Statistical controversies in clinical research: Value of adverse events relatedness to study treatment: analyses of data from randomized double-blind placebo-controlled clinical trials

Process of drug registration in Israel: the correlation between the number of discussions within the Ministry of Health and postapproval variations by EMA and/or FDA

OBJECTIVES

US FDA and EMA allow facilitated regulatory pathways to expedite access to new treatments. Limited supportive data may result in major postapproval variations. In Israel, partly relying on Food and Drug Administration (FDA) and European Medicines Agency (EMA), clinical data are reviewed independently by the Advisory Committee of Drug Registration (ACDR). In this study, the correlation between the number of discussions at the ACDR and major postapproval variations is examined.

DESIGN

This is an observational retrospective comparative cohort study.

SETTING

Applications with FDA and/or EMA approval at time of assessment in Israel were included. The timeframe was chosen to allow a minimum of 3 years of postmarketing approval experience for potential major label variations. Data regarding the number of discussions at ACDR were extracted from protocols. Data on postapproval major variations were extracted from the FDA and EMA websites.

RESULTS

Between 2014 and 2016, 226 (176 drugs) applications, met the study criteria. 198 (87.6%) and 28 (12.4%) were approved following single and multiple discussions, respectively. A major postapproval variation was recorded in 129 (65.2%) compared with 23 (82.1%) applications approved following single and multiple discussions, respectively (p=0.002). Increased risk for major variation was found for medicines approved following multiple discussions (HR=1.98, 95% CI: 1.26 to 3.09) with a median time of 1.2 years, applications approved based on phase II trials (HR=2.58, 95% CI: 1.72 to 3.87), surrogate endpoints (HR=1.99, 95% CI: 1.44 to 2.74) and oncologic indications (HR=2.48, 95% CI: 1.78 to 3.45).

CONCLUSIONS

Multiple ACDR discussions associated with limited supportive data are predictive for major postapproval variations. Moreover, our findings demonstrate that approval by the FDA and/or EMA does not pave the way to automatic approval in Israel. In a substantial per cent of the cases, submission of the same clinical data resulted in different safety and efficacy considerations, requiring additional supporting data in some cases or even rejection of the application in others.

Early Adverse Event Derived Biomarkers in Predicting Clinical Outcomes in Patients with Advanced Non-Small Cell Lung Cancer Treated with Immunotherapy

RATIONALE

Adverse events (AEs) have been shown to have clinical associations, in addition to patient safety assessments of drugs of interest. However, due to their complex content and associated data structure, AE evaluation has been restricted to descriptive statistics and small AE subset for efficacy analysis, limiting the opportunity for global discovery. This study takes a unique approach to utilize AE-associated parameters to derive a set of innovative AE metrics. Comprehensive analysis of the AE-derived biomarkers enhances the chance of discovering new predictive AE biomarkers of clinical outcomes.

METHODS

We utilized a set of AE-associated parameters (grade, treatment relatedness, occurrence, frequency, and duration) to derive 24 AE biomarkers. We further innovatively defined early AE biomarkers by landmark analysis at an early time point to assess the predictive value. Statistical methods included the Cox proportional hazards model for progression-free survival (PFS) and overall survival (OS), two-sample t-test for mean difference of AE frequency and duration between disease control (DC: complete response (CR) + partial response (PR) + stable disease (SD)) versus progressive disease (PD), and Pearson correlation analysis for relationship of AE frequency and duration versus treatment duration. Two study cohorts (Cohort A: vorinostat + pembrolizumab, and B: Taminadenant) from two immunotherapy trials in late-stage non-small cell lung cancer were used to test the potential predictiveness of AE-derived biomarkers. Data from over 800 AEs were collected per standard operating procedure in a clinical trial using the Common Terminology Criteria for Adverse Events v5 (CTCAE). Clinical outcomes for statistical analysis included PFS, OS, and DC.

