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"Small population studies"
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Recommendations for the design of small population clinical trials
by
Irony, Ilan
,
Lau, Lilian Pek Lian
,
Roes, Kit CB
in
Analysis
,
Biomedical Research - methods
,
Care and treatment
2018
Background
Orphan drug development faces numerous challenges, including low disease prevalence, patient population heterogeneity, and strong presence of paediatric patient populations. Consequently, clinical trials for orphan drugs are often smaller than those of non-orphan drugs, and they require the development of efficient trial designs relevant to small populations to gain the most information from the available data. The International Rare Diseases Research Consortium (IRDiRC) is aimed at promoting international collaboration and advance rare diseases research worldwide, and has as one of its goals to contribute to 1000 new therapies for rare diseases. IRDiRC set up a Small Population Clinical Trials (SPCT) Task Force in order to address the shortcomings of our understanding in carrying out clinical trials in rare diseases.
Results
The IRDiRC SPCT Task Force met in March 2016 to discuss challenges faced in the design of small studies for rare diseases and present their recommendations, structured around six topics: different study methods/designs and their relation to different characteristics of medical conditions, adequate safety data, multi-arm trial designs, decision analytic approaches and rational approaches to adjusting levels of evidence, extrapolation, and patients’ engagement in study design.
Conclusions
Recommendations have been issued based on discussions of the Small Population Clinical Trials Task Force that aim to contribute towards successful therapy development and clinical use. While randomised clinical trials are still considered the gold standard, it is recommended to systematically take into consideration alternative trial design options when studying treatments for a rare disease. Combining different sources of safety data is important to give a fuller picture of a therapy’s safety profile. Multi-arm trials should be considered an opportunity for rare diseases therapy development, and funders are encouraged to support such trial design via international networks. Patient engagement is critical in trial design and therapy development, a process which sponsors are encouraged to incorporate when conducting trials and clinical studies. Input from multiple regulatory agencies is recommended early and throughout clinical development. Regulators are often supportive of new clinical trial designs, provided they are well thought through and justified, and they also welcome discussions and questions on this topic. Parallel advice for multiregional development programs should also be considered.
Journal Article
Association of G-protein coupled purinergic receptor P2Y2 with ischemic stroke in a Han Chinese population of North China
2019
The G-protein-coupled purinergic receptor P2Y2 (P2RY2) plays an important role in the mechanism of atherosclerosis, which is relevant to ischemic stroke. This retrospective case-control study aimed to assess the relationship between P2RY2 gene polymorphisms and ischemic stroke risk in the northern Han Chinese population. In this study, clinical data and peripheral blood specimens were collected from 378 ischemic stroke patients and 344 controls. The ischemic stroke participants were recruited from the First Affiliated Hospital of China Medical University and the First Affiliated Hospital of Liaoning Medical University. The controls were recruited from the Health Check Center at the First Affiliated Hospital of China Medical University. Ischemic stroke patients were divided into two subgroups according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification: large-artery atherosclerosis (n = 178) and small-artery occlusion (n = 200) strokes. All subjects were genotyped for three single nucleotide polymorphisms (rs4944831, rs1783596, and rs4944832) in the P2RY2 gene using peripheral venous blood samples. The distribution of the dominant rs4944832 phenotype (GG vs. GA+AA) differed significantly between small-artery occlusion patients and control subjects (odds ratio (OR) = 1.720, 95% confidence interval (CI): 1.203-2.458, P < 0.01). Multivariable logistic regression analysis revealed that the GG genotype of rs4944832 was significantly more prevalent in small-artery occlusion patients than in control subjects (OR = 1.807, 95% CI: 1.215-2.687, P < 0.01). The overall distribution of the haplotype established by rs4944831-rs1783596-rs4944832 was significantly different between ischemic stroke patients and controls (P < 0.01). In ischemic stroke patients, the frequency of the G-C-G haplotype was significantly higher than in control subjects (P = 0.028), whereas the frequency of the T-C-A haplotype was lower than in control subjects (P = 0.047). These results indicate that the G-C-G haplotype of P2RY2 is a susceptibility haplotype for ischemic stroke. In addition, the GG genotype of rs4944832 may be associated with the development of small-artery occlusion in the northern Han Chinese population. The study protocol was approved by the Ethics Committee of the First Affiliated Hospital of China Medical University on February 20, 2012 (No. 2012-38-1) and the First Affiliated Hospital of Liaoning Medical University, China, on March 1, 2013 (No. 2013-03-1). All participants gave their informed consent. This trial was registered with the ISRCTN Registry (ISRCTN11439124) on October 24, 2018. Protocol version (1.0).
