Purpose 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. Methods 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. Results 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). Conclusion 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.

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B a c k g r o u n d : I n t h e p h a s e I I I C h e c k M a t e 2 2 7 s t u d y , fi r s t-l i n e nivolumab þ ipilimumab significantly prolonged progression-free survival (co-primary endpoint) versus chemotherapy in patients with advanced nonesmall-cell lung cancer (NSCLC) and high tumour mutational burden (TMB; !10 mutations/megabase). Aim: To evaluate patient-reported outcomes (PROs) in this population. Methods: Disease-related symptoms and general health status were assessed using the validated PRO questionnaires Lung Cancer Symptom Scale (LCSS) and EQ-5D, respectively. LCSS average symptom burden index (ASBI) and three-item global index (3-IGI) and EQ-5D visual analogue scale (VAS) and utility index (UI) scores and changes from baseline were analysed descriptively. Longitudinal changes were assessed by mixed-effect model repeated measures (MMRMs) and time to first deterioration/improvement analyses. Results: In the high TMB population, PRO questionnaire completion rates were w90% at baseline and >80% for most on-treatment assessments. During treatment, mean changes from baseline with nivolumab þ ipilimumab showed early, clinically meaningful improvements in LCSS ASBI/3-IGI and EQ-5D VAS/UI; with chemotherapy, symptoms and health-related quality of life remained stable (LCSS ASBI/3-IGI, EQ-5D UI) or improved following induction (EQ-5D VAS). MMRM-assessed changes in symptom burden were improved with nivolumab þ ipilimumab versus chemotherapy. Symptom deterioration by week 12 was lower with nivolumab þ ipilimumab versus chemotherapy (22.3% versus 35.0%; absolute risk reduction: 12.7% [95% confidence interval 2.4e22.5]), irrespective of discontinuation. Time to first deterioration was delayed with nivolumab þ ipilimumab versus chemotherapy across LCSS and EQ-5D summary measures. Conclusion: First-line nivolumab þ ipilimumab demonstrated early, sustained improvements in PROs versus chemotherapy in patients with advanced NSCLC and high TMB. Clinical trial registration: NCT02477826.

The platelet P2Y(12) receptor is the target of clopidogrel therapy, which has been shown to reduce thromboembolic complications of atherosclerotic disease but has limitations in terms of variability of response and irreversibility of effect. This receptor is also a target for ticagrelor (AZD6140), the first reversibly binding oral P2Y(12) receptor antagonist that does not require metabolic activation and yields more consistent inhibition of platelet aggregation than clopidogrel therapy. Single nucleotide polymorphisms (SNPs) have been described in the gene for this receptor (P2RY12), some of which have been associated with variability in platelet reactivity. SNPs in P2RY1 and ITGB3 have also been reported by some groups to affect platelet reactivity to adenosine diphosphate (ADP). We assessed whether SNPs in these genes influenced the pharmacodynamic response to ticagrelor in patients enrolled in both the DISPERSE study (stable atherosclerotic disease) and the DISPERSE2 study (non-ST-segment elevation acute coronary syndromes). Platelet aggregation data (at baseline and 4 weeks) and DNA samples from clopidogrel-naive Caucasian patients treated with ticagrelor were available for 151 patients. Seventy four SNPs within three genes were genotyped. After adjustment for multiple comparisons, none of these SNPs were found to significantly influence inhibition of ADP-induced platelet aggregation by ticagrelor.