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A Study of GWP42003 as Adjunctive Therapy in the First Line Treatment of Schizophrenia or Related Psychotic Disorder

A Double-blind, Randomised, Placebo-controlled, Parallel Group Study of GWP42003 as Adjunctive Therapy in the First Line Treatment of Schizophrenia or Related Psychotic Disorder

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02006628
Enrollment
88
Registered
2013-12-10
Start date
2014-02-25
Completion date
2015-01-08
Last updated
2022-09-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizophrenia, Schizophrenia-related Psychotic Disorder

Keywords

GWP42003, Cannabinoids, Schizophrenia, CBD, Cannabidiol

Brief summary

A study to compare the change in symptom severity in participants with schizophrenia or related psychotic disorder when treated with GWP42003 or placebo in conjunction with existing anti-psychotic therapy over a period of six weeks.

Detailed description

This eight-week (six-week treatment period and two-week follow-up), multi-centre, double-blind, randomized, placebo-controlled, parallel group study aimed to determine the efficacy, safety and tolerability of GWP42003 in participants with schizophrenia or a related psychotic disorder. Eligible participants entered the study at a Screening and Randomization Visit (Day 1), where eligibility was established. Once all inclusion and exclusion criteria were reviewed, participants were randomized to receive either GWP42003 or placebo in conjunction with their prescribed anti-psychotic medications and began treatment on Day 1 as instructed. Assessments were performed on Days 8, 22, and 43. A safety follow-up visit was conducted on Day 57.

Interventions

DRUGPlacebo

Placebo oral solution (0 milligrams \[mg\]/mL CBD) contained the excipients sesame oil, ethanol, sucralose, and strawberry flavoring.

GWP42003 was an oral solution containing 100 mg/mL CBD dissolved in the excipients sesame oil, ethanol, sucralose and strawberry flavoring.

Sponsors

Jazz Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

(all must be fulfilled): * Participant gave written informed consent for participation in the study and did not require involuntary treatment. * Participant was male or female aged 18 to 65 years. * Participant was able (in the investigator's opinion) and willing to comply with all study requirements. * Participant was diagnosed with schizophrenia or a related psychotic disorder (such as schizoaffective or schizophreniform disorder) as defined by the Diagnostic and Statistical Manual of Mental Disorders Version 4. * Participant was treated for a minimum of four-weeks and was on a stable dose of his or her current anti-psychotic (AP) medication. * Participant showed the capacity to respond at least partially to first line AP medication in the opinion of the investigator. * Participant remained stable on his or her dose of AP and concomitant medications for the duration of the study, in the opinion of the investigator. * Participant was willing for his or her name to be notified to the responsible authorities for participation in this study, as applicable in individual countries. * Participant was willing to allow his or her primary care practitioner and consultant, if appropriate, to be notified of participation in the study.

Exclusion criteria

(any of the following): * Participant had any known or suspected hypersensitivity to cannabinoids or any of the excipients of the Investigational Medicinal Product (IMP). * Participant had a Positive and Negative Symptom Scale total score of \<60 at Day 1. * Participant presented with a current clinical picture and/or history that is consistent with: i. delirium or dementia. ii. acute drug induced psychosis. iii. bipolar disorder. * Participant was taking more the one AP medication during the study. * Female participants of child bearing potential and male participants whose partner was of child bearing potential, unless willing to ensure that they or their partner used effective contraception, for example, oral contraception, double barrier, intra-uterine device, during the study and for three months thereafter (a male condom was not used in conjunction with a female condom). * Female participant who was pregnant, lactating, or planning pregnancy during the course of the study and for three months thereafter. * Participants who had received an IMP within 30 days prior to the screening visit. * Participants who had any other significant disease or disorder which, in the opinion of the investigator, either put the participant at risk because of participation in the study, or may have influenced the result of the study, or the participant's ability to participate in the study. * Participant had any abnormalities following a physical examination that, in the opinion of the investigator, prevented the participant from safe participation in the study. * Participant was unwilling to abstain from donation of blood during the study. * Participant had travelled outside the country of residence during the study. * Participant previously randomized into this study.

