Ensuring Stakeholder Feedback in the Design and Conduct of Clinical Trials for Rare Diseases: ISCTM Position Paper of the Orphan Disease Working Group.

The 1983 Orphan Drug Act in the United States (US) changed the landscape for development of therapeutics for rare or orphan diseases, which collectively affect approximately 300 million people worldwide, half of whom are children. The act has undoubtedly accelerated drug development for orphan diseases, with over 6,400 orphan drug applications submitted to the US Food and Drug Administration (FDA) from 1983 to 2023, including 350 drugs approved for over 420 indications. Drug development in this population is a global and collaborative endeavor. This position paper of the International Society for Central Nervous System Clinical Trials and Methodology (ISCTM) describes some potential best practices for the involvement of key stakeholder feedback in the drug development process. Stakeholders include advocacy groups, patients and caregivers with lived experience, public and private research institutions (including academia and pharmaceutical companies), treating clinicians, and funders (including the government and independent foundations). The authors articulate the challenges of drug development in orphan diseases and propose methods to address them. Challenges range from the poor understanding of disease history to development of endpoints, targets, and clinical trials designs, to finding solutions to competing research priorities by involved parties.

Patient Centricity: Design and Conduct of Clinical Trials in Orphan Diseases: Third of Three Sets of Expanded Proceedings from the 2020 ISCTM Autumn Conference on Pediatric Drug Development.

This article expands on a session, titled "Patient Centricity: Design and Conduct of Clinical Trials in Orphan Diseases," that was presented as part of a two-day meeting on Pediatric Drug Development at the International Society for Central Nervous System (CNS) Clinical Trials and Methodology (ISCTM) Autumn Conference in Boston, Massachusetts, in October 2020. Speakers from various areas of pediatric drug development addressed a variety of implications of including children in drug development programs, including implications for rare/orphan diseases. The speakers have written summaries of their talks. The session's lead Chair was Dr. Joan Busner, who wrote introductory and closing comments. Dr. Simon Day, regulatory consultant, outlined some of the past mistakes that have plagued trials that did not consult with patient groups in the early design phase. Dr. Atul Mahableshwarkar provided an industry perspective of a recent trial that benefited from the inclusion of patient input. Drs. Lucas Kempf and Maria Sheean provided regulatory input from the perspectives of the United States (US) Food and Drug Administration (FDA) and European Medicines Agency (EMA), respectively. Dr. Judith Dunn outlined a novel approach for assessing and rank ordering patient and clinician clinical meaningfulness and the disconnect that may occur. Dr. Busner provided closing comments, tied together the presented issues, and provided a synopsis of the lively discussion that followed the session. In addition to the speakers above, the discussion included two representatives from patient advocacy groups, as well as an additional speaker who described the challenges of conducting a pediatric trial in the US and European Union (EU), given the often competing regulatory requirements. This article should serve as an expert-informed reference to those interested and involved in CNS drug development programs that are aimed at children and rare diseases and seek to ensure a patient-centric approach.

Special Challenges in Pediatric Drug Development: First of Three Sets of Expanded Proceedings from the ISCTM Autumn Conference on Pediatric Drug Development.

This paper expands upon a session, entitled, "Special Challenges in Pediatric Drug Development," that was presented as part of a two-day meeting on Pediatric Drug Development at the International Society for Central Nervous System (CNS) Clinical Trials and Methodology (ISCTM) Autumn Conference in Boston, Massachusetts, in October 2020. Drug development in this age group is particularly important because many illnesses have their onset in this age group, many other illnesses that are more common in adults also occur in this time period, and many rare conditions that require special consideration (i.e., orphan conditions) are commonly detected in childhood as well. The special challenges addressed by our speakers in this session were cognitive and functional capacity assessment, challenges of recruitment and assessment of children for research and development of appropriate biomarkers for use in child populations, and the special challenges in training raters to address symptoms in pediatric populations. The speakers have written summaries of their talks. The session's lead chair was Philip D. Harvey, PhD, who wrote introductory and closing comments. This paper should serve as an expert-informed reference to those interested in and involved in addressing the special challenges facing those involved in CNS pediatric drug development.

Implications of Pediatric Initiatives on CNS Drug Development for All Ages-2020 and Beyond: Second of Three Sets of Expanded Proceedings from the 2020 ISCTM Autumn Conference on Pediatric Drug Development.