Journal Article
The experimental approach to rodent population dynamics
by
Crebs, C.J. (Vancouver Univ. (Canada). Dept. of Zoology)
in
ANIMAL ECOLOGY
,
Different Approaches to the Study of Small Rodent Population of Dynamics
,
DINAMICA DE LA POBLACION
1988
Four paradigms can be followed to help us understand the dynamics of rodent populations. Natural observations are the traditional way to do ecology and it is important to have a good description of the population changes that are to be explained. Laboratory experiments were used in the 1940s and 1950s but provided little insight into events in the field. Field experiments began in the 1950s and have provided the greatest insights into the factors causing changes in numbers. Six factors have been manipulated in field experiments: food, predators, cover, density, physiological condition, and genetic composition. Field experiments can be used to test single-factor or multi-factor hypotheses of population regulation. They have the additional advantage of defining operationally verbal expressions like \"food-limitation\" that provoke fuzzy thinking. There is no need to separate natural observations from field experiments because they are the \"control\" for any manipulation done in the field. Mathematical modelling would seem to be the best of all possible worlds, but in rodent population dynamics it has been the worst because we do not know what the relevant variables to model are. Mathematical models are not a means of discovery and cannot be used to reject logically impossible ideas in the real world. Stenseth's attempt to reject the Chitty hypothesis as logically impossible is itself logically impossible. Whether the Chitty hypothesis is correct or not can be determined only by field experiments. Nor are mathematical models useful for defining concepts operationally in ecology, and I doubt if models ever produce new principles in ecology. I argue that the only useful goal for mathematical modellers in rodent ecology is to analyze how particular variables (like female territoriality) may affect population dynamics. This goal can be achieved only by a closer liaison between modellers and field ecologists at every step in the analysis.
Journal Article
Incidence and US Costs of Corticosteroid-Associated Adverse Events: A Systematic Literature Review
by
Crofford, Leslie
,
Watson, Maria
,
Kan, Hong
in
Adrenal Cortex Hormones - adverse effects
,
Adverse Drug Reaction Reporting Systems
,
adverse events
2011
The objective of this systematic literature review was to evaluate the incidences and risks for adverse events (AEs) associated with oral and parenteral corticosteroids. An assessment was performed to estimate the costs of such AEs.
A systematic review of literature published from 2007 to 2009 was conducted to identify the incidence rates and risk ratios of corticosteroid-related AEs. The review protocol was developed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The literature search was expanded to include additional search terms for psychiatric conditions, infections, and peptic ulcers. Costs obtained from a separate narrative literature review were applied to AEs likely to affect third-party payers in the United States.
A total of 357 publications were identified from the primary (n = 323) and secondary (n = 34) searches. Of these, 310 were excluded because they did not evaluate AEs related to corticosteroids, were an excluded publication type, or for other reasons. A final list of 47 studies were used for data extraction. Across patient populations, the most frequently reported corticosteroid-associated AEs were psychiatric events, infections, gastric conditions, and fractures. Corticosteroid-associated AEs reported to occur at an incidence >30% were sleep disturbances, lipodystrophy, adrenal suppression, metabolic syndrome, weight gain, and hypertension. Vertebral fractures were reported at an incidence of 21% to 30%. Dose-response relationships were documented for fractures, acute myocardial infarction, hypertension, and peptic ulcer. The costs of managing AEs that may occur with corticosteroids can be substantial. The literature reported 1-year per-patient costs of up to $26,471.80 for nonfatal myocardial infarction, and per-event costs as high as $18,357.90 for fracture. The findings from the present review should be interpreted cautiously due to several limitations, including the retrospective design of most of the studies identified, risk for confounding due to underlying disease activity or patient population, and the relatively small number of studies that reported each AE association. As this cost analysis was preliminary, a comprehensive pharmacoeconomic analysis should be undertaken to confirm the findings.
Based on the findings from this review, systemic corticosteroids are a common cause of AEs that may be costly to payers.
