Seth C. Hopkins, Sasagu Tomioka, Steven T. Szabo, Kenneth S. Koblan
{"title":"A clinical trial inclusion criteria to enrich for patients presenting with canonical symptom structure in bipolar depression","authors":"Seth C. Hopkins, Sasagu Tomioka, Steven T. Szabo, Kenneth S. Koblan","doi":"10.1016/j.cct.2024.107644","DOIUrl":null,"url":null,"abstract":"<div><p>Clinical drug development in psychiatry is challenging due to heterogeneous patient populations and the uncertainty of measuring neuropsychiatric constructs with symptom rating scales. Here we describe the development and implementation of an enrichment algorithm that identifies canonical versus anomalous symptom presentations, at the individual subject level, based on MADRS ratings obtained at screening and baseline. Data from 5 randomized, placebo-controlled, phase 3 trials in bipolar I disorder was used (<em>N</em> = 2026 subjects and 15,239 MADRS assessments). A variance-covariance difference (VCD) vector was developed to encode individual symptom structure using the 10 items of MADRS from the two sequential assessments. An anomaly score, calculated from each subject's VCD vector was derived by isolation forest to quantify the degree of disparity from the hypothesized canonical item structure. A retrospective application of the algorithm reliably identified a threshold anomaly score above which the psychometric properties of MADRS deteriorate. Consistent with increasing the certainty of MADRS ratings, subjects with a canonical symptom structure at baseline demonstrated greater effect sizes post-baseline in a phase 2 placebo-controlled trial of non-racemic amisulpride (SEP-4199) for bipolar depression, analyzed retrospectively. Our analyses show that the developed algorithm can reduce the symptom structure heterogeneity at baseline and thus improve the measurement certainty of psychiatric symptoms in clinical trials. This novel enrichment method has been prospectively implemented in a Phase 3 clinical study of SEP-4199 and is consistent with regulatory guidelines aimed at increasing the statistical power and lowering patient-burden in clinical trials.</p><p>Clinical Trials Registry: <span><span>NCT00868452</span><svg><path></path></svg></span>, <span><span>NCT00868699</span><svg><path></path></svg></span>, <span><span>NCT01284517</span><svg><path></path></svg></span>, <span><span>NCT01986101</span><svg><path></path></svg></span>, <span><span>NCT03543410</span><svg><path></path></svg></span>, <span><span>NCT05169710</span><svg><path></path></svg></span></p></div>","PeriodicalId":10636,"journal":{"name":"Contemporary clinical trials","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Contemporary clinical trials","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1551714424002271","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Clinical drug development in psychiatry is challenging due to heterogeneous patient populations and the uncertainty of measuring neuropsychiatric constructs with symptom rating scales. Here we describe the development and implementation of an enrichment algorithm that identifies canonical versus anomalous symptom presentations, at the individual subject level, based on MADRS ratings obtained at screening and baseline. Data from 5 randomized, placebo-controlled, phase 3 trials in bipolar I disorder was used (N = 2026 subjects and 15,239 MADRS assessments). A variance-covariance difference (VCD) vector was developed to encode individual symptom structure using the 10 items of MADRS from the two sequential assessments. An anomaly score, calculated from each subject's VCD vector was derived by isolation forest to quantify the degree of disparity from the hypothesized canonical item structure. A retrospective application of the algorithm reliably identified a threshold anomaly score above which the psychometric properties of MADRS deteriorate. Consistent with increasing the certainty of MADRS ratings, subjects with a canonical symptom structure at baseline demonstrated greater effect sizes post-baseline in a phase 2 placebo-controlled trial of non-racemic amisulpride (SEP-4199) for bipolar depression, analyzed retrospectively. Our analyses show that the developed algorithm can reduce the symptom structure heterogeneity at baseline and thus improve the measurement certainty of psychiatric symptoms in clinical trials. This novel enrichment method has been prospectively implemented in a Phase 3 clinical study of SEP-4199 and is consistent with regulatory guidelines aimed at increasing the statistical power and lowering patient-burden in clinical trials.
期刊介绍:
Contemporary Clinical Trials is an international peer reviewed journal that publishes manuscripts pertaining to all aspects of clinical trials, including, but not limited to, design, conduct, analysis, regulation and ethics. Manuscripts submitted should appeal to a readership drawn from disciplines including medicine, biostatistics, epidemiology, computer science, management science, behavioural science, pharmaceutical science, and bioethics. Full-length papers and short communications not exceeding 1,500 words, as well as systemic reviews of clinical trials and methodologies will be published. Perspectives/commentaries on current issues and the impact of clinical trials on the practice of medicine and health policy are also welcome.