Patent ID: 8501413

Claim:
A method for predicting development of acquired resistance to the therapeutic effects of an epidermal growth factor (EGFR) tyrosine kinase inhibitor in a patient that is suffering from a cancer, wherein the method comprises the steps of: (a) obtaining a sample from the patient, wherein the cancer harbors a somatic gain-of-function mutation in the tyrosine kinase domain of EGFR that enhances the sensitivity of the cancer to the tyrosine kinase inhibitor, (b) testing the sample to determine whether the gene encoding EGFR is present in a mutant form that encodes a T790M mutant of EGFR in addition to the somatic gain of function mutation, and (c) identifying the cancer as one that has become or will become resistant to the EGFR tyrosine kinase inhibitor if the T790M mutant form is present or as having continuing sensitivity to the EGFR tyrosine kinase inhibitor if the T790M mutant form is absent, wherein the testing of the sample in step (b) is performed by a method selected from the group consisting of: (i) performing PCR amplification using a pair of primers that flank the region encoding amino acid 790 of EGFR to form amplicons that include the bases encoding amino acid 790 of EGFR, and evaluating the amplicons to determine if a mutation is present that would result in a T790M mutation in EGFR; (ii) performing PCR amplification using a pair of primers, and evaluating the amplicons to determine if a mutation is present that would result in a T790M mutation in EGFR, and wherein one of the primers used in the PCR amplification step binds at a position that includes the bases encoding a T790M mutation in EGFR; and (iii) probing the sample with a probe oligonucleotide, wherein the probe binds preferentially to a 2369C→T mutant or a wild type EGFR sequence, and detecting binding of the probe.