Project description:The introduction of tyrosine kinase inhibitors (TKI) for the treatment of metastatic non-small cell lung cancer (NSCLC) harbouring sensitizing epidermal growth factor receptor (EGFR) gene mutations revolutionized the diagnostic and treatment algorithm of this subset of patients almost two decades ago. Since then, a number of trials have evaluated the role of TKI therapy in early-stage disease, with encouraging disease-free survival (DFS) results but lack of a survival advantage. ADAURA, a phase III trial evaluating 3 years of adjuvant osimertinib versus placebo in patients harbouring EGFR mutations with completely resected stage IB-IIIA NSCLC, recently reported a profound DFS benefit (hazard ratio 0.21), favourable quality of life and reduction in the risk of brain metastases. These results led to osimertinib's fast track approval by the US Food and Drug Administration, with this drug thus becoming the first EGFR-TKI approved for the treatment of early-stage disease. However, the key endpoint of overall survival remains immature and questions around indication (i.e. stage, need for adjuvant chemotherapy), optimal treatment duration, biomarkers of response and cost-effectiveness remain to be answered. In this article, we critically appraise the findings of ADAURA and discuss future challenges.
Project description:Patients with advanced non-small-cell lung cancer (NSCLC) and somatic activating mutations of the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene represent a biologically distinct disease entity that shows exquisite sensitivity to the reversible EGFR-TK inhibitors (-TKIs) gefitinib or erlotinib. Phase III randomized studies have clearly demonstrated that a reversible EGFR-TKI is significantly superior in terms of response rate, progression-free survival and quality of life to platinum-based chemotherapy in advanced NSCLC patients who carry an activating EGFR mutation, thus resulting into a new standard of care for this biologically selected group of patients. Unfortunately, approximately one third of EGFR-mutated patients show primary resistance to gefitinib or erlotinib, whereas virtually all patients who initially benefit from treatment will eventually develop acquired resistance. Importantly, revealing the molecular mechanisms that underlie resistance to reversible EGFR-TKIs is key to the development of EGFR-targeting strategies with the potential to prevent, delay or overcome such resistance. Early results of clinical trials with irreversible EGFR-TKIs or dual combination strategies aiming to block EGFR-mediated signaling at different levels have shown encouraging results in EGFR-mutated patients pretreated or not with a reversible EGFR-TKI. Therefore, in the near future it is reasonable to hypothesize that EGFR-mutated NSCLCs could be treated with multiple lines of EGFR-targeting therapies beyond disease progression, limiting chemotherapy to selected cases of resistant disease. This evolving treatment scenario highlights once again how important is the identification of a single oncogenic "addiction" that functions as unique determinant of progression and survival of NSCLC.
Project description:IntroductionEpidermal growth factor receptor gene (EGFR) mutations are relatively common oncogenic drivers in non-small cell lung cancer (NSCLC). The outcomes of patients who present with less common EGFR mutations or more than one EGFR mutation are uncertain. We reviewed our experience with the S768I mutation of exon 20 of EGFR to provide insight into the clinical significance of this mutation.MethodsWe used a natural language search program to search our electronic medical record system and every EGFR mutation analysis of patients with NSCLC treated at Mayo Clinic that was performed in our Department of Molecular Genetics to identify patients with EGFR S768I mutation. Relevant clinical and laboratory data were abstracted for selected cases, including evaluation of response after treatment with tyrosine kinase inhibitors.ResultsA total of 1527 patients with NSCLC who underwent EGFR testing were reviewed. The S768I mutation was present in nine patients (0.59%), four of whom were female. Only three had an isolated S768I mutation, four had a concurrent G719 mutation, and two had a concurrent L858R mutation. Among patients with stage IV disease treated with erlotinib (n = 4), one had an isolated S768I mutation and three had additional mutations (two patients with G719 and one patient with L858R). The tumor response to erlotinib of patients with stage IV disease was highly variable (progression-free survival ranged from 3 to 30 months and overall survival ranged from 5 to more than 51 months).ConclusionsS768I mutations in exon 20 of the EGFR gene are rare and are typically seen in conjunction with sensitizing EGFR mutations. Because of this mutation's rarity and the variability of responses of treated cases, its exact prognostic and predictive role is not fully understood. In our experience, S768I mutations in isolation do not necessarily confer sensitivity to erlotinib, but in conjunction with sensitizing EGFR mutations, S768I mutations do not restrict efficacy.
