Meta-analysis of the placebo response in ulcerative colitis

Placebo Rates in Randomized Controlled Trials of Proctitis Therapy: A Systematic Review and Meta-Analysis Placebo Response in Proctitis

BACKGROUND AND AIMS

Treatment options for proctitis are limited. To assist trial design for novel therapeutics, we conducted a systematic review and meta-analysis of proctitis randomized controlled trials [RCTs] to quantify placebo rates and identify factors influencing them.

METHODS

We searched MEDLINE, EMBASE and CENTRAL from inception to June 2021. Placebo-controlled trials of pharmacological interventions for proctitis were eligible. Placebo clinical response and remission rates for induction and maintenance trials were extracted and pooled using a random-effects model. Mixed-effects meta-regression was used to evaluate the impact of patient and study-level characteristics.

RESULTS

Twenty RCTs [17 induction and four maintenance phases] were included. The most common intervention was aminosalicylates and most studies investigated topical medications. The pooled placebo clinical response and remission rates for induction trials were 28% (95% confidence interval [CI] 22-35%; n = 17) and 20% [95% CI 12-32%; n = 9], respectively. Pooled placebo endoscopic response and remission rates were 32% [95% CI 26-39%, n = 12] and 18% [95% CI 9-33%, n = 6], respectively. For maintenance trials, the pooled placebo clinical remission rate was 29% [95% CI 16-46%, n = 17]. Trials published after 2005 and trials with a longer duration of follow-up were associated with significantly lower placebo response rates. Nineteen of 20 studies were assessed as having an unclear risk of bias, reflecting the historical nature of trials.

CONCLUSIONS

Placebo response and remission rates in proctitis trials are influenced by trial phase and the endpoint being assessed. These contemporary rates will inform trial design for novel therapeutics for treatment of proctitis, which is a large unmet need.

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.

Rapid Changes in Laboratory Parameters and Early Response to Adalimumab: A Pooled Analysis From Patients With Ulcerative Colitis in Two Clinical Trials

BACKGROUND AND AIMS

The efficacy and safety of adalimumab for induction and maintenance of clinical remission in patients with moderately to severely active ulcerative colitis were demonstrated in the ULTRA 1 and 2 clinical trials. This post-hoc, pooled analysis evaluated early changes in laboratory parameters, Mayo subscores, mucosal healing, and health-related quality of life.

METHODS

Mean changes in laboratory parameters including albumin, high-sensitivity C-reactive protein, total protein, haematocrit, haemoglobin, red blood cell and platelet counts, Inflammatory Bowel Disease Questionnaire, and Short Form 36 Health Survey were evaluated from baseline to Weeks 4 and 8. Mean changes in Mayo subscores of rectal bleeding and stool frequency were evaluated from baseline to Weeks 2, 4, 6, and 8. Mucosal healing was assessed with endoscopy at baseline and Week 8. Categorical variables were evaluated with the Cochran-Mantel-Haenszel test; continuous variables were evaluated with analysis of covariance and considered significant if p <0.05.

RESULTS

Treatment with adalimumab significantly improved laboratory and quality-of-life measures at Weeks 4 and 8 compared with placebo [p <0.05 and p <0.001]. Mean reductions from baseline in rectal bleeding and stool frequency were significantly larger in patients receiving adalimumab compared with placebo at Week 2 and sustained through Week 8 [p <0.01]. Normal mucosa at Week 8 was achieved by 13% of patients receiving adalimumab compared with 6% of those receiving placebo [p <0.001].

CONCLUSIONS

Adalimumab resulted in rapid improvements in laboratory markers and early reductions in rectal bleeding and stool frequency. Early improvement in quality-of-life scores correlated with the clinical and laboratory findings.

