HyperalgesiaLFSNCT04197154
Pain-related Fear as a Facilitator of Nocebo Hyperalgesia
A study testing Threat manipulation, Conditioning of moderate pain and Conditioning of high pain in people with Hyperalgesia and Chronic Pain Syndrome, run by Leiden University Medical Center at 1 site in Netherlands.
Trial summary
Nocebo hyperalgesia is characterized by adverse pain outcomes, induced by patients' expectations. In the lab, nocebo effects are commonly studied via classical conditioning, a method that employs pairings of neutral cues/treatments with different pain intensities to install differential pain-related expectations. Read more about this study
- Who is it for?
- Ages 17 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Hyperalgesia, Chronic Pain Syndrome, Chronic Pain, Psychogenic
- What is being tested?
- Threat manipulation, Conditioning of moderate pain and Conditioning of high pain
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 72 participants
- Where
- 1 siteNetherlands
- Study dates
- 14 Oct 2019to 14 Feb 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 17 to 35 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Aged 17 - 35 years
- Good understanding of the English language
- Normal or corrected to normal vision
Who cannot join
- Ever having experienced serious medical or psychiatric conditions (e.g., heart or lung disease, panic attacks, drug addiction, clinical depression),
- Ever having experienced chronic pain complaints (pain for more than 6 months),
- Experiencing acute physical pain (e.g., headache; above 3 on a 10-point NRS scale), or having used pain medication on the day of testing,
- Pregnancy or breastfeeding,
- Having recent injuries to the wrists or arms on the day of testing,
- Previous participation in this or similar studies (e.g., using conditioning or thermal pain).
- Having consumed psychotropic medication, recreational drugs, analgesic medication, or more than 3 units of alcohol, in the 24 hours prior to the study appointment.
- After inclusion, participants who do not reach a sensation of high pain (at least 6 on the NRS) with the highest administered temperature or participants who appear unable to distinguish between moderate and high pain stimuli (reporting at least a mean difference of 1.5 NRS points between nocebo and control trials during induction) will also be excluded.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Pain-related Fear as a Facilitator of Nocebo Hyperalgesia: An Experimental Study
Nocebo hyperalgesia is characterized by adverse pain outcomes, induced by patients' expectations. In the lab, nocebo effects are commonly studied via classical conditioning, a method that employs pairings of neutral cues/treatments with different pain intensities to install differential pain-related expectations. In such conditioning experiments, participants are typically taught that a (sham) treatment exaggerates their pain, by surreptitiously administering high intensity (e.g. pain) stimuli in combination with this treatment. Verbal suggestions are also often used to inform participants of the supposed adverse effects of such treatments. In nocebo studies, higher pain levels and suggestions that are of more threatening nature may induce fear, thereby adding a crucial element to the experimental manipulation. Since nocebo effects are hypothesized to arise in clinical settings due to a combination of several psychological and cognitive mechanisms, it is important to study the role that factors such as higher pain levels, conditioned pain-related fear, or more threatening verbal suggestions may play in the formation of nocebo hyperalgesia. To date, no studies have focused on the fear-inducing effect that different pain intensities or verbal threat suggestions may have and how this fear, in turn, may strengthen the acquisition of nocebo effects. This study aims to investigate whether higher pain intensity or higher pain-related fear induced via threatening suggestions facilitate the acquisition and hinder subsequent extinction of nocebo hyperalgesia. This study will be conducted at Leiden University.
Read the detailed description
The investigators expect that higher pain intensity and/or higher pain-related fear induced via threatening suggestions will lead to stronger acquisition of nocebo hyperalgesia and/or more durable nocebo hyperalgesia after extinction.
Main outcome variables:
- The magnitude of induced nocebo hyperalgesia is defined as the difference in pain ratings for the first nocebo trial compared to the first control trial of the extinction phase.
- The reduction of nocebo hyperalgesia is defined as the change in reported pain between the first and last nocebo trial of the extinction phase.
- Fear levels (for mediation analyses) are measured via eye-blink startle modulation and self-reported fear during nocebo trials (relative to control trials).