Journal Article
The place of modelling in ecology
by
Lomnicki, A. (Jagiellonian Univ., Krakow (Poland). Inst. of Environmental Biology)
in
ANIMAL ECOLOGY
,
Biology
,
Different Approaches to the Study of Small Rodent Population of Dynamics
1988
This is an attempt to answer the question why there are great differences of opinion about the value of mathematical modelling in ecology. Some reasons for the gap between empirical and theoretical ecologists are discussed, examples which show the necessity of mathematical modelling in ecology are presented, and suggestions as to what can be done to close this gap between the empirically and mathematically minded ecologists are offered. Although ecology cannot progress without the applications of mathematical models, such models are of value only when they are applied and tested by field and laboratory ecologists.
Journal Article
Empiricism and modelling in small rodent research: How to partition efforts
by
Hansson L
in
animal ecology
,
Different Approaches to the Study of Small Rodent Population of Dynamics
,
ecologia animal
1988
Mathematical models attempting to illuminate problems in rodent ecology have not been very successful; fairly few new insights have emerged. It is suggested that models should not be developed for planning or directing new research, or to formulate primary hypotheses, but to check consistency and logic of predictions of important hypotheses generated by empiricists. Important factors in the population ecology of small rodents are thought to be detected by people actively engaged in field research while problems with factor interactions, quantification or range of applicability will be disclosed by modelling, at least in more complicated hypotheses. The latter treatment may also be useful in hypotheses for larger organisms to be tested under crucial field conditions rather than with field experiments. In such cases close cooperation between empricists and modellers is necessary.
Journal Article
Ramucirumab plus erlotinib in patients with untreated, EGFR-mutated, advanced non-small-cell lung cancer (RELAY): a randomised, double-blind, placebo-controlled, phase 3 trial
by
Pasello, Giulia
,
Nadal, Ernest
,
Goto, Yasushi
in
Adenocarcinoma of Lung - drug therapy
,
Adenocarcinoma of Lung - genetics
,
Adenocarcinoma of Lung - pathology
2019
Dual blockade of the EGFR and VEGF pathways in EGFR-mutated metastatic non-small-cell lung cancer (NSCLC) is supported by preclinical and clinical data, yet the approach is not widely implemented. RELAY assessed erlotinib, an EGFR tyrosine kinase inhibitor (TKI) standard of care, plus ramucirumab, a human IgG1 VEGFR2 antagonist, or placebo in patients with untreated EGFR-mutated metastatic NSCLC.
This is a worldwide, double-blind, phase 3 trial done in 100 hospitals, clinics, and medical centres in 13 countries. Eligible patients were aged 18 years or older (20 years or older in Japan and Taiwan) at the time of study entry, had stage IV NSCLC, with an EGFR exon 19 deletion (ex19del) or exon 21 substitution (Leu858Arg) mutation, an Eastern Cooperative Oncology Group performance status of 0 or 1, and no CNS metastases. We randomly assigned eligible patients in a 1:1 ratio to receive oral erlotinib (150 mg/day) plus either intravenous ramucirumab (10 mg/kg) or matching placebo once every 2 weeks. Randomisation was done by an interactive web response system with a computer-generated sequence and stratified by sex, geographical region, EGFR mutation type, and EGFR testing method. The primary endpoint was investigator-assessed progression-free survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered at ClinicalTrials.gov, NCT02411448, and is ongoing for long-term survival follow-up.
Between Jan 28, 2016, and Feb 1, 2018, 449 eligible patients were enrolled and randomly assigned to treatment with ramucirumab plus erlotinib (n=224) or placebo plus erlotinib (n=225). Median duration of follow-up was 20·7 months (IQR 15·8–27·2). At the time of primary analysis, progression-free survival was significantly longer in the ramucirumab plus erlotinib group (19·4 months [95% CI 15·4–21·6]) than in the placebo plus erlotinib group (12·4 months [11·0–13·5]), with a stratified hazard ratio of 0·59 (95% CI 0·46–0·76; p<0·0001). Grade 3–4 treatment-emergent adverse events were reported in 159 (72%) of 221 patients in the ramucirumab plus erlotinib group versus 121 (54%) of 225 in the placebo plus erlotinib group. The most common grade 3–4 treatment-emergent adverse events in the ramucirumab plus erlotinib group were hypertension (52 [24%]; grade 3 only) and dermatitis acneiform (33 [15%]), and in the placebo plus erlotinib group were dermatitis acneiform (20 [9%]) and increased alanine aminotransferase (17 [8%]). Treatment-emergent serious adverse events were reported in 65 (29%) of 221 patients in the ramucirumab plus erlotinib group and 47 (21%) of 225 in the placebo plus erlotinib group. The most common serious adverse events of any grade in the ramucirumab plus erlotinib group were pneumonia (seven [3%]) and cellulitis and pneumothorax (four [2%], each); the most common in the placebo plus erlotinib group were pyrexia (four [2%]) and pneumothorax (three [1%]). One on-study treatment-related death due to an adverse event occurred (haemothorax after a thoracic drainage procedure for a pleural empyema) in the ramucirumab plus erlotinib group.
