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American Journal of Cancer Research 2021Clinical endpoints are essential for assessing the safety and efficacy of new cancer therapies. They are used by oncologists to help guide clinical decision making.... (Review)
Review
Clinical endpoints are essential for assessing the safety and efficacy of new cancer therapies. They are used by oncologists to help guide clinical decision making. While overall survival (OS) has frequently been regarded as the "gold standard" primary clinical endpoint, it's utility is constrained by several disadvantages. The time-consuming nature of trials using OS has led to a recent push to explore surrogate clinical endpoints and their potential to serve as primary clinical endpoints in lieu of OS. Additionally, it is becoming evident that other endpoints add valuable information about quality of life and treatment failure as their use is becoming increasingly prevalent in oncology clinical trials. Without a doubt, the use of clinical endpoints will continue to expand and evolve as new cancer therapies are developed and novel treatments, including immunotherapy, draw interest. This review explores the roles of primary and surrogate clinical endpoints as well as the benefits and drawbacks of each specific endpoint. In addition, it directly compares the unique features of each suggesting some of the specific uses each one fulfills.
PubMed: 33948349
DOI: No ID Found -
Biometrics Jun 2023Hung et al. (2007) considered the problem of controlling the type I error rate for a primary and secondary endpoint in a clinical trial using a gatekeeping approach in...
Hung et al. (2007) considered the problem of controlling the type I error rate for a primary and secondary endpoint in a clinical trial using a gatekeeping approach in which the secondary endpoint is tested only if the primary endpoint crosses its monitoring boundary. They considered a two-look trial and showed by simulation that the naive method of testing the secondary endpoint at full level α at the time the primary endpoint reaches statistical significance does not control the familywise error rate at level α. Tamhane et al. (2010) derived analytic expressions for familywise error rate and power and confirmed the inflated error rate of the naive approach. Nonetheless, many people mistakenly believe that the closure principle can be used to prove that the naive procedure controls the familywise error rate. The purpose of this note is to explain in greater detail why there is a problem with the naive approach and show that the degree of alpha inflation can be as high as that of unadjusted monitoring of a single endpoint.
Topics: Humans; Models, Statistical; Endpoint Determination; Computer Simulation; Research Design; Sample Size
PubMed: 35355244
DOI: 10.1111/biom.13668 -
European Heart Journal Dec 2023Endpoint adjudication (EA) is a common feature of contemporary randomized controlled trials (RCTs) in cardiovascular medicine. Endpoint adjudication refers to a process...
Endpoint adjudication (EA) is a common feature of contemporary randomized controlled trials (RCTs) in cardiovascular medicine. Endpoint adjudication refers to a process wherein a group of expert reviewers, known as the clinical endpoint committee (CEC), verify potential endpoints identified by site investigators. Events that are determined by the CEC to meet pre-specified trial definitions are then utilized for analysis. The rationale behind the use of EA is that it may lessen the potential misclassification of clinical events, thereby reducing statistical noise and bias. However, it has been questioned whether this is universally true, especially given that EA significantly increases the time, effort, and resources required to conduct a trial. Herein, we compare the summary estimates obtained using adjudicated vs. non-adjudicated site designated endpoints in major cardiovascular RCTs in which both were reported. Based on these data, we lay out a framework to determine which trials may warrant EA and where it may be redundant. The value of EA is likely greater when cardiovascular trials have nuanced primary endpoints, endpoint definitions that align poorly with practice, sub-optimal data completeness, greater operator variability, and lack of blinding. EA may not be needed if the primary endpoint is all-cause death or all-cause hospitalization. In contrast, EA is likely merited for more nuanced endpoints such as myocardial infarction, bleeding, worsening heart failure as an outpatient, unstable angina, or transient ischaemic attack. A risk-based approach to adjudication can potentially allow compromise between costs and accuracy. This would involve adjudication of a small proportion of events, with further adjudication done if inconsistencies are detected.
