Study Design
This is a single-site, randomised, double-blind, placebo-controlled, parallel, phase IIb clinical trial examining if IV scopolamine exhibits an antidepressant effect in individuals with bipolar disorder. Study visits will take place at the Clinical Research Facility Galway (CRFG), in University Hospital Galway, Galway, Ireland. Patients will be recruited from mental health services in the West of Ireland including a specialised bipolar disorder clinic at University Hospital Galway.
Individuals will have a diagnosis of bipolar disorder according to the Diagnostic Statistics Manual (DSM)-V and must be experiencing a depressive episode of at least moderate severity based on a clinical interview by a trained clinician and a Hamilton Depression Rating Scale (HDRS) score ≥ 14. Exclusion criteria include being euthymic or experiencing a manic or hypomanic episode; treatment with any cholinergic medications (i.e. biperiden, procyclidine); a history of a previous allergic reaction or sensitivity to scopolamine, treatment with oral steroids, a history of an alcohol or substance use disorder in the three months prior to study entry, an intellectual disability (intelligence quotient < 70), dementia or cognitive impairment and severity of depressive episode so that participation in a clinical trial is not appropriate.
Patients meeting all inclusion criteria will be enrolled into the study (duration ~6 weeks total). The maximum time between Visit 1 (screening) and Visit 2 is 14 days. The screening visit and Visit 2 can occur on the same day. At Visit 2, all participants will receive a placebo run-in (100 ml of Saline IV). This has been utilised in other IV Scopolamine RCTs [5-7, 9] and has the advantage of reducing a subsequent placebo effect (which might result in a Type II error) and a lower loss to follow-up rate post-randomisation [19, 24].
Within 7 days of Visit 2, participants will be assessed against the placebo run-in criteria and if these criteria are met (HDRS score ≥ 8 at Visit 3), they will be randomised to receive either placebo (n=25) or 4 µg/kg Scopolamine (n=25) IV in 100 ml of Saline over 15 minutes at:
• Visit 3 (Day 0),
• Visit 4 (days 2-6) and
• Visit 5 (days 6-10)
Participants will receive Scopolamine or placebo in addition to their current treatment regimen. At least two days will elapse between IV infusions (Visits 2-5). Two follow-up visits (Visits 6 and 7) will occur at days 15 (+/-5 days) and days 29 (+/- 7 days) with at least two days between Visits 5 and the first follow-up visit (Visit 6) and at least three days between the two follow-up visits (Visits 6 and 7). If a trial participant requires medical intervention during or post- infusion, the treating physician must assess if it is appropriate to proceed with the current and/or future infusions. The flow of the study visits is presented in Figure 1.
Note timeline between visits:
Visit 1 and 2: ≤14 days. Can also occur on the same day and thus data does from screening visit does not need to be replicated at Visit 2.
Visit 2 and 3: ≥2 days and ≤7 days
Visit 3 and Visit 4 and Visit 5 and Visit 6: ≥2 days
Visit 6 and Visit 7: ≥3 days
Psychometric Instruments
Clinical Instruments
Alcohol Use Disorder Identification Test (AUDIT)[25].
A 10-item questionnaire to identify harmful use or dependence on alcohol.
Clinical Global Impression (CGI)[26].
A rating scale that measures illness severity (CGI-S) (1-7), and global improvement (CGI-I) (1-7)) and has an efficacy index (which relates therapeutic effects to adverse effects) (1-4).
Fagerstrom Test for Nicotine Dependence [27].
A 6-item questionnaire examining nicotine dependence.
Global Assessment of Functioning (GAF) [28].
A rating scale from 1-100 that measures an individual’s functioning and is observer rated.
Hamilton Depression Rating Scale (HDRS) [29].
A 21-item observer rated instrument that measures symptoms of depression.
Montgomery and Asberg Depression Rating Scale (MADRS) [30].
A 10-item observer rated scale that measures symptoms of depression.
NEO Personality Inventory-Five Factor Inventory (NEO PI-FFI) [31].
This 60-item personality inventory measures personality traits in five dimensions (neuroticism, extraversion, openness to experience, agreeableness and conscientiousness).
Patient Rated Inventory of Side Effects (PRISE) [32].
A 9-item self-report instrument measuring adverse effects associated with the gastrointestinal, genitourinary, nervous and cardiac systems, sense organs, skin, sexual functioning, sleep and other general adverse effects.
Profile of Mood State (POMS) [33].
A rating scale where 65 adjectives are rated by participants on a 5-point Likert scale. Six factors are derived from these adjectives (tension, depression, anger, fatigue, vigour and confusion).
