Trial Outcomes & Findings for Development of Pregnenolone as a Treatment for Depression (NCT NCT03645096)

NCT ID: NCT03645096

Last Updated: 2024-05-01

Results Overview

Determine if an increase in Amygdala-PCC functional connectivity is observed with pregnenolone as compared to placebo. Amygdala-PCC functional connectivity was measured using resting state fMRI blood-oxygen-level dependent (BOLD) response and transformed to standardized z-scores (with μ=0 and σ=1) for analysis. Functional connectivity was measured three times corresponding to three treatments (500 mg pregnenolone, 800 mg pregnenolone, and placebo). Better outcomes are represented by greater functional connectivity, and are indicated by a higher z-score at 500 mg or 800 mg, relative to that at placebo (i.e., there is no absolute threshold).

Recruitment status

COMPLETED

Study phase

PHASE1

Target enrollment

34 participants

Primary outcome timeframe

7 days

Results posted on

2024-05-01

Participant Flow

Subjects were screened for eligibility from September 2019 through November 2021 at UT Southwestern in Dallas, TX. 34 Subjects were consented by a research study coordinator in a private office within Dr. Brown's PNE Lab.

29 of 34 participants were randomized. It was determined that 5 subjects were not eligible for the study and were not randomized.

Participant milestones

Participant milestones
Measure
Pregnenolone 500 > Pregnenolone 800 > Placebo
3 exposures in order: 1. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Matching placebo capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Pregnenolone 500 > Placebo > Pregnenolone 800
3 exposures in order: 1. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 800 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Pregnenolone 800 > Pregnenolone 500 > Placebo
3 exposures in order: 1. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Matching placebo capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Pregnenolone 800 > Placebo > Pregnenolone 500
3 exposures in order: 1. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 500 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Placebo > Pregnenolone 500 > Pregnenolone 800
3 exposures in order: 1. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 800 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Placebo > Pregnenolone 800 > Pregnenolone 500
3 exposures in order: 1. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 500 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
First Treatment (21 Days)
STARTED
4
4
7
7
5
2
First Treatment (21 Days)
COMPLETED
4
3
5
7
3
2
First Treatment (21 Days)
NOT COMPLETED
0
1
2
0
2
0
Second Treatment (21 Days)
STARTED
4
3
5
7
3
2
Second Treatment (21 Days)
COMPLETED
3
2
5
5
3
2
Second Treatment (21 Days)
NOT COMPLETED
1
1
0
2
0
0
Third Treatment (21 Days)
STARTED
3
2
5
5
3
2
Third Treatment (21 Days)
COMPLETED
3
1
4
3
3
2
Third Treatment (21 Days)
NOT COMPLETED
0
1
1
2
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Development of Pregnenolone as a Treatment for Depression