Topics: Humans; Myocardial Infarction; Ischemic Attack, Transient; Hemorrhage; Heart Failure; Angina, Unstable
PubMed: 37935635
DOI: 10.1093/eurheartj/ehad718 -
Journal of Clinical Epidemiology Dec 2020Studies often combine several events, for example, death or myocardial infarction or stroke, into a single study outcome. This is called a composite endpoint. Composite... (Review)
Review
Studies often combine several events, for example, death or myocardial infarction or stroke, into a single study outcome. This is called a composite endpoint. Composite endpoints make doing trials easier by reducing the sample size or follow-up period required to demonstrate the effectiveness of an intervention. However, interpreting the results of composite endpoints can be confusing. To avoid misleading conclusions about the effectiveness of an intervention, it is important for readers of studies reporting a composite endpoint to ascertain that the clinical importance, the frequency of events, and the effect of the intervention on each component of the composite endpoint are similar.
Topics: Endpoint Determination; Epidemiologic Research Design; Humans; Sample Size
PubMed: 32739473
DOI: 10.1016/j.jclinepi.2020.07.017 -
Journal of Hepatology Nov 2023Representatives from academia, industry, regulatory agencies, and patient advocacy groups convened under the American Association for the Study of Liver Diseases (AASLD)... (Review)
Review
Guidance on treatment endpoints and study design for clinical trials aiming to achieve cure in chronic hepatitis B and D: Report from the 2022 AASLD-EASL HBV-HDV Treatment Endpoints Conference.
Representatives from academia, industry, regulatory agencies, and patient advocacy groups convened under the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) in June 2022 with the primary goal of achieving consensus on chronic HBV and HDV treatment endpoints to guide clinical trials aiming to "cure" HBV and HDV. Conference participants reached an agreement on some key points. The preferred primary endpoint for phase II/III trials evaluating finite treatments for chronic hepatitis B (CHB) is a "functional" cure, defined as sustained HBsAg loss and HBV DNA less than the lower limit of quantitation (LLOQ) 24 weeks off-treatment. An alternate endpoint would be "partial cure" defined as sustained HBsAg level <100 IU/mL and HBV DNA
endpoint for chronic hepatitis D, but HDV RNA primary endpoint of phase II/III trials assessing finite strategies. For trials assessing maintenance therapy, the primary endpoint should be HDV RNA endpoint would be ≥2 log reduction in HDV RNA combined with normalization of alanine aminotransferase level. Suitable candidates for phase II/III trials would be treatment-naiive or experienced patients with quantifiable HDV RNA. Novel biomarkers (hepatitis B core-related antigen [HBcrAg] and HBV RNA) remain exploratory, while nucleos(t)ide analogs and pegylated interferon still have a role in combination with novel agents. Importantly, patient input is encouraged early on in drug development under the FDA/EMA patient-focused drug development programs. PubMed: 37377088
DOI: 10.1016/j.jhep.2023.06.002 -
Scientific Reports May 2023The purpose of this retrospective, longitudinal study is to evaluate the relationship between MD slope from visual field tests collected over a short period of time...
The purpose of this retrospective, longitudinal study is to evaluate the relationship between MD slope from visual field tests collected over a short period of time (2 years) and the current United States' Food and Drug Administration (FDA) recommended endpoints for visual field outcomes. If this correlation is strong and highly predictive, clinical trials employing MD slopes as primary endpoints could be employed in neuroprotection clinical trials with shorter duration and help expedite the development of novel IOP-independent therapies. Visual field tests of patients with or suspected glaucoma were selected from an academic institution and evaluated based on two functional progression endpoints: (A) five or more locations worsening by at least 7 dB, and (B) at least five test locations based upon the GCP algorithm. A total of 271 (57.6%) and 278 (59.1%) eyes reached Endpoints A and B, respectively during the follow up period. The median (IQR) MD slope of eyes reaching vs. not reaching Endpoint A and B were -1.19 (-2.00 to -0.41) vs. 0.36 (0.00 to 1.00) dB/year and -1.16 (-1.98 to -0.40) vs. 0.41 (0.02 to 1.03) dB/year, respectively (P < 0.001). It was found that eyes experiencing rapid 24-2 visual field MD slopes over a 2-year period were on average tenfold more likely to reach one of the FDA accepted endpoints during or soon after that period.