Skills Vs. Pills: Comparative Effectiveness for Low Sexual Desire in Women

This study compared the effectiveness of a skill-based bibliotherapy intervention and a placebo pill intervention purported to be efficacious in increasing women's sexual desire. Forty-five participants were randomized into the two groups after completing pretest measures of sexual desire and functioning. After completing their interventions, participants completed 6-week posttest and 12-week follow-up measures. Results demonstrated that when compared to the placebo pill group, the bibliotherapy group made statistically greater gains from pretest to follow-up in sexual desire and satisfaction. Nevertheless, the placebo pill group evidenced short-term improvements in sexual desire over time. Findings have implications for future research and current treatments for low sexual desire in women.

Azathioprine for refractory ulcerative proctitis: A retrospective multicenter study

BACKGROUND

Efficacy of azathioprine (AZA) in refractory ulcerative proctitis (UP) is unknown.

METHODS

All patients treated with AZA for refractory UP in three referral centers between 2002 and 2012 were included. "Treatment success" in the long-term was defined as the absence of colectomy during follow-up, no need for anti-TNF during follow-up, no ongoing systemic steroids use, no adverse event leading to AZA withdrawal, and clinically quiescent disease at last follow-up.

RESULTS

Of the 1279 adult patients with ulcerative colitis, 25 patients were treated with AZA for refractory UP (median disease duration 4.9 years). Of these, 4 had no short-term clinical assessment. Of the remaining 21, 4 were primary non responders to AZA, 7 discontinued AZA for adverse events and 10 showed clinical improvement. At the long-term assessment at last follow up after a median of 46 months, 5 patients had treatment success and were still on AZA treatment, the remaining 20 were treatment failures. Of these, 5 discontinued AZA for adverse events and 15 were treated with infliximab (clinical response in 11 patients, primary non-response in one patient, and 3 underwent colectomy).

CONCLUSION

AZA may be efficacious in maintaining clinical response in one-fifth of patients with refractory UP in a real-life setting.

Eldelumab [Anti-IP-10] Induction Therapy for Ulcerative Colitis: A Randomised, Placebo-Controlled, Phase 2b Study

BACKGROUND AND AIMS

Interferon-γ-inducible protein-10 [IP-10] mediates immune cell trafficking from the circulation to the inflamed colon and decreases gut epithelial cell survival. IP-10 expression is increased in patients with ulcerative colitis [UC]. We report efficacy and safety results from a dose-ranging induction study of eldelumab, a fully human monoclonal antibody to IP-10, in moderately to severely active UC.

METHODS

A total of 252 adults with UC [Mayo score ≥ 6 and endoscopic subscore ≥ 2] were randomised 1:1:1 to placebo or eldelumab 15 or 25 mg/kg administered intravenously on Days 1 and 8 and every other week thereafter. The primary endpoint was clinical remission [Mayo score ≤ 2; no individual subscale score > 1] at Week 11. Key secondary endpoints included Mayo score clinical response and mucosal healing at Week 11.

RESULTS

Neither eldelumab 15 or 25 mg/kg resulted in significant increases vs placebo in the proportion of patients achieving Week 11 clinical remission. Remission and response rates were 17.6% and 47.1% with eldelumab 25mg/kg, 13.1% and 44.0% with eldelumab 15mg/kg, and 9.6% and 31.3% with placebo. Clinical remission and response rates were higher in anti-tumour necrosis factor [TNF]-naïve patients treated with eldelumab compared with placebo. Eldelumab treatment was well tolerated and no immunogenicity was observed.

CONCLUSIONS

The primary endpoint was not achieved with induction treatment with eldelumab 15 or 25 mg/kg in patients with UC. Trends towards clinical remission and response were observed in the overall population and were more pronounced in anti-TNF naïve patients. Eldelumab safety signals were consistent with those reported previously [ClinicalTrials.gov number, NCT01294410].

