Patent ID: 7445897

Claim:
A method for predicting efficacy of a drug in a subject, said subject having a disease or disorder amenable to treatment with the drug and wherein said drug is a substrate of multi-drug resistance 1 (MDR1) gene, the method comprising: isolating a biological sample from the subject, the biological sample comprising nucleic acids and/or proteins; and analyzing the biological sample to determine at least one of (a) the nucleotide T at position 1199 of SEQ ID NO:5, and (b) the presence or absence of the S4001 variant of SEQ ID NO:4; wherein the presence of T at nucleotide position 1199 of SEQ ID NO:5 or the presence of the S4001 variant of SEQ ID NO:4 is indicative of an increased efficacy of the drug in the subject relative to the efficacy of the drug in an individual that is homozygous for a wild-type MDR1 gene.