported with ketamine. METHODS: Cardiovascular effects of esketamine nasal spray, combined with an oral antidepressant, were evaluated in 1708 esketamine-treated adults with TRD in six trials (five double-blind, placebo-controlled (486 placebo-treated patients); one open-label) of 4-52 weeks' duration. Patients with established cardiovascular disease, including uncontrolled hypertension (> 140/> 90 mmHg), history of hypertensive crisis, or clinically significant electrocardiogram (ECG) abnormalities, were excluded from enrollment. Effects on cardiac repolarization were assessed in a phase I randomized, positive- and active-controlled thorough corrected QT (QTc) interval study. For adverse events, odds ratio (OR) [95% confidence interval] for esketamine/antidepressant versus antidepressant/placebo was calculated. RESULTS: Adverse events related to increased BP were reported in 12.8% of all esketamine-treated patients (in double-blind trials: esketamine/antidepressant 11.6% vs. antidepressant/placebo 3.9%; OR 3.2 [1.9-5.8]). Among the patients without a history of hypertension, new antihypertensive medication was initiated by 2.1% (6/280) of patients in the esketamine/antidepressant group versus 1.2% (2/171) of patients in the antidepressant/placebo group, in the double-blinded studies. Adverse events related to abnormal heart rate were reported in 3.0% of all esketamine-treated patients (in double-blind trials: 1.6% vs. 0.8%; OR 1.9 [0.5-8.6]). Overall, three cardiovascular adverse events related to BP increase were reported as serious and severe, and there was one fatal event considered unrelated (acute cardiac failure). BP increases reached the maximum postdose value within ~ 40 min of esketamine dosing and returned to the predose range by ~ 1.5 h postdose. In two studies (4-week duration, age 18-64 years), the largest mean maximum systolic/diastolic postdose BP increases were 13.3/8.7 mmHg for esketamine/antidepressant and 6.1/4.9 mmHg for antidepressant/placebo, and in a short-term elderly study (age ≥ 65 years) were 16.0/9.5 and 11.1/6.8 mmHg, respectively. Across studies/study phases, < 2% of patients discontinued esketamine due to adverse events of increased BP and tachycardia. No clinically relevant effect on ECG parameters was observed. Therapeutic and supratherapeutic doses of esketamine did not prolong the QTcF (QT corrected by Fridericia's equation) interval (baseline-corrected values of - 2.02 to 2.16 ms, and - 3.51 to 4.89 ms, respectively). CONCLUSIONS: BP elevations following esketamine dosing are generally transient, asymptomatic, and not associated with serious cardiovascular safety sequalae. Further evaluation of long-term cardiovascular outcomes is warranted.

Relapse prevention in treatment-resistant major depressive disorder with rapid-acting antidepressants.

Major depressive disorder (MDD) is the leading cause of disability worldwide and reduces life expectancy. Achieving and sustaining remission from depression is challenging after initial improvement of an acute episode with an antidepressant, especially for patients whose depressive episodes have proven treatment-resistant in response to conventional antidepressant pharmacotherapy. While standard antidepressants are at least partly effective for the short-term treatment of acute depressive episodes of MDD, many patients relapse within 6 months of apparent clinical remission, with faster and higher rates observed in those with treatment-resistant depression (TRD). Efficacy of IV ketamine, a rapid-acting N-methyl d-aspartate (NMDA) receptor antagonist, in maintaining antidepressant effect was suggested in a few small, single center, open-label studies and case series. More recently, maintenance of antidepressant effects beyond the initial acute (induction) treatment period has been shown with esketamine nasal spray, an enantiomer of ketamine, in conjunction with an oral antidepressant in three phase 2/3 registration studies (SYNAPSE, SUSTAIN-1, SUSTAIN-2) of adult patients with TRD. In these studies the maintenance of efficacy of an intermittently-dosed esketamine treatment regimen was established in which twice-weekly dose administration during a 4-week induction period was followed initially by weekly administration and later by either weekly or every-other-week administration. During long-term maintenance therapy the antidepressant effect persisted in most patients with this regimen, despite their history of being resistant to conventional antidepressants prior to entering esketamine studies. These data suggest that the neurobiological changes induced by initial esketamine treatment, which putatively underlie its antidepressant effect, can be maintained using repeated administration.

