Placebos and the Placebo Effect in Drug Trials

Re-evaluating the placebo response in recent canine dietary epilepsy trials

The placebo response is a common phenomenon. Limited evidence is available about its magnitude in canine epilepsy trials, even though it can significantly influence the efficacy evaluation of new treatments. It was hypothesised that the placebo response is diminished when epilepsy trials are conducted in a prospective crossover design. Seizure data spanning six months from three previous multicenter epilepsy studies were analysed. The monthly seizure frequency of 60 dogs diagnosed with idiopathic epilepsy was calculated, comparing baseline data with placebo treatment. Furthermore, differentiation was made between dogs randomised to the placebo group early (Phase 1: first 3 months) or later during the study (Phase 2: second 3 months).The analysis did not reveal any placebo response in terms of monthly seizure frequency. Instead, an increase was noted during the placebo treatment period, with a mean of 2.95 seizures per month compared to 2.30 seizures per month before study entry (p = 0.0378). Additionally, a notable phase effect was observed. Dogs receiving the placebo in the second study phase exhibited a significant increase in monthly seizure frequency compared to baseline (p = 0.0036). Conversely, no significant difference from baseline was observed for dogs receiving the placebo in the first study phase. These findings underscore the considerable variability in placebo responses observed in trials for canine epilepsy, contrasting with previous limited data. The identified phase effect should be carefully considered in the design and evaluation of canine epilepsy trials to ensure a more accurate assessment of efficacy for new treatments.

Irritable bowel syndrome in children: the placebo response rate and influencing factors a meta-analysis

BACKGROUND

Irritable bowel syndrome is common in children and exhibits a high placebo response. This study was to explore the placebo response rate and its influencing factors in children with irritable bowel syndrome.

METHODS

A systematic search was performed on Pubmed, Embase, MEDLINE, Cochrane Library, CNKI, Wanfang, and CBM from database inception to March 2022. Randomized controlled trials of irritable bowel syndrome in children were included in the study. The primary outcome was the placebo response rate of improvement.

RESULTS

Thirteen studies were included, with 445 patients in the placebo group. The rate of improvement and abdominal pain disappearance were 28.2% (95% CI, 16.6-39.9%) and 5% (95% CI, 0-18.4%). The placebo response based on the abdominal pain score was 0.675 (95% CI, 0.203-1.147). The mode of administration (P < 0.01), dosing schedule (P < 0.01), and clinical outcome assessor (P = 0.04) have a significant impact on the magnitude of placebo effect.

CONCLUSIONS

The placebo response rate for pediatric irritable bowel syndrome was 28.2%. In clinical trials, reducing dosing frequency, selecting appropriate dosage forms, and using patient-reported outcomes can help mitigate the placebo effect.

IMPACT

This is the first meta-analysis to assess the placebo response rates for improvement and disappearance in children with IBS. The finding suggested that the mode of administration, dosing schedule, and clinical outcome assessor could potentially influence the magnitude of the placebo effect in children with IBS. This study would provide a basis for estimating sample size in clinical trial design with a placebo control.

Analysis of research topics and trends in investigator-initiated research/trials (IIRs/IITs): A topic modeling study

BACKGROUND

With the exponential growth of publications in the field of investigator-initiated research/trials (IIRs/IITs), it has become necessary to employ text mining and bibliometric analysis as tools for gaining deeper insights into this area of study. By using these methods, researchers can effectively identify and analyze research topics within the field.

METHODS

This study retrieved relevant publications from the Web of Science Core Collection and conducted bioinformatics analysis. The latent Dirichlet allocation model, which is based on machine learning, was utilized to identify subfield research topics.

RESULTS

A total of 4315 articles related to IIRs/IITs were obtained from the Web of Science Core Collection. After excluding duplicates and articles with missing abstracts, a final dataset of 3333 articles was included for bibliometric analysis. The number of publications showed a steady increase over time, particularly since 2000. The United States, Germany, the United Kingdom, the Netherlands, Canada, Denmark, Japan, Switzerland, and France emerged as the most productive countries in terms of IIRs/IITs. The citation analysis revealed intriguing trends, with certain highly cited articles showing a significant increase in citation frequency in recent years. A model with 45 topics was deemed the best fit for characterizing the extensively researched fields within IIRs/IITs. Our analysis revealed 10 top topics that have garnered significant attention, spanning domains such as community health, cancer treatment, brain development and disease mechanisms, nursing research, and stem cell therapy. These top topics offer researchers valuable directions for further investigation and innovation. Additionally, we identified 12 hot topics, which represent the most cutting-edge and highly regarded research areas within the field.

CONCLUSION

This study contributes to a comprehensive understanding of the current research landscape and provides valuable insights for researchers working in this domain.

Placebo effect in randomized controlled trials for Meniere's disease: A meta-analysis

PURPOSE

Meniere's Disease is a condition known for its recurrent vertigo, fluctuating sensorineural hearing loss, aural fullness, and tinnitus. Previous studies have demonstrated significant influence of placebo treatments. Our objective was to quantify the magnitude of the placebo effect in randomized controlled trials for Meniere's Disease.

MATERIALS AND METHODS

A systematic review was performed by searching PubMed, SCOPUS, CINAHL, and Cochrane databases from inception through September 27, 2022. Data extraction, quality rating, and risk of bias assessment were performed by two independent reviewers. A meta-analysis of mean differences with 95 % confidence interval, weighted summary proportions, and proportion differences were calculated using random and fixed effects models.

