Adjusting for differential proportions of second-line treatment in cancer clinical trials. Part I: Structural nested models and marginal structural models to test and estimate treatment arm effects

2004 ◽  
Vol 23 (13) ◽  
pp. 1991-2003 ◽  
Author(s):  
Takuhiro Yamaguchi ◽  
Yasuo Ohashi
Keyword(s):  
Clinical Trials ◽  
Structural Models ◽  
Marginal Structural Models ◽  
Cancer Clinical Trials ◽  
Line Treatment ◽  
Second Line ◽  
Nested Models ◽  
Structural Nested Models

Marginal structural models to estimate the effects of time-varying treatments on clustered outcomes in the presence of interference

2017 ◽  
Vol 28 (2) ◽  
pp. 613-625 ◽  
Author(s):  
Jiwei He ◽  
Alisa Stephens-Shields ◽  
Marshall Joffe
Keyword(s):  
Structural Models ◽  
Marginal Structural Models ◽  
Time Varying ◽  
Nested Models ◽  
Unit Level ◽  
Inverse Probability Weights ◽  
Effect Of Treatment ◽  
Working Correlation ◽  
Structural Nested Models ◽  
Cluster Level

Marginal structural models are a class of causal models useful for characterizing the effect of treatment in the presence of time-varying confounding. They are more widely used than structural nested models, partly because these models are easier to understand and to implement. We extend marginal structural models to situations with clustered observations with unit- and cluster-level treatment and introduce an appropriate inferential method. We consider how to formulate models with cluster-level and unit-level treatments. For unit-level treatments, we consider cases with and without interference. We also consider the use of unit-specific inverse probability weights and certain working correlation structures to improve the efficiency of estimators in some situations. We apply our method to different scenarios including 2 or 3 units per cluster and a mixture of larger clusters. Simulation examples and data from the treatment arm of a glaucoma clinical trial were used to illustrate our method.

Ixabepilone, mitoxantrone, and prednisone in patients with metastatic castration-resistant prostate cancer refractory to docetaxel-based therapy: A phase II study of the DOD Prostate Cancer Clinical Trials Consortium

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 5058-5058
Author(s):  
E. Small ◽  
A. Harzstark ◽  
V. K. Weinberg ◽  
D. C. Smith ◽  
P. Mathew ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Trials ◽  
Phase Ii ◽  
Vasovagal Syncope ◽  
Objective Response ◽  
Study Drug ◽  
Cancer Clinical Trials ◽  
Second Line ◽  
Castration Resistant Prostate Cancer ◽  
Grade 3

5058 Background: Mitoxantrone (M) plus prednisone (P) and ixabepilone (Ix) each have modest, non cross-resistant activity as second line chemotherapy regimens in docetaxel-refractory patients with CRPC. These agents were therefore combined in a phase I study which demonstrated anti-cancer activity and defined the recommended phase II dose used in this trial. Methods: Patients with metastatic CRPC and progression after 3 or more cycles of docetaxel were enrolled in a phase II multicenter study of the combination of prednisone 5 mg BID, Ix (35 mg/m2) and M (12 mg/m2) administered intravenously on day 1 every 21 days, with pegfilgrastim (6 mg on day 2) support. Results: To date, 43 pts have been enrolled and have received a median of 4 cycles. Of 37 patients currently evaluable for response, 14 (38%; 95% CI: 22–55%) have had a confirmed ≥50% decline in PSA and 19 (51%; 95% CI 34–68%) have had a confirmed ≥30% decline in PSA. Two of 15 patients with evaluable measurable disease (13%) have had a RECIST-defined objective response. All 43 patients are evaluable for toxicity. Grade 3 or 4 neutropenia was seen in 6 pts (17%) and grade 3 or 4 thrombocytopenia was seen in 3 (8%). Nonhematologic grade 3/4 events possibly related to study drug have included grade 3 fatigue (3 pts), grade 3 pneumonia (2 pts), and grade 3 atrial fibrillation, grade 4 myocardial infarction, grade 4 prostatitis, grade 3 nausea/vomiting, grade 3 neuropathy, grade 3 elevated transaminases, grade 3 dizziness, grade 3 dehydration, grade 3 shortness of breath, and grade 4 vasovagal syncope (1 pt each). Grade 2 neuropathy has been seen in 4 patients. Conclusions: The Ix, M, P regimen is active as second-line therapy in CRPC patients with progressive disease after docetaxel therapy and is reasonably well tolerated. Further investigation of this regimen is warranted. This study was supported in part by CTEP/NCI and the DOD Prostate Cancer Clinical Trials Consortium. [Table: see text]

