Methods for the analysis of multiple endpoints in small populations: A review

Riluzole for Degenerative Cervical Myelopathy: A Secondary Analysis of the CSM-PROTECT Trial

Importance

The modified Japanese Orthopaedic Association (mJOA) scale is the most common scale used to represent outcomes of degenerative cervical myelopathy (DCM); however, it lacks consideration for neck pain scores and neglects the multidimensional aspect of recovery after surgery.

Objective

To use a global statistical approach that incorporates assessments of multiple outcomes to reassess the efficacy of riluzole in patients undergoing spinal surgery for DCM.

Design, Setting, and Participants

This was a secondary analysis of prespecified secondary end points within the Efficacy of Riluzole in Surgical Treatment for Cervical Spondylotic Myelopathy (CSM-PROTECT) trial, a multicenter, double-blind, phase 3 randomized clinical trial conducted from January 2012 to May 2017. Adult surgical patients with DCM with moderate to severe myelopathy (mJOA scale score of 8-14) were randomized to receive either riluzole or placebo. The present study was conducted from July to December 2023.

Intervention

Riluzole (50 mg twice daily) or placebo for a total of 6 weeks, including 2 weeks prior to surgery and 4 weeks following surgery.

Main Outcomes and Measures

The primary outcome measure was a difference in clinical improvement from baseline to 1-year follow-up, assessed using a global statistical test (GST). The 36-Item Short Form Health Survey Physical Component Score (SF-36 PCS), arm and neck pain numeric rating scale (NRS) scores, American Spinal Injury Association (ASIA) motor score, and Nurick grade were combined into a single summary statistic known as the global treatment effect (GTE).

Results

Overall, 290 patients (riluzole group, 141; placebo group, 149; mean [SD] age, 59 [10.1] years; 161 [56%] male) were included. Riluzole showed a significantly higher probability of global improvement compared with placebo at 1-year follow-up (GTE, 0.08; 95% CI, 0.00-0.16; P = .02). A similar favorable global response was seen at 35 days and 6 months (GTE for both, 0.07; 95% CI, -0.01 to 0.15; P = .04), although the results were not statistically significant. Riluzole-treated patients had at least a 54% likelihood of achieving better outcomes at 1 year compared with the placebo group. The ASIA motor score and neck and arm pain NRS combination at 1 year provided the best-fit parsimonious model for detecting a benefit of riluzole (GTE, 0.11; 95% CI, 0.02-0.16; P = .007).

Conclusions and Relevance

In this secondary analysis of the CSM-PROTECT trial using a global outcome technique, riluzole was associated with improved clinical outcomes in patients with DCM. The GST offered probability-based results capable of representing diverse outcome scales and should be considered in future studies assessing spine surgery outcomes.

Perspective on statistical power and equivalence tests

The use of both sexes or genders should be considered in experimental design, analysis, and reporting. Since there is no requirement to double the sample size or to have sufficient power to study sex differences, challenges for the statistical analysis can arise. In this article, we focus on the topics of statistical power and ways to increase this power. We also discuss the choice of an appropriate design and statistical method and include a separate section on equivalence tests needed to show the absence of a relevant difference.

Bayesian Multivariate Logistic Regression for Superiority and Inferiority Decision-Making under Observable Treatment Heterogeneity

The effects of treatments may differ between persons with different characteristics. Addressing such treatment heterogeneity is crucial to investigate whether patients with specific characteristics are likely to benefit from a new treatment. The current paper presents a novel Bayesian method for superiority decision-making in the context of randomized controlled trials with multivariate binary responses and heterogeneous treatment effects. The framework is based on three elements: a) Bayesian multivariate logistic regression analysis with a Pólya-Gamma expansion; b) a transformation procedure to transfer obtained regression coefficients to a more intuitive multivariate probability scale (i.e., success probabilities and the differences between them); and c) a compatible decision procedure for treatment comparison with prespecified decision error rates. Procedures for a priori sample size estimation under a non-informative prior distribution are included. A numerical evaluation demonstrated that decisions based on a priori sample size estimation resulted in anticipated error rates among the trial population as well as subpopulations. Further, average and conditional treatment effect parameters could be estimated unbiasedly when the sample was large enough. Illustration with the International Stroke Trial dataset revealed a trend toward heterogeneous effects among stroke patients: Something that would have remained undetected when analyses were limited to average treatment effects.

Istore: a project on innovative statistical methodologies to improve rare diseases clinical trials in limited populations

BACKGROUND

The conduct of rare disease clinical trials is still hampered by methodological problems. The number of patients suffering from a rare condition is variable, but may be very small and unfortunately statistical problems for small and finite populations have received less consideration. This paper describes the outline of the iSTORE project, its ambitions, and its methodological approaches.

METHODS

In very small populations, methodological challenges exacerbate. iSTORE's ambition is to develop a comprehensive perspective on natural history course modelling through multiple endpoint methodologies, subgroup similarity identification, and improving level of evidence.

RESULTS

The methodological approaches cover methods for sound scientific modeling of natural history course data, showing similarity between subgroups, defining, and analyzing multiple endpoints and quantifying the level of evidence in multiple endpoint trials that are often hampered by bias.