This article expands upon a session, titled "Implications of Pediatric Initiatives on CNS Drug Development for All Ages-2020 and Beyond," that was presented as part of a two-day meeting on pediatric drug development at the International Society for Central Nervous System (CNS) Clinical Trials and Methodology (ISCTM) Autumn Conference in Boston, Massachusetts, in October 2020. Speakers from various areas of pediatric drug development addressed a variety of implications of including children in drug development programs. The speakers wrote summaries of their talks, which are included here. The session's lead chair was Dr. Gahan Pandina, who wrote introductory and closing comments. Dr. Joseph Horrigan addressed the current landscape of pediatric development programs. Dr. Gahan Pandina addressed how the approach to research in pediatric populations affects the drug development process and vice versa. Dr. Alison Bateman-House discussed the ethical implications of research in the pediatric population. Dr. Luca Pani discussed some of the global regulatory issues and challenges concerning research in pediatric patients. Dr. Judith Kando served as a discussant and posed new questions about means of facilitating pediatric research. Finally, Dr. Gahan Pandina provided closing comments and tied together the presented issues. This paper should serve as an expert-informed reference to those interested and involved in CNS drug development programs that are aimed at children and/or required, through regulations, to include children as part of the approval process.

An Optimized Version of the Positive and Negative Symptoms Scale (PANSS) for Pediatric Trials.

OBJECTIVE: The accepted primary outcome measure for evaluating psychotic symptoms is decades old, long, and initially designed for adults. Surprisingly, the psychometric properties of primary outcome measures have never been reported for a pediatric sample using modern methods. The present study's aim is to use a pediatric sample to evaluate the psychometrics of the most used primary outcome measure in pediatric schizophrenia trials, the Positive and Negative Syndrome Scale (PANSS). METHOD: To evaluate the factor structure, item characteristics, and treatment sensitivity of the PANSS in a pediatric sample, secondary analyses of PANSS data at baseline and weekly throughout an 8-week randomized double-blind study of 3 antipsychotic agents (registered and previously published) were conducted. Subjects were 118 youths receiving outpatient psychiatric treatment for schizophrenia spectrum disorders (mean age = 14.26 years, SD = 2.41 years). RESULTS: A 10-item short form, keeping 2 strongest items for each factor, had r = 0.89 with the full-length scale. Each of the five 2-item subscales has alphas ranging from 0.66 to 0.84. Item Response Theory (IRT) found that the 10-item scale and 2-item subscores had high reliability across the severity range typical of those for clinical trials. Criterion validity was high, with equal sensitivity to clinical changes over time. CONCLUSION: A 10-item PANSS version eliminates weaker items in the pediatric population while preserving coverage of 5 factors and similar sensitivity to clinical changes over time. It thus may be more appropriate for subsequent pediatric trials, and for clinical use when time and efficiency are paramount.

Clinician- and Patient-reported Endpoints in CNS Orphan Drug Clinical Trials: ISCTM Position Paper on Best Practices for Endpoint Selection, Validation, Training, and Standardization.

OBJECTIVE: The International Society of CNS Clinical Trials Methodology (ISCTM) Working Group on Rare Disease/Orphan Drug Development is dedicated to improving and streamlining trials to best develop new treatments for rare diseases. The rarity of these disorders requires a drug development strategy that differs from those of nonrare conditions. Rare disease drug development programs are challenged with small sample sizes, heterogeneous clinical presentations, and few, if any, off-the-shelf endpoints. When disease-specific clinical endpoints exist, they might not be validated and are typically not well known or broadly used in clinical practice. This paper aims to provide an overview of the special issues surrounding endpoints in rare disease drug development, with guidance, practical applications, and discussion. DISCUSSION: The paper covers regulatory considerations in endpoint selection; identification of relevant measurement domains; methods of quantifying clinical meaningfulness; incorporation of patient- and clinician-reported outcomes; considerations for global clinician- and patient-rated clinical assessments; cognition assessment challenges in rare diseases; translation considerations; training, standardization, and calibration of assessors; and endpoint quality assurance. Additionally, it provides guidance and resources for those involved in drug development for rare diseases. CONCLUSION: In keeping with the mission of ISCTM and the rare disease/orphan drug development working group, this article is designed to encourage thoughtful consideration and provide insight and guidance to promote and further efforts in in central nervous system (CNS) rare disease drug development efforts.

Time course of the effects of lisdexamfetamine dimesylate in two phase 3, randomized, double-blind, placebo-controlled trials in adults with binge-eating disorder.

