Patent ID: 7300768

Claim:
An enzymatic assay for determining the amount in a human blood serum or plasma sample of a chemotherapeutic agent selected from the group consisting of imatinib and chemotherapeutically active metabolites thereof comprising: a) forming in an aqueous medium a mixture containing said sample suspected of containing said chemotherapeutic agent with NADH; an abl protein tyrosine kinase which is inhibited by said chemotherapeutic agent; lactate dehydrogenase in an amount effective to convert NADH in the mixture to NAD; ATP; phosphoenol pyruvate; pyruvate kinase; and a tyrosine-containing polypeptide capable of being phosphorylated by an abl protein tyrosine kinase; b) incubating said mixture under conditions which cause said chemotherapeutic agent in the sample to react with said abl protein tyrosine kinase; c) thereafter measuring the rate at which the NADH is converted to NAD; and d) quantifying the amount of the chemotherapeutic agent in the sample based upon said rate.