Trial Outcomes & Findings for Study of SDX in Patients With Idiopathic Hypersomnia (IH) (NCT NCT05668754)

NCT ID: NCT05668754

Last Updated: 2026-06-30

Results Overview

Scores level of daytime sleepiness ranging from 0 to 24, with a higher score indicating worsened sleepiness

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

66 participants

Primary outcome timeframe

Start to end of DBWP (2 weeks)

Results posted on

2026-06-30

Participant Flow

66 subjects enrolled into the study by entering the Open-Label Titration Period (OLTP). After subjects titrated to their highest tolerated dose over the 5-week period, 50 were randomized into the Double-Blind Withdrawal Period (DBWP).

Participant milestones

Participant milestones
Measure	Treatment X SDX QD Open-Label Titration Period - participants titrate to highest tolerable daily dose (80, 160, 240, or 320mg) over a 5-week period.	Treatment Y SDX BID Open-Label Titration Period - participants titrate to highest tolerable daily dose (80, 160, 240, or 320mg) over a 5-week period.	Treatment B Placebo QD DB Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Treatment A SDX QD DB Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Treatment D Placebo BID DB Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Treatment C SDX BID DB Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.
Open-Label Titration Period STARTED	32	34	0	0	0	0
Open-Label Titration Period COMPLETED	27	30	0	0	0	0
Open-Label Titration Period NOT COMPLETED	5	4	0	0	0	0
Double-Blind Withdrawal Period STARTED	0	0	7	16	8	19
Double-Blind Withdrawal Period COMPLETED	0	0	7	16	8	19
Double-Blind Withdrawal Period NOT COMPLETED	0	0	0	0	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Treatment X SDX QD n=32 Participants Open-Label Titration Period - participants titrate to highest tolerable daily dose (80, 160, 240, or 320mg) over a 5-week period.	Treatment Y SDX BID n=34 Participants Open-Label Titration Period - participants titrate to highest tolerable daily dose (80, 160, 240, or 320mg) over a 5-week period.	Treatment B Placebo QD DB n=7 Participants Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Treatment A SDX QD DB n=15 Participants Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Treatment D Placebo BID DB n=8 Participants Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Treatment C SDX BID DB n=17 Participants Double-Blind Withdrawal Period - subjects retain their regimen assignment (QD vs BID) and titrated dose (80, 160, 240, or 320mg) from the open-label titration period; however, are randomized to either SDX or Placebo.	Total n=113 Participants Total of all reporting groups
Age, Continuous Open-Label Titration Period	35.4 years STANDARD_DEVIATION 11.85 • n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	36.9 years STANDARD_DEVIATION 13.93 • n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	—	—	—	—	36.2 years STANDARD_DEVIATION 12.89 • n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Age, Continuous Double-Blind Withdrawal Period	—	—	36.9 years STANDARD_DEVIATION 14.44 • n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	36.5 years STANDARD_DEVIATION 11.08 • n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	35.1 years STANDARD_DEVIATION 8.92 • n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	39.5 years STANDARD_DEVIATION 16.44 • n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	37.4 years STANDARD_DEVIATION 13.17 • n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Sex: Female, Male Open-Label Titration Period · Female	23 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	24 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	47 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Sex: Female, Male Open-Label Titration Period · Male	9 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	10 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	19 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Sex: Female, Male Double-Blind Withdrawal Period · Female	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	4 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	11 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	6 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	12 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	33 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Sex: Female, Male Double-Blind Withdrawal Period · Male	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	3 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	4 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	2 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	5 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	14 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · American Indian or Alaska Native	0 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · Asian	2 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	1 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	3 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · Native Hawaiian or Other Pacific Islander	0 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · Black or African American	6 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	10 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	16 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · White	24 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	23 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	47 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · More than one race	0 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Open-Label Titration Period · Unknown or Not Reported	0 Participants n=32 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=34 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=66 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · American Indian or Alaska Native	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · Asian	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	1 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	1 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	1 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	3 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · Native Hawaiian or Other Pacific Islander	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · Black or African American	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	1 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	2 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	5 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	8 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · White	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	5 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	12 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	8 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	11 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	36 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · More than one race	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.
Race (NIH/OMB) Double-Blind Withdrawal Period · Unknown or Not Reported	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=7 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=15 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=8 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=17 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.	0 Participants n=47 Participants • Overall Number of Baseline Participants is the total number of participants for all Treatment Arms within the study for both the Open-Label Titration Period and the Double-Blind Withdrawal Period combined. Please see the Baseline Analysis Population Description for details.

PRIMARY outcome

Timeframe: Start to end of DBWP (2 weeks)

Population: All subjects in the Double-Blind Withdrawal Period who qualified to be entered into the Double-Blind Withdrawal Period who received at least 1 dose of study medication in the Withdrawal Period and had at least 1 post randomization ESS score in the Withdrawal Period.

Scores level of daytime sleepiness ranging from 0 to 24, with a higher score indicating worsened sleepiness

Outcome measures

Outcome measures
Measure	Treatment B Placebo QD DB n=7 Participants Double-Blind Withdrawal Period	Treatment A SDX QD DB n=15 Participants Double-Blind Withdrawal Period	Treatment D Placebo BID DB n=8 Participants Double-Blind Withdrawal Period	Treatment C SDX BID DB n=17 Participants Double-Blind Withdrawal Period
Change From Baseline in Epworth Sleepiness Scale (ESS) Score	-0.6 score on a scale Interval -4.1 to 2.9	-0.1 score on a scale Interval -2.4 to 2.2	5.6 score on a scale Interval 2.5 to 8.8	0.0 score on a scale Interval -2.1 to 2.2

SECONDARY outcome

Timeframe: Changes from Titration Baseline to Week 5 (5 weeks)

Population: All randomized subjects in the Open-Label Titration Period who received at least 1 dose of study medication and had at least 1 post-randomization ESS score in the Titration Period.

Scores level of daytime sleepiness ranging from 0 to 24, with a higher score indicating worsened sleepiness

Outcome measures

Outcome measures
Measure	Treatment B Placebo QD DB n=26 Participants Double-Blind Withdrawal Period	Treatment A SDX QD DB n=30 Participants Double-Blind Withdrawal Period	Treatment D Placebo BID DB Double-Blind Withdrawal Period	Treatment C SDX BID DB Double-Blind Withdrawal Period
Change From Baseline in Epworth Sleepiness Scale (ESS) Score	-7.4 units on a scale Interval -9.2 to -5.6	-7.8 units on a scale Interval -9.5 to -6.1	—	—

Adverse Events

Treatment X SDX QD

Serious events: 1 serious events

Other events: 22 other events

Deaths: 0 deaths