Esketamine Maintenance Dosing for Sustained Depression Remission

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Solution Overview

Problem

There is a need for an effective, long-term, and safe treatment for depression, particularly in patients diagnosed as having treatment-refractory or treatment-resistant depression, as existing treatments like esketamine show limited sustained antidepressant effects and potential neurotoxicity concerns.

Innovation Solution

Administer esketamine in combination with at least one antidepressant, initially twice weekly during an induction phase, followed by reinitiating the highest tolerable dose with a second antidepressant in a second induction phase, and continuing esketamine treatment for at least six months to achieve long-term treatment of treatment-resistant depression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If esketamine is administered at low, subanesthetic doses, then antidepressant effect is achieved, but the duration of action is limited and sustained effect cannot be maintained

Engineering Contradiction:
Improveantidepressant effectVSAvoidduration of antidepressant effect
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent implements an induction phase with frequent dosing (twice weekly) before transitioning to maintenance dosing. This preliminary intensive treatment phase prepares the system by establishing initial therapeutic effect and neuroplastic changes, which then enables sustained response at lower maintenance doses, resolving the contradiction between achieving reliable antidepressant effect and maintaining duration of action

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs periodic dosing schedules with an induction phase (twice weekly for 4 weeks) followed by maintenance phases with varying frequencies (once weekly, once every two weeks, or once monthly). This periodic action pattern allows the antidepressant effect to be reliably initiated and then sustained over extended periods through strategically timed dosing intervals

Inventive Principle:
Principle #19Periodic action

2Duration of action of stationary object

If esketamine is administered repeatedly over long term, then sustained antidepressant effect may be achieved, but neurotoxicity risk increases

Engineering Contradiction:
Improvelong-term treatment durationVSAvoidneurotoxicity
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic dosing adjustment where the frequency and amount of esketamine administration are adapted based on individual patient response and tolerability. The induction phase uses higher frequency (twice weekly) followed by progressively spaced maintenance dosing (weekly, biweekly, or monthly), allowing long-term treatment while minimizing neurotoxicity risk through personalized dynamic adjustment rather than fixed dosing

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes dosing parameters (frequency and amount) based on patient response during induction and maintenance phases. By adjusting these parameters individually for each patient, the treatment can be continued long-term to achieve sustained antidepressant effect while keeping the actual dose and frequency at tolerable levels to reduce neurotoxicity risk

Inventive Principle:
Principle #35Parameter changes

3Reliability

If esketamine is administered alone, then treatment simplicity is maintained, but treatment efficacy for treatment-resistant depression is insufficient

Engineering Contradiction:
Improvetreatment efficacyVSAvoidtreatment regimen complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines esketamine administration with continuation of oral antidepressant therapy that the patient is already receiving. This merging of treatments allows esketamine to provide the breakthrough efficacy needed for treatment-resistant depression while the oral antidepressant maintains baseline treatment, achieving enhanced reliability without requiring complete discontinuation of existing therapy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The oral antidepressant serves as an intermediary that bridges the gap between standard treatment and esketamine therapy. It maintains continuous baseline treatment while esketamine provides the additional therapeutic push needed for treatment-resistant cases, allowing combination therapy to be more tolerable and manageable than complete treatment overhaul

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If induction phase with frequent dosing is implemented, then initial antidepressant response is achieved, but treatment time and resource consumption increase

Engineering Contradiction:
Improveinitial antidepressant responseVSAvoidinduction phase duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The induction phase uses accelerated frequent dosing (twice weekly) for a limited period (4 weeks) to rapidly achieve therapeutic effect and cross the threshold into sustained response. This rushing through the critical initial phase establishes treatment efficacy quickly, after which maintenance dosing can proceed at lower frequency, minimizing the time loss associated with intensive induction

Inventive Principle:
Principle #21Skipping (Rushing through)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The combination therapy with esketamine and antidepressants provides sustained antidepressant effects, maintaining stable remission or response for extended periods, reducing the risk of neurotoxicity and improving patient outcomes.

Implementation Method 1

Ketamine (a racemic mixture of the corresponding S- and R-enantiomers) is a nonselective antagonist at the phencyclidine binding site of the glutamate N-methyl-D-aspartate (NMDA) receptor

Methodology Applied
Scientific EffectNMDA receptor antagonism:

Data Source

PatentEP3501542B1Esketamine for the treatment of depression
Publication Date: 2026.01.28 JANSSEN PHARMA NV
  • EP3501542B1 patent drawingFigure 1
  • EP3501542B1 patent drawingFigure 2
  • EP3501542B1 patent drawingFigure 3~4

AI summary

The present invention provides methods of maintaining stable remission or stable response achieved by a patient with depression following administration of a therapeutically effective amount of esketamine during an initial administration phase, comprising continuing administration of a therapeutically effective amount of esketamine for at least five months during a subsequent administration phase. The present invention also provides methods for the long term treatment of depression in a patient, comprising administering to the patient in need of the treatment a clinically proven safe and clinically proven effective therapeutically effective amount of esketamine for at least six months. In some embodiments, the depression is major depressive disorder or treatment resistant depression.