CONCLUSION

Through its expected results, iSTORE will contribute to the rare diseases research field by providing an approach to better inform about and thus being able to plan a clinical trial. The methodological derivations can be synchronized and transferability will be outlined.

Incorporating Data from Multiple Endpoints in the Analysis of Clinical Trials: Example from RSV Vaccines

BACKGROUND

To meet regulatory approval, interventions must demonstrate efficacy against a primary outcome in randomized clinical trials. However, when there are multiple clinically relevant outcomes, selecting a single primary outcome is challenging. Incorporating data from multiple outcomes may increase statistical power in clinical trials. We examined methods for analyzing data on multiple endpoints, inspired by real-world trials of interventions against respiratory syncytial virus (RSV).

METHOD

We developed a novel permutation test representing a weighted average of individual outcome test statistics ( wavP ) to evaluate intervention efficacy in a multiple endpoint analysis. We compared the power and type I error rate of this approach to the Bonferroni correction ( bonfT ) and the minP permutation test. We evaluated the different approaches using simulated data from three hypothetical trials varying the intervention efficacy, correlation, and incidence of the outcomes, and data from a real-world RSV clinical trial.

RESULTS

When the vaccine efficacy against different outcomes was similar, wavP yielded higher power than bonfT and minP ; in some scenarios the improvement in power was substantial. In settings where vaccine efficacy was notably larger against one endpoint compared with the others, all three methods had similar power. We developed an R package, PERmutation basEd ANalysis of mulTiple Endpoints (PERMEATE), to guide the selection of the most appropriate method for analyzing multiple endpoints in clinical trials.

CONCLUSIONS

Analyzing multiple endpoints using a weighted permutation method can increase power, whereas controlling the type I error rate compared with established methods under conditions mirroring real-world RSV clinical trials.

Optimal multiple testing and design in clinical trials

A central goal in designing clinical trials is to find the test that maximizes power (or equivalently minimizes required sample size) for finding a false null hypothesis subject to the constraint of type I error. When there is more than one test, such as in clinical trials with multiple endpoints, the issues of optimal design and optimal procedures become more complex. In this paper, we address the question of how such optimal tests should be defined and how they can be found. We review different notions of power and how they relate to study goals, and also consider the requirements of type I error control and the nature of the procedures. This leads us to an explicit optimization problem with objective and constraints that describe its specific desiderata. We present a complete solution for deriving optimal procedures for two hypotheses, which have desired monotonicity properties, and are computationally simple. For some of the optimization formulations this yields optimal procedures that are identical to existing procedures, such as Hommel's procedure or the procedure of Bittman et al. (2009), while for other cases it yields completely novel and more powerful procedures than existing ones. We demonstrate the nature of our novel procedures and their improved power extensively in a simulation and on the APEX study (Cohen et al., 2016).

Composite endpoints, including patient reported outcomes, in rare diseases

BACKGROUND

When assessing the efficacy of a treatment in any clinical trial, it is recommended by the International Conference on Harmonisation to select a single meaningful endpoint. However, a single endpoint is often not sufficient to reflect the full clinical benefit of a treatment in multifaceted diseases, which is often the case in rare diseases. Therefore, the use of a combination of several clinically meaningful outcomes is preferred. Many methodologies that allow for combining outcomes in a so-called composite endpoint are however limited in a number of ways, not in the least in the number and type of outcomes that can be combined and in the poor small-sample properties. Moreover, patient reported outcomes, such as quality of life, often cannot be integrated in a composite analysis, in spite of their intrinsic value.

RESULTS

Recently, a class of non-parametric generalized pairwise comparisons tests have been proposed, which members do allow for any number and type of outcomes, including patient reported outcomes. The class enjoys good small-sample properties. Moreover, this very flexible class of methods allows for prioritizing the outcomes by clinical severity, allows for matched designs and for adding a threshold of clinical relevance. Our aim is to introduce the generalized pairwise comparison ideas and concepts for rare disease clinical trial analysis, and demonstrate their benefit in a post-hoc analysis of a small-sample trial in epidermolysis bullosa. More precisely, we will include a patient relevant outcome (Quality of life), in a composite endpoint. This publication is part of the European Joint Programme on Rare Diseases (EJP RD) series on innovative methodologies for rare diseases clinical trials, which is based on the webinars presented within the educational activity of EJP RD. This publication covers the webinar topic on composite endpoints in rare diseases and includes participants' response to a questionnaire on this topic.

CONCLUSIONS

Generalized pairwise comparisons is a promising statistical methodology for evaluating any type of composite endpoints in rare disease trials and may allow a better evaluation of therapy efficacy including patients reported outcomes in addition to outcomes related to the diseases signs and symptoms.

