Esketamine Augmentation in Treatment-Resistant Obsessive-Compulsive Disorder: A Retrospective Chart Review.

OBJECTIVE: Converging evidence supports the role of the glutamate, an excitatory amino acid neurotransmitter, in the pathophysiology of obsessive-compulsive disorder (OCD). Ketamine and esketamine, both noncompetitive N -methyl- d -aspartate antagonists, have emerged as a promising medication for this psychiatric disorder, given its possible efficacy with faster onset and good tolerability. The purpose of this retrospective chart review is to evaluate whether unbiased clinical documentation supports formal clinical trials of esketamine for an OCD indication. METHODS: A retrospective chart review of patients with treatment-resistant OCD receiving a single dose of esketamine (0.5mg/kg) added to standard therapy was conducted. The Yale-Brown Obsessive-Compulsive Scale and the Montgomery-Åsberg Depression Rating Scale were used to evaluate OCD and depressive symptoms respectively at baseline, 24 hours, and 7 days after esketamine administration. Descriptive statistics were used to analyze the data. RESULTS: Eight subjects were identified in this retrospective chart review: esketamine was administered subcutaneously in 7 and intravenously in 1. One week after infusion, 25% of the sample met criteria for treatment response and 50% for partial response. Major depressive disorder was a comorbid diagnosis in 75% of the sample and 2 of these subjects showed a positive antidepressant response. CONCLUSIONS: Our findings provide preliminary evidence that esketamine may reduce obsessive-compulsive symptoms in a subset of treatment-resistant OCD patients.

Arketamine for bipolar depression: Open-label, dose-escalation, pilot study.

There are significantly fewer options for the treatment of bipolar depression than major depressive disorder, with an urgent need for alternative therapies. In this pilot study, we treated six subjects with bipolar disorder types I and II (according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria) who had been in a current depressive episode for at least four weeks. Four subjects were female (66.66%), and the mean age was 45.33 (±12.32). Subjects received adjunct treatment with two arketamine intravenous infusions one week apart-0.5 mg/kg first and then 1 mg/kg. The mean baseline Montgomery-Åsberg Depression Rating Scale (MADRS) total score was 36.66, which decreased to 27.83 24h after the first infusion of 0.5 mg/kg of arketamine (p = 0.036). In respect of the 1 mg/kg dose, the mean MADRS total score before the second infusion was 32.0, which dropped to 17.66 after 24h (p < 0.001). Arketamine appears to have rapid-acting antidepressant properties, consistent with previous animal studies on major depression. All individuals tolerated both doses, exhibiting nearly absent dissociation, and no manic symptoms. To the best of our knowledge, this pilot trial is the first to test the feasibility and safety of the (R)-enantiomer of ketamine (arketamine) for bipolar depression.

Arketamine as adjunctive therapy for treatment-resistant depression: A placebo-controlled pilot study.

BACKGROUND: Racemic ketamine is a mixture of (R)-ketamine (arketamine) and (S)-ketamine (esketamine), with the latter regarded as the main isomer for antidepressant effects. However, preclinical data and one open-label human trial suggest arketamine might exert a more potent and longer-lasting antidepressant effect with fewer side effects. We aimed to explore the feasibility of a randomized controlled trial of arketamine for treatment-resistant depression (TRD) and to assess its efficacy and safety compared to placebo. METHODS: This is a, randomized, double-blind, crossover, pilot trial (n = 10). All participants received saline and arketamine (0.5 mg/kg) with a one-week interval. Treatment effects were analyzed with a linear mixed effects (LME) model. RESULTS: Our analysis suggested the presence of a carryover effect, so the main efficacy analysis was limited to the first week, which demonstrated a main effect of time (p = 0.038) but not for treatment (p = 0.40) or their interaction (p = 0.95). This indicates that depression improved over time, but without significant difference between arketamine and placebo. Analyzing the two weeks together, findings were the same. Dissociation and other adverse events were minimal. LIMITATIONS: This was a pilot study with a small sample and underpowered. CONCLUSIONS: Arketamine was not superior to placebo for TRD but demonstrated to be extremely safe. Our findings reinforce the importance of continuing studies with this drug, with better powered clinical trials, perhaps considering a parallel design with higher or flexible doses and repeated administrations.

Brain-derived neurotrophic factor serum levels following ketamine and esketamine intervention for treatment-resistant depression: secondary analysis from a randomized trial.

OBJECTIVES: Evidence suggests that ketamine's influence on brain-derived neurotrophic factor (BDNF) might be involved in its mechanism of rapid antidepressant action. We aimed to evaluate the differential impact of ketamine and esketamine on serum BDNF levels and its association with response patterns in treatment-resistant depression (TRD). METHODS: Participants (n = 53) are from a randomized, double-blind clinical trial comparing the efficacy of single-dose ketamine (0.5mg/kg, n = 27) and esketamine (0.25mg/kg, n = 26) in TRD. Depression severity was assessed before and 24 hours, 72 hours, and 7 days after the intervention, using the Montgomery-Åsberg Depression Rating Scale (MADRS). Blood samples were collected before infusion, 24 hours, and 7 days afterwards. RESULTS: There were no significant changes in BDNF levels at post-infusion evaluation points, and no difference in BDNF levels comparing ketamine and esketamine. Both drugs exhibited similar therapeutic effect. There was no association between BDNF levels and response to treatment or severity of depressive symptoms. CONCLUSION: There was no significant treatment impact on BDNF serum levels - neither with ketamine nor esketamine - despite therapeutic response. These results suggest that ketamine or esketamine intervention for TRD has no impact on BDNF levels measured at 24 hours and 7 days after the infusion.