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Pregnenolone 500 > Pregnenolone 800 > Placebo
n=4 Participants
3 exposures in order: 1. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Matching placebo capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Pregnenolone 500 > Placebo > Pregnenolone 800
n=4 Participants
3 exposures in order: 1. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 800 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Pregnenolone 800 > Pregnenolone 500 > Placebo
n=7 Participants
3 exposures in order: 1. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Matching placebo capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Pregnenolone 800 > Placebo > Pregnenolone 500
n=7 Participants
3 exposures in order: 1. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 2. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 500 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Placebo > Pregnenolone 500 > Pregnenolone 800
n=5 Participants
3 exposures in order: 1. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 500 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 800 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Placebo > Pregnenolone 800 > Pregnenolone 500
n=2 Participants
3 exposures in order: 1. Matching placebo capsule by mouth, daily for 7 days followed by 14 day washout. 2. Pregnenolone 800 mg capsule by mouth, daily for 7 days followed by 14 day washout. 3. Pregnenolone 500 mg capsule by mouth, daily for 7 days. Pregnenolone 500 mg: Pregnenolone 500 mg capsule. Pregnenolone 800 mg: Pregnenolone 800 mg capsule. Placebo: Placebo capsule manufactured to mimic pregnenolone capsule.
Total
n=29 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
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Age, Categorical
Between 18 and 65 years
4 Participants
n=5 Participants
4 Participants
n=7 Participants
7 Participants
n=5 Participants
7 Participants
n=4 Participants
5 Participants
n=21 Participants
2 Participants
n=8 Participants
29 Participants
n=8 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
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Age, Continuous
50.50 years
STANDARD_DEVIATION 7.19 • n=5 Participants
43.25 years
STANDARD_DEVIATION 16.86 • n=7 Participants
44.29 years
STANDARD_DEVIATION 10.94 • n=5 Participants
43.71 years
STANDARD_DEVIATION 11.22 • n=4 Participants
46.00 years
STANDARD_DEVIATION 8.40 • n=21 Participants
51.00 years
STANDARD_DEVIATION 1.41 • n=8 Participants
45.62 years
STANDARD_DEVIATION 10.31 • n=8 Participants
Sex: Female, Male
Female
4 Participants
n=5 Participants
4 Participants
n=7 Participants
7 Participants
n=5 Participants
7 Participants
n=4 Participants
5 Participants
n=21 Participants
2 Participants
n=8 Participants
29 Participants
n=8 Participants
Sex: Female, Male
Male
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
n=5 Participants
1 Participants
n=7 Participants
1 Participants
n=5 Participants
1 Participants
n=4 Participants
2 Participants
n=21 Participants
1 Participants
n=8 Participants
6 Participants
n=8 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
3 Participants
n=5 Participants
3 Participants
n=7 Participants
6 Participants
n=5 Participants
6 Participants
n=4 Participants
3 Participants
n=21 Participants
1 Participants
n=8 Participants
22 Participants
n=8 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
1 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
1 Participants
n=8 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Race (NIH/OMB)
Asian
1 Participants
n=5 Participants
0 Participants
n=7 Participants
1 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
2 Participants
n=8 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=5 Participants
1 Participants
n=7 Participants
1 Participants
n=5 Participants
3 Participants
n=4 Participants
1 Participants
n=21 Participants
1 Participants
n=8 Participants
7 Participants
n=8 Participants
Race (NIH/OMB)
White
3 Participants
n=5 Participants
3 Participants
n=7 Participants
5 Participants
n=5 Participants
4 Participants
n=4 Participants
4 Participants
n=21 Participants
1 Participants
n=8 Participants
20 Participants
n=8 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
0 Participants
n=8 Participants
0 Participants
n=8 Participants
Region of Enrollment
United States
4 participants
n=5 Participants
4 participants
n=7 Participants
7 participants
n=5 Participants
7 participants
n=4 Participants
5 participants
n=21 Participants
2 participants
n=8 Participants
29 participants
n=8 Participants
HAM-D
14.75 units on a scale
STANDARD_DEVIATION 2.50 • n=5 Participants
12.75 units on a scale
STANDARD_DEVIATION 4.92 • n=7 Participants
13.00 units on a scale
STANDARD_DEVIATION 4.28 • n=5 Participants
14.14 units on a scale
STANDARD_DEVIATION 5.34 • n=4 Participants
16.00 units on a scale
STANDARD_DEVIATION 3.81 • n=21 Participants
11.50 units on a scale
STANDARD_DEVIATION 7.78 • n=8 Participants
13.90 units on a scale
STANDARD_DEVIATION 4.39 • n=8 Participants

PRIMARY outcome

Timeframe: 7 days

Population: Some fMRI data may have been unusable due to motion in the scanner.

Determine if an increase in Amygdala-PCC functional connectivity is observed with pregnenolone as compared to placebo. Amygdala-PCC functional connectivity was measured using resting state fMRI blood-oxygen-level dependent (BOLD) response and transformed to standardized z-scores (with μ=0 and σ=1) for analysis. Functional connectivity was measured three times corresponding to three treatments (500 mg pregnenolone, 800 mg pregnenolone, and placebo). Better outcomes are represented by greater functional connectivity, and are indicated by a higher z-score at 500 mg or 800 mg, relative to that at placebo (i.e., there is no absolute threshold).

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=18 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
n=20 Participants
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
n=18 Participants
Matching placebo capsule by mouth, daily for 7 days.
Amygdala-PCC Functional Connectivity
-0.0815 z-score
Standard Deviation 0.1680
-0.0530 z-score
Standard Deviation 0.1715
-0.0456 z-score
Standard Deviation 0.1736

PRIMARY outcome

Timeframe: 7 days

Population: Some fMRI data may have been unusable due to motion in the scanner.

