Efficacy and safety of aticaprant, a kappa receptor antagonist, adjunctive to oral SSRI/SNRI antidepressant in major depressive disorder: results of a phase 2 randomized, double-blind, placebo-controlled study.

This was a double-blind, randomized, phase 2 study of adults (18-64 years) with DSM-5 diagnosis of major depressive disorder (MDD), with moderate-to-severe episode severity (Montgomery-Åsberg Depression Rating Scale [MADRS] ≥25) despite an adequate course with ongoing antidepressant for ≥6 weeks to ≤12 months. Following a double-blind placebo lead-in period (up to 3 weeks), participants were randomized to receive once daily aticaprant 10 mg or continue placebo, added to their ongoing treatment, for 6 weeks. Of 184 participants enrolled, 169 were included in safety analyses (aticaprant n = 85, placebo n = 84) and 166 in full intent-to-treat (fITT) efficacy analyses; 121 placebo lead-in non-responders (<30% reduction in MADRS total score) in fITT were included in enriched ITT (eITT) analyses. Improvement (least squares mean difference [upper limit 1-sided 80% CI] versus placebo) in MADRS total score at week 6 for aticaprant was significant versus placebo (eITT: -2.1 [-1.09], 1-sided p = 0.044; effect size (ES) 0.23; fITT -3.1 [2.21], 1-sided p = 0.002; ES 0.36). The between-group difference was larger among participants with Snaith-Hamilton Pleasure Scale (SHAPS) score greater/equal to versus less than baseline median SHAPS. The most common treatment-emergent adverse events reported for aticaprant (versus placebo) were headache (11.8% versus 7.1%), diarrhea (8.2% versus 2.4%), nasopharyngitis (5.9% versus 2.4%), and pruritus (5.9% versus 0%). One participant (1.2%) in each arm discontinued treatment due to an adverse event. In this study of participants with MDD and inadequate response to SSRI/SNRI, adjunctive treatment with aticaprant significantly reduced depressive symptoms versus placebo, without resulting in significant safety signals, supporting further investigation in larger trials.

Long-term safety and maintenance of response with esketamine nasal spray in participants with treatment-resistant depression: interim results of the SUSTAIN-3 study.

Patients with treatment-resistant depression (TRD) have higher rates of relapse and pronounced decreases in daily functioning and health-related quality of life compared to patients with major depressive disorder who are not treatment-resistant, underscoring the need for treatment choices with sustained efficacy and long-term tolerability. Adults with TRD who participated in ≥1 of 6 phase 3 "parent" studies could continue esketamine treatment, combined with an oral antidepressant, by enrolling in phase 3, open-label, long-term extension study, SUSTAIN-3. Based on their status at parent-study end, eligible participants entered a 4-week induction phase followed by an optimization/maintenance phase, or directly entered the optimization/maintenance phase of SUSTAIN-3. Intranasal esketamine dosing was flexible, twice-weekly during induction and individualized to depression severity during optimization/maintenance. At the interim data cutoff (01 December 2020), 1148 participants were enrolled, 458 at induction and 690 at optimization/maintenance. Mean (median) cumulative duration of maintenance esketamine treatment was 31.5 (37.7) months (totaling 2769 cumulative patient-years). Common treatment-emergent adverse events (≥20%) were headache, dizziness, nausea, dissociation, somnolence, and nasopharyngitis. Mean Montgomery-Åsberg Depression Rating Scale (MADRS) total score decreased during induction, and this reduction persisted during optimization/maintenance (mean [SD] change from the baseline to the endpoint of each phase: induction -12.8 [9.73]; optimization/maintenance +1.1 [9.93]), with 35.6% and 46.1% of participants in remission (MADRS total score ≤12) at induction and optimization/maintenance endpoints, respectively. Improvement in depression ratings generally persisted among participants who remained in maintenance treatment, and no new safety signal was identified during long-term treatment (up to 4.5 years) using intermittent-dosed esketamine in conjunction with daily antidepressant.

