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Enzyme Inhibitor

Tryptophan for Schizophrenia (TrypNAC-II Trial)

Phase 1 & 2
Recruiting
Led By Robert W Buchanan, M.D.
Research Sponsored by University of Maryland, Baltimore
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Age: 18 to 55 years
Be between 18 and 65 years old
Timeline
Screening 3 weeks
Treatment Varies
Follow Up change from baseline after 3 hours on each challenge day.
Awards & highlights

TrypNAC-II Trial Summary

This trial will give 6 grams of tryptophan to human participants to study the effects of kynurenic acid on neurotransmitters. They will use cognitive tests and magnetic resonance imaging techniques to measure brain activity and chemistry.

Who is the study for?
This trial is for adults aged 18-55 with schizophrenia, schizoaffective disorder, or schizophreniform disorder. Participants must be on a stable dose of antipsychotic medication for at least two months and agree to use contraception. Exclusions include organic brain disorders, conditions affecting tryptophan metabolism, high caffeine intake, pregnancy/lactation, metal in the body that affects MRI scans, certain medications like MAO inhibitors and substance misuse within the last three months.Check my eligibility
What is being tested?
The study tests how N-acetylcysteine (NAC) combined with tryptophan impacts cognitive functions in people with schizophrenia-related conditions. Researchers will increase KYNA levels using tryptophan and observe changes through cognitive tests and MRIs to see how NAC influences brain activity and chemistry.See study design
What are the potential side effects?
Potential side effects may include gastrointestinal discomfort from high doses of tryptophan or allergic reactions to NAC. Since MRIs are involved, participants might experience discomfort due to the confined space or loud noises during scanning.

TrypNAC-II Trial Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
Select...
I am between 18 and 55 years old.

TrypNAC-II Trial Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~the measure will be collected at baseline.
This trial's timeline: 3 weeks for screening, Varies for treatment, and the measure will be collected at baseline. for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Kynurenic acid levels
Medial prefrontal cortex glutamate levels using magnetic resonance spectroscopy (MRS)
Medial prefrontal cortex glutathione metabolite levels using magnetic resonance spectroscopy (MRS)
+2 more
Secondary outcome measures
Electrophysiological measure
Improvement in cognitive function
Peripheral Blood Mononuclear Cell (PBMC) kynurenine 3-monooxygenase (KMO) activity
+1 more

Side effects data

From 2014 Phase 3 trial • 264 Patients • NCT00650091
17%
Cough
14%
Dyspnea
13%
Upper respiratory tract infection
13%
Nausea
12%
Idiopathic Pulmonary Fibrosis
10%
Fatigue
10%
Idiopathic pulmonary fibrosis
8%
Diarrhoea
8%
Bronchitis
6%
Dizziness
5%
Sinusitis
5%
Nasopharyngitis
5%
Pneumonia
4%
Headache
3%
Atrial Fibrillation
3%
Constipation
3%
Acute Myocardial infarction
3%
Oedema peripheral
3%
Arthralgia
1%
Vomiting
1%
Adverse Drug Reaction
1%
pneumothorax
1%
Epistaxis
1%
Dyspnoea
1%
Lung Squamous Cell Carcinoma
1%
Death
1%
prostatitis
1%
Dehydration
1%
Intersticial Lung Disease
1%
Prostate Cancer
1%
syncope
1%
Drug Fever
1%
Exacerbation of Idiopathic Pulmonary Fibrosis
1%
Atelectasis
1%
Respiratory Tract Infection
100%
80%
60%
40%
20%
0%
Study treatment Arm
Initial Study: Pred/AZA/NAC
N-Acetylcysteine
Placebo
Initial Study: Placebo

TrypNAC-II Trial Design

2Treatment groups
Experimental Treatment
Placebo Group
Group I: N-acetylcysteine & TryptophanExperimental Treatment2 Interventions
N-acetylcysteine 140 mg/kg up to a maximum of 15 g. Thirty minutes after N-acetylcysteine administration participants will receive Tryptophan, 6 grams.
Group II: Placebo & TryptophanPlacebo Group2 Interventions
Placebo 140 mg/kg up to a maximum of 15 g. Thirty minutes after placebo administration participants will receive Tryptophan, 6 grams.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
N-acetylcysteine (NAC)
1998
Completed Phase 3
~780
Tryptophan
2015
Completed Phase 3
~210

Find a Location

Who is running the clinical trial?