Development of a Rasch-Built Amyotrophic Lateral Sclerosis Impairment Multidomain Scale to Measure Disease Progression in ALS

BACKGROUND AND OBJECTIVES

Current scales used in amyotrophic lateral sclerosis (ALS) attempt to summarize different functional domains or "dimensions" into 1 overall score, which may not accurately characterize the individual patient's disease severity or prognosis. The use of composite score risks declaring treatments ineffective if not all dimensions of ALS disease progression are affected equally. We aimed to develop the ALS Impairment Multidomain Scale (AIMS) to comprehensively characterize disease progression and increase the likelihood of identifying effective treatments.

METHODS

The Revised ALS Functional Rating Scale (ALSFRS-R) and a preliminary questionnaire, based on literature review and patient input, were completed online by patients from the Netherlands ALS registry at bimonthly intervals over a period of 12 months. A 2-week test-retest, factor analysis, Rasch analysis, and a signal-to-noise optimization strategy were performed to create a multidomain scale. Reliability, longitudinal decline, and associations with survival were evaluated. The sample size required to detect a 35% reduction in progression rate over 6 or 12 months was assessed for a clinical trial that defines the ALSFRS-R or AIMS subscales as a primary endpoint family.

RESULTS

The preliminary questionnaire, consisting of 110 questions, was completed by 367 patients. Three unidimensional subscales were identified, and a multidomain scale was constructed with 7 bulbar, 11 motor, and 5 respiratory questions. Subscales fulfilled Rasch model requirements, with excellent test-retest reliability of 0.91-0.94 and a strong relationship with survival (p < 0.001). Compared with the ALSFRS-R, signal-to-noise ratios were higher as patients declined more uniformly per subscale. Consequently, the estimated sample size reductions achieved with the AIMS compared with those achieved with the ALSFRS-R were 16.3% and 25.9% for 6-month and 12-month clinical trials, respectively.

DISCUSSION

We developed the AIMS, consisting of unidimensional bulbar, motor, and respiratory subscales, which may characterize disease severity better than a total score. AIMS subscales have high test-retest reliability, are optimized to measure disease progression, and are strongly related to survival time. The AIMS can be easily administered and may increase the likelihood of identifying effective treatments in ALS clinical trials.

What makes TMB an ambivalent biomarker for immunotherapy? A subtle mismatch between the sample-based design of variant callers and real clinical cohort

Tumor mutation burden (TMB) is a widely recognized biomarker for predicting the efficacy of immunotherapy. However, its use still remains highly controversial. In this study, we examine the underlying causes of this controversy based on clinical needs. By tracing the source of the TMB errors and analyzing the design philosophy behind variant callers, we identify the conflict between the incompleteness of biostatistics rules and the variety of clinical samples as the critical issue that renders TMB an ambivalent biomarker. A series of experiments were conducted to illustrate the challenges of mutation detection in clinical practice. Additionally, we also discuss potential strategies for overcoming these conflict issues to enable the application of TMB in guiding decision-making in real clinical settings.

How are health technology assessment bodies responding to the assessment challenges posed by cell and gene therapy?

BACKGROUND

The aims of this research were to provide a better understanding of the specific evidence needs for assessment of clinical and cost-effectiveness of cell and gene therapies, and to explore the extent that the relevant categories of evidence are considered in health technology assessment (HTA) processes.

METHODS

A targeted literature review was conducted to identify the specific categories of evidence relevant to the assessment of these therapies. Forty-six HTA reports for 9 products in 10 cell and gene therapy indications across 8 jurisdictions were analysed to determine the extent to which various items of evidence were considered.

RESULTS

The items to which the HTA bodies reacted positively were: treatment was for a rare disease or serious condition, lack of alternative therapies, evidence indicating substantial health gains, and when alternative payment models could be agreed. The items to which they reacted negatively were: use of unvalidated surrogate endpoints, single arm trials without an adequately matched alternative therapy, inadequate reporting of adverse consequences and risks, short length of follow-up in clinical trials, extrapolating to long-term outcomes, and uncertainty around the economic estimates.

CONCLUSIONS

The consideration by HTA bodies of evidence relating to the particular features of cell and gene therapies is variable. Several suggestions are made for addressing the assessment challenges posed by these therapies. Jurisdictions conducting HTAs of these therapies can consider whether these suggestions could be incorporated within their existing approach through strengthening deliberative decision-making or performing additional analyses.

Incorporating data from multiple endpoints in the analysis of clinical trials: example from RSV vaccines

Background

To achieve licensure, interventions typically must demonstrate efficacy against a primary outcome in a randomized clinical trial. However, selecting a single primary outcome a priori is challenging. Incorporating data from multiple and related outcomes might help to increase statistical power in clinical trials. Inspired by real-world clinical trials of interventions against respiratory syncytial virus (RSV), we examined methods for analyzing data on multiple endpoints.

Method

We simulated data from three different populations in which the efficacy of the intervention and the correlation among outcomes varied. We developed a novel permutation-based approach that represents a weighted average of individual outcome test statistics ( varP ) to evaluate intervention efficacy in a multiple endpoint analysis. We compared the power and type I error rate of this approach to two alternative methods: the Bonferroni correction ( bonfT ) and another permutation-based approach that uses the minimum P-value across all test statistics ( minP ).

