Trial Outcomes & Findings for Evaluation of [11C]Cimbi-36 as an Agonist PET Radioligand for Imaging of 5-HT2A Receptors (NCT NCT01778686)
NCT ID: NCT01778686
Last Updated: 2025-02-20
Results Overview
Cerebral Cimbi-36 receptor binding is measured with PET scanning for 2 hours, at baseline and after intervention. The resultant time-activity curves for brain tissue are used together with time-activity curves obtained with blood samples and kinetic modelling to yield unitless values of BPND at baseline and after intervention, respectively. As outcome, the mean percent difference from baseline to intervention in each arm is measured.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
24 participants
Primary outcome timeframe
2 hours
Results posted on
2025-02-20
Participant Flow
Participant milestones
| Measure |
Citalopram and Pindolol
Citalopram intravenous infusion starting 30 min before scanning, 40 mg/h for 1 hour.
Pindolol peroral administration starting 3 days before scanning:
Day 1: 2.5 mg 3 times daily, day 2: 5 mg 3 times daily, day 3: 7.5 mg 3 times daily, Day 4 (scan day) 7.5 mg morning and noon.
Citalopram and Pindolol: Citalopram: selective serotonin reuptake inhibitor
Pindolol: non-selective beta blocker and 5-HT1A receptor antagonist
|
Placebo
Placebo for pindolol: sugar tablets that resembles pindolol
Placebo for ATD: amino acid drink balanced formula (containing tryptophan)
Placebo for Seropram: NaCl infusion
Placebo: On the second PET scanning day, subjects received a protein drink as well as a 50 ml saline infusion over 1 hour starting 30 min before PET scanning.
|
Acute Tryptophan Depletion
Amino acid drink without tryptophan. Ingested 4-5 hours prior to PET scanning.
Acute tryptophan depletion
|
|---|---|---|---|
|
Overall Study
STARTED
|
8
|
8
|
8
|
|
Overall Study
COMPLETED
|
8
|
8
|
7
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
1
|
Reasons for withdrawal
| Measure |
Citalopram and Pindolol
Citalopram intravenous infusion starting 30 min before scanning, 40 mg/h for 1 hour.
Pindolol peroral administration starting 3 days before scanning:
Day 1: 2.5 mg 3 times daily, day 2: 5 mg 3 times daily, day 3: 7.5 mg 3 times daily, Day 4 (scan day) 7.5 mg morning and noon.
Citalopram and Pindolol: Citalopram: selective serotonin reuptake inhibitor
Pindolol: non-selective beta blocker and 5-HT1A receptor antagonist
|
Placebo
Placebo for pindolol: sugar tablets that resembles pindolol
Placebo for ATD: amino acid drink balanced formula (containing tryptophan)
Placebo for Seropram: NaCl infusion
Placebo: On the second PET scanning day, subjects received a protein drink as well as a 50 ml saline infusion over 1 hour starting 30 min before PET scanning.
|
Acute Tryptophan Depletion
Amino acid drink without tryptophan. Ingested 4-5 hours prior to PET scanning.
Acute tryptophan depletion
|
|---|---|---|---|
|
Overall Study
Adverse Event
|
0
|
0
|
1
|
Baseline Characteristics
Evaluation of [11C]Cimbi-36 as an Agonist PET Radioligand for Imaging of 5-HT2A Receptors
Baseline characteristics by cohort
| Measure |
Citalopram and Pindolol
n=8 Participants
Citalopram intravenous infusion starting 30 min before scanning, 40 mg/h for 1 hour.
Pindolol peroral administration starting 3 days before scanning:
Day 1: 2.5 mg 3 times daily, day 2: 5 mg 3 times daily, day 3: 7.5 mg 3 times daily, Day 4 (scan day) 7.5 mg morning and noon.
Citalopram and Pindolol: Citalopram: selective serotonin reuptake inhibitor
Pindolol: non-selective beta blocker and 5-HT1A receptor antagonist
|
Placebo
n=8 Participants
Placebo for pindolol: sugar tablets that resembles pindolol
Placebo for ATD: amino acid drink balanced formula (containing tryptophan)
Placebo for Seropram: NaCl infusion
Placebo: On the second PET scanning day, subjects received a protein drink as well as a 50 ml saline infusion over 1 hour starting 30 min before PET scanning.
|
Acute Tryptophan Depletion
n=8 Participants
Amino acid drink without tryptophan. Ingested 4-5 hours prior to PET scanning.