Esketamine Nasal Spray Plus Oral Antidepressant in Patients With Treatment-Resistant Depression: Assessment of Long-Term Safety in a Phase 3, Open-Label Study (SUSTAIN-2).

OBJECTIVE: To evaluate long-term safety and efficacy of esketamine nasal spray plus a new oral antidepressant (OAD) in patients with treatment-resistant depression (TRD). METHODS: This phase 3, open-label, multicenter, long-term (up to 1 year) study was conducted between October 2015 and October 2017. Patients (≥ 18 years) with TRD (DSM-5 diagnosis of major depressive disorder and nonresponse to ≥ 2 OAD treatments) were enrolled directly or transferred from a short-term study (patients aged ≥ 65 years). Esketamine nasal spray (28-mg, 56-mg, or 84-mg) plus new OAD was administered twice a week in a 4-week induction (IND) phase and weekly or every-other-week for patients who were responders and entered a 48-week optimization/maintenance (OP/MAINT) phase. RESULTS: Of 802 enrolled patients, 86.2% were direct-entry and 13.8% were transferred-entry; 580 (74.5%) of 779 patients who entered the IND phase completed the phase, and 150 (24.9%) of 603 who entered the OP/MAINT phase completed the phase. Common treatment-emergent adverse events (TEAEs) were dizziness (32.9%), dissociation (27.6%), nausea (25.1%), and headache (24.9%). Seventy-six patients (9.5%) discontinued esketamine due to TEAEs. Fifty-five patients (6.9%) experienced serious TEAEs. Most TEAEs occurred on dosing days, were mild or moderate in severity, and resolved on the same day. Two deaths were reported; neither was considered related to esketamine. Cognitive performance generally either improved or remained stable postbaseline. There was no case of interstitial cystitis or respiratory depression. Treatment-emergent dissociative symptoms were transient and generally resolved within 1.5 hours postdose. Montgomery-Åsberg Depression Rating Scale total score decreased during the IND phase, and this reduction persisted during the OP/MAINT phase (mean [SD] change from baseline of respective phase to endpoint: IND, -16.4 [8.76]; OP/MAINT, 0.3 [8.12]). CONCLUSIONS: Long-term esketamine nasal spray plus new OAD therapy had a manageable safety profile, and improvements in depression appeared to be sustained in patients with TRD. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02497287.

Analysis of Clinical Trial Exit Interview Data in Patients with Treatment-Resistant Depression.

BACKGROUND: Clinical outcome assessments may not fully capture patients' perspectives of treatment benefit or tolerability. Incorporating individual exit interviews might enhance the description of the patient experience of drug effects. OBJECTIVE: The objective of this study was to evaluate the patient treatment experience in a clinical trial of treatment-resistant depression utilizing exit interview methodology. METHODS: Individual patient interviews were conducted with subjects exiting two phase II clinical trials involving investigational agents for treatment-resistant depression. Interviews included standardized questions about patients' perceptions of health changes and interest in continued use of the investigational agent. Constant comparative analysis of blinded data was used to identify, code, and categorize the data followed by a subsequent analysis of unblinded data to evaluate any potential treatment differences. RESULTS: Ninety subjects completed exit interviews across the two trials. Most subjects (90%, Trial 2001; 74%, Trial 2002) reported at least one health change. Most subjects rated these changes to be at least moderately important, with most being rated "very important" to "extremely important." After unblinding, participants receiving active therapy alone reported most of the positive health changes (80% of overall positive changes in Trial 2001, 89% in Trial 2002), whereas patients taking placebo alone reported the majority of negative health changes (57% in Trial 2002). Positive changes included not only anticipated changes in mood but also potential cognitive benefits such as mental alertness, improved sleep, and better concentration. CONCLUSIONS: Standardized interview data provided direct patient insight into the treatment experience from the patient perspective. Data from these interviews assisted in phase III endpoint selection by providing data on relevant concepts in the target treatment-resistant depression population receiving a new treatment, thus enabling the selection of tools to capture noted treatment effects and, by eliminating irrelevant constructs or measures, thereby reducing data "noise." TRIAL REGISTRATION: ClinicalTrials.gov NCT01640080; NCT01627782.