Use of Placebo in Pediatric Inflammatory Bowel Diseases: A Position Paper From ESPGHAN, ECCO, PIBDnet, and the Canadian Children IBD Network

Performing well-designed and ethical trials in pediatric inflammatory bowel diseases (IBD) is a priority to support optimal therapy and reduce the unacceptable long lag between adult and pediatric drug approval. Recently, clinical trials in children have been incorporating placebo arms into their protocols under conditions that created controversy. Therefore, 4 organizations (the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition; European Crohn's and Colitis Organization; the Canadian Children IBD Network; and the Global Pediatric IBD Network) jointly provide a statement on the role of placebo in pediatric IBD trials. Consensus was achieved by 94 of 100 (94%) voting committees' members that placebo should only be used if there is genuine equipoise between the active treatment and placebo; for example, this may be considered in trials of drugs with new mechanisms of action without existing adult data, especially when proven effective alternatives do not exist outside the trial. Placebo may also be used in situations where it is an "add-on" to an effective therapy or to evaluate exit-strategies of maintenance therapy after long-term deep remission. It has been, however, agreed that no child enrolled in a trial should receive a known inferior treatment both within and outside the trial. This also includes withholding therapy in children who show clinical response after a short induction therapy. Given the similarity between pediatric and adult IBD regarding pathophysiology and response to treatments, drugs generally cannot be considered being in genuine equipoise with placebo if it has proven efficacy in adults. Continued collaboration of all stakeholders is needed to facilitate drug development and evaluation in pediatric IBD.

Placebo effects and their determinants in gastrointestinal disorders

Placebo effects in clinical trials have sparked an interest in the placebo phenomenon, both in randomized controlled trials (RCTs) and in experimental gastroenterology. RCTs have demonstrated similar short-term and long-term placebo response rates in gastrointestinal compared to other medical diagnoses. Most mediators and moderators of placebo effects in gastrointestinal diseases are also of similar type and size to other medical diagnoses and not specific for gastrointestinal diagnoses. Other characteristics such as an increase in the placebo response over time and the placebo-enhancing effects of unbalanced randomization were not seen, at least in IBS. Experimental placebo and nocebo studies underscore the 'power' of expectancies and conditioning processes in shaping gastrointestinal symptoms not only at the level of self-reports, but also within the brain and along the brain-gut axis. Brain imaging studies have redressed earlier criticism that placebo effects might merely reflect a response bias. These findings raise hope that sophisticated trials and experiments designed to boost positive expectations and minimize negative expectations could pave the way for a practical and ethically sound use of placebo knowledge in daily practice. Rather than focusing on a 'personalized' choice of drugs based on biomarkers or genes, it might be the doctor-patient communication that needs to be tailored.

Placebo responses and placebo effects in functional bowel disorders

The nature and determinants of the placebo response are widely unknown, as are the underlying psychological and biological mechanisms. Placebo response rates in functional bowel disorders (functional dyspepsia, irritable bowel syndrome) trials are similar to those in nonintestinal pain conditions and are comparable with other organic gastrointestinal diseases (duodenal ulcer, inflammatory bowel diseases). In this narrative review, different methodologies (meta-analyses, reanalyses, and experimental setups) are discussed that have been applied to the study of the placebo response in functional dyspepsia and the irritable bowel syndrome.

Leukocytapheresis in pediatric patients with ulcerative colitis

OBJECTIVE

Leukocytapheresis (LCAP) is a nonpharmacologic therapy that has recently been used to treat ulcerative colitis (UC). This multicenter open-label study prospectively assessed the efficacy and safety of LCAP in pediatric patients with UC.

PATIENTS AND METHODS

Twenty-three patients ages 8 to 16 years with moderate (n = 19) to severe (n = 4) steroid-resistant UC were enrolled. One of 2 LCAP columns with different volumes (model EX and the half-volume model EI) was selected, according to body weight. LCAP was performed once per week for 5 consecutive weeks. Clinical and laboratory data were collected at predetermined time points. The primary endpoint was decreased stool frequency/hematochezia score, and secondary endpoints were clinical, laboratory, and endoscopic improvements.