OBJECTIVE: This study examined the time course of efficacy-related endpoints for lisdexamfetamine dimesylate (LDX) versus placebo in adults with protocol-defined moderate to severe binge-eating disorder (BED). METHODS: In two 12-week, double-blind, placebo-controlled studies, adults meeting DSM-IV-TR BED criteria were randomized 1:1 to receive placebo or dose-optimized LDX (50 or 70 mg). Analyses across visits used mixed-effects models for repeated measures (binge eating days/week, binge eating episodes/week, Yale-Brown Obsessive Compulsive Scale modified for Binge Eating [Y-BOCS-BE] scores, percentage body weight change) and chi-square tests (Clinical Global Impressions-Improvement [CGI-I; from the perspective of BED symptoms] scale dichotomized as improved or not improved). These analyses were not part of the prespecified testing strategy, so reported p values are nominal (unadjusted and descriptive only). RESULTS: Least squares mean treatment differences for change from baseline in both studies favored LDX over placebo (all nominal p values < .001) starting at Week 1 for binge eating days/week, binge-eating episodes/week, and percentage weight change and at the first posttreatment assessment (Week 4) for Y-BOCS-BE total and domain scores. On the CGI-I, more participants on LDX than placebo were categorized as improved starting at Week 1 in both studies (both nominal p values < .001). Across these efficacy-related endpoints, the superiority of LDX over placebo was maintained at each posttreatment assessment in both studies (all nominal p values < .001). DISCUSSION: In adults with BED, LDX treatment appeared to be associated with improvement on efficacy measures as early as 1 week, which was maintained throughout the 12-week studies.

A comparative analysis between site-based and centralized ratings and patient self-ratings in a clinical trial of Major Depressive Disorder.

We compared scores from three different ratings methods in a clinical trial of patients with Major Depressive Disorder (MDD). The Quick Inventory of Depressive Symptoms (QIDS-SR16) was compared to site-based clinician and centralized (site-independent) ratings of the Inventory of Depressive Symptoms (IDSc30). An extracted QIDSc16 was used for a matched comparison with the QIDS-SR16. Patient self-ratings were more depressed at baseline than either site-based ratings (p = 0.131) or centralized ratings (p = 0.005), but significantly less depressed at the end of double-blind treatment than either site-based (p = 0.006) or centralized ratings (p = 0.014), and after 12 weeks (site-based ratings: p = 0.048; centralized ratings: p = 0.004). The matched comparisons with patient self-ratings revealed ICC of r = 0.55 (site-based raters) and r = 0.49 (centralized raters) at baseline. After baseline, the correlations between the two different clinician ratings and patient self-ratings improved to r-values between 0.78 and 0.89. At the end of double-blind treatment, site-based raters separated the combination treatment from placebo on the IDSc30 (p = 0.030) whereas neither centralized ratings nor patient self-ratings achieved statistical significance. Alternatively, patient self-ratings separated the combination treatment from buspirone (p = 0.030) whereas neither clinician rating method achieved significance. A "dual" scoring concordance range reduced the placebo response rate and increased the drug effect between the combination treatment and placebo. These findings reveal scoring variability between each of the three ratings methods and challenge the reliability of any single method to accurately assess symptom severity scores, particularly at baseline. The use of "dual" scoring criteria may help to confirm symptom severity scores and improve ratings precision, particularly prior to enrolling subjects into CNS trials.

The use of research measures in adult clinical practice.

Many psychopathology research assessment tools can be used easily and productively in clinical practice. We conducted a workshop in 2009 and 2010 at the American Psychiatric Association annual meeting designed to bring clinicians some commonly used adult research measures with broad applicability to a variety of conditions. This article reviews what was most helpful to the practicing clinicians at the workshop.

The Clinical Global Impressions scale: errors in understanding and use.

OBJECTIVE: The Clinical Global Impressions Severity and Improvement scales (CGI-S and CGI-I) are widely included as efficacy data in psychopharmacology new drug application submissions. This study was conducted to determine the extent to which clinical trials investigators included information unrelated to efficacy in their CGI ratings. METHOD: Forty-five principal investigators provided CGI-S and CGI-I ratings of narratives of patients with major depressive disorder or generalized anxiety disorder. Investigators were blindly randomized to receive narratives that either did (experimental) or did not (control) contain indication-unrelated medical or psychiatric adverse events. Investigators then completed a survey assessing CGI-S and CGI-I rating patterns. RESULTS: CGI-S and CGI-I ratings were significantly more severe and less improved when the narratives contained medical and psychiatric adverse events unrelated to the diseases under study (major depressive disorder and generalized anxiety disorder) than when the narratives did not (Ps < .04). In response to the survey, 46% and 56% of investigators reported that a psychiatric adverse event unrelated to the disease under study would not affect their CGI-S and CGI-I ratings, respectively. Although 87% of investigators reported that their CGI-S and CGI-I ratings would not be affected by a medical adverse event, actual CGI-S ratings were significantly more severe when an unrelated medical adverse event was described as occurring than when it was not (P < .03). CONCLUSION: Clinical trials investigators' inclusion of indication-irrelevant adverse events threatens the validity of the CGI as an efficacy measure and may contribute to failure to detect efficacy signals in psychopharmacology clinical trials.