Results

When the vaccine efficacy against different outcomes was similar, VarP yielded higher power than bonfT and minP; in some scenarios the improvement in power was substantial. In settings where vaccine efficacy was notably larger against one endpoint compared to the others, all three methods had similar power.

Conclusions

Analyzing multiple endpoints using a weighted permutation method can increase power while controlling the type I error rate in settings where outcomes share similar characteristics, like RSV outcomes. We developed an R package, PERMEATE , to guide selection of the most appropriate method for analyzing multiple endpoints in clinical trials.

Targeted Oral Naltrexone for Mild to Moderate Alcohol Use Disorder Among Sexual and Gender Minority Men: A Randomized Trial

OBJECTIVE

The authors sought to determine the efficacy of targeted naltrexone in sexual and gender minority men (SGM) who binge drink and have mild to moderate alcohol use disorder.

METHODS

In a double-blind placebo-controlled trial, a total of 120 SGM who binge drink and have mild to moderate alcohol use disorder were randomized in a 1:1 ratio to receive targeted oral naltrexone (50 mg) or placebo with weekly counseling for 12 weeks. The study's primary endpoints were binge-drinking intensity, defined as 1) number of drinks in the past 30 days; 2) any binge drinking in the past week; 3) number of binge-drinking days in the past week; and 4) number of drinking days in the past week. The study also measured changes in alcohol use with two alcohol biomarker measures: ethyl glucuronide in urine samples and phosphatidylethanol (PEth) in dried blood spot samples.

RESULTS

Ninety-three percent completed the trial, with 85% of weekly follow-up visits completed. In intention-to-treat analyses, naltrexone was associated with a significantly reduced reported number of binge-drinking days (incidence rate ratio [IRR]=0.74, 95% CI=0.56, 0.98; number needed to treat [NNT]=2), weeks with any binge drinking (IRR=0.83, 95% CI=0.72, 0.96; NNT=7.4), number of drinks per month (IRR=0.69, 95% CI=0.52, 0.91; NNT=5.7 for 10 drinks), and alcohol craving scores (coefficient=-9.25, 95% CI=-17.20, -1.31). In as-treated analyses among those who took their medication on average at least 2.5 days per week (the median frequency in the study), naltrexone reduced any binge drinking (IRR=0.84, 95% CI=0.71, 0.99), number of binge-drinking days (IRR=0.67, 95% CI=0.47, 0.96), and PEth concentrations (coefficient=-55.47, 95% CI=-110.75, -0.20). At 6 months posttreatment, naltrexone had sustained effects in number of drinks per month (IRR=0.69, 95% CI=0.50, 0.97), number of binge-drinking days (IRR=0.67, 95% CI=0.47, 0.95), and any binge drinking in the past week (IRR=0.79, 95% CI=0.63, 0.99).

CONCLUSIONS

Targeted naltrexone significantly reduced drinking outcomes among SGM with mild to moderate alcohol use disorder during treatment, with sustained effects at 6 months posttreatment. Naltrexone may be an important pharmacotherapy to address binge drinking in populations with mild to moderate alcohol use disorder.

TMBcat: A multi-endpoint p-value criterion on different discrepancy metrics for superiorly inferring tumor mutation burden thresholds

Tumor mutation burden (TMB) is a widely recognized stratification biomarker for predicting the efficacy of immunotherapy; however, the number and universal definition of the categorizing thresholds remain debatable due to the multifaceted nature of efficacy and the imprecision of TMB measurements. We proposed a minimal joint p-value criterion from the perspective of differentiating the comprehensive therapeutic advantages, termed TMBcat, optimized TMB categorization across distinct cancer cohorts and surpassed known benchmarks. The statistical framework applies to multidimensional endpoints and is fault-tolerant to TMB measurement errors. To explore the association between TMB and various immunotherapy outcomes, we performed a retrospective analysis on 78 patients with non-small cell lung cancer and 64 patients with nasopharyngeal carcinomas who underwent anti-PD-(L)1 therapy. The stratification results of TMBcat confirmed that the relationship between TMB and immunotherapy is non-linear, i.e., treatment gains do not inherently increase with higher TMB, and the pattern varies across carcinomas. Thus, multiple TMB classification thresholds could distinguish patient prognosis flexibly. These findings were further validated in an assembled cohort of 943 patients obtained from 11 published studies. In conclusion, our work presents a general criterion and an accessible software package; together, they enable optimal TMB subgrouping. Our study has the potential to yield innovative insights into therapeutic selection and treatment strategies for patients.