Topics: Humans; Retrospective Studies; Longitudinal Studies; Neuroprotection; Intraocular Pressure; Vision Disorders; Glaucoma; Visual Field Tests; Disease Progression; Follow-Up Studies
PubMed: 37130950
DOI: 10.1038/s41598-023-34009-x -
Biometrics Dec 2010We consider a clinical trial with a primary and a secondary endpoint where the secondary endpoint is tested only if the primary endpoint is significant. The trial uses a...
We consider a clinical trial with a primary and a secondary endpoint where the secondary endpoint is tested only if the primary endpoint is significant. The trial uses a group sequential procedure with two stages. The familywise error rate (FWER) of falsely concluding significance on either endpoint is to be controlled at a nominal level α. The type I error rate for the primary endpoint is controlled by choosing any α-level stopping boundary, e.g., the standard O'Brien-Fleming or the Pocock boundary. Given any particular α-level boundary for the primary endpoint, we study the problem of determining the boundary for the secondary endpoint to control the FWER. We study this FWER analytically and numerically and find that it is maximized when the correlation coefficient ρ between the two endpoints equals 1. For the four combinations consisting of O'Brien-Fleming and Pocock boundaries for the primary and secondary endpoints, the critical constants required to control the FWER are computed for different values of ρ. An ad hoc boundary is proposed for the secondary endpoint to address a practical concern that may be at issue in some applications. Numerical studies indicate that the O'Brien-Fleming boundary for the primary endpoint and the Pocock boundary for the secondary endpoint generally gives the best primary as well as secondary power performance. The Pocock boundary may be replaced by the ad hoc boundary for the secondary endpoint with a very little loss of secondary power if the practical concern is at issue. A clinical trial example is given to illustrate the methods.
Topics: Biomarkers; Clinical Trials as Topic; Humans; Models, Statistical; Research Design
PubMed: 20337631
DOI: 10.1111/j.1541-0420.2010.01402.x -
Hepatology (Baltimore, Md.) Nov 2023Representatives from academia, industry, regulatory agencies, and patient advocacy groups convened under the American Association for the Study of Liver Diseases (AASLD)...
Guidance on treatment endpoints and study design for clinical trials aiming to achieve cure in chronic hepatitis B and D: Report from the 2022 AASLD-EASL HBV-HDV Treatment Endpoints Conference.
Representatives from academia, industry, regulatory agencies, and patient advocacy groups convened under the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) in June 2022 with the primary goal of achieving consensus on chronic HBV and HDV treatment endpoints to guide clinical trials aiming to "cure" HBV and HDV. Conference participants reached an agreement on some key points. The preferred primary endpoint for phase II/III trials evaluating finite treatments for chronic hepatitis B (CHB) is a "functional" cure, defined as sustained HBsAg loss and HBV DNA less than the lower limit of quantitation (LLOQ) 24 weeks off-treatment. An alternate endpoint would be "partial cure" defined as sustained HBsAg level < 100 IU/mL and HBV DNA < LLOQ 24 weeks off-treatment. Clinical trials should initially focus on patients with HBeAg positive or negative CHB, who are treatment-naive or virally suppressed on nucleos(t)ide analogs. Hepatitis flares may occur during curative therapy and should be promptly investigated and outcomes reported. HBsAg loss would be the preferred endpoint for chronic hepatitis D, but HDV RNA < LLOQ 24 weeks off-treatment is a suitable alternate primary endpoint of phase II/III trials assessing finite strategies. For trials assessing maintenance therapy, the primary endpoint should be HDV RNA < LLOQ assessed at on-treatment week 48. An alternate endpoint would be ≥2 log reduction in HDV RNA combined with normalization of alanine aminotransferase level. Suitable candidates for phase II/III trials would be treatment-naiive or experienced patients with quantifiable HDV RNA. Novel biomarkers (hepatitis B core-related antigen [HBcrAg] and HBV RNA) remain exploratory, while nucleos(t)ide analogs and pegylated interferon still have a role in combination with novel agents. Importantly, patient input is encouraged early on in drug development under the FDA/EMA patient-focused drug development programs.