Assessment of health-related quality of life and health status in patients with treatment-resistant depression treated with esketamine nasal spray plus an oral antidepressant.

BACKGROUND: Patients with treatment-resistant depression (TRD) report significant deficits in physical and mental health, as well as severely impaired health-related quality of life (HRQoL) and functioning. Esketamine effectively enhances the daily functioning in these patients while also improving their depressive symptoms. This study assessed HRQoL and health status of patients with TRD, who were treated with esketamine nasal spray and an oral antidepressant (ESK + AD) vs. placebo nasal spray and an AD (AD + PBO). METHODS: Data from TRANSFORM-2, a phase 3, randomized, double-blind, short-term flexibly dosed study, were analyzed. Patients (aged 18-64 years) with TRD were included. The outcome assessments included the European Quality of Life Group, Five Dimension, Five Level (EQ-5D-5L), EQ-Visual Analogue Scale (EQ-VAS), and Sheehan Disability Scale (SDS). The health status index (HSI) was calculated using EQ-5D-5L scores. RESULTS: The full analysis set included 223 patients (ESK + AD: 114; AD + PBO: 109; mean [SD] age: 45.7 [11.89]). At Day 28, a lower percentage of patients reported impairment in the ESK + AD vs. AD + PBO group in all five EQ-5D-5L dimensions: mobility (10.6% vs. 25.0%), self-care (13.5% vs. 32.0%), usual activities (51.9% vs. 72.0%), pain/discomfort (35.6% vs. 54.0%), and anxiety/depression (69.2% vs. 78.0%). The mean (SD) change from baseline in HSI at Day 28 was 0.310 (0.219) for ESK + AD and 0.235 (0.252) for AD + PBO, with a higher score reflecting better levels of health. The mean (SD) change from baseline in EQ-VAS score at Day 28 was greater in ESK + AD (31.1 [25.67]) vs. AD + PBO (22.1 [26.43]). The mean (SD) change in the SDS total score from baseline to Day 28 also favored ESK + AD (-13.6 [8.31]) vs. AD + PBO (-9.4 [8.43]). CONCLUSIONS: Greater improvements in HRQoL and health status were observed among patients with TRD treated with ESK + AD vs. AD + PBO. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02418585.

A Meta-Analysis of the Antidepressant Responses in Pivotal Trials on Esketamine Nasal Spray and Atypical Antipsychotics.

Purpose: This meta-analysis assessed whether atypical antipsychotics (AAPs) and esketamine nasal spray (ESK-NS), which are mechanistically distinct, differ in antidepressant outcomes. Patients and Methods: Data were extracted from 12 trials of ESK-NS or AAPs in depressed patients (4276) with inadequate response or resistance to conventional antidepressants. Montgomery-Åsberg Depression Rating Scale (MADRS) score reductions from baseline and response rates (≥50% reduction) were analyzed. Results: At endpoint, the estimated MADRS score reduction of pooled ESK-NS arms was greater than pooled AAP arms (+9.16 points, p < 0.0001). The reduction also was greater in the pooled control arms of the ESK-NS trials than the pooled control arms of the AAP trials (+7.57 points, p < 0.0001). The mean difference in the reductions between pooled ESK-NS and control arms was 1.87 points greater than that between pooled AAP and control arms, but this difference was not significant (95% CI: -4.49, 0.74, p = 0.16). Relative to their respective control arms, the mean difference in response rates was 25% for the pooled ESK-NS and 9% for the pooled AAP arms; the mean response rate was 16% greater in the pooled ESK-NS studies than the pooled AAP studies (p = 0.0004). Comparisons against specific AAPs showed mean differences in the MADRS score reductions at 1 week between the experimental and control arms that were numerically larger in the ESK-NS trials than in the aripiprazole trials (mean difference of 1.71 points, p = 0.06) and the brexpiprazole trials (mean difference of 2.05 points, p = 0.02). Conclusion: The ESK-NS arms showed numerically larger MADRS score reductions at week-1 and endpoint, and a significantly larger response rate compared with AAP arms. Prospective studies involving direct comparisons are warranted to compare the relative efficacy between these treatment regimens.