RESULTS

An early AE was defined as event occurrence at or prior to day 30 from initial treatment date. The early AEs were then used to calculate the 24 early AE biomarkers to assess overall AE, each toxicity category, and each individual AE. These early AE-derived biomarkers were evaluated for global discovery of clinical association. Both cohorts showed that early AE biomarkers were associated with clinical outcomes. Patients previously experienced with low-grade AEs (including treatment related AEs (TrAE)) had improved PFS, OS, and were associated with DC. The significant early AEs included low-grade TrAE in overall AE, endocrine disorders, hypothyroidism (pembrolizumab's immune-related adverse event (irAE)), and platelet count decreased (vorinostat related TrAE) for Cohort A and low-grade AE in overall AE, gastrointestinal disorders, and nausea for Cohort B. In contrast, patients with early development of high-grade AEs tended to have poorer PFS, OS, and correlated with PD. The associated early AEs included high-grade TrAE in overall AE, gastrointestinal disorders with two members, diarrhea and vomiting, for Cohort A and high-grade AE in overall AE, three toxicity categories, and five related individual AEs for Cohort B. One low-grade TrAE, alanine aminotransferase increased (vorinostat + pembrolizumab related), was an irAE and correlated with worse OS in Cohort A.

CONCLUSIONS

The study demonstrated the potential clinical utility of early AE-derived biomarkers in predicting positive and negative clinical outcomes. It could be TrAEs or combination of TrAEs and nonTrAEs from overall AEs, toxicity category AEs, to individual AEs with low-grade event leaning to encouraging effect and high-grade event to undesirable impact. Moreover, the methodology of the AE-derived biomarkers could change current AE analysis practice from a descriptive summary into modern informative statistics. It modernizes AE data analysis by helping clinicians discover novel AE biomarkers to predict clinical outcomes and facilitate the generation of vast clinically meaningful research hypotheses in a new AE content to fulfill the demands of precision medicine.

Imaging Findings in Children Presenting with CNS Nelarabine Toxicity

Nelarabine is a nucleoside analog critical for the treatment of patients with T-cell acute lymphoblastic leukemia/lymphoma. However, clinical peripheral and central neurologic adverse events associated with nelarabine administration have been reported. Neuroimaging of brain neurotoxicity has only been described in very few reports in pediatric patients so far. Six children with diagnosed T-cell acute lymphoblastic leukemia who clinically experienced possible, probable, or definite nelarabine-induced toxicity and underwent spine and/or brain MR imaging were reviewed. Neuroimaging findings showed a mixture of patterns including features of acute toxic leukoencephalopathy (seen in 6 cases), posterior reversible encephalopathy syndrome (2 cases), involvement of deep gray structures (1 case) and brainstem (2 cases), cranial and spinal neuropathy (2 cases each), and myelopathy (2 cases). Even though neuroimaging findings are nonspecific, the goal of this article was to alert the pediatric neuroradiologists, radiologists, and clinicians about the possibility of nelarabine-induced neurotoxicity and its broad neuroimaging spectrum.

Harms in Systematic Reviews Paper 1: An introduction to research on harms

OBJECTIVE

Most systematic reviews of interventions focus on potential benefits. Common methods and assumptions that are appropriate for assessing benefits can be inappropriate for harms. This paper provides a primer on researching harms, particularly in systematic reviews.

STUDY DESIGN AND SETTING

Commentary describing challenges with assessing harm.

RESULTS

Investigators should be familiar with various terminologies used to describe, classify, and group harms. Published reports of clinical trials include limited information about harms, so systematic reviewers should not depend on these studies and journal articles to reach conclusions about harms. Visualizations might improve communication of multiple dimensions of harms such as severity, relatedness, and timing.

CONCLUSION

The terminology, classification, detection, collection, and reporting of harms create unique challenges that take time, expertise, and resources to navigate in both primary studies and evidence syntheses. Systematic reviewers might reach incorrect conclusions if they focus on evidence about harms found in published reports of randomized trials of a particular health problem. Systematic reviews could be improved through better identification and reporting of harms in primary studies and through better training and uptake of appropriate methods for synthesizing evidence about harms.