For EMG analyses this study follows typical pre-processing of EMG recordings, similar to previous studies. The EMG signal will be digitized at 1,000 Hz from 200 ms before the startle probe until 1,500 ms after probe onset. The startle probe is a 100 dBA burst of white noise with instantaneous rise time presented binaurally for 100 ms through earphones. Each 2-4 consecutive startle probe responses of the same cue (nocebo vs control) will be averaged for further analyses. Participants who exhibited a startle response in less than 20% of trials in the first half of induction will be labeled as non-responders. Trials during which, for example, baseline is higher than startle response peak due to an occasional blink before the probe presentation, will be labelled as non-response or reject trials.
- Main planned analyses: To examine whether higher pain stimulation (high-pain nocebo group) leads to stronger nocebo hyperalgesia, as compared to lower pain stimulation (control nocebo group), a 2x2 mixed model analysis of variance (ANOVA) will be performed with group (high-pain nocebo group, control nocebo group) as the between-subjects factor and trial type as within-subjects factor with two levels (first nocebo extinction trial, first control extinction trial).
- Secondary analyses:
2a. To examine whether an impact of higher pain stimulation on the magnitude of nocebo hyperalgesia was mediated by pain-related fear levels, a mediation analysis will be conducted for the high pain nocebo and control nocebo groups, to assess if fear mediates the relationship between pain levels and the magnitude of nocebo hyperalgesia (calculated difference scores between the first nocebo extinction trial and the first control extinction trial).
2b. To examine whether higher pain-related fear induced via a threat suggestion (high-threat nocebo) led to stronger nocebo hyperalgesia, as compared to no threat suggestion (control nocebo group), a 2x2 mixed model ANOVA will be performed with group (high-threat nocebo, control nocebo group) as the between-subjects factor and trial type as within-subjects factor with two levels (first nocebo extinction trial, first control extinction trial).
2c. To examine whether higher pain stimulation (high-pain nocebo group) led to more durable nocebo effect, as compared to lower pain stimulation (control nocebo group), a 2x2 mixed model ANOVA will be performed with group (high-pain nocebo group, control nocebo group) as the between-subjects factor and trial as within-subjects factor with two levels (first nocebo extinction trial, last nocebo extinction trial).
2d. To examine whether an impact of higher pain stimulation on the durability of nocebo hyperalgesia was mediated by pain-related fear levels, a mediation analysis will be conducted to assess if fear mediates the relationship between pain levels and the magnitude of nocebo hyperalgesia after extinction (calculated difference scores between the first nocebo extinction trial and the last nocebo extinction trial).
2e. To examine whether higher pain-related fear induced via a threat suggestion led to more durable nocebo hyperalgesia, as compared to no threat suggestion, a 2x2 mixed model ANOVA will be performed with group (high-threat nocebo, control nocebo group) as the between-subjects factor and trial as within-subjects factor with two levels (first nocebo extinction trial, last nocebo extinction trial).
- Being tested
- Threat manipulation (control, no threat), Threat manipulation, Conditioning of moderate pain, Conditioning of high pain, Extinction
- Keywords
- Nocebo, Pain, Fear, Conditioning, Negative suggestions, Extinction
- Medical subject headings
- Hyperalgesia, Chronic Pain, Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Threat manipulation (control, no threat)Behavioural
Before the start of conditioning, a mock skin-sensitivity test informs participants that their skin reacts to heat normally and it is safe for them to participate. A skin-sensitivity reading shows participants a scale that is in the green (no danger) zone.
Threat manipulationBehavioural
Before the start of conditioning, a mock skin-sensitivity test informs participants that their skin is very sensitive and their nerve fibers are very responsive and they may have adverse reactions to the heat-pain application. A skin-sensitivity reading shows participants a scale that is in the red (higher danger) zone.
Conditioning of moderate painBehavioural
Also called Nocebo Induction
During nocebo trials of the acquisition phase, conditioned stimuli (i.e., on-screen visual cues "ON" signaling the activation of sham electrical stimulation) are paired to unconditioned moderate-pain stimuli, to induce a negative association between the activation of electrical stimuli and an increase in pain. During control trials of the acquisition phase, the deactivation of the sham electrical stimulation (i.e., on-screen message "OFF") is paired to 'baseline' pain of lower intensity.
Conditioning of high painBehavioural
Also called Nocebo Induction
During nocebo trials of the acquisition phase, conditioned stimuli (i.e., on-screen visual cues "ON" signaling the activation of sham electrical stimulation) are paired to unconditioned high-pain stimuli, to induce a negative association between the activation of electrical stimuli and an increase in pain. During control trials of the acquisition phase, the deactivation of the sham electrical stimulation (i.e., on-screen message "OFF") is paired to pain of lower intensity.