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.

Evaluation of Individual Items of the Patient Health Questionnaire (PHQ-9) and Montgomery-Asberg Depression Rating Scale (MADRS) in Adults with Treatment-Resistant Depression Treated with Esketamine Nasal Spray Combined with a New Oral Antidepressant.

OBJECTIVE: The objective of this study was to determine which symptoms measured by the Patient Health Questionnaire (PHQ-9) and Montgomery-Asberg Depression Rating Scale (MADRS) improve in those treated with esketamine nasal spray in combination with oral antidepressant (AD) compared with those treated with placebo plus AD for adult patients with treatment-resistant depression (TRD). These results complement the interpretation of PHQ-9 and MADRS total scores. METHODS: The TRANSFORM 2 study evaluated the efficacy and safety of esketamine nasal spray in combination with AD. This post-hoc analysis used PHQ-9 and MADRS data to evaluate symptom changes. The total scores change and proportions of individual item change scores on the PHQ-9 and MADRS were evaluated at days 15 and 28; analysis of variance was used to test differences on total scores. Generalized estimation equations of logistic regression models were used to estimate the likelihood of improvement on instrument items. RESULTS: The mean total score reduction of the PHQ-9, indicating improvement, was greater in the esketamine plus AD arm compared with placebo plus AD at day 15 (- 1.8; p = 0.045) and day 28 (- 2.8; p = 0.006). Proportions of those who improved (≥ 1 point on a 4-point scale and ≥ 2 points on a 7-point scale for the PHQ-9 and MADRS, respectively) was greater in the esketamine plus AD group compared with the placebo plus AD group across all items. The odds of improving for those in the esketamine plus AD group compared with the placebo plus AD group were over two times greater on the PHQ-9 items: "Little interest/pleasure in things" (OR 2.252, 95% CI 1.165-4.355); "Feeling down, depressed, or hopeless" (OR 2.767, 95% CI 1.400-5.470); and "Feeling tired or having little energy" (OR 2.171, 95% CI 1.153-4.087). The mean reduction in total scores on the MADRS, indicating improvement, was numerically greater at day 15 (- 2.0; p = 0.189) and statistically significantly greater at day 28 (- 4.4; p = 0.017) in the esketamine plus AD arm compared with placebo plus AD. The odds of improving for those in the esketamine plus AD group compared with the placebo plus AD group were over two times greater on the MADRS items measuring "Apparent sadness" (OR 2.007, 95% CI 1.096-3.674); and "Inability to feel" (OR 2.099, 95% CI 1.180-3.735). CONCLUSION: Improvement in mean total scores in those treated with esketamine plus AD compared with placebo plus AD are important results to confirm efficacy. The odds of improving in those treated with esketamine plus AD was at least two times greater than with placebo plus AD on three patient- and two clinician-reported individual symptoms of TRD. These findings provide patient-relevant quantification of the esketamine plus AD treatment benefit, adding understanding as to which symptoms are most improved with treatment. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02418585; first posted 16 April 2015.

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).

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 Esketamine Nasal Spray on Olfactory Function and Nasal Tolerability in Patients with Treatment-Resistant Depression: Results from Four Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase III Studies.