RESULTS

A total of 15 studies (N = 892) were included in the review. Significant improvement was seen in the functional level scores of the pooled placebo groups, with a mean difference of -0.6 points, (95%CI: -1.2 to -0.1). There was no difference in pure tone audiometry, speech discrimination score, or vertigo frequency at 1 and 3 months for the placebo group. Patient-reported vertigo episodes were improved in 52.5 % (95%CI: 39.2 to 65.5) of the placebo group and was significantly less than the pooled experimental group (90.1 %, 95%CI: 39.2 to 65.5, p < 0.001).

CONCLUSIONS

The placebo effect in Meniere's Disease trials is associated with some symptomatic improvement in subjective outcomes, such as patient reported vertigo episodes. However, the clinical significance is questionable across other outcomes measures, especially when analyzing objective data. The extent and strength of the placebo effect continues to be a hurdle in the search for better treatment options.

Prediction of Clinical Trials Outcomes Based on Target Choice and Clinical Trial Design with Multi-Modal Artificial Intelligence

Drug discovery and development is a notoriously risky process with high failure rates at every stage, including disease modeling, target discovery, hit discovery, lead optimization, preclinical development, human safety, and efficacy studies. Accurate prediction of clinical trial outcomes may help significantly improve the efficiency of this process by prioritizing therapeutic programs that are more likely to succeed in clinical trials and ultimately benefit patients. Here, we describe inClinico, a transformer-based artificial intelligence software platform designed to predict the outcome of phase II clinical trials. The platform combines an ensemble of clinical trial outcome prediction engines that leverage generative artificial intelligence and multimodal data, including omics, text, clinical trial design, and small molecule properties. inClinico was validated in retrospective, quasi-prospective, and prospective validation studies internally and with pharmaceutical companies and financial institutions. The platform achieved 0.88 receiver operating characteristic area under the curve in predicting the phase II to phase III transition on a quasi-prospective validation dataset. The first prospective predictions were made and placed on date-stamped preprint servers in 2016. To validate our model in a real-world setting, we published forecasted outcomes for several phase II clinical trials achieving 79% accuracy for the trials that have read out. We also present an investment application of inClinico using date stamped virtual trading portfolio demonstrating 35% 9-month return on investment.

Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress

BACKGROUND

Chronic pain conditions impose significant burdens worldwide. Pharmacological treatments like opioids have limitations. Non-invasive non-pharmacological therapies (NINPT) encompass diverse interventions including physical, psychological, complementary and alternative approaches, and other innovative techniques that provide analgesic options for chronic pain without medications.

MAIN BODY

This review elucidates the mechanisms of major NINPT modalities and synthesizes evidence for their clinical potential across chronic pain populations. NINPT leverages peripheral, spinal, and supraspinal mechanisms to restore normal pain processing and limit central sensitization. However, heterogeneity in treatment protocols and individual responses warrants optimization through precision medicine approaches.

CONCLUSION

Future adoption of NINPT requires addressing limitations in standardization and accessibility as well as synergistic combination with emerging therapies. Overall, this review highlights the promise of NINPT as a valuable complementary option ready for integration into contemporary pain medicine paradigms to improve patient care and outcomes.

The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

BACKGROUND

Migraine affects 1.1 billion people globally and is the second leading cause of disability worldwide. In clinical trials, treatment efficacy is evaluated by comparing the differential responses in the treatment and placebo arms. Although placebo response in preventive migraine trials has been studied, there is limited research examining temporal trends. This study evaluates the trend of placebo response over thirty years in migraine prevention trials and investigates the association of potential confounders, such as patient, treatment, and study characteristics on placebo response using meta-analysis with regression.

METHODS

We conducted literature searches from January 1990 to August 2021 in bibliographical databases (PubMed, Cochrane Library, and EMBASE). Studies were selected according to PICOS criteria and included randomized, double-blind, placebo-controlled trials evaluating preventive migraine treatments in adult patients diagnosed with episodic or chronic migraine, with or without aura. The protocol was registered with PROSPERO (CRD42021271732). Migraine efficacy outcomes included were either continuous (e.g., monthly migraine days) or dichotomous (e.g., ≥ 50% responder rate (yes/no)). We assessed the correlation of the change in outcome from baseline in the placebo arm, with the year of publication. The relationship between placebo response and year of publication was also assessed after accounting to confounders.

RESULTS

A total of 907 studies were identified, and 83 were found eligible. For the continuous outcomes, the change from baseline in mean placebo response showed an increase over the years (rho = 0.32, p = 0.006). The multivariable regression analysis also showed an overall increase in placebo response over the years. The correlation analysis of dichotomous responses showed no significant linear trend between publication year and mean placebo response (rho = 0.08, p = 0.596). Placebo response also varied by route of administration.

CONCLUSION

Placebo response increased over the past 30 years in migraine preventive trials. This phenomenon should be considered when designing clinical trials and conducting meta-analyses.

Efficacy of Perilla frutescens (L.) Britton var. frutescens extract on mild knee joint pain: A randomized controlled trial

Objectives: This study aimed to evaluate the clinical efficacy and safety of PE extracts developed for the purpose of relieving pain and improving knee joint function on semi-healthy people with mild knee joint pain.