Ramucirumab plus erlotinib demonstrated superior progression-free survival compared with placebo plus erlotinib in patients with untreated EGFR-mutated metastatic NSCLC. Safety was consistent with the safety profiles of the individual compounds in advanced lung cancer. The RELAY regimen is a viable new treatment option for the initial treatment of EGFR-mutated metastatic NSCLC.
Eli Lilly.
Journal Article
The Area and Population of Cities: New Insights from a Different Perspective on Cities
by
Makse, Hernán A.
,
Rozenfeld, Hernán D.
,
Rybski, Diego
in
Algorithms
,
Approximation
,
Ballungsraum
2011
The distribution of city populations has attracted much attention, in part because it constrains models of local growth. However, there is no consensus on the distribution below the very upper tail, because available data need to rely on “legal” rather than “economic” definitions for medium and small cities. To remedy this difficulty, we construct cities “from the bottom up” by clustering populated areas obtained from high-resolution data. We find that Zipf 's law for population holds for cities as small as 5,000 inhabitants in Great Britain and 12,000 inhabitants in the US. We also find a Zipf 's law for areas. JEL: R11, R12, R23
Journal Article
Neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab compared with neoadjuvant chemotherapy alone in patients with early-stage non-small-cell lung cancer (KEYNOTE-671): a randomised, double-blind, placebo-controlled, phase 3 trial
2024
At the first interim analysis of the KEYNOTE-671 trial, adding perioperative pembrolizumab to neoadjuvant chemotherapy significantly improved event-free survival in participants with early-stage non-small-cell lung cancer (NSCLC). We report overall survival and health-related quality of life outcomes from the second interim analysis.
KEYNOTE-671 was a global phase 3 trial done at 189 medical centres. Eligible participants (aged ≥18 years) with resectable stage II, IIIA, or IIIB (N2) NSCLC were randomly assigned (1:1) to four cycles of neoadjuvant pembrolizumab (200 mg administered intravenously every 3 weeks) plus cisplatin-based chemotherapy followed by surgery and 13 cycles of adjuvant pembrolizumab (200 mg administered intravenously every 3 weeks) or to four cycles of neoadjuvant placebo (administered intravenously every 3 weeks) plus cisplatin-based chemotherapy followed by surgery and 13 cycles of adjuvant placebo (administered intravenously every 3 weeks). Randomisation was done centrally using an interactive response technology system and was stratified by disease stage, PD-L1 expression, histology, and geographical region in blocks of four. Participants, investigators, and sponsor personnel were masked to treatment assignments; local pharmacists were unmasked to support treatment preparation. The dual primary endpoints were overall survival and event-free survival evaluated in the intention-to-treat population. This study is registered at ClinicalTrials.gov, NCT03425643, and is ongoing but closed to enrolment.
Between May 11, 2018, and Dec 15, 2021, 797 participants were randomly assigned to the pembrolizumab group (n=397) or the placebo group (n=400). Median study follow-up at the second interim analysis was 36·6 months (IQR 27·6–47·8). 36-month overall survival estimates were 71% (95% CI 66–76) in the pembrolizumab group and 64% (58–69) in the placebo group (hazard ratio 0·72 [95% CI 0·56–0·93]; one-sided p=0·0052; threshold, one-sided p=0·0054). Median event-free survival was 47·2 months (95% CI 32·9 to not reached) in the pembrolizumab group and 18·3 months (14·8–22·1) in the placebo group (hazard ratio 0·59 [95% CI 0·48–0·72]). In the as-treated population, grade 3–5 treatment-related adverse events occurred in 179 (45%) of 396 participants in the pembrolizumab group and in 151 (38%) of 399 participants in the placebo group. Treatment-related adverse events led to death in four (1%) participants in the pembrolizumab group and three (1%) participants in the placebo group.
The significant overall survival benefit of neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab compared with neoadjuvant chemotherapy alone coupled with a manageable safety profile support the use of perioperative pembrolizumab in patients with resectable, early-stage NSCLC.
Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.