Brain-derived neurotrophic factor serum levels following ketamine and esketamine intervention for treatment-resistant depression: secondary analysis from a randomized trial

Abstract Objectives Evidence suggests that ketamine's influence on brain-derived neurotrophic factor (BDNF) might be involved in its mechanism of rapid antidepressant action. We aimed to evaluate the differential impact of ketamine and esketamine on serum BDNF levels and its association with response patterns in treatment-resistant depression (TRD). Methods Participants (n = 53) are from a randomized, double-blind clinical trial comparing the efficacy of single-dose ketamine (0.5mg/kg, n = 27) and esketamine (0.25mg/kg, n = 26) in TRD. Depression severity was assessed before and 24 hours, 72 hours, and 7 days after the intervention, using the Montgomery-Åsberg Depression Rating Scale (MADRS). Blood samples were collected before infusion, 24 hours, and 7 days afterwards. Results There were no significant changes in BDNF levels at post-infusion evaluation points, and no difference in BDNF levels comparing ketamine and esketamine. Both drugs exhibited similar therapeutic effect. There was no association between BDNF levels and response to treatment or severity of depressive symptoms. Conclusion There was no significant treatment impact on BDNF serum levels - neither with ketamine nor esketamine - despite therapeutic response. These results suggest that ketamine or esketamine intervention for TRD has no impact on BDNF levels measured at 24 hours and 7 days after the infusion. This clinical trial is registered on the Japan Primary Registries Network: UMIN000032355.

Intravenous arketamine for treatment-resistant depression: open-label pilot study.

We aimed to analyze the efficacy and safety of arketamine, the R(-)-enantiomer of ketamine, for treatment-resistant depression (TRD) in humans. Open-label pilot trial, seven subjects with TRD received a single intravenous infusion of arketamine (0.5 mg/kg); primary outcome was change in Montgomery-Åsberg Depression Rating Scale (MADRS) 24 h after. Mean MADRS dropped from 30.7 before infusion to 10.4 after one day, a mean difference of 20.3 points [CI 95% 13.6-27.0; p < 0.001]; dissociation was nearly absent. Arketamine might produce fast-onset and sustained antidepressant effects in humans with favorable safety profile, like previously reported with animals; further controlled-trials are needed.

Efficacy and safety of adjunctive therapy using esketamine or racemic ketamine for adult treatment-resistant depression: A randomized, double-blind, non-inferiority study.

BACKGROUND: Ketamine and its enantiomers have recently been highlighted as one of the most effective therapeutic options in refractory depression. However, racemic ketamine and esketamine have not been directly compared. The aim of this study is to assess the efficacy and safety of esketamine compared to ketamine in patients with treatment-resistant depression (TRD). METHODS: This is a randomized, double-blind, active-controlled, bicentre, non-inferiority clinical trial, with two parallel groups. Participants were randomly assigned to a 40-min single intravenous infusion of ketamine 0.5 mg/kg or esketamine 0.25 mg/kg. The primary outcome was the difference in remission rates for depression 24 h following intervention using the Montgomery-Åsberg Depression Rating Scale (MADRS), with a non-inferiority margin of 20%. RESULTS: 63 subjects were included and randomly assigned (29 to receive ketamine and 34 to receive esketamine). At 24 h, 24.1% of participants in the ketamine group and 29.4% of participants in the esketamine group showed remission, with a difference of 5.3% (95% CILB -13.6%), confirming non-inferiority. MADRS scores improved from 33 (SD 9.3) to 16.2 (SD 10.7) in the ketamine group and from 33 (SD 5.3) to 17.5 (SD 12.2) in the esketamine one, with a difference of -5.27% (95% CILB, -13.6). Both groups presented similar mild side effects. CONCLUSIONS: Esketamine was non-inferior to ketamine for TRD 24 h following infusion. Both treatments were effective, safe, and well tolerated. TRIAL REGISTRATION: Registered in Japan Primary Registries Network: UMIN000032355.

Comparative study of esketamine and racemic ketamine in treatment-resistant depression: Protocol for a non-inferiority clinical trial.

INTRODUCTION: The use of ketamine as an option in the treatment of depressive disorder is growing rapidly, supported by numerous clinical trials attesting its efficacy and safety. Esketamine, the S (+) enantiomer of ketamine, is the most widely used form in the anesthetic environment in some countries, and new studies have shown that it may also be effective in depression and with better tolerability. However, no study so far has directly compared esketamine with racemic ketamine. Here we propose a protocol of a clinical trial to evaluate esketamine as a noninferior medication when compared to ketamine in the treatment of patients with treatment-resistant depression. METHODS/DESIGN: This study protocol is for a randomized, controlled, double-blind noninferiority clinical trial. Subjects will be 18 years or older, with major depression characterized as treatment-resistant. Participants will receive a single infusion of either esketamine (0.25 mg/kg) or ketamine (0.5 mg/kg) over 40 minutes. The primary outcome will be the difference in remission rates between the 2 treatment arms at 24 and 72 hours after drug infusion. Secondary outcomes will include other timepoints, measurements of cognition, dissociation, and blood biomarkers. DISCUSSION: A head-to-head study is the best way to evaluate whether the esketamine is in fact comparable to the racemic ketamine in terms of both efficacy and safety, and, if positive, it would be an initial step to increase the access to that type of treatment worldwide. ETHICS AND DISSEMINATION: The study was approved by the local Institutional Review Board (University Hospital Professor Edgard Santos-Federal University of Bahia-Number: 46657415.0.0000.0049). Subjects will only participate after voluntarily agreeing and signing the Informed Consent Form. The study findings will be published in peer-reviewed journals and presented at national and international conferences. TRIAL REGISTRATION: This trial has been registered in the Japan Primary Registries Network (JPRN): UMIN000032355, which is affiliated with the World Health Organization.