417 research outputs found
Sorafenib dose escalation is not uniformly associated with blood pressure elevations in normotensive patients with advanced malignancies.
Hypertension after treatment with vascular endothelial growth factor (VEGF) receptor inhibitors is associated with superior treatment outcomes for advanced cancer patients. To determine whether increased sorafenib doses cause incremental increases in blood pressure (BP), we measured 12-h ambulatory BP in 41 normotensive advanced solid tumor patients in a randomized dose-escalation study. After 7 days' treatment (400 mg b.i.d.), mean diastolic BP (DBP) increased in both study groups. After dose escalation, group A (400 mg t.i.d.) had marginally significant further increase in 12-h mean DBP (P = 0.053), but group B (600 mg b.i.d.) did not achieve statistically significant increases (P = 0.25). Within groups, individuals varied in BP response to sorafenib dose escalation, but these differences did not correlate with changes in steady-state plasma sorafenib concentrations. These findings in normotensive patients suggest BP is a complex pharmacodynamic biomarker of VEGF inhibition. Patients have intrinsic differences in sensitivity to sorafenib's BP-elevating effects
Designing exploratory cancer trials using change in tumour size as primary endpoint
In phase III cancer clinical trials, overall survival is commonly used as the definitive endpoint. In phase II clinical trials, however, more immediate endpoints such as incidence of complete or partial response within 1 or 2 months or progression-free survival (PFS) are generally used. Because of the limited ability to detect change in overall survival with response, the inherent variability of PFS and the long wait for progression to be observed, more informative and immediate alternatives to overall survival are desirable in exploratory phase II trials. In this paper, we show how comparative trials can be designed and analysed using change in tumour size as the primary endpoint. The test developed is based on the framework of score statistics and will formally incorporate the information of whether patients survive until the time at which change in tumour size is assessed. Using an example in non-small cell lung cancer, we show that the sample size requirements for a trial based on change in tumour size are favourable compared with alternative randomized trials and demonstrate that these conclusions are robust to our assumptions
Improving phase II oncology trials using best observed RECIST response as an endpoint by modelling continuous tumour measurements.
In many phase II trials in solid tumours, patients are assessed using endpoints based on the Response Evaluation Criteria in Solid Tumours (RECIST) scale. Often, analyses are based on the response rate. This is the proportion of patients who have an observed tumour shrinkage above a predefined level and no new tumour lesions. The augmented binary method has been proposed to improve the precision of the estimator of the response rate. The method involves modelling the tumour shrinkage to avoid dichotomising it. However, in many trials the best observed response is used as the primary outcome. In such trials, patients are followed until progression, and their best observed RECIST outcome is used as the primary endpoint. In this paper, we propose a method that extends the augmented binary method so that it can be used when the outcome is best observed response. We show through simulated data and data from a real phase II cancer trial that this method improves power in both single-arm and randomised trials. The average gain in power compared to the traditional analysis is equivalent to approximately a 35% increase in sample size. A modified version of the method is proposed to reduce the computational effort required. We show this modified method maintains much of the efficiency advantages
Phase II trial of dasatinib for recurrent or metastatic c-KIT expressing adenoid cystic carcinoma and for nonadenoid cystic malignant salivary tumors
Adenoid cystic carcinoma (ACC) is a subtype of malignant salivary gland tumors (MSGT), in which 90% of cases express cKIT. Dasatinib is a potent and selective inhibitor of five oncogenic protein tyrosine kinases (PTKs)/kinase families including cKIT. We conducted a phase II study to determine the antitumor activity of dasatinib in ACC and non-ACC MSGT
Double‐Robust Semiparametric Estimator for Differences in Restricted Mean Lifetimes in Observational Studies
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95382/1/BIOM_1759_sm_SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/95382/2/j.1541-0420.2012.01759.x.pd
Estimating Differences in Restricted Mean Lifetime Using Observational Data Subject to Dependent Censoring
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87174/1/j.1541-0420.2010.01503.x.pd
A randomized phase 2 study of temsirolimus and cetuximab versus temsirolimus alone in recurrent/metastatic, cetuximab‐resistant head and neck cancer: The MAESTRO study
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155947/1/cncr32929_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155947/2/cncr32929.pd
A randomized phase 2 network trial of tivantinib plus cetuximab versus cetuximab in patients with recurrent/metastatic head and neck squamous cell carcinoma
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154935/1/cncr32762.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154935/2/cncr32762_am.pd
Evaluation of treatment efficacy using a Bayesian mixture piecewise linear model of longitudinal biomarkers
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111181/1/sim6445.pd
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