Structured Clinical Interview for DSM-5 Disorders (SCID-5-RV) [34].
This is a semi-structured interview that evaluates pathology and includes a demographic section followed by nine diagnostic modules, including two that examine mood disorders.
Visual Analog Scale (VAS).
A self-report scale used to indicate on a 10-point Likert how participants feel they are on various items, with the VAS utilised for the following terms in this study: (1) happy, (2) restless, (3) sad, (4) anxious, (5) anger, (6) drowsiness and (7) alertness. These items are consistent with those used by Furey et al. (2012) in their study of Scopolamine in mood disorders.
Young Mania Rating Scale (YMRS) [35].
An 11-item observer rated instrument that measures symptoms of elation.
Cognitive Instruments
The Cambridge Neuropsychological Test Automated Battery (CANTAB) [36].
Tests conducted from this battery will entail: (1) Emotion Recognition Task (ERT) (assesses ability to identify emotions through facial expressions), (2) Paired Associates Learning (PAL) (assesses visual memory and new learning), (3) One Touch Stockings of Cambridge (OTC) (assess executive function through spatial planning and working memory), and (4) Rapid Visual Information Processing (RVP) (assesses attention).
Wechsler Adult Intelligence Scale 3rd Edition (WAIS-III) [37].
Full scale, verbal and performance Intelligence Quotient (IQ) will be estimated using an abbreviated version of this instrument, and will comprise the verbal subscales of vocabulary and similarities, and the performance subscales of block-design and matrix reasoning.
See Table 1 for the schedule of these psychometric assessments.
Table 1. Schedule of Assessments
Procedures
|
Visit 1
Screening
|
Visit 2
PLACEBO
|
Visit 3
Randomisation
Day 0
Scopolamine or Placebo
|
Visit 4
Day 4 (± 2 Days)
Scopolamine or Placebo
|
Visit 5
Day 8 (± 2 Days)
Scopolamine or Placebo
|
Visit 6
Day 15
(± 5 Days)
Follow-Up
|
Visit 7
Day 29
(± 7 Days)
Follow-Up
|
|
|
IV Infusion
|
IV Infusion
|
IV Infusion
|
IV Infusion
|
|
|
Pre
|
During
|
Post
|
Pre
|
During
|
Post
|
Pre
|
During
|
Post
|
Pre
|
During
|
Post
|
Signed informed consent
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Inclusion/Exclusion
|
X
|
X
|
|
|
X
|
|
|
|
|
|
|
|
|
|
|
Randomisation
|
|
|
|
|
X
|
|
|
|
|
|
|
|
|
|
|
IWRS
|
|
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
|
|
Demography
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
MEHI
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Medical/Surgical History/History BPD
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Current Medication
|
X
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
X
|
Vital Signs – HR, BP & RR
|
X
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
|
|
SCID-RV
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
HDRS
|
X
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
X
|
YMRS
|
X
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
X
|
AUDIT
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Pregnancy Discussion
|
X
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
|
|
Contraception Advice
|
X
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
|
|
Serum Pregnancy TestD
|
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Pregnancy urine dipstickD
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
|
|
U&Es, LFTs, TFTs º
|
X
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Fagerstrom
|
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CGI-S
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
X
|
CGI-I
|
|
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
X
|
VAS
|
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
|
|
MADRS
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
X
|
GAF
|
|
|
|
|
X
|
|
|
|
|
|
X
|
|
|
X
|
X
|
ECG
|
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Height (cm) & Weight (kg)
|
|
X
|
|
|
|
|
|
|
|
|
|
|
|
|
|
IV Cannulation
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
|
|
Infusion administration
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
|
Adverse Events
|
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
Cannulation Site Check
|
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
|
|
POMS (Optional)
|
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
X
|
|
X
|
X
|
X
|
CANTAB ** (Optional)
|
|
|
|
X
|
|
|
X
|
|
|
|
|
|
|
X
|
|
WAIS * (Optional)
|
|
|
|
X*
|
|
|
X*
|
|
|
X*
|
|
|
X*
|
X*
|
X*
|
NEO-PI-FFI * (Optional)
|
|
|
|
X*
|
|
|
X*
|
|
|
X*
|
|
|
X*
|
X*
|
X*
|
PRISE (Optional)
|
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
X
|
|
|
Subjective Assessment
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
X
|
* Can be undertaken at any of the marked visit
** These include the Emotion Recognition Task (ERT), Paired Associates Learning (PAL), One Touch Stockings of Cambridge (OTC), and Rapid Visual Information Processing (RVP) (assesses attention) tests.
