Trial · NCT00788073

Safety, Tolerability and Efficacy Study of STX209 in Subjects With Fragile X Syndrome

NCT00788073, Phase 2, Completed, Seaside Therapeutics, Inc.; results first posted 2013-05-06

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Safety, Tolerability and Efficacy Study of STX209 in Subjects With Fragile X Syndrome. Trials, record NCT00788073. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT00788073

On this page

Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Safety, Tolerability and Efficacy Study of STX209 in Subjects With Fragile X Syndrome
NCT number: NCT00788073
Status: Completed
Phases: Phase 2
Enrollment: 63 participants, actual
Lead sponsor: Seaside Therapeutics, Inc.
Conditions: Fragile X Syndrome
Interventions: STX209, Placebo
First posted: 2008-11-10
Last updated: 2013-05-06
Results first posted: 2013-05-06

Source ClinicalTrials.gov

Registered outcomes1

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Aberrant Behavior Checklist Irritability Subscore	After 4 weeks of treatment	The Aberrant Behavior Checklist-Community Edition (ABC-C) is a 58-item questionnaire composed of five different independent subscales. The questionnaire is completed by the parent/caregiver and lists aberrant behaviors and asks about the severity of the problem. ABC-Irritability is one of the subscales and comprises of 15 items. Minimum score is 0, maximum is 45. A decreased score indicates few aberrant behaviors and clinical improvement. The entire ABC-C assessment is administered at baseline and then at the end of each Intervention Period (4 weeks after Baseline).

Source ClinicalTrials.gov

Outcomes2

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Aberrant Behavior Checklist Irritability Subscore	After 4 weeks of treatment		Points on a scale	LEAST_SQUARES_MEAN
POST_HOC	ABC-FXS Social Avoidance Subscore	4 week treatment period		Points on a scale	LEAST_SQUARES_MEAN

Source ClinicalTrials.gov

Results by group4

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Value	Spread	Units
Aberrant Behavior Checklist Irritability Subscore	STX209:Placebo	-5.1	Standard Error 0.95	Points on a scale
Aberrant Behavior Checklist Irritability Subscore	Placebo:STX209	-5.3	Standard Error 0.95	Points on a scale
ABC-FXS Social Avoidance Subscore	STX209:Placebo	-1.2	Standard Error 0.24	Points on a scale
ABC-FXS Social Avoidance Subscore	Placebo:STX209	-0.1	Standard Error 0.24	Points on a scale

Source ClinicalTrials.gov

Participant flow12

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
STX209 Then Placebo	STARTED	STX209:Placebo	30
STX209 Then Placebo	STARTED	Placebo:STX209	33
STX209 Then Placebo	COMPLETED	STX209:Placebo	29
STX209 Then Placebo	COMPLETED	Placebo:STX209	30
STX209 Then Placebo	NOT COMPLETED	STX209:Placebo	1
STX209 Then Placebo	NOT COMPLETED	Placebo:STX209	3
Placebo Then STX209	STARTED	STX209:Placebo	29
Placebo Then STX209	STARTED	Placebo:STX209	30
Placebo Then STX209	COMPLETED	STX209:Placebo	27
Placebo Then STX209	COMPLETED	Placebo:STX209	29

1 to 10 of 12Source ClinicalTrials.gov

See all 12 participant flow

Adverse events22

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	upper respiratory tract infection	Respiratory, thoracic and mediastinal disorders	STX209	8	63	8
other	upper respiratory tract infection	Respiratory, thoracic and mediastinal disorders	Placebo	6	63	6
other	headache	Nervous system disorders	STX209	5	63	5
other	headache	Nervous system disorders	Placebo	1	63	1
other	sedation	Nervous system disorders	STX209	5	63	5
other	sedation	Nervous system disorders	Placebo	1	63	1
other	fatigue	General disorders	STX209	4	63	4
other	fatigue	General disorders	Placebo	1	63	1
other	irritability	Psychiatric disorders	STX209	4	63	4
other	irritability	Psychiatric disorders	Placebo	4	63	4

1 to 10 of 22Source ClinicalTrials.gov

See all 22 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	STX209
Total, all-cause mortality	Placebo
Total, other adverse events	STX209	42	63
Total, other adverse events	Placebo	31	63
Total, serious adverse events	STX209	1	63
Total, serious adverse events	Placebo	0	63

Source ClinicalTrials.gov

Papers0

The papers the trial lists on ClinicalTrials.gov.

None in this release.

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons1

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison
STX209 vs Placebo: serious adverse events

Source Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT00788073

GET https://conductscience.org/api/trials/v1/NCT00788073/events?page=2

API reference For AI assistants