Design outcomes

Primary

MeasureTime frameDescription
Change From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreDay 1 through Day 43The PANSS was a 30-item medical scale completed by a trained rater that assessed the positive and negative symptoms of schizophrenia as well as symptoms of general psychopathology. The PANSS Total score was derived from the sum of the 30 items, which were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total score is the summed total for each of the PANSS positive symptom ('P'), negative symptom ('N'), general psychopathology symptom ('G') scores and could range from 30 to 210 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.
Percentage Of PANSS Total Score Responders At End Of Treatment (Day 43)Day 1 through Day 43The percentage of PANSS treatment responders, defined as participants with ≥20% improvement in PANSS Total score between baseline and End of Treatment, is presented. The percentage of participants was calculated by dividing the number of participants with a ≥20% improvement in PANSS Total score (yes) by the total number of participants.
Change From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreDay 1 through Day 43The PANSS 'P' scale measured the severity of positive symptoms, including delusions, conceptual disorganization, hallucinations, hyperactivity, grandiosity, suspiciousness/persecution, and hostility. Individual items were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total 'P' score could range from 7 to 49 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.
Change From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreDay 1 through Day 43The PANSS 'N' scale measured the severity of negative symptoms, including blunted affect, emotional withdrawal, poor rapport, passive/apathetic social withdrawal, difficulty in abstract thinking, lack of spontaneity and flow of conversation, and stereotyped thinking. Individual items were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total 'N' score could range from 7 to 49 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.
Change From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreDay 1 through Day 43The PANSS 'G' scale measured the severity of general psychopathology symptoms, including somatic concern, anxiety, guilt feelings, tension, mannerisms and posturing, depression, motor retardation, uncooperativeness, unusual thought content, disorientation, poor attention, lack of judgement and insight, disturbance of violation, poor impulse control, preoccupation, and active social avoidance. Individual items were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total 'G' score could range from 16 to 112 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.
Change From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)Day 1 through Day 43The SANS assessed 5 symptom complexes to obtain clinical ratings of negative symptoms in participants with schizophrenia or related psychotic disorder. Symptom complexes were affective blunting, alogia (impoverished thinking), avolition/apathy, anhedonia/asociality, and disturbance of attention. Assessments were conducted on a 6-point scale (0 = not at all; 5 = severe). The total score could range from 0 to 125 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.
Change From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)Day 1 through Day 43The CGI-S was a 7-point scale that required the clinician to rate the severity of a participant's illness at the time of assessment, relative to the clinician's past experience of participants who had the same diagnosis. Considering total clinical experience, participants were assessed on severity of mental illness at the time of rating on the following scale: 1 = normal, not at all ill; 2 = borderline mentally ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; or 7 = extremely ill. Lower scores equated to milder severity of symptoms, that is, closer to psychologically normal.
Clinical Global Impression Improvement Scale (CGI-I) Values At Day 8 And End Of Treatment (Day 43)Day 8 through Day 43The CGI-I was a 7-point scale that required the clinician to assess how much a participant's illness had improved or worsened relative the first assessment at the beginning of the intervention. This was rated on the following scale: 1 = very much improved; 2 = much improved; 3 = minimally improved; 4 = no change; 5 = minimally worse; 6 = much worse; or 7 = very much worse. Lower scores equated to improvement of symptoms.
Change From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreDay 1 through Day 43The BACS was an instrument used to assess the aspects of cognition found to be most impaired and most strongly correlated with outcome in participants with schizophrenia or related psychotic disorder. The BACS consisted of 6 domains: verbal memory (score range 0 to 75), working memory (score range 0 to 28), motor speed (score range 0 to 100), verbal fluency (score \> 0, with no set maximum value), attention and speed of information processing (score range 0 to 110), and executive functions (score range 0 to 22). A score was obtained for each of the 6 domains. A composite summary score was then calculated as the arithmetic mean of the unweighted scores from the 6 domains. While there was not an upper limit on the composite score, overall, an increase in score was indicative of an improvement in cognition.