ExtinctionBehavioural
Also called Nocebo Attenuation
During extinction, the previously conditioned nocebo effects on pain are attenuated by pairing the nocebo and control visual cues (i.e., on-screen messages "ON" and "OFF") to pain stimuli of only lower intensity.
| Study group | Role | What they receive |
|---|---|---|
| 1. Control nocebo group | Experimental | Conditioning and extinction of a nocebo response using moderate pain stimuli, nocebo negative suggestions, and no threat suggestions. Receives: Behavioral: Threat manipulation (control, no threat); Behavioral: Conditioning of moderate pain; Behavioral: Extinction |
| 2. High-pain nocebo group | Experimental | Conditioning and extinction of a nocebo response using higher pain stimuli, nocebo negative suggestions, and no threat suggestions. Receives: Behavioral: Threat manipulation (control, no threat); Behavioral: Conditioning of high pain; Behavioral: Extinction |
| 3. High-threat nocebo | Experimental | Conditioning and extinction of a nocebo response using moderate pain stimuli, nocebo negative suggestions, and threat suggestions (i.e., fear-inducing suggestions). Receives: Behavioral: Threat manipulation; Behavioral: Conditioning of moderate pain; Behavioral: Extinction |
What is being measured
The primary outcome is the main question the study is designed to answer.
Magnitude of nocebo hyperalgesia
The magnitude of induced nocebo hyperalgesia is defined as the difference in pain ratings for the first nocebo trial compared to the first control trial of the extinction phase.
Measured: On the testing day, in the first trials of the extinction phase
Secondary outcomes (1)
Reduction of nocebo hyperalgesia
The reduction of nocebo hyperalgesia is defined as the change in reported pain between the first and last nocebo trial of the extinction phase.
Measured: On the testing day, in the extinction phase
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Dec 2019
- Study start14 Oct 2019
- Primary completion14 Feb 2020
- Study completion14 Feb 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HyperalgesiaStudies of the same condition, open and under way.
- More trials run by Leiden University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 72 participants (actual)
Sponsor and investigators
- Lead sponsor
- Leiden University Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Universiteit Leiden, KU Leuven, Maastricht University
- Responsible party
- Principal investigator, AWMEvers, Leiden University Medical Center
- Investigators
- Andrea WM Evers, Principal investigator, Leiden University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04197154
- Sponsor's protocol ID
- CEP19-0614/347
- Acronym
- LFS
- Status last verified
- Feb 2020
- First submitted
- 9 Dec 2019
- Last updated
- 19 Feb 2020
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All data are collected pseudonymised; consent forms are the only sources containing personal data and will not be shared, but are monitored by the department's Data Monitor.
Study at a glance
From the registry record, last updated by the sponsor on 19 Feb 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pain-related Fear as a Facilitator of Nocebo Hyperalgesia: An Experimental Study
- ClinicalTrials.gov ID
- NCT04197154
- Acronym / sponsor ID
- LFS / CEP19-0614/347
- Keywords
- Nocebo, Pain, Fear, Conditioning, Negative suggestions, Extinction
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 72 participants (actual)
- Lead sponsor
- Leiden University Medical CenterUniversity, hospital or other
- Collaborators
- Universiteit Leiden, KU Leuven, Maastricht University
- Study start
- 14 Oct 2019 (actual)
- Primary completion
- 14 Feb 2020 (actual)
- Study completion
- 14 Feb 2020 (actual)
- First posted
- 12 Dec 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Nocebo hyperalgesia is characterized by adverse pain outcomes, induced by patients' expectations. In the lab, nocebo effects are commonly studied via classical conditioning, a method that employs pairings of neutral cues/treatments with different pain intensities to install differential pain-related expectations. In such conditioning experiments, participants are typically taught that a (sham) treatment exaggerates their pain, by surreptitiously administering high intensity (e.g. pain) stimuli in combination with this treatment. Verbal suggestions are also often used to inform participants of the supposed adverse effects of such treatments. In nocebo studies, higher pain levels and suggestions that are of more threatening nature may induce fear, thereby adding a crucial element to the experimental manipulation. Since nocebo effects are hypothesized to arise in clinical settings due to a combination of several psychological and cognitive mechanisms, it is important to study the role that factors such as higher pain levels, conditioned pain-related fear, or more threatening verbal suggestions may play in the formation of nocebo hyperalgesia. To date, no studies have focused on the fear-inducing effect that different pain intensities or verbal threat suggestions may have and how this fear, in turn, may strengthen the acquisition of nocebo effects. This study aims to investigate whether higher pain intensity or higher pain-related fear induced via threatening suggestions facilitate the acquisition and hinder subsequent extinction of nocebo hyperalgesia. This study will be conducted at Leiden University.
