Estimating survival benefit in castrate metastatic prostate cancer: Decision making in proceeding to a definitive phase III trial Journal Article


Authors: Verbel, D. A.; Kelly, W. K.; Smaletz, O.; Regan, K.; Curley, T.; Heller, G.; Scher, H. I.
Article Title: Estimating survival benefit in castrate metastatic prostate cancer: Decision making in proceeding to a definitive phase III trial
Abstract: Objectives. In designing a Phase II trial, the acceptable clinical activity region for a new therapy is often developed using data from historically treated patients. This region incorrectly ignores the variability of this estimate, because the efficacy of the prior treatment lies somewhere around the estimate. The size of this interval is dependent on the sample size used. This report illustrates the use of a published method that accounts for this uncertainty and aids in the decision to proceed to a definitive trial. Methods. A historical data set of low-risk patients with progressive castrate metastatic prostate cancer and a group of similar patients treated in a Phase II chemotherapy trial were used. The 1-year Kaplan-Meier estimate of survival was obtained for both. This approach uses the 75% upper confidence bound of the 1-year survival probability from the historical data set to define the lower limit of acceptable clinical activity. Use of this bound makes the approach more conservative, and hence the decision to proceed to a Phase III trial more difficult. Results. In the low-risk historical patients, the 1-year Kaplan-Meier estimate of survival was 66.4% (75% upper confidence bound 71.0%). In the Phase II patients, the 1-year Kaplan-Meier estimate of survival was 89.5% (95% lower confidence bound 78.2%). Conclusions. A hypothesis test using the 75% upper confidence bound to define the lower limit of acceptable clinical activity demonstrates that the 1-year survival probability on Taxol/estramustine/carboplatin is greater than that of the historical population, and hence should be taken into a definitive trial. The design provides investigators increased confidence in making this decision. © 2003, Elsevier Science Inc.
Keywords: cancer chemotherapy; cancer survival; controlled study; treatment outcome; survival analysis; retrospective studies; major clinical study; clinical trial; cancer growth; drug efficacy; paclitaxel; research design; carboplatin; metastasis; controlled clinical trial; phase 2 clinical trial; cohort studies; antineoplastic combined chemotherapy protocols; prostate cancer; prostatic neoplasms; probability; androgen antagonists; phase 3 clinical trial; castration; antineoplastic agents, hormonal; kaplan meier method; decision making; sample size; decision support techniques; estramustine; clinical trials, phase iii; humans; human; male; priority journal; article
Journal Title: Urology
Volume: 61
Issue: 1
ISSN: 0090-4295
Publisher: Elsevier Science, Inc.  
Date Published: 2003-01-01
Start Page: 142
End Page: 144
Language: English
DOI: 10.1016/s0090-4295(02)02097-6
PUBMED: 12559285
PROVIDER: scopus
DOI/URL:
Notes: Export Date: 12 September 2014 -- Source: Scopus
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MSK Authors
  1. Glenn Heller
    399 Heller
  2. William K Kelly
    115 Kelly
  3. David A Verbel
    20 Verbel
  4. Howard Scher
    1130 Scher
  5. Kevin P Regan
    9 Regan