RESULTS

The stool frequency/hematochezia score decreased significantly from 4.5 ± 1.2 before treatment to 1.6 ± 1.9 after the fifth treatment. Clinical parameters, including stool frequency, presence of visible blood, abdominal pain, and body temperature, were significantly improved. Fecal calprotectin decreased significantly. Endoscopic findings evaluated using Matts score also improved (P < 0.01). The steroid dose decreased from 1.1 ± 0.4 mg/kg before treatment to 0.8 ± 0.5 mg/kg after treatment. There were no significant differences in changes between the EX and EI columns. The incidence of adverse effects was 61%, although none was serious. The most common adverse effects were decreased hematocrit and hemoglobin concentration.

CONCLUSIONS

The present study showed that LCAP was well tolerated in children with UC, mostly moderate, and was as effective as in adults. The types of pediatric patients best suited to LCAP remain to be determined.

Maintenance of remission in inflammatory bowel disease using omega-3 fatty acids (fish oil): a systematic review and meta-analyses

The objective was to systematically review the efficacy and safety of n-3 (omega-3 fatty acids, fish oil) for maintaining remission in Crohn's disease (CD) and ulcerative colitis (UC). Electronic databases were searched systematically for randomized controlled trials of n-3 for maintenance of remission in inflammatory bowel disease (IBD). Studies of patients of any age group who were in remission at the time of recruitment and were followed for at least 6 months were included. The primary outcome was relapse rate at the end of the follow-up period. Nine studies were eligible for inclusion; six studies of CD (n = 1039) and three of UC (n = 138). There was a statistically significant benefit for n-3 in CD (relative risk [RR] 0.77; 95% confidence interval [CI] 0.61-0.98); however, the studies were heterogeneous (I(2) = 58%). The absolute risk reduction was -0.14 (95% CI: -0.25 to -0.02). Opinions may vary on whether this is a clinically significant effect. Two well-done studies with a larger sample size reported no benefit. A sensitivity analysis excluding a small pediatric study resulted in the pooled RR being no longer statistically significant. A funnel plot analysis suggested publication bias for the smaller studies. For UC, there was no difference in the relapse rate between the n-3 and control groups (RR 1.02; 95% CI: 0.51-2.03). The pooled analysis showed a higher rate of diarrhea (RR 1.36; 95% CI: 1.01-1.84) and symptoms of the upper gastrointestinal tract (RR 1.96; 95% CI: 1.37-2.80) in the n-3 treatment group. There are insufficient data to recommend the use of omega 3 fatty acids for maintenance of remission in CD and UC.

Treatment of relapsing mild-to-moderate ulcerative colitis with the probiotic VSL#3 as adjunctive to a standard pharmaceutical treatment: a double-blind, randomized, placebo-controlled study

OBJECTIVES

VSL#3 is a high-potency probiotic mixture that has been used successfully in the treatment of pouchitis. The primary end point of the study was to assess the effects of supplementation with VSL#3 in patients affected by relapsing ulcerative colitis (UC) who are already under treatment with 5-aminosalicylic acid (ASA) and/or immunosuppressants at stable doses.

METHODS

A total of 144 consecutive patients were randomly treated for 8 weeks with VSL#3 at a dose of 3,600 billion CFU/day (71 patients) or with placebo (73 patients).