Determine if an increase in dlPFC-Insula functional connectivity is observed with pregnenolone as compared to placebo. dlPFC-Insula functional connectivity was measured using resting state fMRI blood-oxygen-level dependent (BOLD) response and transformed to standardized z-scores (with μ=0 and σ=1) for analysis. Functional connectivity was measured three times corresponding to three treatments (500 mg pregnenolone, 800 mg pregnenolone, and placebo). Better outcomes are represented by greater functional connectivity, and are indicated by a higher z-score at 500 mg or 800 mg, relative to that at placebo (i.e., there is no absolute threshold).

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=18 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
n=20 Participants
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
n=18 Participants
Matching placebo capsule by mouth, daily for 7 days.
dlPFC-Insula Functional Connectivity
0.0495 z-score
Standard Deviation 0.2524
0.1413 z-score
Standard Deviation 0.3036
0.0855 z-score
Standard Deviation 0.2941

PRIMARY outcome

Timeframe: 7 days

Population: All participants with available data for each treatment condition.

Determine if an increase in occipital GABA concentration is observed with pregnenolone, as compared to placebo. Occipital GABA concentration using spectroscopy with tCr reference. Higher concentration values are representative of a greater anti-depressant effect.

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=17 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
n=19 Participants
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
n=18 Participants
Matching placebo capsule by mouth, daily for 7 days.
GABA Concentration.
0.0947 millimolars (mM)
Standard Deviation 0.0294
0.0861 millimolars (mM)
Standard Deviation 0.0264
0.0974 millimolars (mM)
Standard Deviation 0.0262

SECONDARY outcome

Timeframe: 7 days

Population: All participants with available data for each treatment condition.

Assess bioavailability of pregnenolone by demonstrating increases in serum pregnenolone and allopregnanolone with pregnenolone administration. Change (increases) in blood serum pregnenolone levels are indicative of bioavailability.

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=16 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
n=19 Participants
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
n=17 Participants
Matching placebo capsule by mouth, daily for 7 days.
Pregnenolone Level
10902.60 pg/mL
Standard Deviation 11849.18
11484.75 pg/mL
Standard Deviation 13038.50
769.63 pg/mL
Standard Deviation 554.50

SECONDARY outcome

Timeframe: 7 days

Population: All participants with available data for each treatment condition.

Assess bioavailability of pregnenolone by demonstrating increases in serum pregnenolone and allopregnanolone with pregnenolone administration. Change (increases) in blood serum allopregnanolone levels are indicative of bioavailability.

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=16 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
n=19 Participants
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
n=17 Participants
Matching placebo capsule by mouth, daily for 7 days.
Allopregnanolone Level
2478.39 pg/mL
Standard Deviation 1801.67
2489.08 pg/mL
Standard Deviation 2180.59
124.22 pg/mL
Standard Deviation 224.62

SECONDARY outcome

Timeframe: 7 days

Population: All participants with available data for each treatment condition.

Assess safety and tolerability of pregnenolone at the doses tested. SAFTEE is a side effect self-report assessment scale that consists of 56 potential side effects. Participants rate how bothersome each side effect is on a scale of "none" (0), "mild" (1), "moderate" (2), "severe" (3). Total scores range from 0 to 168. A higher total score (sum of all items) indicates a higher level of side effect burden.

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=20 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
n=22 Participants
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
n=20 Participants
Matching placebo capsule by mouth, daily for 7 days.
Systematic Assessment for Treatment Emergent Events (SAFTEE)
16.15 units on a scale
Standard Deviation 12.42
19.14 units on a scale
Standard Deviation 12.41
17.60 units on a scale
Standard Deviation 9.65

SECONDARY outcome

Timeframe: 7 days

Identify a dose of pregnenolone that demonstrates bioavailability (see "Pregnenolone Level" and "Allopregnanolone Level" outcome measures), tolerability (see "SAFTEE" outcome measure); and is associated with a significant change in a biosignature.

Outcome measures

Outcome measures
Measure
Pregnenolone (500 mg)
n=21 Participants
Pregnenolone 500 mg capsule by mouth, daily for 7 days.
Pregnenolone (800 mg)
Pregnenolone 800 mg capsule by mouth, daily for 7 days.
Placebo
Matching placebo capsule by mouth, daily for 7 days.
Pregnenolone Dose
500 mg

Adverse Events

Pregnenolone 800

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Pregnenolone 500

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

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Sherwood Brown

UT Southwestern Medical Center

Phone: 214-645-6950

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place