Date: October 29, 2007
To: Franklin Stephenson (OBRR/DH)
From: Iftekhar Mahmood (OBRR/DH)
Subject: Wilate Analytical Method
Through: Basil Golding (Director OBRR/DH)
CC: Timothy Lee (OBRR/DH)/p>
Franklin please send this memo to the sponsor (Octapharma)
Before conducting a new PK study for Wilate, the sponsor is advised to compare the currently used manual method with the automated method for measuring VWF by the Ristocetin Cofactor method, using the same reference standard for VWF concentrate. The sponsor should test several known concentrations of Wilate and Humate-P by the two aforementioned analytical methods. The assay should cover the range of concentrations that one would expect in clinical settings. The results should allow us to evaluate the magnitude of the discrepancies between VWF:RCo values derived from these two methods, and to compare their sensitivity. At least 10 concentrations should be chosen and some should be within a narrow range. The purpose of testing a narrow range of concentrations is to determine the sensitivity of the method. For example, can a concentration of 8 units be distinguished from 10 units. Since several concentrations of Wilate and Humate-P will be tested, the linearity of the standard curve may be an issue. This can be resolved by using two standard curves with different concentration ranges.