Major Depressive DisorderPhase 2NCT04479852

A Study of the Safety and Efficacy of SP-624 in the Treatment of Adults With Major Depressive Disorder

A Phase 2 study testing SP-624 in people with Major Depressive Disorder, run by Sirtsei Pharmaceuticals, Inc. at 39 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

This is a Phase 2 clinical study evaluating the safety and effectiveness of SP-624 as compared to placebo in the treatment of adults with Major Depressive Disorder. Read more about this study

Who is it for?: Ages 18 to 65 years
Conditions the study is for: Major Depressive Disorder
What is being tested?: SP-624
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 319 participants
Where: 39 sitesUnited States
Study dates: 30 Sep 2020to 9 Aug 2022
Phase: Phase 2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 65 years
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Willing and able to provide written informed consent to participate in the study
Males and females, aged 18 to 65 years
In generally good physical health
Body mass index (BMI) must be between 18 and 40 kg/m2
Females of reproductive potential and males with partners of reproductive potential must agree to remain abstinent or use adequate and reliable contraception throughout the study and for at least 30 days after the last dose of study drug
Subjects must meet criteria for moderate to severe Major Depressive Disorder, as confirmed by the Mini International Neuropsychiatric Interview (MINI)
Willing and able to comply with the study design schedule and other requirements

Who cannot join

Female who is pregnant, breastfeeding, or less than six months postpartum at Screening
History or presence of any clinically significant medical condition, disease, or surgical history that could jeopardize the safety of the subject or validity of the study data, or interfere with the absorption, distribution, metabolism, or excretion of the study drug
Failure to discontinue all psychoactive medications or psychoactive supplements including antidepressants and mood stabilizers, within a time period prior to Baseline corresponding to at least five half-lives of the medication in question
Presence of a clinically significant abnormality on physical examination or electrocardiogram (ECG), including a corrected QT interval using Fridericia's formula (QTcF) >450 msec for males and >470 msec for females
Presence of uncontrolled hypertension, defined as consistent systolic blood pressure (SBP) >160 mmHg or consistent diastolic blood pressure (DBP) >95 mmHg despite present therapy
Screening laboratory value(s) outside the laboratory reference range that are considered to be clinically significant by the Investigator (clinical chemistry, hematology, coagulation, and urinalysis)
Screening liver function tests (ALT, AST, Alkaline phosphatase) > 2x the upper limit of normal
Subjects who, in the opinion of the Investigator, are not suitable candidates for the study

Trial locations and contacts

39 sites in 1 country.

City, postcode or hospital

39 sites in 1 country

United States39 sites

Lehigh Center for Clinical Research
Allentown, Pennsylvania, 18104
Institute for Advanced Medical Research
Alpharetta, Georgia, 30022
Atlanta Center for Medical Research
Atlanta, Georgia, 30331
Donald J. Garcia, Jr., MD, PA
Austin, Texas, 78737
Hassman Research Institute
Berlin, New Jersey, 08009
SPRI Clinical Trials
Brooklyn, New York, 11235
New Hope Clinical Research
Charlotte, North Carolina, 28211
Center for Emotional Fitness
Cherry Hill, New Jersey, 08002
American Medical Research
Chicago, Illinois, 60612
MCB Clinical Research Centers
Colorado Springs, Colorado, 80910
Future Search Trials of Dallas
Dallas, Texas, 75231
Midwest Clinical Research Center
Dayton, Ohio, 45417
iResearch Atlanta
Decatur, Georgia, 30030
Core Clinical Research
Everett, Washington, 98201
Sarkis Clinical Trials
Gainesville, Florida, 32607
CBH Health
Gaithersburg, Maryland, 20877
Collaborative Neuroscience Research
Garden Grove, California, 92845
Clinical Trials of America
Hickory, North Carolina, 28601
Red Oak Psychiatry Associates
Houston, Texas, 77090
Clinical Neuroscience Solutions, Inc.
Jacksonville, Florida, 32256
Altea Research Institute
Las Vegas, Nevada, 89102
Innovative Clinical Research
Lauderhill, Florida, 33319
Capstone Clinical Research
Libertyville, Illinois, 60048
Woodland International Research Group
Little Rock, Arkansas, 72211
Hassman Research Institute
Marlton, New Jersey, 08053
Clinical Neuroscience Solutions, Inc.
Memphis, Tennessee, 38119
Manhattan Behavioral Medicine
New York, New York, 10036
Pacific Research Partners
Oakland, California, 94607
Cutting Edge Research Group
Oklahoma City, Oklahoma, 73116
Clinical Neuroscience Solutions, Inc.
Orlando, Florida, 32801
Alea Research
Phoenix, Arizona, 85012
Oregon Center for Clinical Investigations
Portland, Oregon, 97214
Woodland Research Northwest
Rogers, Arkansas, 72758
Midwest Research Group
Saint Charles, Missouri, 63304
Oregon Center for Clinical Investigations
Salem, Oregon, 97301
Artemis Institute for Clinical Research
San Diego, California, 92103
Richmond Behavioral Associates
Staten Island, New York, 10312
Collaborative Neuroscience Research
Torrance, California, 90502
Grayline Research Center
Wichita Falls, Texas, 76309

Other trials in United States

About this study

Official title: A Multicenter, Double-Blind, Randomized, Placebo-Controlled Study of the Safety and Efficacy of SP-624 in the Treatment of Adults With Major Depressive Disorder

This is a Phase 2 clinical study evaluating the safety and effectiveness of SP-624 as compared to placebo in the treatment of adults with Major Depressive Disorder.