Efficacy and Safety of Intranasal Esketamine for the Rapid Reduction of Symptoms of Depression and Suicidality in Patients at Imminent Risk for Suicide: Results of a Double-Blind, Randomized, Placebo-Controlled Study.

(Reprinted with permission from AmJ Psychiatry 2018; 175:620-630).

Efficacy and Safety of Flexibly Dosed Esketamine Nasal Spray Combined With a Newly Initiated Oral Antidepressant in Treatment-Resistant Depression: A Randomized Double-Blind Active-Controlled Study.

OBJECTIVE: About one-third of patients with depression fail to achieve remission despite treatment with multiple antidepressants. This study compared the efficacy and safety of switching patients with treatment-resistant depression from an ineffective antidepressant to flexibly dosed esketamine nasal spray plus a newly initiated antidepressant or to a newly initiated antidepressant (active comparator) plus placebo nasal spray. METHODS: This was a phase 3, double-blind, active-controlled, multicenter study conducted at 39 outpatient referral centers. The study enrolled adults with moderate to severe nonpsychotic depression and a history of nonresponse to at least two antidepressants in the current episode, with one antidepressant assessed prospectively. Confirmed nonresponders were randomly assigned to treatment with esketamine nasal spray (56 or 84 mg twice weekly) and an antidepressant or antidepressant and placebo nasal spray. The primary efficacy endpoint, change from baseline to day 28 in Montgomery-Åsberg Depression Rating Scale (MADRS) score, was assessed by a mixed-effects model using repeated measures. RESULTS: Of 435 patients screened, 227 underwent randomization and 197 completed the 28-day double-blind treatment phase. Change in MADRS score with esketamine plus antidepressant was significantly greater than with antidepressant plus placebo at day 28 (difference of least square means=-4.0, SE=1.69, 95% CI=-7.31, -0.64); likewise, clinically meaningful improvement was observed in the esketamine plus antidepressant arm at earlier time points. The five most common adverse events (dissociation, nausea, vertigo, dysgeusia, and dizziness) all were observed more frequently in the esketamine plus antidepressant arm than in the antidepressant plus placebo arm; 7% and 0.9% of patients in the respective treatment groups discontinued study drug because of an adverse event. Adverse events in the esketamine plus antidepressant arm generally appeared shortly after dosing and resolved by 1.5 hours after dosing. CONCLUSIONS: Current treatment options for treatment-resistant depression have considerable limitations in terms of efficacy and patient acceptability. Esketamine is expected to address an unmet medical need in this population through its novel mechanism of action and rapid onset of antidepressant efficacy. The study supports the efficacy and safety of esketamine nasal spray as a rapidly acting antidepressant for patients with treatment-resistant depression.

Efficacy of Esketamine Nasal Spray Plus Oral Antidepressant Treatment for Relapse Prevention in Patients With Treatment-Resistant Depression: A Randomized Clinical Trial.

Importance: Controlled studies have shown short-term efficacy of esketamine for treatment-resistant depression (TRD), but long-term effects remain to be established. Objective: To assess the efficacy of esketamine nasal spray plus an oral antidepressant compared with an oral antidepressant plus placebo nasal spray in delaying relapse of depressive symptoms in patients with TRD in stable remission after an induction and optimization course of esketamine nasal spray plus an oral antidepressant. Design, Setting, and Participants: In this phase 3, multicenter, double-blind, randomized withdrawal study conducted from October 6, 2015, to February 15, 2018, at outpatient referral centers, 705 adults with prospectively confirmed TRD were enrolled; 455 entered the optimization phase and were treated with esketamine nasal spray (56 or 84 mg) plus an oral antidepressant. After 16 weeks of esketamine treatment, 297 who achieved stable remission or stable response entered the randomized withdrawal phase. Interventions: Patients who achieved stable remission and those who achieved stable response (without remission) were randomized 1:1 to continue esketamine nasal spray or discontinue esketamine treatment and switch to placebo nasal spray, with oral antidepressant treatment continued in each group. Main Outcomes and Measures: Time to relapse was examined in patients who achieved stable remission, as assessed using a weighted combination log-rank test. Results: Among the 297 adults (mean age [SD], 46.3 [11.13] years; 197 [66.3%] female) who entered the randomized maintenance phase, 176 achieved stable remission; 24 (26.7%) in the esketamine and antidepressant group and 39 (45.3%) in the antidepressant and placebo group experienced relapse (log-rank P = .003, number needed to treat [NNT], 6). Among the 121 who achieved stable response, 16 (25.8%) in the esketamine and antidepressant group and 34 (57.6%) in the antidepressant and placebo group experienced relapse (log-rank P < .001, NNT, 4). Esketamine and antidepressant treatment decreased the risk of relapse by 51% (hazard ratio [HR], 0.49; 95% CI, 0.29-0.84) among patients who achieved stable remission and 70% (HR, 0.30; 95% CI, 0.16-0.55) among those who achieved stable response compared with antidepressant and placebo treatment. The most common adverse events reported for esketamine-treated patients after randomization were transient dysgeusia, vertigo, dissociation, somnolence, and dizziness (incidence, 20.4%-27.0%), each reported in fewer patients (<7%) treated with an antidepressant and placebo. Conclusions and Relevance: For patients with TRD who experienced remission or response after esketamine treatment, continuation of esketamine nasal spray in addition to oral antidepressant treatment resulted in clinically meaningful superiority in delaying relapse compared with antidepressant plus placebo. Trial Registration: ClinicalTrials.gov identifier: NCT02493868.