Detailed description
The investigators expect that higher pain intensity and/or higher pain-related fear induced via threatening suggestions will lead to stronger acquisition of nocebo hyperalgesia and/or more durable nocebo hyperalgesia after extinction.
Main outcome variables:
- The magnitude of induced nocebo hyperalgesia is defined as the difference in pain ratings for the first nocebo trial compared to the first control trial of the extinction phase.
- The reduction of nocebo hyperalgesia is defined as the change in reported pain between the first and last nocebo trial of the extinction phase.
- Fear levels (for mediation analyses) are measured via eye-blink startle modulation and self-reported fear during nocebo trials (relative to control trials).
For EMG analyses this study follows typical pre-processing of EMG recordings, similar to previous studies. The EMG signal will be digitized at 1,000 Hz from 200 ms before the startle probe until 1,500 ms after probe onset. The startle probe is a 100 dBA burst of white noise with instantaneous rise time presented binaurally for 100 ms through earphones. Each 2-4 consecutive startle probe responses of the same cue (nocebo vs control) will be averaged for further analyses. Participants who exhibited a startle response in less than 20% of trials in the first half of induction will be labeled as non-responders. Trials during which, for example, baseline is higher than startle response peak due to an occasional blink before the probe presentation, will be labelled as non-response or reject trials.
- Main planned analyses: To examine whether higher pain stimulation (high-pain nocebo group) leads to stronger nocebo hyperalgesia, as compared to lower pain stimulation (control nocebo group), a 2x2 mixed model analysis of variance (ANOVA) will be performed with group (high-pain nocebo group, control nocebo group) as the between-subjects factor and trial type as within-subjects factor with two levels (first nocebo extinction trial, first control extinction trial).
- Secondary analyses:
2a. To examine whether an impact of higher pain stimulation on the magnitude of nocebo hyperalgesia was mediated by pain-related fear levels, a mediation analysis will be conducted for the high pain nocebo and control nocebo groups, to assess if fear mediates the relationship between pain levels and the magnitude of nocebo hyperalgesia (calculated difference scores between the first nocebo extinction trial and the first control extinction trial).
2b. To examine whether higher pain-related fear induced via a threat suggestion (high-threat nocebo) led to stronger nocebo hyperalgesia, as compared to no threat suggestion (control nocebo group), a 2x2 mixed model ANOVA will be performed with group (high-threat nocebo, control nocebo group) as the between-subjects factor and trial type as within-subjects factor with two levels (first nocebo extinction trial, first control extinction trial).
2c. To examine whether higher pain stimulation (high-pain nocebo group) led to more durable nocebo effect, as compared to lower pain stimulation (control nocebo group), a 2x2 mixed model ANOVA will be performed with group (high-pain nocebo group, control nocebo group) as the between-subjects factor and trial as within-subjects factor with two levels (first nocebo extinction trial, last nocebo extinction trial).
2d. To examine whether an impact of higher pain stimulation on the durability of nocebo hyperalgesia was mediated by pain-related fear levels, a mediation analysis will be conducted to assess if fear mediates the relationship between pain levels and the magnitude of nocebo hyperalgesia after extinction (calculated difference scores between the first nocebo extinction trial and the last nocebo extinction trial).
2e. To examine whether higher pain-related fear induced via a threat suggestion led to more durable nocebo hyperalgesia, as compared to no threat suggestion, a 2x2 mixed model ANOVA will be performed with group (high-threat nocebo, control nocebo group) as the between-subjects factor and trial as within-subjects factor with two levels (first nocebo extinction trial, last nocebo extinction trial).