A review of the patterns of docetaxel use for hormone refractory prostate cancer (HRPC) at the Princess Margaret Hospital

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16161-e16161
Author(s):  
S. N. Chin ◽  
L. Wang ◽  
A. Lau ◽  
M. Moore ◽  
S. S. Sridhar
Keyword(s):  
Clinical Trial ◽  
Clinical Trials ◽  
Clinical Practice ◽  
Median Duration ◽  
Response Rates ◽  
Routine Clinical Practice ◽  
Phase Iii ◽  
Line Treatment ◽  
Second Line ◽  
First Line

e16161 Background: Docetaxel is standard of care for the treatment of HRPC, based on two large randomized clinical trials. The aim of this study was to determine if docetaxel use and effectiveness in routine clinical practice was similar to that seen in the TAX 327 randomized phase III clinical trial. Methods: A retrospective chart review was undertaken to assess patterns of docetaxel use for HRPC at our institution for the 2-year period since its approval for the first-line treatment of HRPC in 2005. Results: Eighty-eight patients, median age 71 and baseline PSA 107, received docetaxel in the first line setting. Main reasons for initiating docetaxel were rising PSA (90%) and progressive symptoms (71%). Eighteen percent of patients received docetaxel for rising PSA alone. A median of 7 cycles was administered. PSA response rates were 61%, time to response 1.5 months, and response duration 6.8 months. Disease progression was the most common reason for treatment discontinuation (36%). Main toxicities were fatigue (32%) and neuropathy (22%). Kaplan Meier survival analysis showed median duration of survival was 15.9 months (95% CI 12.4–20.5) from first drug use. 1-year survival was 0.63 (95% CI 0.52–0.72). Post-docetaxel, 36 patients received second-line treatment, mostly with mitoxantrone (89%). Second-line response rates were 22%, and median duration of response was 4 months. Conclusions: In routine clinical practice, docetaxel is a well-tolerated regimen for the treatment of HRPC. Response rates and toxicity profiles were comparable to the randomized trials. However, compared with the TAX 327 clinical trial, survival was slightly shorter than expected (15.9 vs. 18.9 months), possibly due to inclusion of patients with poorer performance status and comorbidities, who may be excluded from clinical trials. Second-line response rates were also comparable with previous reports. No significant financial relationships to disclose.

scholarly journals Role of immunotherapy in the management of hepatocellular carcinoma: current standards and future directions

2020 ◽  
Vol 27 (S3) ◽  
Author(s):  
A. Weinmann ◽  
P.R. Galle
Keyword(s):  
Hepatocellular Carcinoma ◽  
Overall Survival ◽  
Clinical Trials ◽  
Statistical Significance ◽  
Phase Iii ◽  
Advanced Hepatocellular Carcinoma ◽  
Line Treatment ◽  
Second Line ◽  
First Line ◽  
Promising Therapeutic Approach

 The multikinase inhibitor sorafenib was the only approved systemic therapy in advanced hepatocellular carcinoma (hcc) for about a decade. In recent years, the number of approved agents has increased significantly as a result of a number of positive phase iii clinical trials. Lenvatinib as a first-line treatment, and regorafenib, cabozantinib, and ramucirumab in the second-line setting are now approved by the U.S. Food and Drug Administration (fda) and the European Medicines Agency. In phase ii studies, immunotherapy with nivolumab and monotherapy using pembrolizumab yielded impressive results for overall survival in therapy-naïve and pretreated patients, leading to the accelerated approval by the fda of nivolumab and pembrolizumab for second-line treatment. However, phase iii trials of nivolumab in the first line and pembrolizumab in the second line as single agents failed to reach statistical significance, although clinical benefit for a subset of patients with long durations of response could be demonstrated. Despite that setback, immunotherapy for hcc is a promising therapeutic approach, and the combination of immunotherapy with other treatment modal­ities such as monoclonal antibodies, tyrosine kinase inhibitors, or local therapies has the potential to increase the overall response rate and survival. Recently, the results of a phase iii trial of combination atezolizumab–bevacizumab compared with sorafenib showed a highly significant survival benefit and median overall survival that was not reached in the immunotherapy arm, making the combination the preferred standard of care in first-line therapy. Despite the impressive results and generally good toxicity profile of immunotherapy, patients who respond to therapy constitute only a subset of the overall population, and response rates are still limited. This review focuses on the currently reported results and ongoing clinical trials of checkpoint inhibitor–based immunotherapy in hcc.