Targeted scoring criteria reduce variance in global impressions.

OBJECTIVE: This study examined the confounding effect of treatment emergent physical or psychic symptoms on clinical global impression (CGI) ratings in CNS trials and examined the benefit of targeted scoring criteria on clarifying ratings and reducing scoring variance. METHODS: Twenty-four raters participating in an investigator meeting training session scored a series of scripted CGI scenarios that included treatment emergent symptoms. RESULTS: The addition of treatment emergent gastrointestinal (GI) symptoms or anxiety symptoms significantly changed the rating of clinical global improvement and caused a broad CGI-improvement (CGI-I) scoring variance reflecting scoring ambiguity amongst these raters. Re-rating after a presentation of well-defined criteria that addressed these scoring issues narrowed the variance and significantly improved inter-rater reliability. CONCLUSIONS: It is clear that CNS trials must define scoring criteria for global ratings prior to the initiation of a study to assure ratings consistency. The actual definition of global must be study-specific and may depend upon the targeted symptoms of interest and mechanism of drug action. The targeted criteria that define global must be included in all published reports about the trial.

Emotional expression in children treated with ADHD medication: development of a new measure.

OBJECTIVE: Although existing instruments contain items addressing the effect of ADHD medications on emotional expression, a review of measures did not yield any instruments that thoroughly evaluated positive and negative aspects of emotional expression. METHOD: The Expression and Emotion Scale for Children (EESC), a parent-report measure, was developed from an analysis of qualitative data from parent focus groups and expert opinion. Data from 179 parents and children treated with stimulants or atomoxetine are used to examine the psychometric properties of the EESC. RESULTS: The EESC demonstrates good internal consistency and test-retest reliability. A factor analysis yields three factors (positive, flat, and emotional lability) that were consistent with the predicted structure of the measure. Small to moderate correlations between the EESC and psychological symptom measures are found, with the strength of the relationships varying by symptom measure. CONCLUSION: The EESC shows appropriate psychometric properties and is appropriate for use in clinical and research settings.

Efficacy and safety of atomoxetine in adolescents with attention-deficit/hyperactivity disorder and major depression.

This double-blind study examined efficacy and safety of atomoxetine (ATX; < or =1.8mg/kg per day) in adolescents aged 12-18 with Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnoses of both attention-deficit/hyperactivity disorder (ADHD) and co-morbid major depressive disorder (MDD). Diagnoses were confirmed by the Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version and persistently elevated scores on the Attention-Deficit/Hyperactivity Disorder Rating Scale-IV, Parent version, Investigator-administered and -scored (ADHDRS-IV-Parent:Inv, > or =1.5 standard deviations above age and gender norms) and Children's Depression Rating Scale-Revised (CDRS-R, > or = 40). Patients were treated for approximately 9 weeks with ATX (n = 72) or placebo (n = 70). Mean decrease in ADHDRS-IV-Parent:Inv total score was significantly greater in the ATX group (-13.3 +/- 10.0) compared with the placebo group (-5.1 +/- 9.9; p < 0.001). Mean CDRS-R score improvement was not significantly different between groups (ATX, -14.8 +/- 13.3; placebo, -12.8 +/- 10.4). Rates of treatment-emergent mania did not differ between groups (ATX, 0.0%; placebo, 1.5%). ATX treatment was associated with significantly more nausea and decreased appetite (p = 0.002; p = 0.003). No spontaneously reported adverse events involving suicidal ideation or suicidal behavior occurred in either group. ATX was an effective and safe treatment for ADHD in adolescents with ADHD and MDD. However, this trial showed no evidence for ATX of efficacy in treating MDD.

High-dose atomoxetine treatment of ADHD in youths with limited response to standard doses.