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| 1. Control nocebo group | Experimental | Behavioral: Threat manipulation (control, no threat), Behavioral: Conditioning of moderate pain, Behavioral: ExtinctionConditioning and extinction of a nocebo response using moderate pain stimuli, nocebo negative suggestions, and no threat suggestions. |
| 2. High-pain nocebo group | Experimental | Behavioral: Threat manipulation (control, no threat), Behavioral: Conditioning of high pain, Behavioral: ExtinctionConditioning and extinction of a nocebo response using higher pain stimuli, nocebo negative suggestions, and no threat suggestions. |
| 3. High-threat nocebo | Experimental | Behavioral: Threat manipulation, Behavioral: Conditioning of moderate pain, Behavioral: ExtinctionConditioning and extinction of a nocebo response using moderate pain stimuli, nocebo negative suggestions, and threat suggestions (i.e., fear-inducing suggestions). |
Who may qualify
- Ages
- 17 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- Aged 17 - 35 years
- Good understanding of the English language
- Normal or corrected to normal vision
Key exclusion criteria (8 listed)
- Ever having experienced serious medical or psychiatric conditions (e.g., heart or lung disease, panic attacks, drug addiction, clinical depression),
- Ever having experienced chronic pain complaints (pain for more than 6 months),
- Experiencing acute physical pain (e.g., headache; above 3 on a 10-point NRS scale), or having used pain medication on the day of testing,
- Pregnancy or breastfeeding,
- Having recent injuries to the wrists or arms on the day of testing,
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Threat manipulation (control, no threat)Before the start of conditioning, a mock skin-sensitivity test informs participants that their skin reacts to heat normally and it is safe for them to participate. A skin-sensitivity reading shows participants a scale that is in the green (no danger) zone. | Behavioural | 1. Control nocebo group, 2. High-pain nocebo group |
| Threat manipulationBefore the start of conditioning, a mock skin-sensitivity test informs participants that their skin is very sensitive and their nerve fibers are very responsive and they may have adverse reactions to the heat-pain application. A skin-sensitivity reading shows participants a scale that is in the red (higher danger) zone. | Behavioural | 3. High-threat nocebo |
| Conditioning of moderate painAlso: Nocebo InductionDuring nocebo trials of the acquisition phase, conditioned stimuli (i.e., on-screen visual cues "ON" signaling the activation of sham electrical stimulation) are paired to unconditioned moderate-pain stimuli, to induce a negative association between the activation of electrical stimuli and an increase in pain. During control trials of the acquisition phase, the deactivation of the sham electrical stimulation (i.e., on-screen message "OFF") is paired to 'baseline' pain of lower intensity. | Behavioural | 1. Control nocebo group, 3. High-threat nocebo |
| Conditioning of high painAlso: Nocebo InductionDuring nocebo trials of the acquisition phase, conditioned stimuli (i.e., on-screen visual cues "ON" signaling the activation of sham electrical stimulation) are paired to unconditioned high-pain stimuli, to induce a negative association between the activation of electrical stimuli and an increase in pain. During control trials of the acquisition phase, the deactivation of the sham electrical stimulation (i.e., on-screen message "OFF") is paired to pain of lower intensity. | Behavioural | 2. High-pain nocebo group |
| ExtinctionAlso: Nocebo AttenuationDuring extinction, the previously conditioned nocebo effects on pain are attenuated by pairing the nocebo and control visual cues (i.e., on-screen messages "ON" and "OFF") to pain stimuli of only lower intensity. | Behavioural | 1. Control nocebo group, 2. High-pain nocebo group, 3. High-threat nocebo |
Primary outcome
Magnitude of nocebo hyperalgesia
Time frame: On the testing day, in the first trials of the extinction phase
The magnitude of induced nocebo hyperalgesia is defined as the difference in pain ratings for the first nocebo trial compared to the first control trial of the extinction phase.
1 secondary outcome
Reduction of nocebo hyperalgesia
Time frame: On the testing day, in the extinction phase
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Feb 2020.
- Individual participant dataSharing planned: Yes. All data are collected pseudonymised; consent forms are the only sources containing personal data and will not be shared, but are monitored by the department's Data Monitor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Andrea WM Evers principal investigator
Leiden University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Threat manipulation, Conditioning of moderate pain and Conditioning of high pain in people with Hyperalgesia and Chronic Pain Syndrome, run by Leiden University Medical Center at 1 site in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Feb 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Magnitude of nocebo hyperalgesia (time frame: On the testing day, in the first trials of the extinction phase). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Feb 2020.