Countries

Poland, Romania, United Kingdom

Participant flow

Participants by arm

ArmCount
GWP42003 1000 mg/Day
Participants received GWP42003 (100 mg/mL), 5 mL BID administered orally, 5 mL in the morning and 5 mL in the evening for 6 weeks.
43
Placebo
Participants received placebo (0 mL CBD), volume matched to the 5 mL BID dose level, administered orally, 5 mL in the morning and 5 mL in the evening for 6 weeks.
45
Total88

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event11
Overall StudyWithdrawal by Subject21

Baseline characteristics

CharacteristicGWP42003 1000 mg/DayPlaceboTotal
Age, Continuous40.9 years
STANDARD_DEVIATION 12.49
40.8 years
STANDARD_DEVIATION 11
40.8 years
STANDARD_DEVIATION 11.69
Sex: Female, Male
Female
15 Participants22 Participants37 Participants
Sex: Female, Male
Male
28 Participants23 Participants51 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
8 / 4310 / 45
serious
Total, serious adverse events
0 / 431 / 45

Outcome results

Primary

Change From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total Score

The PANSS was a 30-item medical scale completed by a trained rater that assessed the positive and negative symptoms of schizophrenia as well as symptoms of general psychopathology. The PANSS Total score was derived from the sum of the 30 items, which were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total score is the summed total for each of the PANSS positive symptom ('P'), negative symptom ('N'), general psychopathology symptom ('G') scores and could range from 30 to 210 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreBaseline score79.3 score on a scaleStandard Deviation 12.45
GWP42003 1000 mg/DayChange From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreEnd of Treatment score68.1 score on a scaleStandard Deviation 14.79
GWP42003 1000 mg/DayChange From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreChange from baseline-11.2 score on a scaleStandard Deviation 7.87
PlaceboChange From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreBaseline score80.6 score on a scaleStandard Deviation 14.9
PlaceboChange From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreEnd of Treatment score71.9 score on a scaleStandard Deviation 15.49
PlaceboChange From Baseline To End Of Treatment (Day 43) In Positive And Negative Syndrome Scale (PANSS) Total ScoreChange from baseline-8.8 score on a scaleStandard Deviation 8.87
p-value: 0.133295% CI: [-6.5, 0.9]ANCOVA
Primary

Change From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) Score

The BACS was an instrument used to assess the aspects of cognition found to be most impaired and most strongly correlated with outcome in participants with schizophrenia or related psychotic disorder. The BACS consisted of 6 domains: verbal memory (score range 0 to 75), working memory (score range 0 to 28), motor speed (score range 0 to 100), verbal fluency (score \> 0, with no set maximum value), attention and speed of information processing (score range 0 to 110), and executive functions (score range 0 to 22). A score was obtained for each of the 6 domains. A composite summary score was then calculated as the arithmetic mean of the unweighted scores from the 6 domains. While there was not an upper limit on the composite score, overall, an increase in score was indicative of an improvement in cognition.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreBaseline score32.21 score on a scaleStandard Deviation 6.042
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreEnd of Treatment score35.73 score on a scaleStandard Deviation 6.981
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreChange from Baseline3.48 score on a scaleStandard Deviation 3.031
PlaceboChange From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreBaseline score32.91 score on a scaleStandard Deviation 7.158
PlaceboChange From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreEnd of Treatment score35.05 score on a scaleStandard Deviation 7.31
PlaceboChange From Baseline To The End Of Treatment (Day 43) In Brief Assessment Of Cognition In Schizophrenia (BACS) ScoreChange from Baseline2.14 score on a scaleStandard Deviation 3.442
p-value: 0.067795% CI: [-0.1, 2.72]ANCOVA
Primary