A Joint Model Considering Measurement Errors for Optimally Identifying Tumor Mutation Burden Threshold

Tumor mutation burden (TMB) is a recognized stratification biomarker for immunotherapy. Nevertheless, the general TMB-high threshold is unstandardized due to severe clinical controversies, with the underlying cause being inconsistency between multiple assessment criteria and imprecision of the TMB value. The existing methods for determining TMB thresholds all consider only a single dimension of clinical benefit and ignore the interference of the TMB error. Our research aims to determine the TMB threshold optimally based on multifaceted clinical efficacies accounting for measurement errors. We report a multi-endpoint joint model as a generalized method for inferring the TMB thresholds, facilitating consistent statistical inference using an iterative numerical estimation procedure considering mis-specified covariates. The model optimizes the division by combining objective response rate and time-to-event outcomes, which may be interrelated due to some shared traits. We augment previous works by enabling subject-specific random effects to govern the communication among distinct endpoints. Our simulations show that the proposed model has advantages over the standard model in terms of precision and stability in parameter estimation and threshold determination. To validate the feasibility of the proposed thresholds, we pool a cohort of 73 patients with non-small-cell lung cancer and 64 patients with nasopharyngeal carcinoma who underwent anti-PD-(L)1 treatment, as well as validation cohorts of 943 patients. Analyses revealed that our approach could grant clinicians a holistic efficacy assessment, culminating in a robust determination of the TMB screening threshold for superior patients. Our methodology has the potential to yield innovative insights into therapeutic selection and support precision immuno-oncology.

Review of neuropsychological outcomes in isolated methylmalonic acidemia: recommendations for assessing impact of treatments

Methylmalonic acidemia (MMA) due to methylmalonyl-CoA mutase deficiency (OMIM #251,000) is an autosomal recessive disorder of organic acid metabolism associated with life-threatening acute metabolic decompensations and significant neuropsychological deficits. "Isolated" MMA refers to the presence of excess methylmalonic acid without homocysteine elevation. Belonging to this class of disorders are those that involve complete deficiency (mut⁰) and partial deficiency (mut^-) of the methylmalonyl-CoA mutase enzyme and other disorders causing excess methylmalonic acid excretion. These other disorders include enzymatic subtypes related to cobalamin A defect (cblA) (OMIM #25,110), cobalamin B defect (cblB) (OMIM #251,110) and related conditions. Neuropsychological attributes associated with isolated MMA have become more relevant as survival rates increased following improved diagnostic and treatment strategies. Children with this disorder still are at risk for developmental delay, cognitive difficulties and progressive declines in functioning. Mean IQ for all types apart from cblA defect enzymatic subtype is rarely above 85 and much lower for mut⁰ enzymatic subtype. Identifying psychological domains responsive to improvements in biochemical status is important. This review suggests that processing speed, working memory, language, attention, and quality of life may be sensitive to fluctuations in metabolite levels while IQ and motor skills may be less amenable to change. Due to slower developmental trajectories, Growth Scale Values, Projected Retained Ability Scores and other indices of change need to be incorporated into clinical trial study protocols. Neuropsychologists are uniquely qualified to provide a differentiated picture of cognitive, behavioral and emotional consequences of MMA and analyze benefits or shortcomings of novel treatments.

Evaluating treatment effects in group sequential multivariate longitudinal studies with covariate adjustment

Jeffries et al. (2018) investigated testing for a treatment difference in the setting of a randomized clinical trial with a single outcome measured longitudinally over a series of common follow-up times while adjusting for covariates. That paper examined the null hypothesis of no difference at any follow-up time versus the alternative of a difference for at least one follow-up time. We extend those results here by considering multivariate outcome measurements, where each individual outcome is examined at common follow-up times. We consider the case where there is interest in first testing for a treatment difference in a global function of the outcomes (e.g., weighted average or sum) with subsequent interest in examining the individual outcomes, should the global function show a treatment difference. Testing is conducted for each follow-up time and may be performed in the setting of a group sequential trial. Testing procedures are developed to determine follow-up times for which a global treatment difference exists and which individual combinations of outcome and follow-up time show evidence of a difference while controlling for multiplicity in outcomes, follow-up, and interim analyses. These approaches are examined in a study evaluating the effects of tissue plasminogen activator on longitudinally obtained stroke severity measurements.

Cohort-based association study of germline genetic variants with acute and chronic health complications of childhood cancer and its treatment: Genetic Risks for Childhood Cancer Complications Switzerland (GECCOS) study protocol

INTRODUCTION

Childhood cancer and its treatment may lead to various health complications. Related impairment in quality of life, excess in deaths and accumulated healthcare costs are relevant. Genetic variations are suggested to contribute to the wide inter-individual variability of complications but have been used only rarely to risk-stratify treatment and follow-up care. This study aims to identify germline genetic variants associated with acute and late complications of childhood cancer.

METHODS AND ANALYSIS

The Genetic Risks for Childhood Cancer Complications Switzerland (GECCOS) study is a nationwide cohort study. Eligible are patients and survivors who were diagnosed with childhood cancers or Langerhans cell histiocytosis before age 21 years, were registered in the Swiss Childhood Cancer Registry (SCCR) since 1976 and have consented to the Paediatric Biobank for Research in Haematology and Oncology, Geneva, host of the national Germline DNA Biobank Switzerland for Childhood Cancer and Blood Disorders (BISKIDS).GECCOS uses demographic and clinical data from the SCCR and the associated Swiss Childhood Cancer Survivor Study. Clinical outcome data consists of organ function testing, health conditions diagnosed by physicians, second primary neoplasms and self-reported information from participants. Germline genetic samples and sequencing data are collected in BISKIDS. We will perform association analyses using primarily whole-exome or whole-genome sequencing to identify genetic variants associated with specified health conditions. We will use clustering and machine-learning techniques and assess multiple health conditions in different models.