scholarly journals Towards an optimal treatment algorithm for metastatic pancreatic ductal adenocarcinoma (PDA)

2018 ◽  
Vol 25 (1) ◽  
pp. 90 ◽  
Author(s):  
M. Uccello ◽  
M. Moschetta ◽  
G. Mak ◽  
T. Alam ◽  
C. Murias Henriquez ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Optimal Algorithm ◽  
Treatment Algorithm ◽  
Ductal Adenocarcinoma ◽  
Line Treatment ◽  
Second Line ◽  
New Paradigm ◽  
First Line ◽  
First Line Treatment

Chemotherapy remains the mainstay of treatment for advanced pancreatic ductal adenocarcinoma (pda). Two randomized trials have demonstrated superiority of the combination regimens folfirinox (5-fluorouracil, leucovorin, oxaliplatin, and irinotecan) and gemcitabine plus nab-paclitaxel over gemcitabine monotherapy as a first-line treatment in adequately fit subjects. Selected pda patients progressing to first-line therapy can receive secondline treatment with moderate clinical benefit. Nevertheless, the optimal algorithm and the role of combination therapy in second-line are still unclear. Published second-line pda clinical trials enrolled patients progressing to gemcitabine-based therapies in use before the approval of nab-paclitaxel and folfirinox. The evolving scenario in second-line may affect the choice of the first-line treatment. For example, nanoliposomal irinotecan plus 5-fluouracil and leucovorin is a novel second-line option which will be suitable only for patients progressing to gemcitabinebased therapy. Therefore, clinical judgement and appropriate patient selection remain key elements in treatment decision. In this review, we aim to illustrate currently available options and define a possible algorithm to guide treatment choice. Future clinical trials taking into account sequential treatment as a new paradigm in pda will help define a standard algorithm.

scholarly journals Effects of Tocilizumab on Mortality in Hospitalized Patients with COVID-19: A Multicenter Cohort Study

2020 ◽  
Author(s):  
Javier Martínez-Sanz ◽  
Alfonso Muriel ◽  
Raquel Ron ◽  
Sabina Herrera ◽  
José A. Pérez-Molina ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cohort Study ◽  
Structural Models ◽  
Secondary Outcome ◽  
Marginal Structural Models ◽  
Multicenter Cohort Study ◽  
Time To Death ◽  
Risk Of Death ◽  
Proven Efficacy ◽  
Time Varying Covariates

ABSTRACTBackgroundWhile there are no treatments with proven efficacy for patients with severe coronavirus disease 2019 (COVID-19), tocilizumab has been proposed as a candidate therapy, especially among patients with higher systemic inflammation.MethodsWe conducted a cohort study of patients hospitalized with COVID-19 in Spain. The primary outcome was time to death and the secondary outcome time to intensive care unit admission (ICU) or death. We used inverse-probability weighting to fit marginal structural models adjusted for time-varying covariates to determine the causal relationship between tocilizumab use and the outcomes.ResultsA total of 1,229 and 10,673 person/days were analyzed. In the adjusted marginal structural models, a significant interaction between tocilizumab use and high C- reactive protein (CRP) levels was detected. Tocilizumab was associated with decreased risk of death (aHR 0.34, 95% CI 0.16–0.72, p=0.005) and ICU admission or death (aHR 0.38, 95% CI 0.19–0.81, p=0.011) among patients with baseline CRP >150 mg/L, but not among those with CRP ≤150 mg/L. Exploratory subgroup analyses yielded point estimates that were consistent with these findings.ConclusionsIn this large observational study, tocilizumab was associated with a lower risk of death or ICU or death in patients with higher CRP levels. While the results of ongoing clinical trials of tocilizumab in patients with COVID-19 will be important to establish its safety and efficacy, our findings have implications for the design of future clinical trials and support the use of tocilizumab among subjects with higher CRP levels.

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