Methods: A randomized, double-blind, two-arm, single-center, placebo-controlled clinical trial was conducted. Individuals with knee joint pain and a visual analogue scale (VAS) score &lt; 50 mm were included in the study, and participants with radiological arthritis were excluded. Participants were administered either PFE or a placebo capsule (700 mg, twice a day) orally for eight weeks. The comparisons of the changed VAS score and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores between the PFE and placebo groups were primary outcomes, while the five inflammation-related laboratory tests including cartilage oligomeric matrix protein, cyclooxygenase-2, neutrophil and lymphocyte ratio, high sensitive C-reactive protein, and erythrocyte sedimentation rate were secondary outcomes. Also, a safety assessment was done.

Results: Eighty participants (mean age, 38.4 ± 14.0, male: female, 28:52) were enrolled; 75 completed the trial (PFE 36 and placebo 39). After eight weeks, both VAS and WOMAC scores were reduced in the PFE and placebo groups. The changed scores were significantly higher in the PFE group compared to the placebo group: 19.6 ± 10.9 vs. 6.8 ± 10.5; VAS scores (p &lt; 0.001), and 20.5 ± 14.7 vs. 9.3 ± 16.5; total WOMAC scores (p &lt; 0.01) including the sub-scores for pain, stiffness, and functions. No significant changes were reported in the five inflammation-related laboratory parameters. All adverse events were considered minor and unlikely to result from the intervention.

Conclusion: Eight weeks of PFE intake was more effective than placebo in reducing knee joint pain and improving knee joint function in sub-healthy people with mild knee joint pain, and there were no major safety concerns.

Clinical Trial Registration:https://cris.nih.go.kr/cris/search/detailSearch.do?search_lang=E&amp;focus=reset_12&amp;search_page=M&amp;pageSize=10&amp;page=undefined&amp;seq=23101&amp;status=5&amp;seq_group=19745, identifier CRIS: KCT0007219

A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial design to investigate the potential of psychobiotics on seizure semiology and comorbidities in canine epilepsy: study protocol

BACKGROUND

Epilepsy is the most common chronic neurological disease in dogs. More than two-thirds of these patients suffer from associated behavioural comorbidities. The latter could have their origin in partially overlapping pathomechanisms, with the intestinal microbiome as a potential key link between them. The current arsenal of drugs for epilepsy management remains limited. Most canine patients continue to have seizures despite treatment and the occurrence of comorbidities is not sufficiently addressed, limiting quality of life of affected dogs and owners. Therefore, novel additional epilepsy management options are urgently needed. The microbiome-gut-brain axis may serve as a new target for the development of innovative multimodal therapeutic approaches to overcome current shortcomings in epilepsy management.

METHODS

A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial was designed to investigate the potential of the psychobiotic Bifidobacterium longum on behavioural comorbidities in canine epilepsy. Seizure semiology will be evaluated as a secondary outcome measure. Thirty-four privately owned dogs are planned to be included in the ongoing study meeting the following inclusion criteria: Dogs displaying increased anxiety/fear behaviour since the start of the idiopathic epilepsy. Tier II confidence level of the International Veterinary Epilepsy Task Force for the diagnosis of idiopathic epilepsy, with a maximum seizure interval of 3 month and a minimum of three generalised seizures within that period and chronically treated with at least one antiseizure drug without improvement in seizure frequency Each dog will receive the allocated supplement (probiotic vs. placebo) alongside its normal diet for a 3-month period. After a three-week wash out period, the second phase starts by administering the respective other supplement for another 3 months.

DISCUSSION

The current study considers modern high-quality standards for epilepsy medication trials. Common biasing effects should be limited to a possible minimum (regression-to-the mean effect, placebo effect, observer effect), ensuring a high validity and accuracy of the acquired results, thus enabling a representative nature of the efficacy of Bifidobacterium longum as add-on supplement for dogs suffering from epilepsy and its comorbidities. This publication should provide a description of the study procedure and data acquisition methods, including prognosed statistical analysis.

Efficacy and safety of Obex® in overweight and obese subjects: a randomised, double-blind, placebo-controlled clinical trial

BACKGROUND

Obex® may be helpful in reducing body weight and fat. The current study was carried out to evaluate the efficacy and safety of Obex® in the treatment of overweight and obese subjects.

METHODS

A double-blind, randomised, controlled phase III clinical trial was conducted involving 160 overweight and obese subjects (BMI ≥ 25.0 and < 40 kg/m²) aged 20 to 60 years, who received Obex® (n = 80) and placebo (n = 80) plus non-pharmacological treatment (physical activity and nutritional counseling). One sachet of Obex® or placebo were administered before the two main meals each day for 6 months. In addition to anthropometric measurements and blood pressure, fasting plasma and 2 h glucose levels during the oral glucose tolerance test, lipid profile, insulin, liver enzymes, creatinine, and uric acid (UA) were determined, insulin resistance (HOMA-IR) beta-cell function (HOMA-β) were assessed and insulin sensitivity (IS) was calculated with three indirect indexes.

RESULTS

After 3 months of Obex®, 48.3% of the participants (28/58) achieved complete success in reducing both weight and waist circumference by greater than or equal to 5% from baseline, as opposed to 26.0% (13/50) of individuals receiving placebo (p = 0.022). Compared to baseline, at 6 months no differences were found between the groups concerning anthropometric and biochemical measurements, except for high-density lipoprotein cholesterol (HDL-c) levels, which were higher in subjects receiving Obex® compared to those receiving placebo (p = 0.030). After 6 months of treatment, both groups showed reduced cholesterol and triglyceride levels (p < 0.012) compared to baseline value. However, only those intake Obex® showed reduced insulin concentrations and HOMA-IR, improved IS (p < 0.05), and decreased creatinine and UA levels (p < 0.005).