OBJECTIVE: To assess the utility and tolerability of higher than standard atomoxetine doses to treat attention-deficit/hyperactivity disorder (ADHD). METHOD: Two randomized, double-blind trials of atomoxetine nonresponders ages 6 to 16 years were conducted comparing continued treatment with same-dose atomoxetine to treatment using greater than standard efficacious doses (study 1: up to 3.0 mg . kg . day; study 2: up to 2.4 mg . kg . day). RESULTS: The primary outcome measure for both studies was mean ADHD Rating Scale (ADHD RS) total score. For study 1 (N = 122), decreases in ADHD RS total scores were not significantly different between treatment groups (mean change [SD]: continued same dose, -8.9 [11.2]; high dose, -9.8 [13.1]; p = .595). Likewise, for study 2 (N = 125), treatment groups did not differ (mean change [SD]: continued same dose, -6.2 [12.2]; high dose, -8.9 [10.0], p =.110). Tolerability was not significantly different between the continued same-dose and high-dose groups. CONCLUSIONS: These studies provide evidence that current dose recommendations are appropriate for most patients, suggesting no systematic advantage to increasing atomoxetine doses beyond current guidelines. In both studies, continued treatment, whether at a higher dose or the previous dose, was associated with improved outcomes in patients who demonstrated incomplete/inadequate response to acute ADHD treatment, although without a placebo arm, we cannot rule out the possibility that expectancy played a role in symptom improvement.

The clinical global impressions scale: applying a research tool in clinical practice.

OBJECTIVE: This paper reviews the potential value in daily clinical practice of an easily applied research tool, the Clinical Global Impressions (CGI) Scale, for the nonresearcher clinician to quantify and track patient progress and treatment response over time. METHOD: The instrument is described and sample patient scenarios are provided with scoring rationales and a practical charting system. CONCLUSION: The CGI severity and improvement scales offer a readily understood, practical measurement tool that can easily be administered by a clinician in a busy clinical practice setting.

Fluoxetine 40-60 mg versus fluoxetine 20 mg in the treatment of children and adolescents with a less-than-complete response to nine-week treatment with fluoxetine 10-20 mg: a pilot study.

OBJECTIVE: The aim of this study was to compare fluoxetine dosage titration to 40-60 mg/day with fixed fluoxetine 20-mg/day treatment for an additional 10 weeks in pediatric outpatients with major depressive disorder (MDD) who had not met protocol-defined response criteria after 9-week acute fluoxetine treatment. METHODS: Patients unresponsive (less than or equal to 30% decrease in Children's Depression Rating Scale-Revised [CDRS-R] score) after 9-week fluoxetine treatment were randomly reassigned to continue at 20 mg/day or to increase to 40 mg/day. After 4 weeks, patients unresponsive to 40 mg/day could receive 60 mg/day. RESULTS: Twenty-nine (29) patients, 9-17 years of age, received fluoxetine 40-60 mg/day (n = 14) or 20 mg/day (n = 15). At the conclusion of this study phase, 10 patients (71%) on 40-60 mg/day met the response criteria, versus 5 patients (36%) on 20 mg/day (p = 0.128). Mean CDRS-R scores improved in both treatment groups (fluoxetine 40-60 mg/day, -9.4; fluoxetine 20 mg/day, -1.5; p = 0.099). Adverse events were similar in both groups. However, this study phase was statistically underpowered for detecting differences between treatment groups. CONCLUSION: More than two thirds of patients whose dosage was increased responded within 10 weeks, suggesting dose escalation may benefit some patients. Approximately one third of patients unresponsive to initial treatment with fluoxetine 20 mg responded to this fixed dosage within another 10 weeks. Fluoxetine 20-60 mg/day was well tolerated.

Once-daily atomoxetine treatment for children and adolescents with attention deficit hyperactivity disorder: a randomized, placebo-controlled study.

OBJECTIVE: The authors assessed the efficacy of once-daily atomoxetine administration in the treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD). METHOD: In a double-blind study, children and adolescents with ADHD (N=171, age range=6-16 years) were randomly assigned to receive 6 weeks of treatment with either atomoxetine (administered once daily) or placebo. RESULTS: Outcomes among atomoxetine-treated patients were superior to those of the placebo treatment group as assessed by investigator, parent, and teacher ratings. The treatment effect size (0.71) was similar to those observed in previous atomoxetine studies that used twice-daily dosing. Parent diary ratings suggested that drug-specific effects were sustained late in the day. Discontinuations due to adverse events were low (less than 3%) for both treatment groups, and no serious safety concerns were observed. CONCLUSIONS: Once-daily administration of atomoxetine is an effective treatment for children and adolescents with ADHD.