Analysis of adverse events attribution and reporting in cancer clinical trials: A systematic review

We systematically reviewed the quality of AEs reports in published oncology trials analyzing also the bias in the attribution process. We searched MEDLINE, PubMed (2000-2019) selecting randomized, double-blind, placebo-controlled, and phase 3 cancer trials using exclusively targeted therapy or immunotherapy-related drugs. The proportion of publications with complete AE reports (including both all-cause and drug-related AE data) and the AEs attribution ratio (patients with drug-related over all-cause AE) were investigated. Among 60 trials (38,174 patients) included, 40 (66.6 %) presented an incomplete report of AEs attribution. Journals with the lowest impact factor were significantly associated with deficient reports of grade 3-4 AEs (p = 0.02). Under placebo administration, the median incidence of all-grade drug-related AEs was 49 % (IQR 39-56). The median attribution ratio for all-grade AEs in the active and placebo arms was 88.9 % (IQR 79.8-93) and 53.9 % (IQR 43.4-60.9), respectively. The AEs reporting and attribution process appear to be more unreliable than expected.

Real-World Safety of CFTR Modulators in the Treatment of Cystic Fibrosis: A Systematic Review

Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies target the underlying cause of cystic fibrosis (CF), and are generally well-tolerated; however, real-world studies indicate the frequency of discontinuation and adverse events (AEs) may be higher than what was observed in clinical trials. The objectives of this systematic review were to summarize real-world AEs reported for market-available CFTR modulators (i.e., ivacaftor (IVA), lumacaftor/ivacaftor (LUM/IVA), tezacaftor/ivacaftor (TEZ/IVA), and elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA)), and to identify ways in which the pharmacist on CF healthcare teams may contribute to mitigating and managing these AEs. The MEDLINE, EMBASE, CINAHL, and Web of Science Core Collection online databases were searched from 2012 to 1 Aug 2020. Full manuscripts or conference abstracts of observational studies, case series, and case reports were eligible for inclusion. The included full manuscripts and conference abstracts comprised of 54 observational studies, 5 case series, and 9 case reports. The types of AEs reported generally aligned with what have been observed in clinical trials. LUM/IVA was associated with a higher frequency of respiratory-related AE and discontinuation in real-world studies. A signal for mental health and neurocognitive AEs was identified with all 4 CFTR modulators. A systematic approach to monitoring for AEs in people with CF on CFTR modulators in the real-world setting is necessary to help better understand potential AEs, as well as patient characteristics that may be associated with higher risk of certain AEs. Pharmacists play a key role in the safe initiation and monitoring of people with CF on CFTR modulator therapies.

Adverse Event Burden Score-A Versatile Summary Measure for Cancer Clinical Trials

Simple Summary

In cancer clinical trials, adverse event data are collected after every treatment cycle, using the Common Terminology Criteria for adverse events, which includes 837 terms. The vast number of potentially reportable adverse events over multiple treatment cycles makes summarizing and analyzing adverse event data challenging. The current standard reporting of adverse event data includes the frequency of the maximum (worst) grade of commonly occurring adverse events. In this article, we propose a single quantitative summary measure that incorporates both the frequency and the severity of multiple adverse events over time; the adverse event burden score. This score is a well-defined measure that enables statistical comparisons analogous to other quantitative endpoints in clinical trials. The adverse event burden score can readily accommodate different trial settings, diseases, and treatments, with diverse safety profiles.

Abstract

This article introduces the adverse event (AE) burden score. The AE burden by treatment cycle is a weighted sum of all grades and AEs that the patient experienced in a cycle. The overall AE burden score is the total AE burden the patient experienced across all treatment cycles. AE data from two completed Alliance multi-center randomized double-blind placebo-controlled trials, with different AE profiles (NCCTG 97-24-51: 176 patients, and A091105: 83 patients), were utilized for illustration. Results of the AE burden score analyses corroborated the trials’ primary results. In 97-24-51, the overall AE burden for patients on the treatment arm was 2.2 points higher than those on the placebo arm, with a higher AE burden for patients who went off treatment early due to AE. Similarly, in A091105, the overall AE burden was 1.6 points higher on the treatment arm. On the placebo arms, the AE burden in 97-24-51 remained constant over time; and increased in later cycles in A091105, likely attributable to the increase in disease morbidity. The AE burden score enables statistical comparisons analogous to other quantitative endpoints in clinical trials, and can readily accommodate different trial settings, diseases, and treatments, with diverse AE profiles.

