title: Association Between Plasma Genotyping and Outcomes of Treatment With Osimertinib (AZD9291) in Advanced Non-Small-Cell Lung Cancer.
abstract: Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have demonstrated potent activity against TKI resistance mediated by EGFR T790M. We studied whether noninvasive genotyping of cell-free plasma DNA (cfDNA) is a useful biomarker for prediction of outcome from a third-generation EGFR-TKI, osimertinib.
  
  
  
  Plasma was collected from all patients in the first-in-man study of osimertinib. Patients who were included had acquired EGFR-TKI resistance and evidence of a common EGFR-sensitizing mutation. Genotyping of cell-free plasma DNA was performed by using BEAMing. Plasma genotyping accuracy was assessed by using tumor genotyping from a central laboratory as reference. Objective response rate (ORR) and progression-free survival (PFS) were analyzed in all T790M-positive or T790M-negative patients.
  
  
  
  Sensitivity of plasma genotyping for detection of T790M was 70%. Of 58 patients with T790M-negative tumors, T790M was detected in plasma of 18 (31%). ORR and median PFS were similar in patients with T790M-positive plasma (ORR, 63%; PFS, 9.7 months) or T790M-positive tumor (ORR, 62%; PFS, 9.7 months) results. Although patients with T790M-negative plasma had overall favorable outcomes (ORR, 46%; median PFS, 8.2 months), tumor genotyping distinguished a subset of patients positive for T790M who had better outcomes (ORR, 69%; PFS, 16.5 months) as well as a subset of patients negative for T790M with poor outcomes (ORR, 25%; PFS, 2.8 months).
  
  
  
  In this retrospective analysis, patients positive for T790M in plasma have outcomes with osimertinib that are equivalent to patients positive by a tissue-based assay. This study suggests that, upon availability of validated plasma T790M assays, some patients could avoid a tumor biopsy for T790M genotyping. As a result of the 30% false-negative rate of plasma genotyping, those with T790M-negative plasma results still need a tumor biopsy to determine presence or absence of T790M.
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan. geoffrey_oxnard@dfci.harvard.edu.
authors.forename: Geoffrey R
authors.initials: GR
authors.lastname: Oxnard
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Thress
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Alden
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Rachael
authors.initials: R
authors.lastname: Lawrance
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Cloud P
authors.initials: CP
authors.lastname: Paweletz
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Mireille
authors.initials: M
authors.lastname: Cantarini
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: James Chih-Hsin
authors.initials: JC
authors.lastname: Yang
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: J Carl
authors.initials: JC
authors.lastname: Barrett
authors.affiliation: Geoffrey R. Oxnard, Ryan S. Alden, Cloud P. Paweletz, and Pasi A. Jänne, Dana-Farber Cancer Institute, Boston; Kenneth S. Thress and J. Carl Barrett, AstraZeneca, Waltham, MA; Rachael Lawrance and Mireille Cantarini, AstraZeneca, Macclesfield, United Kingdom; and James Chih-Hsin Yang, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Pasi A
authors.initials: PA
authors.lastname: Jänne
mesh_terms: D000178:Acrylamides; D000814:Aniline Compounds; D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics*; D004273:DNA, Neoplasm / Q000097:blood / Q000235:genetics; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D005838:Genotype; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000235:genetics*; D010879:Piperazines / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D012189:Retrospective Studies; D016896:Treatment Outcome; D007211:Indoles; D011743:Pyrimidines
chemical_list: D000178:Acrylamides; D000814:Aniline Compounds; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D066246:ErbB Receptors; D010879:Piperazines; D047428:Protein Kinase Inhibitors; C000596361:osimertinib; D007211:Indoles; D011743:Pyrimidines; C512478:EGFR protein, human