Conditions: Major Depressive Disorder
Being tested: SP-624, Placebo
Medical subject headings: Depressive Disorder, Major

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

SP-624Drug
Oral capsule
PlaceboDrug
Oral capsule

Study groups in NCT04479852
Study group	Role	What they receive
SP-624	Experimental	Daily oral capsule, 20 mg/day Receives: Drug: SP-624
Placebo	Placebo comparator	Daily oral capsule Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Change From Baseline to Week 4 in Montgomery Asberg Depression Rating Scale (MADRS) Total Score
The Montgomery Asberg Depression rating scale is a 10-item scale used to assess the severity of depression. Individual items are scored on a 7-point scale (0 to 6). The total score is the sum of individual items, ranging from 0 to 60; where a higher score indicates more depression.
Measured: Baseline to Week 4

Secondary outcomes (5)

Change From Baseline to Week 4 in Clinical Global Impression - Severity (CGI-S) Total Score
The CGI-S is a 7-point scale to rate the severity of the participant's illness at the time of assessment, relative to the clinician's past experience with participants who have the same diagnosis. A score of 1 represents "normal" and 7 represents "most extremely ill".
Measured: Baseline to Week 4
Change From Baseline to Week 4 in the 17-item Hamilton Depression Rating Scale (HAM D-17) Total Score
The 17-item Hamilton Depression rating scale is used to assess the severity of depression. Individual items are scored on either a 3-point (0 to 2) or a 5-point scale (0 to 4), with 0=No difficulty/absent and 4=most severe. The total score is the sum of individual items, ranging from 0 to 52; where a higher score indicates more depression.
Measured: Baseline to Week 4
Change From Baseline to Week 4 in the Sheehan Disability Scale (SDS)
The Sheehan Disability Scale is a 3-part scale that measures the degree of disruption on work, social, and family life using an 11-point scale where 0 represents "no disruption" and 10 represents "extreme disruption". Each item (work, social, and family life) can have a score of 0-10. A total global functioning impairment score can be utilized by summing the scores from work, social, and family life scales for a value range from 0 to 30, where a higher score represents a worse outcome, i.e., more disruption on work, social, and family life. In addition to the 11-point scale, participants are asked to indicate the number of days in the past week that were "lost" and numbers of days that were "unproductive". The results of these questions have a range from 0 to 7 and are not included in the overall scale total.
Measured: Baseline to Week 4
Change From Baseline to Week 4 in the Quick Inventory of Depressive Symptomology - Self Report (QIDS-SR)
The Quick Inventory of Depressive Symptomology - Self Report (QIDS-SR), is a 16 item self-reported scale where each item has a 4-point scale where 0 represents least impact scores while 3 represents greatest impact scores. Some questions are linked such that the highest score in a group of questions is entered once. For example, there are 4 questions related to sleep and the highest score on any of the 4 sleep items is entered once. The total score ranges from 0 to 27 where a higher score indicates more depression.
Measured: Baseline to Week 4
Change From Baseline to Week 4 in the Quality of Life Enjoyment and Satisfaction Questionnaire - Short Form (Q-LES-Q-SF)
The Quality of Life Enjoyment and Satisfaction Questionnaire - Short Form (Q-LES-Q-SF) is a 16 item satisfaction scale where each item has a 5-point scale. A score of 1 represents "very poor satisfaction", while a score of 5 represents "very good satisfaction". Only the first 14 items are summed for a total score that ranges from 14 to 70, where a lower score represents a worse outcome.
Measured: Baseline to Week 4

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

30 Sep 20209 Aug 2022

First posted21 Jul 2020
Study start30 Sep 2020
Primary completion27 Jun 2022
Study completion9 Aug 2022

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Major Depressive DisorderStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 2
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 319 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04479852
Sponsor's protocol ID: SP-624-201
Status last verified: Aug 2024
First submitted: 16 Jul 2020
Last updated: 12 Jun 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Major Depressive Disorder trials

Study at a glance

From the registry record, last updated by the sponsor on 12 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Multicenter, Double-Blind, Randomized, Placebo-Controlled Study of the Safety and Efficacy of SP-624 in the Treatment of Adults With Major Depressive Disorder
ClinicalTrials.gov ID: NCT04479852
Acronym / sponsor ID: SP-624-201
Conditions: Major Depressive Disorder
Phase: Phase 2
Study type: Interventional
Recruitment status: Completed
Enrolment: 319 participants (actual)
Lead sponsor: Sirtsei Pharmaceuticals, Inc.Industry (pharma, biotech, devices)
Study start: 30 Sep 2020 (actual)
Primary completion: 27 Jun 2022 (actual)
Study completion: 9 Aug 2022 (actual)
First posted: 21 Jul 2020 (actual)
Results: Posted 12 Jun 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