CONCLUSIONS

The consumption of Obex® together with lifestyle changes increased HDL-c, contributed to a rapid reduction of weight and waist circumference, as well as improved insulin homeostasis, which did not occur in the placebo group, and appears to be safe as an adjunct at conventional obesity treatment.

TRIAL REGISTRATION

Clinical trial protocol was registered in the Cuban public registry of clinical trials under code RPCEC00000267 on 17/04/2018 and also registered in the international registry of clinical trials, ClinicalTrials.gov, under code: NCT03541005 on 30/05/2018.

Good Scientific Practice and Ethics in Sports and Exercise Science: A Brief and Comprehensive Hands-on Appraisal for Sports Research

Sports and exercise training research is constantly evolving to maintain, improve, or regain psychophysical, social, and emotional performance. Exercise training research requires a balance between the benefits and the potential risks. There is an inherent risk of scientific misconduct and adverse events in most sports; however, there is a need to minimize it. We aim to provide a comprehensive overview of the clinical and ethical challenges in sports and exercise research. We also enlist solutions to improve method design in clinical trials and provide checklists to minimize the chances of scientific misconduct. At the outset, historical milestones of exercise science literature are summarized. It is followed by details about the currently available regulations that help to reduce the risk of violating good scientific practices. We also outline the unique characteristics of sports-related research with a narrative of the major differences between sports and drug-based trials. An emphasis is then placed on the importance of well-designed studies to improve the interpretability of results and generalizability of the findings. This review finally suggests that sports researchers should comply with the available guidelines to improve the planning and conduct of future research thereby reducing the risk of harm to research participants. The authors suggest creating an oath to prevent malpractice, thereby improving the knowledge standards in sports research. This will also aid in deriving more meaningful implications for future research based on high-quality, ethically sound evidence.

Placebo response in pharmacological trials in patients with functional dyspepsia-A systematic review and meta-analysis

BACKGROUND

Pharmacological trials in functional dyspepsia (FD) are associated with high placebo response rates. We aimed to identify the magnitude and contributing factors to the placebo response.

METHODS

We conducted a systematic review and meta-analysis including randomized controlled trials (RCTs) with a dichotomous outcome in adult patients with FD that compared an active pharmacotherapeutic treatment with placebo. Our main outcome was identification of the magnitude of the pooled placebo response rate for the following endpoints: symptom responder, symptom-free responder, adequate relief responder, and combined endpoint responder (i.e., the primary endpoint of each specific trial regarding treatment response). Several putative moderators (i.e., patient, disease, and trial characteristics) were examined.

KEY RESULTS

We included 26 RCTs in our analysis. The pooled placebo response rate was 39.6% (95% CI 30.1-50.0) using the symptom responder definition, 20.5% (12.8-31.0) using the symptom-free responder definition, 38.5% (33.8-43.6) using the adequate relief responder definition, and 35.5% (31.6-39.7) using the combined endpoint responder definition. A lower overall baseline symptom score was significantly associated with a higher placebo response rate. No other moderators were found to significantly impact the placebo response rate. Due to the lack of data, no analyses could be performed according to individual FD subtypes or symptoms.

CONCLUSIONS AND INFERENCES

The pooled placebo response rate in pharmacological trials in FD is about 39%, depending on which responder definitions is used. Future trials should consider applying an entry criterion based on minimal level of symptom severity to decrease the placebo response. We also suggest separate reporting of core FD symptoms pending more concrete harmonization efforts in FD trials.

Effect of a Short-Term Intervention with Lactobacillus salivarius Probiotic on Early Childhood Caries-An Open Label Randomized Controlled Trial

ECC is a significant therapeutic and social problem and a global burden on public health. The aim of this clinical trial was to test whether a 2-week daily consumption of chewing tablets containing thermally inactivated L. salivarius reduces the 12-month caries increment compared to the control group. The investigation was a single-center, randomized, controlled open-label, blinded end-point evaluation trial in two parallel groups. At baseline, 140 generally healthy children between 3 and 6 years of age with or without ECC were randomly assigned to the probiotic test group (n = 70) or to the treatment as the usual control group (n = 70). The primary outcome measure was the 1-year increment in caries incidence and prevalence. Secondary endpoints assessed were the initial, cavitated and obvious dentinal caries increment as well as the measurement of dental plaque accumulation, as an indicator of the ECC risk. Data were collected through the clinical assessment of the children's caries (dmft and ICDAS II) and oral hygiene status (DI-S of OHI-S index). Caries incidence and prevalence were statistically significantly lower in the probiotic group versus the control group (p < 0.001 and p = 0.0075). The initial and final mean OHI-S scores in the probiotic group did not show any significant differences. In conclusion, the regular short-term intake of probiotics may reduce caries development. Our findings suggest that self-administered probiotic therapy may provide a good complement to increase the effectiveness of individual preventive home care in preschool children. This is the first clinical study evaluating the effect of a short-term probiotic intervention on reducing early childhood caries with 12 months of follow-up.

Transcranial Direct Current Stimulation vs Sham for the Treatment of Inattention in Adults With Attention-Deficit/Hyperactivity Disorder: The TUNED Randomized Clinical Trial

IMPORTANCE

Transcranial direct current stimulation (tDCS) may improve symptoms of inattention in adults with attention-deficit/hyperactivity disorder (ADHD). However, previous trials are characterized by small sample sizes, heterogeneous methodologies, and short treatment periods using clinic-based tDCS.