Change From Baseline To The End Of Treatment (Day 43) In PANSS 'G' Score

The PANSS 'G' scale measured the severity of general psychopathology symptoms, including somatic concern, anxiety, guilt feelings, tension, mannerisms and posturing, depression, motor retardation, uncooperativeness, unusual thought content, disorientation, poor attention, lack of judgement and insight, disturbance of violation, poor impulse control, preoccupation, and active social avoidance. Individual items were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total 'G' score could range from 16 to 112 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreChange from Baseline-5.3 score on a scaleStandard Deviation 4.34
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreBaseline score38.7 score on a scaleStandard Deviation 6.71
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreEnd of Treatment score33.4 score on a scaleStandard Deviation 7.69
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreChange from Baseline-4.1 score on a scaleStandard Deviation 4.78
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreBaseline score39.7 score on a scaleStandard Deviation 8.95
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'G' ScoreEnd of Treatment score35.6 score on a scaleStandard Deviation 9.04
p-value: 0.196395% CI: [-3.2, 0.7]ANCOVA
Primary

Change From Baseline To The End Of Treatment (Day 43) In PANSS 'N' Score

The PANSS 'N' scale measured the severity of negative symptoms, including blunted affect, emotional withdrawal, poor rapport, passive/apathetic social withdrawal, difficulty in abstract thinking, lack of spontaneity and flow of conversation, and stereotyped thinking. Individual items were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total 'N' score could range from 7 to 49 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreBaseline score22.6 score on a scaleStandard Deviation 5.04
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreEnd of Treatment score19.9 score on a scaleStandard Deviation 5.32
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreChange from Baseline-2.7 score on a scaleStandard Deviation 3.55
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreBaseline score23.4 score on a scaleStandard Deviation 5.11
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreEnd of Treatment score20.5 score on a scaleStandard Deviation 5.22
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'N' ScoreChange from Baseline-2.9 score on a scaleStandard Deviation 3.06
p-value: 0.964795% CI: [-1.3, 1.4]ANCOVA
Primary

Change From Baseline To The End Of Treatment (Day 43) In PANSS 'P' Score

The PANSS 'P' scale measured the severity of positive symptoms, including delusions, conceptual disorganization, hallucinations, hyperactivity, grandiosity, suspiciousness/persecution, and hostility. Individual items were rated on a 7-point scale, where 1 = absent and 7 = extreme. The total 'P' score could range from 7 to 49 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreBaseline score18.0 score on a scaleStandard Deviation 3.89
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreEnd of Treatment score14.8 score on a scaleStandard Deviation 4.01
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreChange from Baseline-3.2 score on a scaleStandard Deviation 2.6
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreBaseline score17.5 score on a scaleStandard Deviation 3.29
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreEnd of Treatment score15.7 score on a scaleStandard Deviation 3.73
PlaceboChange From Baseline To The End Of Treatment (Day 43) In PANSS 'P' ScoreChange from Baseline-1.7 score on a scaleStandard Deviation 2.76
p-value: 0.018895% CI: [-2.5, -0.2]ANCOVA
Primary

Change From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)

The CGI-S was a 7-point scale that required the clinician to rate the severity of a participant's illness at the time of assessment, relative to the clinician's past experience of participants who had the same diagnosis. Considering total clinical experience, participants were assessed on severity of mental illness at the time of rating on the following scale: 1 = normal, not at all ill; 2 = borderline mentally ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; or 7 = extremely ill. Lower scores equated to milder severity of symptoms, that is, closer to psychologically normal.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)End of Treatment score3.5 score on a scaleStandard Deviation 1.09
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)Change from Baseline-0.5 score on a scaleStandard Deviation 0.74
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)Baseline score4.0 score on a scaleStandard Deviation 0.7
PlaceboChange From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)End of Treatment score3.8 score on a scaleStandard Deviation 0.78
PlaceboChange From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)Change from Baseline-0.3 score on a scaleStandard Deviation 0.49
PlaceboChange From Baseline To The End Of Treatment (Day 43) In The Clinical Global Impression Severity Scale (CGI-S)Baseline score4.0 score on a scaleStandard Deviation 0.65
p-value: 0.044395% CI: [-0.5, 0]ANCOVA
Primary