This is a Phase 2 clinical study evaluating the safety and effectiveness of SP-624 as compared to placebo in the treatment of adults with Major Depressive Disorder.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 2

Arm	Type	Receives
SP-624	Experimental	Drug: SP-624Daily oral capsule, 20 mg/day
Placebo	Placebo comparator	Drug: PlaceboDaily oral capsule

Who may qualify

Ages: 18 to 65 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (7 listed)

Willing and able to provide written informed consent to participate in the study
Males and females, aged 18 to 65 years
In generally good physical health
Body mass index (BMI) must be between 18 and 40 kg/m2
Females of reproductive potential and males with partners of reproductive potential must agree to remain abstinent or use adequate and reliable contraception throughout the study and for at least 30 days after the last dose of study drug

Key exclusion criteria (8 listed)

Female who is pregnant, breastfeeding, or less than six months postpartum at Screening
History or presence of any clinically significant medical condition, disease, or surgical history that could jeopardize the safety of the subject or validity of the study data, or interfere with the absorption, distribution, metabolism, or excretion of the study drug
Failure to discontinue all psychoactive medications or psychoactive supplements including antidepressants and mood stabilizers, within a time period prior to Baseline corresponding to at least five half-lives of the medication in question
Presence of a clinically significant abnormality on physical examination or electrocardiogram (ECG), including a corrected QT interval using Fridericia's formula (QTcF) >450 msec for males and >470 msec for females
Presence of uncontrolled hypertension, defined as consistent systolic blood pressure (SBP) >160 mmHg or consistent diastolic blood pressure (DBP) >95 mmHg despite present therapy

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
SP-624Oral capsule	Drug	SP-624
PlaceboOral capsule	Drug	Placebo

Primary outcome

Change From Baseline to Week 4 in Montgomery Asberg Depression Rating Scale (MADRS) Total Score
Time frame: Baseline to Week 4
The Montgomery Asberg Depression rating scale is a 10-item scale used to assess the severity of depression. Individual items are scored on a 7-point scale (0 to 6). The total score is the sum of individual items, ranging from 0 to 60; where a higher score indicates more depression.

5 secondary outcomes

Change From Baseline to Week 4 in Clinical Global Impression - Severity (CGI-S) Total Score
Time frame: Baseline to Week 4
Change From Baseline to Week 4 in the 17-item Hamilton Depression Rating Scale (HAM D-17) Total Score
Time frame: Baseline to Week 4
Change From Baseline to Week 4 in the Sheehan Disability Scale (SDS)
Time frame: Baseline to Week 4
Change From Baseline to Week 4 in the Quick Inventory of Depressive Symptomology - Self Report (QIDS-SR)
Time frame: Baseline to Week 4
Change From Baseline to Week 4 in the Quality of Life Enjoyment and Satisfaction Questionnaire - Short Form (Q-LES-Q-SF)
Time frame: Baseline to Week 4

Results and safety

Results posted to the registry on 12 Jun 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
SP-624	163	133
Placebo	156	130

Primary outcome: Change From Baseline to Week 4 in Montgomery Asberg Depression Rating Scale (MADRS) Total Score

Time frame: Baseline to Week 4. Least squares mean (Standard Error). Unit: Score on a scale

Measure	SP-624 n = 132	Placebo n = 125
Value	-12.6 (0.83)	-10.8 (0.84)

SP-624 vs Placebo: Mean Difference (Final Values): -1.8 (95% CI -4.1 to 0.5), p = 0.133, Mixed Models Analysis

Population analysed: Modified Intent To Treat population - all subjects who are randomized to receive treatment, receive at least one dose of study drug, and have a Baseline and at least one post-dose efficacy assessment.

5 secondary outcomes are reported in the full results.

Adverse events

Time frame: Consent through 2 week follow up, up to 10 weeks (up to 28 day screening period, 4 week treatment period, and 2 week follow up period). Other adverse events reported at 2% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
SP-624	0 of 161 (0%)	35 of 161 (21.7%)	0 of 161
Placebo	2 of 156 (1.3%)	36 of 156 (23.1%)	0 of 156

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 12 Jun 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

Related trials for Major Depressive Disorder

Not yet recruiting
Preventive and Personalized Digital Emotion Regulation Skills Intervention to Reduce Depression and Anxiety in Youths With Adverse Childhood Experiences
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RecruitingPhase 4
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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Greg Rigdon, PhD study director

Sirtsei Pharmaceuticals, Inc.

39 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing SP-624 in people with Major Depressive Disorder, run by Sirtsei Pharmaceuticals, Inc. at 39 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 12 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 39 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 12 Jun 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change From Baseline to Week 4 in Montgomery Asberg Depression Rating Scale (MADRS) Total Score (time frame: Baseline to Week 4). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04479852.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jun 2025.