OBJECTIVE

To determine the efficacy and safety of home-based tDCS in treating inattention symptoms in adult patients with ADHD.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, parallel, sham-controlled clinical trial (tDCS for the Treatment of Inattention Symptoms in Adult Patients With ADHD [TUNED]), conducted from July 2019 through July 2021 in a single-center outpatient academic setting. Of 277 potential participants screened by phone, 150 were assessed for eligibility on site, and 64 were included. Participants were adults with ADHD, inattentive or combined subtype. Exclusion criteria included current stimulant drug treatment, current moderate to severe symptoms of depression or anxiety, diagnosis of bipolar disorder with a manic or depressive episode in the last year, diagnosis of schizophrenia or another psychotic disorder, and diagnosis of autism spectrum disorder; 55 of participants completed follow-up after 4 weeks.

INTERVENTIONS

Thirty-minute daily sessions of home-based tDCS for 4 weeks, 2 mA anodal-right and cathodal-left prefrontal stimulation with 35-cm2 carbon electrodes.

MAIN OUTCOMES AND MEASURES

Inattentive scores in the clinician-administered version of the Adult ADHD Self-report Scale version 1.1 (CASRS-I).

RESULTS

Included in this trial were 64 participants with ADHD (31 [48%] inattentive presentation and 33 [52%] combined presentation), with a mean (SD) age of 38.3 (9.6) years. Thirty participants (47%) were women and 34 (53%) were men. Fifty-five finished the trial. At week 4, the mean (SD) inattention score, as measured with CASRS-I, was 18.88 (5.79) in the active tDCS group and 23.63 (3.97) in the sham tDCS group. Linear mixed-effects models revealed a statistically significant treatment by time interaction for CASRS-I (βinteraction = -3.18; 95% CI, -4.60 to -1.75; P < .001), showing decreased symptoms of inattention in the active tDCS group over the 3 assessments compared to the sham tDCS group. Mild adverse events were more frequent in the active tDCS group, particularly skin redness, headache, and scalp burn.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, daily treatment with a home-based tDCS device over 4 weeks improved attention in adult patients with ADHD who were not taking stimulant medication. Home-based tDCS could be a nonpharmacological alternative for patients with ADHD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04003740.

Informed Consent for Placebo-Controlled Trials: Do Ethics and Science Conflict?

The use of a placebo has been considered the best method for controlling bias in a prospective randomized clinical trial and provides the most rigorous test of treatment efficacy for evaluating a medical therapy. Placebos commonly produce clinically important effects particularly in studies where the primary outcomes are subjective. Yet the potential beneficial or harmful effects of placebos are often not addressed in designing a clinical trial, calculating the sample size, seeking consent, or interpreting clinical trial results. In this manuscript, we use an actual study to indicate three approaches that might be considered in seeking informed consent for placebo-controlled trials, and we explore the fundamental ethical and scientific complexities involved with each.

Influence of placebo effect in mental disorders research: A systematic review and meta-analysis

BACKGROUND

Randomized controlled trials (RCT) in mental disorders research commonly use active control groups including psychotherapeutic shams or inactive medication. This meta-analysis assessed whether placebo conditions (active controls) had an effect compared to no treatment or usual care (passive controls).

METHODS

PubMed, Scopus, PsycINFO, PsycARTICLES, Ovid, the Cochrane Central Register of Controlled Trials and Web of Science were searched from inception to April 2021 and reference lists of relevant articles. Three-arm RCTs, including active and passive control groups, were selected. Where individual standardized mean difference (SMD) was calculable, random effects meta-analyses were performed to estimate an overall effect size with 95% confidence intervals (CI) comparing active vs passive controls. Heterogeneity was assessed using I² statistic and meta-regression. Funnel asymmetry was evaluated using Egger's test (Prospero registration: CRD42021242940).

RESULTS

24 articles with 25 relevant RCTs were included in the review, of which 11 studies were of high risk of bias. There was an improvement in outcomes favouring the placebo conditions, compared to passive controls, overall (25 studies, SMD 0.24, 95% CI 0.06-0.42, I² = 43%) and in subgroups with anxiety (SMD 0.45, 95% CI 0.07-0.84, I² = 59%) or depression (SMD 0.22, 95% CI 0.04-0.39, I² = 0%). Meta-regression did not show a significant explanation for heterogeneity. Egger's test showed no asymmetry (p = .200).

CONCLUSIONS

A small placebo effect was observed in mental disorders research overall, and in patients with anxiety or depression. These findings should be interpreted with caution in the light of heterogeneity and risk of bias.

Impact of lung function and baseline clinical characteristics on patient-reported outcome measures in systemic sclerosis-associated interstitial lung disease

OBJECTIVE

The SENSCIS® trial demonstrated a significant reduction of lung function decline in patients with SSc-associated interstitial lung disease (SSc-ILD) treated with nintedanib, but no significant effect on health-related quality of life (HRQoL). To assess whether SSc/SSc-ILD severity and large changes in lung function correlate with HRQoL, a post-hoc analysis of SENSCIS®, aggregating treatment arms, was undertaken.

METHODS

Patient-reported outcome (PRO) measures [St. George's Respiratory Questionnaire (SGRQ), Functional Assessment of Chronic Illness Therapy (FACIT)-Dyspnoea, and HAQ-Disability Index (HAQ-DI), incorporating the Scleroderma HAQ visual analogue scale (SHAQ VAS)] at baseline and week 52 were assessed for associations to SSc-ILD severity.

