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Cobenfy KarXT and brain activity during surgery for epilepsy or essential tremor

Tests Cobenfy KarXT during brain surgery for epilepsy or essential tremor.

Key facts

Who runs it
University of Texas Southwestern Medical Center
Where
Dallas, United StatesSee the site
Trial code
Registry title
Human Cognition During Surgery: Stimulation-based and Cholinergic Modulation
Status
Not yet recruiting
Phase
Early phase 1
People taking part
30 people, planned
Started
Oct 2026
Expected to end
Sept 2030
Type of study
Interventional, 4 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • Cobenfy KarXT pill (50/20 mg)
  • Placebo
Record updated
23 July 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with essential tremor or hard-to-treat epilepsy who are already having deep brain surgery. It studies how a drug that acts on the cholinergic system affects brain activity and thinking tasks.

Age
18 to 70 years
Sex
All sexes can join.
Disease stage
Essential tremor with tremor not helped by medication, or intractable epilepsy. Surgery with electrodes placed deep in the brain must already be planned as routine care.
Earlier treatment
Cannot join if an anticoagulant or antiplatelet agent was used within the last week.

Main reasons for not taking part

  • Pregnant or breastfeeding, or a positive pregnancy test
  • Moderate or severe liver or kidney problems
  • Untreated narrow angle glaucoma, or bladder or urinary retention problems
  • Allergy to COBENFY or trospium chloride
  • Taking certain listed medicines, such as fluoxetine, paroxetine, bupropion or digoxin

The registry criteria, word for word

Show all 27 criteriaShow less

Who can take part

  • Diagnosis of Essential Tremor
  • Recommended to undergo deep brain stimulation implantation surgery for surgical management of medication-resistant tremor based on clinical indications
  • Diagnosis of intractable epilepsy
  • Undergoing neuromodulation procedure that utilizes insertion of electrodes into subcortical structures, including the thalamus or hippocampus
  • Undergoing neuromodulation procedure that utilizes frame-based insertion of electrodes into the thalamus (ANT or CM)
  • Is patient between 18-70?
  • In general good health, aside from history of epilepsy or essential tremor, as ascertained by medical history, physical exam, clinical labs, and ECG?
  • Candidate for surgery as determined independently by the patient's treating physician/clinical team as part of the patient's routine medical care?
  • Able to read, understand, and provide written, dated informed consent, and participate in cognitive tasks?

Who cannot take part

  • Contraindication to use of cholinergic modulation; Contraindication for cholinergic modulation in both patient sets will be assessed by members of the treatment team (e.g. epileptologist), as well as a neuroanesthesiologist. Multiple medications and conditions are singular disqualifiers; however some medications are eliminated only in combination following neuroanesthesiologist evaluation. Patients at risk of reaction to the treatment arm based on concurrent or recent medications or other health conditions will be excluded from participation
  • Hepatic impairment (moderate or severe)?
  • Renal impairment (moderate or severe)?
  • History of hypersensitivity to COBENFY or trospium chloride?
  • Biliary disease, including symptomatic gallstones, gallbladder disorders, pancreatitis?
  • Patients with recent use (within one week) of anticoagulant or antiplatelet agent
  • Contraindication to use of cholinergic modulation
  • Patients with recent use (within one week) of anticoagulant or antiplatelet agent
  • Female that is pregnant, breastfeeding, or has a positive pregnancy test?
  • Under 18, over 70, or currently a prisoner on medical release?
  • Untreated narrow angle glaucoma?
  • Bladder obstruction, prostatic hyperplasia (BPH), diabetic cystopathy, pre-existing urinary retention?
  • Fluoxetine, paroxetine, bupropion, terbinafine?
  • Buspirone or eletriptan?
  • Digoxin, colchicine, apixaban?
  • Diphenhydramine, beztropine, oxybutynin?
  • Benztropine, trihexyphenidyl, tolterodine, solifenacin, darifenacin, fesoterodine, hyoscyamine, dicyclomine, scopolamine?

Other criteria

  • Study Population

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 70 years old?

Where in United States

  • University of Texas Southwestern Medical CenterDallas, United StatesContact: Bradley C Lega, MDNot yet recruiting

About the trial

What the trial wants to find out

This is a research study to determine how COBENFY KarXT (FDA approved), a drug which has been approved for treatment of certain disorders, affects brain activity and cognitive tasks which may be regulated by the cholinergic system.

Read full original descriptionShow less

This study aims to answer: 1) how cholinergic circuitries act during task performance in humans, and 2) develop a better understanding of how cognitive control interacts with learning, memory and decision making in the setting of cholinergic manipulation.

Participants will complete a single treatment arm, regardless of which surgical procedure they are to receive. An anesthesiologist or other clinical staff will administer either the drug or the saline at a critical point which addresses the research questions, prior to patient surgery. This will be either with the drug, or the placebo pill. Half of the participants will be randomized to receive the drug, and the other half of these the placebo. Participants will be unaware whether the actual drug has been received.

Essential tremor patients who participate will complete a cognitive task during an awake surgery. Epilepsy patients who participate will have a resting state recording during the procedure from the deep cortical layers of the brain. A probe will be used during the surgery to measure the effects of this drug and other procedures of the study on the cholinergic system. This probe is the clinical probe known as the AlphaOmega, which is FDA approved for standard of care procedures.

Researchers will compare the brain activity between treatment arms to determine what brain activity changes based on the cholinergic manipulation.

The 4 groups in the trial

  • Essential Tremor w/PlaceboPlacebo, for comparison

    Subjects will receive placebo pill (equivalent of 50/20mg) 2 hours prior to surgery. During awake surgery, the participant will complete either an episodic memory, a spatial memory, a working memory, or a cognitive control task session.

    Treatment: Placebo

  • Essential Tremor w/Cobenfy KarXT (xanomeline and trospium chloride)Treatment being tested

    Subjects will receive Cobenfy KarXT pill (50/20 mg) 2 hours prior to surgery. During awake surgery, the participant will complete either an episodic memory, a spatial memory, a working memory, or a cognitive control task session.

    Treatment: Cobenfy KarXT pill (50/20 mg)

  • Epilepsy w/PlaceboPlacebo, for comparison

    Subjects will receive placebo pill (equivalent of 50/20mg) 2 hours prior to surgery. A passive recording with the patient under anesthesia during placebo state will be conducted in order to observe layer-specific baseline firing rate that can be linked with extraoperative ex vivo and in vivo recordings in other contexts.

    Treatment: Placebo

  • Epilepsy w/Cobenfy KarXT (xanomeline and trospium chloride)Treatment being tested

    Subjects will receive Cobenfy KarXT pill (50/20 mg) 2 hours prior to surgery. A passive recording with the patient under anesthesia during cholinergic manipulation will be conducted in order to observe layer-specific changes in firing rate that can be linked with extraoperative ex vivo and in vivo recordings in other contexts.

    Treatment: Cobenfy KarXT pill (50/20 mg)

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Studying Human Cognition During Deep Brain Stimulation Surgery Using High-Density Neural Probes and Pharmacological Interventions
Plain-language title
Cobenfy KarXT and brain activity during surgery for epilepsy or essential tremorGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 13 November 2026.
Fit questions
Built from NCT07721272, who can take part
Record updated
23 July 2026