Ethics of Pharma Clinical Trials in the Era of Precision Oncology

Pharmaceutical industry clinical trials are ethically problematic: human research subjects are being used as a means to the end of demonstrating statistically significant efficacy of novel anticancer agents to achieve regulatory registration and marketing approval. Randomized controlled trial design is inequitable since control arm patients are denied access to the postulated best treatment. Most pharma studies do not provide clinically meaningful benefit of increased overall survival and enhanced quality of life (QOL) to cohorts and are not reliably generalizable to real-world patients. Precision oncology now enables prospective identification of patients expressing a specific cancer biomarker to determine their particular eligibility for evaluation of efficiency of molecular-targeted treatments. A patient-centered approach, collecting prospective real-world data in large populations, could provide real-world evidence of cost-effective, sustained clinical benefits of survival and QOL, while preserving the ethical beneficent compact between patient and doctor.

Physician-Reported Experience and Understanding of Adverse Event Attribution in Cancer Clinical Trials

Objectives

To report the results of a survey conducted among Mayo Clinic medical oncologists, hematologists, and cancer prevention specialists to better understand the current practice of determining whether an adverse event that a patient experience in a clinical trial is related to the drug under investigation, a process commonly known as attribution, as well as to formulate recommendations for an improved system.

Patients and Methods

An electronic survey was developed and conducted (from August 2 through 29, 2017) among 165 medical oncologists, hematologists, and cancer prevention specialists at the 3 Mayo Clinic sites: Rochester, Minnesota; Scottsdale, Arizona; and Jacksonville, Florida. The survey included 21 items that queried clinicians about their clinical practice and trial experience, their training and process in adverse event attribution assignment, and their recommendations for improving the current attribution system.

Results

Thirty-seven percent (61 of 165) of physicians responded to the survey. The median number of years in clinical practice was 15 (range, 1-64) and that of clinical trial experience 12. Eighty-nine percent (54 of 61) had served as a trial principal investigator. Only 15% (9 of 60) of responders reported having received any formal attribution training. Eighty percent (48 of 60) were confident about their ability to assign attribution. Seventy-five percent (45 of 60) consulted their colleagues or study chair when assigning attribution. Sixty-seven percent (40 of 60) recommended formal training to improve attribution accuracy.

Conclusion

Very few clinical trialists in our survey received any formal training for adverse event attribution, yet most identified formal training as effective means to improve attribution accuracy. These data underscore an unmet need of formal adverse event attribution training among clinical trialists.

Postmarketing Safety-Related Modifications of Drugs Approved by the US Food and Drug Administration Between 1999 and 2014 Without Randomized Controlled Trials

OBJECTIVE

To investigate whether US Food and Drug Administration approval of new drugs without randomization or an active drug comparator is associated with more postmarketing safety-related label modifications.

METHODS

We searched Drugs@FDA for new drugs approved from January 1, 1999, through December 31, 2014. Drugs approved without supporting randomized controlled trials (RCTs) were matched to between 1 and 2 controls from similar therapeutic categories approved with supporting RCTs within 3 years of the reference drug. Study characteristics, regulatory pathways, and label modifications up to December 2017 were collected from drug labels. Differences in postmarketing safety modifications between cases and controls were assessed using conditional logistic regression.

RESULTS

The study cohort included 52 drugs approved without supporting RCTs and 91 matched controls. Drug approvals not supported by RCTs were associated with lower sample size (odds ratio [OR] per 100 patients, 0.77; 95% CI, 0.68-0.87) and were more likely to receive orphan drug designation (OR, 5.10; 95% CI, 2.23-11.69), fast-track designation (OR, 4.80; 95% CI, 2.25-10.23), and accelerated approval (OR, 7.00; 95% CI, 3.14-15.60). Drugs approved without supporting RCTs were associated with more modifications in black box warnings (28.8% vs 13.2%; OR, 2.67; 95% CI, 1.13-6.27), warnings and precautions (73.1% vs 52.7%; OR, 2.43; 95% CI, 1.16-5.09), and common adverse reactions (48.1% vs 23.1%; OR, 3.09; 95% CI, 1.49-6.41).