University of Maryland, BaltimoreLead Sponsor
688 Previous Clinical Trials
374,581 Total Patients Enrolled
66 Trials studying Schizophrenia
10,182 Patients Enrolled for Schizophrenia
Robert W Buchanan, M.D.Principal InvestigatorUniversity of Maryland
5 Previous Clinical Trials
417 Total Patients Enrolled
5 Trials studying Schizophrenia
417 Patients Enrolled for Schizophrenia

Media Library

Tryptophan (Enzyme Inhibitor) Clinical Trial Eligibility Overview. Trial Name: NCT04013555 — Phase 1 & 2
Schizophrenia Research Study Groups: N-acetylcysteine & Tryptophan, Placebo & Tryptophan
Schizophrenia Clinical Trial 2023: Tryptophan Highlights & Side Effects. Trial Name: NCT04013555 — Phase 1 & 2
Tryptophan (Enzyme Inhibitor) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04013555 — Phase 1 & 2
Schizophrenia Patient Testimony for trial: Trial Name: NCT04013555 — Phase 1 & 2

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

What therapeutic purposes does N-acetylcysteine (NAC) serve?

"N-acetylcysteine (NAC) is traditionally prescribed for dialysis therapy, but has also proved efficacious at treating conditions like corneal ulceration and acute rhinitis. It can even be used to improve the prognosis of individuals with kidney failure."

Answered by AI

Are there still opportunities for participants to join this clinical experiment?

"Per the records found on clinicaltrials.gov, this trial is actively seeking participants as of now. It was first published on January 20th 2020 and underwent its last alteration in December 9th 2021."

Answered by AI

Are participants aged 25 and over permitted to take part in this clinical experiment?

"According to the requirements, individuals aged between 18 and 55 are eligible for this trial. On the other hand, there are 328 clinical trials available for minors and 819 studies that cater to seniors over 65."

Answered by AI

What are the principal aims of this experiment?

"This medical trial aims to analyse the Change from baseline after 3 hours on each Challenge Day, Whole brain gray matter and frontal gray matter cerebral blood flow (CBF). Secondary objectives include monitoring Improvement in cognitive function via MATRICS battery evaluations, Peripheral Blood Mononuclear Cell (PBMC) kynurenine 3-monooxygenase (KMO) activity levels as a way of gauging NAC's impact on primary neuroimaging results and secondary cognitive and electrophysiological measures, Electrophysiological measure which is measured by visual evoked potentials (VEP) interhemispheric transfer times ("

Answered by AI

What is the enrollment capacity for this trial?

"Affirmative. According to the records posted on clinicaltrials.gov, this research project is actively seeking candidates. Initially shared on January 20th 2020 and most recently updated on December 9th 2021, this trial requires 75 individuals from a single location."

Answered by AI

Could you please provide some insight into the research conducted with N-acetylcysteine (NAC)?

"Currently, there are 46 clinical trials assessing the efficacy of N-acetylcysteine (NAC) with 12 in Phase 3. For those who live near New york City, there is a concentration of studies but overall 1530 different sites across the country are conducting these experiments."

Answered by AI

Who is qualified to participate in this investigation?

"To be a viable candidate for this experiment, individuals must possess schizophrenia and fall within the 18 to 55 year old age bracket. 75 total participants are required for the trial's completion."

Answered by AI

Who else is applying?

What state do they live in?
Maryland
New Jersey
How old are they?
18 - 65
What site did they apply to?
Maryland Psychiatric Research Center (MPRC) ; the Treatment Research Program (TRP)
What portion of applicants met pre-screening criteria?
Met criteria
How many prior treatments have patients received?
1

Why did patients apply to this trial?

I've I've tried Joe's to having worked for me I've been diagnosed to schizophrenic since 19 I smoke cigarettes duration just that you know better my better my condition on medication usually I take off anxiety medication and you know for sleep disorder acme sleep just acme also on directions of the day you know just to maintain myself apparently you know it helps but not as official effective as I expected to be.
PatientReceived no prior treatments
Recent research and studies
clinicaltrials.govStudy
The Effects of Kynurenine Aminotransferase Inhibition in People With Schizophrenia
Robert Buchanan 2020. "The Effects of Kynurenine Aminotransferase Inhibition in People With Schizophrenia". ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/NCT04013555.
All > Schizophrenia
~3 spots leftby Jun 2024
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