DISCUSSION

GECCOS will improve knowledge of germline genetic variants associated with childhood cancer-associated health conditions and help to further individualise cancer treatment and follow-up care, potentially resulting in improved efficacy and reduced side effects.

ETHICS AND DISSEMINATION

The Geneva Cantonal Commission for Research Ethics has approved the GECCOS study.Research findings will be disseminated through national and international conferences, publications in peer-reviewed journals and in lay language online.

TRIAL REGISTRATION NUMBER

NCT04702321.

Bivariate Bayesian hypothesis testing with missing data in components

Multiple endpoints and historical data borrowing may be simultaneously incorporated for enhancing efficiency and speeding up the new drug development process in the pharmaceutical industry. O'Brien's test is a widely used weighted combination test for multiplicity adjustment on multiple endpoints to control the overall type error rate in a weak sense. In this research, a modification on the O'Brien's test more specifically on the weights is considered for a trial with two primary endpoints to potentially increase power. The method can handle missing data in the current study and in the prior derivation for dynamic historical data borrowing. Simulations are conducted to compare the performances of different methods. A data example is used to illustrate the applications of the methods.

Constraint-Induced Movement Therapy for Cerebral Palsy: A Randomized Trial

OBJECTIVES

With the Children with Hemiparesis Arm and Hand Movement Project (CHAMP) multisite factorial randomized controlled trial, we compared 2 doses and 2 constraint types of constraint-induced movement therapy (CIMT) to usual customary treatment (UCT).

METHODS

CHAMP randomly assigned 118 2- to 8-year-olds with hemiparetic cerebral palsy to one of 5 treatments with assessments at baseline, end of treatment, and 6 months posttreatment. Primary blinded outcomes were the assisting hand assessment; Peabody Motor Development Scales, Second Edition, Visual Motor Integration; and Quality of Upper Extremity Skills Test Dissociated Movement. Parents rated functioning on the Pediatric Evaluation of Disabilities Inventory-Computer Adaptive Test Daily Activities and Child Motor Activity Log How Often scale. Analyses were focused on blinded and parent-report outcomes and rank-order gains across all measures.

RESULTS

Findings varied in statistical significance when analyzing individual blinded outcomes. parent reports, and rank-order gains. Consistently, high-dose CIMT, regardless of constraint type, produced a pattern of greatest short- and long-term gains (1.7% probability of occurring by chance alone) and significant gains on visual motor integration and dissociated movement at 6 months. O'Brien's rank-order analyses revealed high-dose CIMT produced significantly greater improvement than a moderate dose or UCT. All CIMT groups improved significantly more in parent-reported functioning, compared with that of UCT. Children with UCT also revealed objective gains (eg, 48% exceeded the smallest-detectable assisting hand assessment change, compared with 71% high-dose CIMT at the end of treatment).

CONCLUSIONS

CHAMP provides novel albeit complex findings: although most individual blinded outcomes fell below statistical significance for group differences, high-dose CIMT consistently produced the largest improvements at both time points. An unexpected finding concerns shifts in UCT toward higher dosages, with improved outcomes compared with previous reports.

A 16-week randomized controlled trial of a fish oil and whey protein-derived supplement to improve physical performance in older adults losing autonomy-A pilot study

Background

Low functional capacity may lead to the loss of independence and institutionalization of older adults. A nutritional intervention within a rehabilitation program may attenuate loss of muscle function in this understudied population.

Objective

This pilot study assessed the feasibility for a larger RCT of a nutritional supplementation in older adults referred to an outpatient assessment and rehabilitation program.

Methods

Participants were randomized to receive a supplement (EXP: 2g fish oil with 1500 IU vitamin D3 1x/d + 20-30g whey protein powder with 3g leucine 2x/d) or isocaloric placebo (CTR: corn oil + maltodextrin powder) for 16 weeks. Handgrip and knee extension strength (using dynamometry), physical performance tests and plasma phospholipid n-3 fatty acids (using GCMS) were evaluated at weeks 0, 8 and 16; and lean soft tissue mass (using DXA), at weeks 0 and 16.

Results

Over 2 years, 244 patients were screened, 46 were eligible (18.9%), 20 were randomized, 10 completed the study (6 CTR, 4 EXP). Median age was 87 y (77–94 y; 75% women) and gait speed was 0.69 m/s; 55% had low strength, and all performed under 420m on the 6-minute walk test, at baseline. Overall self-reported compliance to powder and oil was high (96% and 85%) but declined at 16 weeks for fish oil (55%). The EXP median protein intake surpassed the target 1.2–1.5 g/kg/d, without altering usual diet. Proportions of plasma phospholipid EPA and DHA increased significantly 3- and 1.5-fold respectively, at week 8 in EXP, with no change in CTR. Participants were able to complete most assessments with sustained guidance.