CONCLUSION

Food and Drug Administration approval of new drugs without supporting RCTs is associated with more postmarketing safety-related label modifications than drugs approved with supporting RCTs. Robust postmarketing studies are required for drugs approved without supporting RCTs. Health care professionals should be vigilant for unrecognized adverse effects when prescribing these drugs.

Low Concordance of Patient-Reported Outcomes With Clinical and Clinical Trial Documentation

PURPOSE

Health care research increasingly relies on assessment of data extracted from electronic medical records (EMRs). Clinical trial adverse event (AE) logs and patient-reported outcomes (PROs) are sources of data often available in the context of specific research projects. The aim of this study was to evaluate the extent of data concordance from these sources.

PATIENTS AND METHODS

Patients enrolled in clinical trials or receiving standard treatment for lung cancer (n = 62) completed validated questionnaires on physical and psychological symptoms at up to three assessment points. Temporally matched documentation was extracted from EMR notes and, for clinical trial participants (n = 41), AE logs. Evaluated data included symptom assessment, vital signs, medication logs, and laboratory values. Agreement (positive, negative) and Cohen's κ coefficients were calculated to assess concordance of symptoms among sources, with PROs considered the gold standard.

RESULTS

Patient-reported weight loss correlated significantly with clinical measurements ( t = 2.90; P = .02), and average number of PROs correlated negatively with albumin concentration, supporting PROs as the gold standard. Comparisons of PROs versus EMR yielded poor concordance across 11 physical symptoms, anxiety, and depressive symptoms (all κ < 0.40). Providers under-reported the presence of each symptom in the EMR compared with PROs. AE logs showed similarly poor concordance with PROs (all κ < 0.40, except shortness of breath). Negative agreement among sources was higher than positive agreement for all symptoms except pain.

CONCLUSION

There was poor concordance between EMR notes and AE logs with PROs. Findings suggest that EMR notes and AE logs may not be reliable sources for capturing physical and psychological symptoms experienced by patients with lung cancer, supporting use of PRO assessments in oncology practices.

Toxicity associated with tuberculosis chemotherapy in the REMoxTB study

BACKGROUND

The incidence and severity of tuberculosis chemotherapy toxicity is poorly characterised. We used data available from patients in the REMoxTB trial to provide an assessment of the risks associated with the standard regimen and two experimental regimens containing moxifloxacin.

METHODS

All grade 3 & 4 adverse events (AEs) and their relationship to treatment for patients who had taken at least one dose of therapy in the REMoxTB clinical trial were recorded. Univariable logistic regression was used to test the relationship of baseline characteristics to the incidence of grade 3 & 4 AEs and significant characteristics (p < 0.10) were incorporated into a multivariable model. The timing of AEs during therapy was analysed in standard therapy and the experimental arms. Logistic regression was used to investigate the relationship between AEs (total and related-only) and microbiological cure on treatment.

RESULTS

In the standard therapy arm 57 (8.9%) of 639 patients experienced ≥1 related AEs with 80 of the total 113 related events (70.8%) occurring in the intensive phase of treatment. Both four-month experimental arms ("isoniazid arm" with moxifloxacin substituted for ethambutol & "ethambutol arm" with moxifloxacin substituted for isoniazid) had a lower total of related grade 3 & 4 AEs than standard therapy (63 & 65 vs 113 AEs). Female gender (adjOR 1.97, 95% CI 0.91-1.83) and HIV-positive status (adjOR 3.33, 95% CI 1.55-7.14) were significantly associated with experiencing ≥1 related AE (p < 0.05) on standard therapy. The most common adverse events on standard therapy related to hepatobiliary, musculoskeletal and metabolic disorders. Patients who experienced ≥1 related AE were more likely to fail treatment or relapse (adjOR 3.11, 95% CI 1.59-6.10, p < 0.001).

