Abstract: 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 is predicted by: (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, and (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. A finding that the mutant form is present indicates that the cancer has become or will become resistant to the EGFR tyrosine kinase inhibitor.

Abstract: 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 is predicted by: (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, and (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. A finding that the mutant form is present indicates that the cancer has become or will become resistant to the EGFR tyrosine kinase inhibitor.

Abstract: Polymerase chain reaction primers and methods directed to detecting the EGFR mutant C?T at the position corresponding to base 2369 of EGFR cDNA. The invention provides a PCR primer that hybridizes under suitable PCR conditions to a polynucleotide sequence 5? in each respective strand to a mutation of an EGFR gene that encodes a substitution of threonine by methionine at position 790 of the EGFR polypeptide. The invention also provides a PCR primer hybridizes to a sequence that includes a mutant T at the position corresponding to base 2369 of EGFR cDNA but not to a second EGFR polynucleotide containing a wild type C. The invention provides several methods and kits for detecting a mutant epidermal growth factor receptor (EGFR) gene in a sample comprising probing the sample with a means for selectively detecting a nucleotide sequence comprising a mutant T at the position corresponding to base 2369 of EGFR cDNA, and identifying that the base at said position is T.

Abstract: Polymerase chain reaction primers and methods directed to detecting the EGFR mutant C?T at the position corresponding to base 2369 of EGFR cDNA. The invention provides a PCR primer that hybridizes under suitable PCR conditions to a polynucleotide sequence 5? in each respective strand to a mutation of an EGFR gene that encodes a substitution of threonine by methionine at position 790 of the EGFR polypeptide. The invention also provides a PCR primer hybridizes to a sequence that includes a mutant T at the position corresponding to base 2369 of EGFR cDNA but not to a second EGFR polynucleotide containing a wild type C. The invention provides several methods and kits for detecting a mutant epidermal growth factor receptor (EGFR) gene in a sample comprising probing the sample with a means for selectively detecting a nucleotide sequence comprising a mutant T at the position corresponding to base 2369 of EGFR cDNA, and identifying that the base at said position is T.