Change From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)

The SANS assessed 5 symptom complexes to obtain clinical ratings of negative symptoms in participants with schizophrenia or related psychotic disorder. Symptom complexes were affective blunting, alogia (impoverished thinking), avolition/apathy, anhedonia/asociality, and disturbance of attention. Assessments were conducted on a 6-point scale (0 = not at all; 5 = severe). The total score could range from 0 to 125 points, with lower scores equating to milder severity of symptoms, that is, closer to psychologically normal.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)Baseline score52.8 score on a scaleStandard Deviation 17.1
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)End of Treatment score43.6 score on a scaleStandard Deviation 16.54
GWP42003 1000 mg/DayChange From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)Change from Baseline-9.1 score on a scaleStandard Deviation 13.09
PlaceboChange From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)Change from Baseline-6.3 score on a scaleStandard Deviation 8.54
PlaceboChange From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)Baseline score55.3 score on a scaleStandard Deviation 16.24
PlaceboChange From Baseline To The End Of Treatment (Day 43) In The Scale For The Assessment Of Negative Symptoms (SANS)End of Treatment score48.4 score on a scaleStandard Deviation 15.75
p-value: 0.116795% CI: [-7.9, 0.9]ANCOVA
Primary

Clinical Global Impression Improvement Scale (CGI-I) Values At Day 8 And End Of Treatment (Day 43)

The CGI-I was a 7-point scale that required the clinician to assess how much a participant's illness had improved or worsened relative the first assessment at the beginning of the intervention. This was rated on the following scale: 1 = very much improved; 2 = much improved; 3 = minimally improved; 4 = no change; 5 = minimally worse; 6 = much worse; or 7 = very much worse. Lower scores equated to improvement of symptoms.

Time frame: Day 8 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureGroupValue (MEAN)Dispersion
GWP42003 1000 mg/DayClinical Global Impression Improvement Scale (CGI-I) Values At Day 8 And End Of Treatment (Day 43)Day 8 score3.6 score on a scaleStandard Deviation 0.5
GWP42003 1000 mg/DayClinical Global Impression Improvement Scale (CGI-I) Values At Day 8 And End Of Treatment (Day 43)End of Treatment score2.9 score on a scaleStandard Deviation 0.89
PlaceboClinical Global Impression Improvement Scale (CGI-I) Values At Day 8 And End Of Treatment (Day 43)Day 8 score3.8 score on a scaleStandard Deviation 0.56
PlaceboClinical Global Impression Improvement Scale (CGI-I) Values At Day 8 And End Of Treatment (Day 43)End of Treatment score3.4 score on a scaleStandard Deviation 0.87
p-value: 0.018295% CI: [-0.8, -0.1]ANCOVA
Primary

Percentage Of PANSS Total Score Responders At End Of Treatment (Day 43)

The percentage of PANSS treatment responders, defined as participants with ≥20% improvement in PANSS Total score between baseline and End of Treatment, is presented. The percentage of participants was calculated by dividing the number of participants with a ≥20% improvement in PANSS Total score (yes) by the total number of participants.

Time frame: Day 1 through Day 43

Population: ITT analysis set: all participants who provided informed consent, were randomized to 1 of the treatment groups, took at least 1 dose of IMP, and had post-baseline efficacy data. One placebo participant with a PANSS Total score \<60 at Day 1 and 1 GWP42003 participant with no post-baseline efficacy data were excluded from the ITT analysis set.

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
GWP42003 1000 mg/DayPercentage Of PANSS Total Score Responders At End Of Treatment (Day 43)Yes12 Participants
GWP42003 1000 mg/DayPercentage Of PANSS Total Score Responders At End Of Treatment (Day 43)No30 Participants
PlaceboPercentage Of PANSS Total Score Responders At End Of Treatment (Day 43)Yes6 Participants
PlaceboPercentage Of PANSS Total Score Responders At End Of Treatment (Day 43)No38 Participants
p-value: 0.089695% CI: [0.86, 8]Regression, Logistic

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026