Acute tryptophan depletion
|
Total
n=24 Participants
Total of all reporting groups
|
|---|---|---|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
8 Participants
n=5 Participants
|
8 Participants
n=7 Participants
|
8 Participants
n=5 Participants
|
24 Participants
n=4 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
|
Age, Continuous
|
22.4 years
STANDARD_DEVIATION 2.1 • n=5 Participants
|
22.6 years
STANDARD_DEVIATION 2.5 • n=7 Participants
|
22.9 years
STANDARD_DEVIATION 3.2 • n=5 Participants
|
22.6 years
STANDARD_DEVIATION 2.6 • n=4 Participants
|
|
Sex: Female, Male
Female
|
4 Participants
n=5 Participants
|
4 Participants
n=7 Participants
|
4 Participants
n=5 Participants
|
12 Participants
n=4 Participants
|
|
Sex: Female, Male
Male
|
4 Participants
n=5 Participants
|
4 Participants
n=7 Participants
|
4 Participants
n=5 Participants
|
12 Participants
n=4 Participants
|
|
Region of Enrollment
Denmark
|
8 participants
n=5 Participants
|
8 participants
n=7 Participants
|
8 participants
n=5 Participants
|
24 participants
n=4 Participants
|
PRIMARY outcome
Timeframe: 2 hoursCerebral Cimbi-36 receptor binding is measured with PET scanning for 2 hours, at baseline and after intervention. The resultant time-activity curves for brain tissue are used together with time-activity curves obtained with blood samples and kinetic modelling to yield unitless values of BPND at baseline and after intervention, respectively. As outcome, the mean percent difference from baseline to intervention in each arm is measured.
Outcome measures
| Measure |
Citalopram and Pindolol
n=8 Participants
Citalopram intravenous infusion starting 30 min before scanning, 40 mg/h for 1 hour.
Pindolol peroral administration starting 3 days before scanning:
Day 1: 2.5 mg 3 times daily, day 2: 5 mg 3 times daily, day 3: 7.5 mg 3 times daily, Day 4 (scan day) 7.5 mg morning and noon.
Citalopram and Pindolol: Citalopram: selective serotonin reuptake inhibitor
Pindolol: non-selective beta blocker and 5-HT1A receptor antagonist
|
Placebo
n=8 Participants
Placebo for pindolol: sugar tablets that resembles pindolol
Placebo for ATD: amino acid drink balanced formula (containing tryptophan)
Placebo for Seropram: NaCl infusion
Placebo: On the second PET scanning day, subjects received a protein drink as well as a 50 ml saline infusion over 1 hour starting 30 min before PET scanning.
|
Acute Tryptophan Depletion
n=7 Participants
Amino acid drink without tryptophan. Ingested 4-5 hours prior to PET scanning.
Acute tryptophan depletion
|
|---|---|---|---|
|
Percent Change in Neocortical [11C]Cimbi-36 BPND From Baseline to Intervention in Each Arm
|
7.4 percent change
Standard Deviation 16
|
0.6 percent change
Standard Deviation 7.2
|
3.8 percent change
Standard Deviation 0.2
|
Adverse Events
Citalopram and Pindolol
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Placebo
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Acute Tryptophan Depletion
Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Citalopram and Pindolol
n=8 participants at risk
Citalopram intravenous infusion starting 30 min before scanning, 40 mg/h for 1 hour.
Pindolol peroral administration starting 3 days before scanning:
Day 1: 2.5 mg 3 times daily, day 2: 5 mg 3 times daily, day 3: 7.5 mg 3 times daily, Day 4 (scan day) 7.5 mg morning and noon.
Citalopram and Pindolol: Citalopram: selective serotonin reuptake inhibitor
Pindolol: non-selective beta blocker and 5-HT1A receptor antagonist
|
Placebo
n=8 participants at risk
Placebo for pindolol: sugar tablets that resembles pindolol
Placebo for ATD: amino acid drink balanced formula (containing tryptophan)
Placebo for Seropram: NaCl infusion
Placebo: On the second PET scanning day, subjects received a protein drink as well as a 50 ml saline infusion over 1 hour starting 30 min before PET scanning.
|
Acute Tryptophan Depletion
n=8 participants at risk
Amino acid drink without tryptophan. Ingested 4-5 hours prior to PET scanning.
Acute tryptophan depletion
|
|---|---|---|---|
|
General disorders
AE
|
0.00%
0/8
|
0.00%
0/8
|
12.5%
1/8 • Number of events 1
|
Additional Information
Gitte Moos Knudsen
Rigshospitalet and University of Copenhagen
Phone: +4535456720
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place