D Pregnancy test (serum pregnancy test and pregnancy urine dipstick), when required, for female participants only. Serum result confirmed prior to Visit 3.
º Blood tests for U&Es (Urine and Electrolytes), LFTs (Liver Function Tests) and TFTs (Thyroid Function Tests) should be confirmed within acceptable ranges in the previous 4 months of the Screening (Visit 1). Can be performed if required at Visit 1 or 2 (results must be confirmed as acceptable prior to infusion).
AUDIT = Alcohol Use Disorder Identification Test; BP = Blood Pressure; CANTAB = Cambridge Neuropsychological Test Automated Battery, CGI-I = Clinical Global Impression – Improvement, CGI-S= Clinical Global Impression- Severity, ECG= Electrocardiograph; Fagerstrom: Test for Nicotine Dependence, GAF = Global Assessment of Functioning; HDRS = Hamilton Depression Rating Scale; HR = Heart Rate; IV = Intravenous; IWRS = Interactive Web Response System; MADRS = Montgomery and Asberg Depression Rating Scale; MEHI = Modified Edinburgh Handedness Inventory; NEO PI-FFI = NEO Personality Inventory-Five Factor Inventory; POMS = Profile of Mood States; PRISE= Patient Rated Inventory of Side Effects; RR = Respiratory Rate; SCID-RV = Structured Clinical Interview for DSM; VAS = Visual Analogue Scale; YMRS = Young Mania Rating Scale; WAIS = Wechsler Adult Intelligence Scale.
Data collection and randomisation
Clinical interviews and psychometric assessments will be collected by trained clinicians and research associates with a background in psychiatric research. All research staff involved in administration of clinical instruments or data-input will have up-to-date training in Good Clinical Practice (GCP)[38]. Infusions will be dispensed by the pharmacy and prepared by unblinded nurses, all attached to the CRFG.
Participants will be randomly assigned to receive either scopolamine or placebo in a 1:1 ratio. Randomly permuted blocks of sizes 4 and 6 will be used to ensure similar numbers of participants in each arm of the trial. Randomisation will be stratified by the HDRS score at trial entry (a score of <23 indicating a mild-moderate depressive episode and a score ≥23 indicating a severe depressive episode). This will help ensure greater balance between arms in the final trial sample and increase the efficiency of our treatment effect estimates.
A validated randomisation system will be used at Visit 3, (after the HDRS and YMRS are completed) to randomise patients to either arm. This centralised system will ensure allocation concealment, preventing blinded trial staff from knowing which treatment group will be allocated. Blocks of randomly varying length will also reduce the predictability of the allocation sequence. Randomisation will be carried out by the pharmacy team. In the case of an emergency, when knowledge of the treatment assignment is essential for the clinical management of the participant, a treating physician may request to unblind a single participant.
Treatments
Treatment group
Participants randomised to the scopolamine group will receive a 15-minute infusion of IV Scopolamine in 100 ml saline, repeated over 3 visits (Visit 3, 4 & 5).
Placebo group
Participants randomised to the placebo group will receive a 15-minute infusion of IV saline, repeated over 3 visits (Visit 3, 4 & 5).
Non-adherence will be extremely unlikely given the mode of administration, with participants monitored by a team researcher throughout the infusion period.
Sample size calculations
Based on previous data [9], the allocation of 22 participants to each arm will ensure a power of ≥85% to detect a 50% reduction (treatment response) on the HDRS in the scopolamine compared to the placebo group. The sample size is based on a 2-sample t-test with a conservative standard deviation of 13 units and a significance level of 0.05. Allocating 25 participants to each arm will allow a loss to follow-up of approximately 12% post-randomisation (6 participants missing at Visit 6 follow-up). It is suggested that approximately 60 participants will need to be recruited to ensure 50 participants (83.3%) are eligible for randomisation (Visit 3). All participants will attain a placebo infusion at Visit 2.
Safety monitoring
Adverse events (AE’s) and serious adverse events (SAE’s) will be recorded on AE case report forms for all participants from the time of consent for the duration of their participation in the study. A full AE review will be conducted at each study visit to ensure that a complete evaluation of the safety and tolerability of the investigational medical product (placebo or scopolamine) is conducted. The site investigator will follow-up all AE’s reported during the treatment period until resolved, considered stable, including completion of patient participation in the trial (i.e. final follow-up visit). All SAE’s will be followed-up until resolution or until they are clearly determined to be due to a participant’s stable or chronic condition or intercurrent illness(es) including after trial completion if required. SAEs will be reported to the sponsor and principal investigator within 24 hours after site awareness of the SAE to find a reasonable solution. Any suspected unexpected serious adverse reaction (SUSAR) that potentially occur will be reported by the sponsor to the competent authority (HPRA and/or EudraVigilance), the approving ethics committee and PI. Indemnity is in place pertaining to any adverse effects experienced by study participants.