Topics: Humans; Hepatitis B, Chronic; Hepatitis B virus; Hepatitis B Surface Antigens; Antiviral Agents; DNA, Viral; Hepatitis B Core Antigens; RNA; Hepatitis B e Antigens
PubMed: 37326326
DOI: 10.1097/HEP.0000000000000431 -
Gastroenterology Dec 2022Gluten ingestion in patients with celiac disease can lead to gastrointestinal symptoms and small intestinal mucosal injury. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND & AIMS
Gluten ingestion in patients with celiac disease can lead to gastrointestinal symptoms and small intestinal mucosal injury.
METHODS
This gluten challenge phase 2 trial was double blind and placebo controlled, and it assessed the efficacy and safety of a 1200-mg dose of IMGX003 in patients with celiac disease exposed to 2 g of gluten per day for 6 weeks. The change in the ratio of villus height to crypt depth was the primary endpoint. Secondary endpoints included density of intraepithelial lymphocytes and symptom severity. These endpoints were evaluated by analysis of covariance. Additional endpoints included serology and gluten-immunogenic peptides in urine.
RESULTS
Fifty patients were randomized, and 43 patients completed the study (IMGX003, n = 21; placebo, n = 22). The mean change in the ratio of villus height to crypt depth (primary endpoint) for IMGX003 vs placebo was -0.04 vs -0.35 (P = .057). The mean change in the density of intraepithelial lymphocytes (secondary endpoint) for IMGX003 vs placebo was 9.8 vs 24.8 cells/mm epithelium (P = .018). The mean change (worsening) in symptom severity in relative units (secondary endpoint) for IMGX003 vs placebo was 0.22 vs 1.63 (abdominal pain, P = .231), 0.96 vs 3.29 (bloating, P = .204), and 0.02 vs 3.20 (tiredness, P = .113). The 3 × 2-week trend line significance values for these symptoms, respectively, were P = .014, .030, and .002.
CONCLUSIONS
IMGX003 reduced gluten-induced intestinal mucosal damage and symptom severity. (ClinicalTrials.gov, Number: NCT03585478).
Topics: Humans; Glutens; Celiac Disease; Peptide Hydrolases; Intestinal Mucosa
PubMed: 35931103
DOI: 10.1053/j.gastro.2022.07.071 -
Cancers Aug 2020Time to next treatment (TTNT) is an emerging endpoint in clinical studies of primary cutaneous T-cell lymphomas (CTCL), with utility as a surrogate marker for the...
Time to next treatment (TTNT) is an emerging endpoint in clinical studies of primary cutaneous T-cell lymphomas (CTCL), with utility as a surrogate marker for the "duration of clinical benefit". TTNT provides a highly clinically meaningful endpoint that uniquely reflects not only the duration of treatment efficacy on disease and symptom control, but also incorporates the patient experience by accounting for patient compliance and tolerance to the studied therapy(s). Given the distinct challenges of pin-pointing the exact date of progression in patients with multi-compartmental CTCL, TTNT overcomes many of the shortcomings of conventional, disease-focused, clinical endpoints in primary CTCL research. Although widely accepted in clinical research for numerous other incurable malignancies, TTNT currently lacks a standardised definition. In this paper, we describe the value of TTNT as a clinical endpoint, review the applications of TTNT in primary CTCL research, and propose a standardised definition of TTNT to be applied in future clinical research of primary CTCL therapies.
PubMed: 32824427
DOI: 10.3390/cancers12082311