More than sixty years after Calvin Stevens first synthesized ketamine at Parke-Davis—a discovery initially intended to provide a safer anesthetic—the molecule has undergone a profound transformation. Once confined to the operating room, this compound has migrated into the heart of modern psychiatry. Today, its more potent S-enantiomer, esketamine, stands as a blockbuster therapeutic pillar in the fight against treatment-resistant depression (TRD).
Marketed by Johnson & Johnson under the brand name Spravato, the nasal spray has traveled a rigorous regulatory path. Initially cleared by the U.S. Food and Drug Administration (FDA) in March 2019 as an add-on to conventional antidepressants, its utility was expanded in January 2025, when it became the first and only monotherapy approved specifically for adults battling TRD. As sales trajectory climbs—reaching approximately $1.7 billion in the last fiscal year, with Wall Street analysts projecting figures near $2.3 billion by 2026—J&J is moving to cement the drug’s clinical legacy. The company’s latest effort involves a comprehensive data synthesis presented at Psych Congress Elevate, focusing on remission rates across six key clinical trials.
A Legacy of Discovery: The Chronology of Esketamine
The story of esketamine is one of accidental innovation and clinical persistence. In the early 1960s, the quest for a fast-acting, safe anesthetic led to the synthesis of ketamine. While it became a staple in emergency medicine, its dissociative side effects were well-documented. However, researchers eventually observed that these same effects, when modulated, could influence neuroplasticity and mood regulation in ways traditional monoamine-based antidepressants could not.
The transition to psychiatry was not immediate. It required decades of basic research to understand how N-methyl-D-aspartate (NMDA) receptor antagonism could potentially "reset" neural pathways in depressed brains. The FDA’s 2019 approval of Spravato marked a watershed moment, providing a new option for a patient population that had long exhausted traditional pharmaceutical interventions.
The timeline of its evolution:
- 1960s: Synthesis of ketamine by Calvin Stevens.
- 2019: FDA grants approval for esketamine nasal spray as an add-on therapy for TRD.
- 2025: FDA elevates Spravato to the status of the first and only monotherapy for TRD, significantly expanding its clinical reach.
- 2026: Ongoing clinical data presentations, such as those at Psych Congress Elevate, aim to standardize the use of the drug in earlier stages of treatment.
The Magnitude of the Problem: Defining Treatment Resistance
The potential market for Spravato is as vast as it is underserved. In 2021, the National Institute of Mental Health (NIMH) estimated that roughly 21 million U.S. adults—8.3% of the population—had experienced at least one major depressive episode. Within that cohort, approximately 8.9 million individuals seek medical treatment.
"There are millions upon millions of patients, some of them your friends and mine, some of them your family members, who are being treated for depression and are simply not in remission," notes Dr. Rakesh Jain, a clinical professor of psychiatry at the Texas Tech University School of Medicine and the lead author of the recent data analysis.
For these patients, "treatment resistance" is not merely a label; it is a clinical reality defined by the failure to respond to standard oral antidepressants. Roughly one-third of the treated population falls into this category. The frustration of these patients is often compounded by the "treatment cliff"—the sharp decline in efficacy when moving from a first-line treatment to a second or third. Data from the landmark STAR*D trial, the largest real-world study of its kind, demonstrated that while initial remission rates for antidepressants are modest, they plummet significantly with each subsequent failure.
Supporting Data: Why Remission Matters
The central theme of the new data presented by Dr. Jain is the pursuit of remission—not merely symptom reduction. In clinical terms, remission is defined by a score of 10 or below on the Montgomery-Åsberg Depression Rating Scale (MADRS), a 10-item clinician-rated instrument.
"We actually tightened the rules on Spravato a little bit," Dr. Jain explained. "We said, okay, 12 is fine, but can we go to 10? And it performed quite well, even at 10. That’s the key."
The analysis compiled data from six disparate studies, including two four-week, placebo-controlled trials (TRD4005 and TRANSFORM-2), an active-controlled trial (ESCAPE-TRD), and three long-term open-label extension studies (ESCAPE-LTE, SUSTAIN-2, and SUSTAIN-3). By looking at both the short-term efficacy and the long-term durability of the drug, the researchers aimed to provide a holistic view of the patient experience.
For instance, in the TRANSFORM-2 trial, Spravato plus an oral antidepressant showed a 42.6% remission rate, compared to 24.0% for the placebo-plus-antidepressant group. More impressively, the open-label extension studies, which tracked patients over several years, reported remission rates of 49.3% at one year, rising to 78.2% at 2.5 years, and holding steady at 43.2% at the 5.5-year mark. While the authors acknowledge that the data is descriptive—lacking formal meta-analysis—it serves as a compelling narrative for the drug’s sustained impact.
The Professional Discourse: Official Responses and Criticisms
Despite the positive data, the adoption of esketamine remains a subject of intense academic and professional debate. Guideline bodies have been cautious, reflecting the complexity of integrating a controlled substance into routine psychiatric practice.
The 2022 VA/DoD clinical practice guidelines offered only a "weak for" recommendation, citing concerns regarding monitoring requirements and feasibility. Furthermore, the United Kingdom’s National Institute for Health and Care Excellence (NICE) declined to recommend the drug for routine NHS use in 2022, citing a lack of clear cost-effectiveness evidence.
Critiques have also emerged in peer-reviewed journals. In the American Journal of Psychiatry, editorials by researchers such as Sanjay Mathew and Nicholas Murphy have questioned whether the long-term usage data justifies the extensive scale of current prescribing, particularly given that some comparative trials showed only marginal differences in MADRS scores when compared to other augmentations. A systematic review by Fountoulakis et al. highlighted that while the drug is effective, its effect sizes in the short term remain comparable to other augmentation strategies, such as atypical antipsychotics.
Dr. Jain, however, defends the data as a necessary corrective to the industry’s tendency to ignore remission rates. He argues that the head-to-head ESCAPE-TRD trial, which showed a clear advantage for esketamine over quetiapine, provides the "real-world" evidence that clinicians need to move beyond academic skepticism.
Implications: Changing the Practice of Psychiatry
The final, and perhaps most difficult, hurdle for J&J is the psychology of the clinician. Psychiatry, by its nature, is a field that prizes evidence-based caution. "Psychiatry is slow to change, it just is," says Dr. Jain.
The operational barriers are also significant. Because Spravato carries risks of dissociation, sedation, and abuse, it is subject to a strict Risk Evaluation and Mitigation Strategy (REMS). This requires the patient to be monitored in a certified setting for at least two hours after each dose, with strict prohibitions against driving until the following day. These logistical constraints naturally limit the speed of adoption.
However, the implications of the new data analysis are clear: J&J is signaling to the psychiatric community that the "wait and see" approach is no longer the gold standard. By presenting evidence that links early, aggressive intervention to long-term remission, the company is attempting to shift the culture of treatment.
As Dr. Jain noted during the presentation, the feedback from clinicians at the event was encouraging. Many practitioners, previously hesitant or under-informed, expressed a desire to integrate Spravato into their treatment protocols earlier. If the medical community follows this sentiment, the "blockbuster" status of Spravato may only be the beginning. The shift represents a fundamental change in how the medical community views the permanence of depression—moving from a model of chronic symptom management to one of active, long-term remission.
For the millions of patients currently navigating the labyrinth of treatment-resistant depression, this evolution in clinical practice is more than a marketing push; it is a potential lifeline that, if managed with the appropriate rigor, could redefine the landscape of mental health care for decades to come.
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