Journal Article
Pembrolizumab versus placebo as adjuvant therapy for completely resected stage IB–IIIA non-small-cell lung cancer (PEARLS/KEYNOTE-091): an interim analysis of a randomised, triple-blind, phase 3 trial
by
Dafni, Urania
,
Lee, Jong-Seok
,
Paz-Ares, Luis
in
Adjuvant therapy
,
Adverse events
,
Antibodies, Monoclonal, Humanized
2022
Pembrolizumab is a standard-of-care for advanced non-small-cell lung cancer (NSCLC). We assessed pembrolizumab as adjuvant therapy for completely resected stage IB–IIIA NSCLC.
In this randomised, triple-blind, phase 3 trial (PEARLS/KEYNOTE-091), patients were recruited from 196 medical centres in 29 countries. Eligible patients were aged 18 years or older, with completely resected, pathologically confirmed stage IB (tumours of ≥4 cm in diameter), II, or IIIA NSCLC per the American Joint Committee on Cancer staging system (7th edition) of any histology or PD-L1 expression level, and an Eastern Cooperative Oncology Group performance status of 0 or 1; adjuvant chemotherapy was to be considered for stage IB disease and was strongly recommended for stage II and IIIA disease, according to national and local guidelines. Using a central interactive voice-response system, eligible participants were randomly assigned (1:1), using a minimisation technique and stratified by disease stage, previous adjuvant chemotherapy, PD-L1 expression, and geographical region, to pembrolizumab 200 mg or placebo, both administered intravenously every 3 weeks for up to 18 cycles. Participants, investigators, and analysts were masked to treatment assignment. Dual primary endpoints were disease-free survival in the overall population and in the population with PD-L1 tumour proportion score (TPS) of 50% or greater. Efficacy was assessed in the intention-to-treat (ITT) population (ie, all participants randomly assigned to a treatment group). Safety was assessed in all participants randomly assigned to treatment who received at least one dose of study treatment. Here we report results of the second interim analysis, prespecified to occur when approximately 118 disease-free survival events had occurred in the PD-L1 TPS of 50% or greater population. This study is registered with ClinicalTrials.gov, NCT02504372, and is active but not recruiting.
Between Jan 20, 2016, and May 6, 2020, 1177 (60%) of 1955 screened participants were randomly assigned to pembrolizumab (n=590, including n=168 with PD-L1 TPS of ≥50%) or placebo (n=587; including n=165 with PD-L1 TPS of ≥50%) and included in the ITT population. Median follow-up as of data cutoff (Sept 20, 2021) for this interim analysis was 35·6 months (IQR 27·1–45·5). In the overall population, median disease-free survival was 53·6 months (95% CI 39·2 to not reached) in the pembrolizumab group versus 42·0 months (31·3 to not reached) in the placebo group (HR 0·76 [95% CI 0·63–0·91], p=0·0014). In the PD-L1 TPS of 50% or greater population, median disease-free survival was not reached in either the pembrolizumab group (95% CI 44·3 to not reached) or the placebo group (95% CI 35·8 to not reached; HR 0·82 [95% CI 0·57–1·18]; p=0·14). Grade 3 or worse adverse events occurred in 198 (34%) of 580 participants who received pembrolizumab and 150 (26%) of 581 participants who received placebo. Grade 3 or worse events that occurred in at least ten participants in either treatment group were hypertension (35 [6%]) and pneumonia (12 [2%]) with pembrolizumab and hypertension (32 [6%]) with placebo. Serious adverse events occurred in 142 (24%) participants in the pembrolizumab group and 90 (15%) in the placebo group; serious adverse events that occurred in more than 1% of participants were pneumonia (13 [2%]), pneumonitis (12 [2%]), and diarrhoea (seven [1%]) with pembrolizumab and pneumonia (nine [2%]) with placebo. Treatment-related adverse events led to death in four (1%) participants treated with pembrolizumab (one due to both cardiogenic shock and myocarditis, one due to both septic shock and myocarditis, one due to pneumonia, and one due to sudden death) and in no participants treated with placebo.
Pembrolizumab significantly improved disease-free survival compared with placebo and was not associated with new safety signals in completely resected, PD-L1-unselected, stage IB–IIIA NSCLC. Pembrolizumab is potentially a new treatment option for stage IB–IIIA NSCLC after complete resection and, when recommended, adjuvant chemotherapy, regardless of PD-L1 expression.
Merck Sharp & Dohme, a subsidiary of Merck & Co.
Journal Article