Conclusion

Because of low eligibility, the pilot study was interrupted and deemed non-feasible; adherence to rigorous study assessments and to supplements was adequate except for long-term fish oil. The non-amended protocol may be applied to populations with greater functional capacity.

Trial registration

ClinicalTrials.gov NCT04454359.

An old friend who has overstayed their welcome: the ALSFRS-R total score as primary endpoint for ALS clinical trials

Objective: The ALSFRS-R is limited by multidimensionality, which originates from the summation of various subscales. This prevents a direct comparison between patients with identical total scores. We aim to evaluate how multidimensionality affects the performance of the ALSFRS-R in clinical trials. Methods: We simulated clinical trial data with different treatment effects for the ALSFRS-R total score and its subscales (i.e. bulbar, fine motor, gross motor and respiratory). We considered scenarios where treatment reduced the rate of ALSFRS-R subscale decline either uniformly (i.e. all subscales respond identically to treatment) or non-uniformly (i.e. subscales respond differently to treatment). Two main analytical strategies were compared: (1) analyzing only the total score or (2) utilizing a subscale-based test (i.e. alternative strategy). For each analytical strategy, we calculated the empirical power and required sample size. Results: Both strategies are valid when there is no treatment benefit and provide adequate control of type 1 error. If all subscales respond identically to treatment, using the total score is the most powerful approach. As the differences in treatment responses between subscales increase, the more the total score becomes affected. For example, to detect a 40% reduction in the bulbar rate of decline with 80% power, the total score requires 1380 patients, whereas this is 336 when using the alternative strategy. Conclusions: Ignoring the multidimensional structure of the ALSFRS-R total score could have negative consequences for ALS clinical trials. We propose determining treatment benefit on a subscale level, prior to stating whether a treatment is generally effective.

Rare Diseases and Otorhinolaryngology, Head and Neck Surgery

Rare diseases pose multiple challenges for patients, relatives, physicians, nursing staff, and therapists. Their rarity impedes research and treatments due to medical and economical reasons. Many diseases in the field otorhinolaryngology, head and neck surgery are rare diseases due to their low prevalence. The initiation of the right management processes requires knowledge about diagnostics, resources like centers, networks and registries, about specifics of the physician-patient relationship, follow-up care including communication with family doctors and the role of self-help groups. Of special interest for university hospitals and our scientific society are the specific aspects of research including European networks and research funding, information management, public relations, education, training, financing, and regulations like orphan drugs and clinical trials in small populations.

Read-through approach for stop mutations in Duchenne muscular dystrophy. An update

Dystrophinopathies are allelic conditions caused by deletions, duplications and point-mutations in the DMD gene, located on the X chromosome (Xp21.2). Mutations that prematurely interrupt the dystrophin protein synthesis lead to the most severe clinical form, Duchenne muscular Dystrophy, characterized by early involvement of muscle strength. There is no known cure for dystrophinopathies. In DMD, treatment with corticosteroids have changed the natural history and the progression of the disease, prolonging ambulation, and slowing the onset of respiratory and cardiac involvement and scoliosis by several years. In the last few years, new perspectives and options are deriving from the discovery of pharmacological approaches able to restore normal, full-length dystrophin and potentially reverse the course of the disease. Read-through (RT) of nonsense mutations, thanks to its ability to bypass the premature stop codon and to act on virtually any region of the dystrophin gene, independently of the location in which the mutation resides, is one of these promising approaches. This non-systematic review shows the different steps that, passing from yeast to humans, have made it possible to use this innovative successful approach to treat serious diseases such as Duchenne muscular dystrophy.

Developing new treatments in partnership for primary mitochondrial disease: What does industry need from academics, and what do academics need from industry?

Developing novel therapeutics for primary mitochondrial disease is likely to require significant academia-industry collaboration. Translational assessments, a tool often used in industry at target validation stage, can highlight disease specific development challenges which requires focused collaborative effort. For PMD, definition of pivotal trial populations and primary endpoints is challenging given lack of clinical precedence, high numbers of subgroups with overlapping symptoms despite common genetics. Disease pathophysiology has not been systematically assessed simultaneously with outcomes in available natural history studies, resulting in a lack of pathophysiology biomarker utilization in clinical trials. Preclinical model systems are available to assist drug development efforts, although these may require better standardization and access. Multistakeholder precompetitive efforts have been used to progress disease pathophysiology biomarker and confirmatory clinical trial endpoint readiness in neurological disease with limited treatment options, such as rare familial Parkinson's disease. This type of approach may be beneficial for PMD therapeutic development, although requires significant funding and time, supported by industry and other funding bodies. Industry expertise on chemistry, data quality and drug development know-how is available to support academic drug development efforts. A combination of industry mindset-reduction of uncertainty to provide an indication statement supportable by evidence-together with academic approach-question-based studies to understand disease mechanisms and patients-has great potential to deliver novel PMD therapeutics.