RESULTS

In all, 65 patients in the VSL#3 group and 66 patients in the placebo group completed the study. The decrease in ulcerative colitis disease activity index (UCDAI) scores of 50% or more was higher in the VSL#3 group than in the placebo group (63.1 vs. 40.8; per protocol (PP) P=0.010, confidence interval (CI)₉₅(%) 0.51-0.74; intention to treat (ITT) P=0.031, CI₉₅(%) 0.47-0.69). Significant results with VSL#3 were recorded in an improvement of three points or more in the UCDAI score (60.5% vs. 41.4%; PP P=0.017, CI₉₅(%) 0.51-0.74; ITT P=0.046, CI₉₅(%) 0.47-0.69) and in rectal bleeding (PP P=0.014, CI₉₅(%) 0.46-0.70; ITT P=0.036, CI₉₅(%) 0.41-0.65), whereas stool frequency (PP P=0.202, CI₉₅(%) 0.39-0.63; ITT P=0.229, CI₉₅(%) 0.35-0.57), physician's rate of disease activity (PP P=0.088, CI₉₅(%) 0.34-0.58; ITT P=0.168, CI₉₅(%) 0.31-0.53), and endoscopic scores (PP P=0.086, CI₉₅(%) 0.74-0.92; ITT P=0.366, CI₉₅(%) 0.66-0.86) did not show statistical differences. Remission was higher in the VSL#3 group than in the placebo group (47.7% vs. 32.4%; PP P=0.069, CI₉₅(%) 0.36-0.60; ITT P=0.132, CI₉₅(%) 0.33-0.56). Eight patients on VSL#3 (11.2%) and nine patients on placebo (12.3%) reported mild side effects.

CONCLUSIONS

VSL#3 supplementation is safe and able to reduce UCDAI scores in patients affected by relapsing mild-to-moderate UC who are under treatment with 5-ASA and/or immunosuppressants. Moreover, VSL#3 improves rectal bleeding and seems to reinduce remission in relapsing UC patients after 8 weeks of treatment, although these parameters do not reach statistical significance.

Clinical trial: oral colon-release parnaparin sodium tablets (CB-01-05 MMX) for active left-sided ulcerative colitis

BACKGROUND

The administration of parnaparin sodium as oral colon-release tablets (CB-01-05 MMX) has been proposed as a novel approach for the treatment of ulcerative colitis (UC).

AIM

To assess the efficacy and the tolerability of 8 weeks' oral daily administration of 210 mg of parnaparin sodium compared with placebo in subjects treated with stable-doses of oral aminosalicylates.

METHODS

This multicenter, randomized, double-blind proof of concept trial compared the efficacy of CB-01-05 MMX 210 mg tablets to placebo in 141 subjects with mild to moderately active left-sided UC treated with stable-doses of aminosalicylates. The efficacy was assessed by clinical activity index (CAI), endoscopic index (EI) and histological score (HS).

RESULTS

A total of 121 subjects (61 in test group and 60 in control group) formed the per protocol (PP) population. After 8 weeks of treatment, clinical remission was achieved in 83.6% of the CB-01-05 MMX group, and in 63.3% in the comparator group (P = 0.011). This effect was also significantly evident in the test group at week 4 (P = 0.028). A significant difference was also detected in rectal bleeding, (disappeared respectively in 75.4% and 55.0%; P = 0.018), and in mucosal friability (recovered respectively in 80.3% and in 56.7%; P = 0.005).

CONCLUSIONS

CB-01-05 MMX was safe and significantly effective in treating subjects with mild-to-moderate left-sided UC treated with stable-doses of aminosalicylates.

[The placebo effect in inflammatory bowel disease]

Since time immemorial, placebos have been used in the treatment of patients with very different diseases. Interest in these substances has recently been renewed, since the use of placebo-controlled clinical trials has become the most useful tool to demonstrate the efficacy of a particular drug in patients with specific diseases. In inflammatory bowel disease (IBD), both in Crohn's disease and in ulcerative colitis, highly significant results have been obtained in patients in the placebo arm of clinical trials, surpassing even those achieved with drugs in other studies. Patients with IBD show certain characteristics that make them especially susceptible to the placebo effect: IBD are chronic diseases occurring in flares and pain is one of the main symptoms. In future, the placebo effect should be adequately quantified in the distinct clinical scenarios of IBD in order to design clinical trials that could demonstrate the true efficacy of the treatments investigated.