Statistics
Primary effect analysis
The mean scores at Visit 6 will be compared across the study arms using an analysis of co-variance (ANCOVA) model. The response variable will be the change in HDRS score (primary outcome measure) from Visit 3 to Visit 6. For this effect analysis of the primary outcome, HDRS score at Visit 3 is added as a co-variate as it is expected that pre-randomisation measurements of the HDRS score will be correlated with scores obtained at Visit 6. The inclusion of stratifying variables (i.e. severe v. mild or moderate depressive symptoms at baseline) and other variables as covariates (i.e. bipolar I or II disorder) will be considered as appropriate to increase the power to detect significant differences between the groups. Inverse probability weighting will be applied to the primary outcome analysis. These weights will be derived based on the inverse of the probability of a patient’s data being missing given their pre-randomisation measurements. This will ensure the estimate and inference is more representative of all patients randomised, reducing bias in the estimation of the treatment effect due to participants being lost to follow-up and missing data. Inference regarding the treatment effectiveness will focus on the point estimate, confidence interval and p-value for hypothesis confirmation.
Secondary effect analysis
Secondary outcomes will be analysed as appropriate (according to the distribution of each outcome), comparing the difference between groups at the specified follow-up visit and relative to baseline values (where specified/measured). Baseline variables predictive of each outcome (the measure at baseline where available), and stratifying variables will be included in ANCOVA or generalised linear models of outcome variables. For secondary outcomes (i.e. acute and long-term effects on cognition (CANTAB), change in other mood rating scales including the MADRS and POMS, changes in functioning (GAF), treatment changes), the focus will be on the point estimates and confidence intervals for hypothesis generation.
Additional analysis of the primary outcome will compare the time course of HDRS under placebo and treatment using a mixed-effects model including fixed-effects terms for time since randomisation/study visit, trial arm and their interactions, and a random effect to account for correlation of multiple observations per participant.
Ethical approval
Required documents including the study protocol (V3.0, 18th December, 2020), informed consent form, participant information leaflet, and any other required documents (i.e. psychometric instruments) have been submitted and approved by the Galway University Hospitals Research Ethics Committee and the Health Products Regulatory Authority (HPRA). The sponsor (Research Office, NUI Galway) will submit and obtain approval from the above parties for substantial amendments to the original approved documents.
Data management and monitoring
All study information will be stored in Microsoft Excel 365 by a data manager using an electronic database. The database will record all subject data to include the baseline characteristics, pre- and post-assessments, and possible adverse events. The computer and database will use password protection with the database only accessible to the study researchers. To ensure the confidentiality of the data, all subjects will be provided with identification numbers. All researchers will have access to the final trial data. Electronic data and paper documents will be kept for 5 years, after which they will be destroyed.
A Data Monitoring Committee (DMC), which is independent from the sponsor and competing interests, comprises clinical experts, trial experts, investigators, and a statistician and will conduct regular monitoring tests (approximately every 4 months) to ensure the authenticity of the data. A trial steering committee, comprising the PI, clinicians and researcher with experience in this area will meet every 6 months to review study progress and address any concerns subsequent to DMC reports. The study will be monitored on an approximate 6 monthly basis by the sponsor by a blinded and unblinded study monitor of extensive experience. These monitoring visits will ensure appropriate patient eligibility for the study, staff training, accurate recording of data including source data verification and protocol deviations. The study will be open to external auditing by the HPRA (a process independent from investigators and the sponsor), throughout the time-frame of this study to ensure adherence to GCP.
The end of trial will be the date of the last visit of the last participant (50th randomised participant). The sponsor, the funder (Stanley Medical Research Institute) and/or data safety and monitoring board/trial steering committee have the right at any time to terminate the study for clinical or administrative reasons.
This trial may be subject to internal or external auditing or inspection procedures to ensure adherence to GCP. Access to all trial-related documents will be given at that time.
Dissemination
The results of this study will be published in peer-reviewed journals and be presented at domestic or international academic congresses. Individualised results will be reported by the researcher to the participants of this study, after data publication in peer-reviewed journals. Data will be available for public access via the National Institute for Mental Health Data Archive one year after submission of all participant data.