CONCLUSIONS

Most AEs considered related to standard therapy occurred in the intensive phase of treatment with female patients and HIV-positive patients demonstrating a significantly higher risk of AEs during treatment. Almost a tenth of standard therapy patients had a significant side effect, whereas both experimental arms recorded a lower incidence of toxicity. That patients with one or more AE are more likely to fail treatment suggests that treatment outcomes could be improved by identifying such patients through targeted monitoring.

Postmarketing Modifications of Drug Labels for Cancer Drugs Approved by the US Food and Drug Administration Between 2006 and 2016 With and Without Supporting Randomized Controlled Trials

Purpose

Modifications in cancer drug indications, dosing, and related toxicities after Food and Drug Administration approval are common. It is unclear whether drug approval without a supporting randomized controlled trial (RCT) influences the probability of such modifications.

Methods

We searched the Drugs@FDA Web site for new drug indications for solid tumors approved between January 2006 and December 2016. Study characteristics, regulatory pathways, and label modifications from approval to October 2017 were collected from drug labels. Label modifications were considered to be major if defined as such in the drug label. Indications approved with and without supporting RCTs were compared using logistic regression. The Benjamini-Hochberg false discovery rate method was used to adjust for multiplicity.

Results

We identified 59 individual drugs for 109 solid tumor indications. Of these, 17 indications (15.6%) were not supported by an RCT, with no change over time. Indications not supported by RCTs were more likely to require companion diagnostic tests (odds ratio [OR], 3.90; P = .02), to include surrogate end points as primary outcomes (OR, 7.88; P < .001), and to receive breakthrough therapy designation (OR, 7.62; P = .006) or accelerated approval (OR, 17.67; P < .001). Indications not supported by RCTs were associated with significantly higher odds of postapproval modifications in common adverse events (71% v 29%; OR, 5.78; P = .002). A nonsignificantly higher odds of postapproval major modifications in warnings and precautions was also observed (88% v 62%; OR, 4.61; P = .051). Postapproval major modifications in indication and usage, dosing and administration, boxed warnings, and contraindications were comparable in the two groups.

Conclusion

Cancer drug indications not supported initially by RCTs are associated with more postmarketing safety-related label modifications. Health care professionals should be vigilant for unrecognized adverse effects when prescribing drugs approved without a supporting RCT.

Comparative "nocebo effects" in older patients enrolled in cancer therapeutic trials: Observations from a 446-patient cohort

BACKGROUND

A nocebo is an inert substance associated with adverse events. Although previous studies have examined the positive (placebo) effects of such inert substances, few have examined negative (nocebo) adverse event profiles, particularly in older patients who have higher morbidity and can experience frequent and severe adverse events from cancer therapy.

METHODS

This study focused on placebo/nocebo-exposed patients who participated in 2 double-blind, placebo-controlled, cancer therapeutic studies, namely, North Central Cancer Therapy Group trial NCCTG 97-24-51 and American College of Surgeons Oncology Group trial Z9001, with the goal of reporting the comparative, age-based adverse event rates, as reported during the conduct of these trials.

RESULTS

Among the 446 patients who received only placebo/nocebo and who were the focus of the current report, 161 were aged ≥65 years at the time of respective trial entry, and 5234 adverse events occurred. Unadjusted adverse event rates did not differ significantly between patients aged ≥65 years and younger patients (rate ratio, 1.01; 99% confidence interval, 0.47-2.02), and the findings were similar findings for grade 2 or worse adverse events and for all symptom-driven adverse events (for example, pain, loss of appetite, anxiety). Adjustment for sex, ethnicity, baseline performance score, and individual trial resulted in no significant age-based differences in adverse event rates. Similar findings were observed with an age threshold of 70 years.

CONCLUSIONS

Adverse events are equally common in older and younger cancer patients who are exposed to nocebo and thus require the same degree of clinical consideration regardless of age. Cancer 2017;123:4193-4198. © 2017 American Cancer Society.