BACKGROUND: Intranasal drug delivery offers a non-invasive and convenient dosing option for patients and physicians, especially for conditions requiring chronic/repeated-treatment administration. However, in some cases such delivery may be harmful to nasal and olfactory epithelia. OBJECTIVE: The aim of this study was to assess the potential impact of long-term intermittent treatment with esketamine nasal spray, taken in conjunction with an oral antidepressant (AD), on olfactory function and nasal tolerability in patients with treatment-resistant depression (TRD). METHODS: A total of 1142 patients with TRD participated from four multicenter, randomized, double-blind, phase III studies: three short-term studies (two in patients aged 18-64 years, one in patients ≥65 years), and one long-term maintenance study of esketamine nasal spray + AD versus placebo nasal spray + AD. Across the four studies, assessments were performed at 208 sites in 21 countries. Olfactory function was measured using the 40-item University of Pennsylvania Smell Identification Test (UPSIT®) and the single-staircase Snap & Sniff® Odor Detection Threshold Test (S&S-T). Nasal tolerability, including nasal examinations and a quantitative, self-administered nasal symptom questionnaire (NSQ), was also assessed. Data were analyzed using analyses of covariance. RESULTS: Of 1142 participants, 734 were women (64.3%). The mean age of all participants ranged from 45.7 to 70.0 years across the studies. Overall, 855 patients received esketamine nasal spray + AD and 432 received placebo nasal spray + AD. Objective evaluation of nasal function showed no evidence of an adverse impact following esketamine administration. Based on the UPSIT® and S&S-T results, intranasal administration of esketamine had no effect on the odor identification or threshold test scores compared with placebo nasal spray + oral AD. Similarly, repeated administration with esketamine nasal spray had no meaningful impact on assessments of nasal function. No dose-response relationship was observed between esketamine doses and the olfactory test scores. Esketamine nasal spray was well tolerated, as indicated by responses on the NSQ and negative nasal examination findings. CONCLUSION: Findings from this analysis indicate that there was no evidence of adverse effect on either olfactory or nasal health measures with repeated intermittent administration of esketamine nasal spray at any dose over the course of short-term (4 weeks) or long-term (16-100 weeks) studies. CLINICAL TRIAL REGISTRATION: TRANSFORM-1: NCT02417064, date of registration: 15/04/2015; TRANSFORM-2: NCT02418585, date of registration: 16/04/2015; TRANSFORM-3: NCT02422186, date of registration: 21/04/2015; SUSTAIN-1: NCT02493868, date of registration: 10/07/2015.

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.

Meaningful Change in Depression Symptoms Assessed with the Patient Health Questionnaire (PHQ-9) and Montgomery-Åsberg Depression Rating Scale (MADRS) Among Patients with Treatment Resistant Depression in Two, Randomized, Double-blind, Active-controlled Trials of Esketamine Nasal Spray Combined With a New Oral Antidepressant.

BACKGROUND: Patients with major depressive disorder who do not respond to ≥2 different pharmacological treatments within the current depressive episode are considered to have treatment resistant depression (TRD). This analysis determined meaningful change thresholds (MCT) of the Patient Health Questionnaire (PHQ-9) and Montgomery-Åsberg Depression Rating Scale (MADRS) using anchor-based methods and compared proportions of meaningful changes in patients with TRD across treatment groups from two Phase 3 trials for esketamine nasal spray (SPRAVATOTM). METHODS: Data from two Phase 3 trials in patients with TRD, TRANSFORM-1 and -2, were used in this analysis. The MCTs for the PHQ-9 and MADRS were derived using a clinician global impression of severity anchor. Blinded probability density functions displayed score distributions between anchor categories. Proportions of meaningful response were compared between treatment groups using chi-square tests supported by unblinded cumulative distribution functions of change scores. RESULTS: Baseline scores were similar for the PHQ-9 and MADRS between the esketamine/antidepressant (AD) and AD/placebo groups. The most appropriate MCT on the PHQ-9 was -6 points. By Day 28, 86.5% of patients reached or exceeded the PHQ-9 MCT in the esketamine/AD group compared to 70% in the placebo/AD group. The most appropriate MCT for the MADRS was -10 points. By Day 28, 78.2% of patients reached or exceeded the MADRS MCT in the esketamine/AD group compared to 65.0% in the placebo/AD group. CONCLUSIONS: Individual-level meaningful change for the PHQ-9 and MADRS was effectively quantified using a clinical anchor to interpret efficacy from patients with TRD and their treating clinicians.

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.

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.