Pharmacological Prevention of Neonatal Opioid Withdrawal in a Pregnant Guinea Pig Model

Newborns exposed to prenatal opioids often experience intense postnatal withdrawal after cessation of the opioid, called neonatal opioid withdrawal syndrome (NOWS), with limited pre- and postnatal therapeutic options available. In a prior study in pregnant mice we demonstrated that the peripherally selective opioid antagonist, 6β-naltrexol (6BN), is a promising drug candidate for preventive prenatal treatment of NOWS, and a therapeutic mechanism was proposed based on preferential delivery of 6BN to fetal brain with relative exclusion from maternal brain. Here, we have developed methadone (MTD) treated pregnant guinea pigs as a physiologically more suitable model, enabling detection of robust spontaneous neonatal withdrawal. Prenatal MTD significantly aggravates two classic maternal separation stress behaviors in newborn guinea pigs: calling (vocalizing) and searching (locomotion) - natural attachment behaviors thought to be controlled by the endogenous opioid system. In addition, prenatal MTD significantly increases the levels of plasma cortisol in newborns, showing that cessation of MTD at birth engages the hypothalamic-pituitary-adrenal (HPA) axis. We find that co-administration of 6BN with MTD prevents these withdrawal symptoms in newborn pups with extreme potency (ID50 ∼0.02 mg/kg), at doses unlikely to induce maternal or fetal withdrawal or to interfere with opioid antinociception based on many prior studies in rodents and non-human primates. Furthermore, we demonstrate a similarly high potency of 6BN in preventing opioid withdrawal in adult guinea pigs (ID50 = 0.01 mg/kg). This high potency appears to run counter to our pharmacokinetic studies showing slow 6BN transit of both the placenta and maternal blood brain barrier in guinea pigs, and calls into question the preferential delivery mechanism. Rather, it suggests a novel receptor mechanism to account for the selectively high potency of 6BN to suppress opioid dependence at all developmental stages, even in adults, as compared to its well-established low potency as a classical opioid antagonist. In conclusion, 6BN is an attractive compound for development of a preventive therapy for NOWS.

Efficacy of team-based collaborative care for distressed patients in secondary prevention of chronic coronary heart disease (TEACH): study protocol of a multicenter randomized controlled trial

BACKGROUND

Coronary heart disease (CHD) is the leading cause of death and years of life lost worldwide. While effective treatments are available for both acute and chronic disease stages there are unmet needs for effective interventions to support patients in health behaviors required for secondary prevention. Psychosocial distress is a common comorbidity in patients with CHD and associated with substantially reduced health-related quality of life (HRQoL), poor health behavior, and low treatment adherence.

METHODS

In a confirmatory, randomized, controlled, two-arm parallel group, multicenter behavioral intervention trial we will randomize 440 distressed CHD patients with at least one insufficiently controlled cardiac risk factor to either their physicians' usual care (UC) or UC plus 12-months of blended collaborative care (TeamCare = TC). Trained nurse care managers (NCM) will proactively support patients to identify individual sources of distress and risk behaviors, establish a stepwise treatment plan to improve self-help and healthy behavior, and actively monitor adherence and progress. Additional e-health resources are available to patients and their families. Intervention fidelity is ensured by a treatment manual, an electronic patient registry, and a specialist team regularly supervising NCM via videoconferences and recommending protocol and guideline-compliant treatment adjustments as indicated. Recommendations will be shared with patients and their physicians who remain in charge of patients' care. Since HRQoL is a recommended outcome by both, several guidelines and patient preference we chose a ≥ 50% improvement over baseline on the HeartQoL questionnaire at 12 months as primary outcome. Our primary hypothesis is that significantly more patients receiving TC will meet the primary outcome criterion compared to the UC group. Secondary hypotheses will evaluate improvements in risk factors, psychosocial variables, health care utilization, and durability of intervention effects over 18-30 months of follow-up.

DISCUSSION

TEACH is the first study of a blended collaborative care intervention simultaneously addressing distress and medical CHD risk factors conducted in cardiac patients in a European health care setting. If proven effective, its results can improve long-term chronic care of this vulnerable patient group and may be adapted for patients with other chronic conditions.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00020824, registered on 4 June, 2020; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00020824.

A flexible multi-domain test with adaptive weights and its application to clinical trials

The design of a clinical trial is often complicated by the multi-systemic nature of the disease; a single endpoint often cannot capture the spectrum of potential therapeutic benefits. Multi-domain outcomes which take into account patient heterogeneity of disease presentation through measurements of multiple symptom/functional domains are an attractive alternative to a single endpoint. A multi-domain test with adaptive weights is proposed to synthesize the evidence of treatment efficacy over numerous disease domains. The test is a weighted sum of domain-specific test statistics with weights selected adaptively via a data-driven algorithm. The null distribution of the test statistic is constructed empirically through resampling and does not require estimation of the covariance structure of domain-specific test statistics. Simulations show that the proposed test controls the type I error rate, and has increased power over other methods such as the O'Brien and Wei-Lachin tests in scenarios reflective of clinical trial settings. Data from a clinical trial in a rare lysosomal storage disorder were used to illustrate the properties of the proposed test. As a strategy of combining marginal test statistics, the proposed test is flexible and readily applicable to a variety of clinical trial scenarios.