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Activity Number:
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325
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Type:
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Contributed
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Date/Time:
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Tuesday, August 4, 2009 : 10:30 AM to 12:20 PM
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Sponsor:
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Biopharmaceutical Section
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| Abstract - #303692 |
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Title:
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Fit Five-Parameter Logistic Function for Assay Data Using SAS
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Author(s):
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Rong Liu*+ and Shuping Zhang and Jason Liao and Shuping Zhang
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Companies:
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Merck & Co., Inc. and Merck & Co., Inc. and Merck Research Laboratories and Merck & Co., Inc.
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Address:
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770 Summeytown Pike, West Point, PA, 19468,
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Keywords:
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five-parameter logistic function ; SAS ; bioassay data
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Abstract:
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Bioassay refers to a type of biological activity that is measured as a function of the dose level of some substance. Bioassays are often a central part of potency studies where the parallelism and relative potency of two dose-response curves is of primary interest. Bioassay with quantitative response showing a sigmoid log-dose relationship is often fitted by the four-parameter logistic (4PL) function assuming the curve is symmetric. However, the five-parameter logistic function has seen an increase use for its ability to incorporate the asymmetric feature of dose response function. Liao and Liu (2008) proposed a reparameterized 5PL model. It extended the 4PL by adding a parameter that controls the degree of asymmetry of the curve and at the same time, preserves the good parameter interpretation of 4PL. This presentation will introduce the 5PL fit for bioassay data using SAS.
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