RESULTS

At baseline and at week 52, forced vital capacity (FVC) <70% predicted was associated with worse PRO measure scores compared with FVC ≥70% predicted [week 52: SGRQ 45.1 vs 34.0 (P < 0.0001); FACIT-Dyspnoea 48.9 vs 44.5 (P < 0.0001); HAQ-DI 0.7 vs 0.6 (P < 0.0228); SHAQ VAS breathing problems 3.6 vs 2.6 (P < 0.0001)]. Patients with diffuse cutaneous SSc and other characteristics associated with SSc-ILD severity had worse PRO measure scores. Patients requiring oxygen or with >30% fibrosis on high-resolution computed tomography at baseline demonstrated worse PRO measure scores at week 52. After 1 year, patients with a major (>10%) improvement/worsening in FVC demonstrated corresponding improvement/worsening in SGRQ and other PRO measures, significant for the SGRQ symptom domain (P < 0.001).

CONCLUSION

Severe SSc-ILD and major deteriorations in lung function have important impacts on HRQoL. Treatments that slow lung function decline and prevent severe SSc-ILD are important to preserve HRQoL.

TRIAL REGISTRATION

clinicaltrials.gov, www.clinicaltrials.gov, NCT02597933.

The Effectiveness and Safety of Medical Cannabis for Treating Cancer Related Symptoms in Oncology Patients

The use of medical cannabis (MC) to treat cancer-related symptoms is rising. However, there is a lack of long-term trials to assess the benefits and safety of MC treatment in this population. In this work, we followed up prospectively and longitudinally on the effectiveness and safety of MC treatment. Oncology patients reported on multiple symptoms before and after MC treatment initiation at one-, three-, and 6-month follow-ups. Oncologists reported on the patients' disease characteristics. Intention-to-treat models were used to assess changes in outcomes from baseline. MC treatment was initiated by 324 patients and 212, 158 and 126 reported at follow-ups. Most outcome measures improved significantly during MC treatment for most patients (p < 0.005). Specifically, at 6 months, total cancer symptoms burden declined from baseline by a median of 18%, from 122 (82-157) at baseline to 89 (45-138) at endpoint (-18.98; 95%CI= -26.95 to -11.00; p < 0.001). Reported adverse effects were common but mostly non-serious and remained stable during MC treatment. The results of this study suggest that MC treatment is generally safe for oncology patients and can potentially reduce the burden of associated symptoms with no serious MC-related adverse effects.

Frunevetmab, a felinized anti-nerve growth factor monoclonal antibody, for the treatment of pain from osteoarthritis in cats

Background

Frunevetmab, a felinized antinerve growth factor monoclonal antibody, effectively decreases osteoarthritis (OA) pain in cats.

Objective

To evaluate the efficacy of frunevetmab given at monthly intervals in a randomized, placebo‐controlled, parallel‐group, double‐blind superiority study.

Animals

Two hundred seventy‐five client‐owned cats with naturally‐occurring OA pain and associated mobility impairment and disability.

Methods

Randomized, placebo‐controlled, parallel‐group, double‐blind, superiority study. Following screening, cats received frunevetmab (nominal dose of 1.0 mg/kg, SC [effective dose range of 1.0‐2.8 mg/kg]) or placebo on days 0, 28, and 56. Outcome measures were owner questionnaires and veterinary physical and orthopedic evaluations at days 28, 56, and 84. Success/failure rates (and numbers needed treat, NNT) and change in scores (and standardized effect size, ES) were analyzed.

Results

Frunevetmab (182) and placebo (93) treated cats were enrolled and received at least 1 treatment. Significant improvement with frunevetmab over placebo occurred at days 28 and 56 for the client specific outcome measures (CSOM) questionnaire (success rates and total scores [NNT of 9 and ES of 0.3 at day 56]); at days 28 and 56 for owner‐assessed global treatment response; and at days 56 and 84 for veterinarian‐assessed joint pain (ES of 0.18 at day 56). Adverse events did not differ between groups, except skin disorders which collectively occurred significantly more frequently in frunevetmab treated (32/182 cats) vs placebo (8/93 cats).

Conclusions and Clinical Importance

Frunevetmab has the potential to address a critical gap in the treatment of pain because of osteoarthritis in cats.

Exogenous melatonin decreases circadian misalignment and body weight among early types

Shift workers experience chronic circadian misalignment, which can manifest itself in reduced melatonin production, and has been associated with metabolic disorders. In addition, chronotype modulates the effect of night shift work, with early types presenting greater circadian misalignment when working night shift as compared to late types. Melatonin supplementation has shown positive results reducing weight gain in animal models, but the effect of exogenous melatonin in humans on body weight in the context of shift work remains inconsistent. The aim of this study was thus to evaluate the effects of exogenous melatonin on circadian misalignment and body weight among overweight night shift workers, according to chronotype, under real-life conditions. We conducted a double-blind, randomized, placebo-controlled, crossover trial where melatonin (3 mg) or placebo was administered on non-night shift nights for 12 weeks in 27 female nurses (37.1 yo, ±5.9 yo; BMI 29.9 kg/m2 , ±3.3 kg/m2 ). Melatonin (or placebo) was only taken on nights when the participants did not work night shifts, that is, on nights when they slept (between night shifts and on days off). Composite Phase Deviations (CPD) of actigraphy-based mid-sleep timing were calculated to measure circadian misalignment. The analyses were performed for the whole group and by chronotype. We found approximately 20% reduction in circadian misalignment after exogenous melatonin administration considering all chronotypes. Moreover, melatonin supplementation in those who presented high circadian misalignment, as observed in early chronotypes, reduced body weight, BMI, waist circumference, and hip circumference, without any change in the participants' calorie intake or physical activity levels.