Efficacy and Safety of Intranasal Esketamine Adjunctive to Oral Antidepressant Therapy in Treatment-Resistant Depression: A Randomized Clinical Trial.

Importance: Approximately one-third of patients with major depressive disorder (MDD) do not respond to available antidepressants. Objective: To assess the efficacy, safety, and dose-response of intranasal esketamine hydrochloride in patients with treatment-resistant depression (TRD). Design, Setting, and Participants: This phase 2, double-blind, doubly randomized, delayed-start, placebo-controlled study was conducted in multiple outpatient referral centers from January 28, 2014, to September 25, 2015. The study consisted of 4 phases: (1) screening, (2) double-blind treatment (days 1-15), composed of two 1-week periods, (3) optional open-label treatment (days 15-74), and (4) posttreatment follow-up (8 weeks). One hundred twenty-six adults with a DSM-IV-TR diagnosis of MDD and history of inadequate response to 2 or more antidepressants (ie, TRD) were screened, 67 were randomized, and 60 completed both double-blind periods. Intent-to-treat analysis was used in evaluation of the findings. Interventions: In period 1, participants were randomized (3:1:1:1) to placebo (n = 33), esketamine 28 mg (n = 11), 56 mg (n = 11), or 84 mg (n = 12) twice weekly. In period 2, 28 placebo-treated participants with moderate-to-severe symptoms were rerandomized (1:1:1:1) to 1 of the 4 treatment arms; those with mild symptoms continued receiving placebo. Participants continued their existing antidepressant treatment during the study. During the open-label phase, dosing frequency was reduced from twice weekly to weekly, and then to every 2 weeks. Main Outcomes and Measures: The primary efficacy end point was change from baseline to day 8 (each period) in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score. Results: Sixty-seven participants (38 women, mean [SD] age, 44.7 [10.0] years) were included in the efficacy and safety analyses. Change (least squares mean [SE] difference vs placebo) in MADRS total score (both periods combined) in all 3 esketamine groups was superior to placebo (esketamine 28 mg: -4.2 [2.09], P = .02; 56 mg: -6.3 [2.07], P = .001; 84 mg: -9.0 [2.13], P < .001), with a significant ascending dose-response relationship (P < .001). Improvement in depressive symptoms appeared to be sustained (-7.2 [1.84]) despite reduced dosing frequency in the open-label phase. Three of 56 (5%) esketamine-treated participants during the double-blind phase vs none receiving placebo and 1 of 57 participants (2%) during the open-label phase had adverse events that led to study discontinuation (1 event each of syncope, headache, dissociative syndrome, and ectopic pregnancy). Conclusions and Relevance: In this first clinical study to date of intranasal esketamine for TRD, antidepressant effect was rapid in onset and dose related. Response appeared to persist for more than 2 months with a lower dosing frequency. Results support further investigation in larger trials. Trial Registration: clinicaltrials.gov identifier: NCT01998958.