The placebo response rate in pharmacological trials in patients with irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Clinical trials in irritable bowel syndrome are associated with high placebo response rates. We aimed to identify the magnitude of the placebo response and the contributing factors to this occurrence.

METHODS

We did a systematic review and meta-analysis with a search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials between April 1, 1959, and April 30, 2020. We included all randomised controlled trials that compared an active pharmacotherapeutic agent with placebo and had a dichotomous outcome of response to therapy (in terms of global improvement or improvement in abdominal pain) in adults (aged ≥18 years) with irritable bowel syndrome. Exclusion criteria were trials reporting on treatment satisfaction as a dichotomous outcome of response to therapy or clinician-reported outcomes and a treatment duration of less than 4 weeks. Our main outcome was identification of the magnitude of the pooled placebo response rate for the following endpoints: global improvement, abdominal pain, and US Food and Drug Administration (FDA) endpoints. We extracted information from published reports and pooled proportions through meta-analysis with random effects. The study was registered with PROSPERO, CRD42020170908.

FINDINGS

Of the 6863 publications identified, 70 articles describing 73 randomised controlled trials were included in our analysis. The pooled placebo response rate was 27·3% (95% CI 24·3-30·9) using the global improvement endpoint, 34·4% (31·2-37·8) using the abdominal pain endpoint, and 17·9% (15·2-21·0) using the composite FDA endpoint responder definition, all with substantial heterogeneity between the trials. Studies published before 2006, and those done in Europe, with a parallel design, a run-in period of 2 weeks or less, a dose schedule of three times a day or more, or a smaller sample size of the control group were significantly associated with an increased pooled placebo response rate.

INTERPRETATION

More than a quarter of patients with irritable bowel syndrome had a placebo response in terms of global improvement, with multiple associated moderators. We recommend future trials apply a run-in period of at least 2 weeks and dose once or twice a day to minimise the placebo response rate.

FUNDING

None.

Does the placebo effect on hot flashes depend on the placebo dose?

PURPOSE

To investigate the presence of a placebo dose-response effect in four randomized, double-blind, placebo-controlled, multi-dose hot flash clinical trials conducted at Mayo Clinic.

METHODS

Hot flash score, frequency, and hot flash-related distress for each placebo dose level were summarized at each time point by mean and standard deviation and changes from baseline were plotted to visualize a possible placebo dose-effect response. Furthermore, a meta-analysis was conducted for each endpoint in the highest and lowest dosage arms across the four trials.

RESULTS

Longitudinal plots of mean hot flash scores, frequencies, and hot flash-related distress scores in patients taking placebo in each study showed a decline in hot flash scores over time without any clinically meaningful differences between the lowest and highest dosage arms in each study. The meta-analysis for each endpoint in the highest and lowest dosage arms across the four trials revealed no clinically important differences either.

CONCLUSION

While the current study cannot rule out the existence of a placebo dose-response effect in multi-dose placebo-controlled trials in patients with hot flashes or other conditions, it suggests, along with the available data in the placebo literature, that, at least in well-conducted multi-dose clinical trials in which the placebo was used as control, such an effect, if it exists at all, should be very small. Therefore, pooling data from different placebo subgroups is unlikely to compromise the validity of comparisons between the combined placebo arms and each treatment arm.

The Placebo and Nocebo Responses in Clinical Trials in Inflammatory Bowel Diseases

Placebo and nocebo responses are mostly discussed in clinical trials with functional bowel disorders. Much less has been investigated and is known in gastrointestinal diseases beyond irritable bowel syndrome (IBS), especially in inflammatory bowel diseases (IBD). For the purpose of this review, we screened the Journal of Interdisciplinary Placebo Studies (JIPS) database with approximately 4,500 genuine placebo research articles and identified nine meta-analyses covering more than 135 randomized and placebo-controlled trials (RCTs) with more than 10,000 patients with Crohn´s disease (CD) and another five meta-analyses with 150 RCTs and more than 10,000 patients with ulcerative colitis (UC). Only three discussed nocebo effects, especially in the context of clinical use of biosimilars to treat inflammation. The articles were critically analyzed with respect to the size of the placebo response in CD and UC, its effects on clinical improvement versus maintenance of remission, and mediators and moderators of the response identified. Finally, we discussed and compared the differences and similarities of the placebo responses in IBD and IBS and the nocebo effect in switching from biologics to biosimilars in IBD management.

Placebo response mitigation with a participant-focused psychoeducational procedure: a randomized, single-blind, all placebo study in major depressive and psychotic disorders

The remarkably high and growing placebo response rates in clinical trials for CNS indications, such as depression and schizophrenia, constitute a major challenge for the drug development enterprise. Despite extensive literature on participant expectancies and other potent psychosocial factors that perpetuate placebo response, no empirically validated participant-focused strategies to mitigate this phenomenon have been available. This study evaluated the efficacy of the Placebo-Control Reminder Script (PCRS), a brief interactive procedure that educates participants about factors known to cause placebo response, which was administered prior to the primary outcome assessments to subjects with major depressive or psychotic disorders who had at least moderate depression. Participants were informed they would participate in a 2-week randomized clinical trial with a 50% chance of receiving either an experimental antidepressant medication or placebo. In actuality, all participants received placebo. Participants randomly assigned to receive the PCRS (n = 70) reported significantly smaller reductions (i.e., less placebo response) in depression than those who did not receive the PCRS (n = 67). The magnitude of this effect was medium (Cohen's d = 0.40) and was not significantly impacted by diagnostic status. The number of adverse events (i.e., nocebo effect) was also lower in the PCRS group, particularly in the first week of the study. These findings suggest that briefly educating participants about placebo response factors can help mitigate the large placebo response rates that are increasingly seen in failed CNS drug development programs.

Endocannabinoid Levels in Ulcerative Colitis Patients Correlate With Clinical Parameters and Are Affected by Cannabis Consumption

BACKGROUND

Inflammatory bowel diseases (IBDs) are chronic, idiopathic, inflammatory, gastrointestinal disorders. The endocannabinoid system may have a role in the pathogenesis of IBD. We aimed to assess whether cannabis treatment influences endocannabinoids (eCBs) level and clinical symptoms of IBD patients.

METHODS

Blood samples and biopsies were taken from IBD patients treated by either cannabis or placebo for 8 weeks. Immunohistochemistry for N-acyl-phosphatidylethanolamine-selective phospholipase D (NAPE-PLD) and fatty acid amide hydrolase (FAAH) expression was done on colon biopsies, and sample levels of anandamide (AEA), eCB2-arachidonylglycerol (2-AG), arachidonic acid (AA), palmitoylethanolamine (PEA), and oleoylethanolamine (OEA) were measured in patient's sera before and after cannabis treatment. Caco-2 cells were cultured with extracts of cannabis with/without tetrahydrocannabinol (THC) and their proteins extracted, and Western blotting for NAPE-PLD and FAAH expression was done.

RESULTS

Thirteen patients with Crohn's disease (CD) and nine patients with ulcerative colitis (UC) were treated with cannabis. Seventeen patients with CD and 10 with UC served as placebo groups. In all CD patients, the levels of eCBs remained unaltered during the treatment period. In UC patients treated with placebo, but not in those treated with cannabis, the levels of PEA, AEA, and AA decreased significantly. The percent reduction in bowel movements was negatively correlated with changes observed in the circulating AEA and OEA, whereas improvement in quality of life was positively correlated with the levels of 2-AG. In the biopsies from UC patients, FAAH levels increased over the study period. In Caco-2 cells, both cannabis extracts increased NAPE-PLD levels but reduced FAAH expression levels.

CONCLUSION

Our study supports the notion that cannabis use affects eCB "tone" in UC patients and may have beneficial effects on disease symptoms in UC patients.

Placebo Responses and Placebo Effects in Functional Gastrointestinal Disorders

Much has been written about the placebo effects in functional gastrointestinal disorders (FGD), especially in irritable bowel syndrome (IBS), driven by the early hypothesis that in randomized controlled trials (RCTs) of IBS, the placebo effect might be specifically high and thus, corrupts the efficacy of novel drugs developed for this condition. This narrative review is based on a specific search method, a database (www.jips.online) developed since 2004 containing more than 4,500 papers (data papers, meta-analyses, systematic reviews, reviews) pertinent to the topic placebo effects/placebo response. Three central questions-deducted from the body of current literature-are addressed to explore the evidence behind this hypothesis: What is the size placebo effect in FGD, especially in IBS, and is it different from the placebo effect seen in other gastrointestinal disorders? Is the placebo effect in FGD different from other functional, non-intestinal disorders, e.g. in other pain syndromes? Is the placebo effect in FGD related to placebo effects seen in psychiatry, e.g. in depression, anxiety disorders, and alike? Following this discussion, a fourth question is raised as the result of the three: What are the consequences of this for future drug trials in FGD? In summary it is concluded that, contrary to common belief and discussion, the placebo effect seen in RCT in FGD is not specifically high and extraordinary as compared to other comparable (i.e. functional) disorders. It shares less than expected commonalities with the placebo effect in psychiatry, and very few predictors have yet been identified that determine its effect size, especially some that are driven by design features of the studies. Current practice of RCT in IBS seems to limit and control the placebo effect quite well, and future trial practice, e.g. head-to-head trial, still offers options to maintain this control, even in the absence of placebos used.

Stratification of patients in NASH clinical trials: A pitfall for trial success

Identifying the most effective therapeutic intervention in patients with NAFLD is challenging. Precise stratification in clinical trials is key to ensuring the inclusion of patients who will benefit (and not those who will be harmed) and/or in whom the natural history can be improved. Clinical trials in NAFLD can provide useful information about the individual components that underlie this complex metabolic disorder and the concomitant medications that could interfere with responses to an experimental intervention. However, to date, clinical trial reporting for NAFLD has been suboptimal, limiting our understanding. Frequently dysmetabolic comorbidities and/or daily habits are not reported or adequately accounted for. Herein, we suggest new strategies to integrate the spectra of comorbidities usually present in patients with NAFLD, accounting for the impact of lifestyle, to develop personalised therapeutic approaches. First, the mechanism of action of the drug being explored should be considered. Second, the same proportion of patients with relevant metabolic comorbidities should be maintained from phase II to III clinical trials, if such comorbidities are expected to impact on the treatment response. Third, innovative trial designs, such as the adaptative, umbrella or basket strategies, could be used to increase the efficiency of clinical trials, potentially benefiting patients while reducing costs and enhancing the likelihood of finding a real benefit of the therapy being studied. Finally, alcohol intake and daily exercise should be assessed objectively not only in the screening period but also during follow-up.