Project description:PurposeThe phase III ADAURA (ClinicalTrials.gov identifier: NCT02511106) primary analysis demonstrated a clinically significant disease-free survival (DFS) benefit with adjuvant osimertinib versus placebo in EGFR-mutated stage IB-IIIA non-small-cell lung cancer (NSCLC) after complete tumor resection (DFS hazard ratio [HR], 0.20 [99.12% CI, 0.14 to 0.30]; P < .001). We report an updated exploratory analysis of final DFS data.MethodsOverall, 682 patients with stage IB-IIIA (American Joint Committee on Cancer/Union for International Cancer Control, seventh edition) EGFR-mutated (exon 19 deletion/L858R) NSCLC were randomly assigned 1:1 (stratified by stage, mutational status, and race) to receive osimertinib 80 mg once-daily or placebo for 3 years. The primary end point was DFS by investigator assessment in stage II-IIIA disease analyzed by stratified log-rank test; following early reporting of statistical significance in DFS, no further formal statistical testing was planned. Secondary end points included DFS in stage IB-IIIA, overall survival, and safety. Patterns of recurrence and CNS DFS were prespecified exploratory end points.ResultsAt data cutoff (April 11, 2022), in stage II-IIIA disease, median follow-up was 44.2 months (osimertinib) and 19.6 months (placebo); the DFS HR was 0.23 (95% CI, 0.18 to 0.30); 4-year DFS rate was 70% (osimertinib) and 29% (placebo). In the overall population, DFS HR was 0.27 (95% CI, 0.21 to 0.34); 4-year DFS rate was 73% (osimertinib) and 38% (placebo). Fewer patients treated with osimertinib had local/regional and distant recurrence versus placebo. CNS DFS HR in stage II-IIIA was 0.24 (95% CI, 0.14 to 0.42). The long-term safety profile of osimertinib was consistent with the primary analysis.ConclusionThese updated data demonstrate prolonged DFS benefit over placebo, reduced risk of local and distant recurrence, improved CNS DFS, and a consistent safety profile, supporting the efficacy of adjuvant osimertinib in resected EGFR-mutated NSCLC.
Project description:Molecular analysis of the mutation status for EGFR and KRAS are now routine in the management of non-small cell lung cancer. Radiogenomics, the linking of medical images with the genomic properties of human tumors, provides exciting opportunities for non-invasive diagnostics and prognostics. We investigated whether EGFR and KRAS mutation status can be predicted using imaging data. To accomplish this, we studied 186 cases of NSCLC with preoperative thin-slice CT scans. A thoracic radiologist annotated 89 semantic image features of each patient's tumor. Next, we built a decision tree to predict the presence of EGFR and KRAS mutations. We found a statistically significant model for predicting EGFR but not for KRAS mutations. The test set area under the ROC curve for predicting EGFR mutation status was 0.89. The final decision tree used four variables: emphysema, airway abnormality, the percentage of ground glass component and the type of tumor margin. The presence of either of the first two features predicts a wild type status for EGFR while the presence of any ground glass component indicates EGFR mutations. These results show the potential of quantitative imaging to predict molecular properties in a non-invasive manner, as CT imaging is more readily available than biopsies.
Project description:For appropriate treatment selection, the updated NCCN Guidelines for Non-Small Cell Lung Cancer (NSCLC) recommend broad molecular profiling for all patients with nonsquamous disease. Three different tyrosine kinase inhibitors (TKIs) are recommended as first-line treatment of EGFR mutation-positive NSCLC: gefitinib, erlotinib, and afatinib. Most patients whose disease responds will still experience progression, and the type of disease progression drives management. Systemic progression requires switching TKI treatment, whereas patients with oligoprogression and central nervous system progression may have their new lesions treated but continue on their TKI. A new third-generation TKI has been approved and others are currently under development, and new combinations of these drugs with a VEGFR inhibitor offer promise to improve outcomes.
Project description:The two essential requirements for pathologic specimens in the era of personalized therapies for non-small cell lung carcinoma (NSCLC) are accurate subtyping as adenocarcinoma (ADC) versus squamous cell carcinoma (SqCC) and suitability for EGFR molecular testing, as well as for testing of other oncogenes such as EML4-ALK and KRAS. Actually, the value of EGFR expressed in patients with NSCLC in predicting a benefit in terms of survival from treatment with an epidermal growth factor receptor targeted therapy is still in debate, while there is a convincing evidence on the predictive role of the EGFR mutational status with regard to the response to tyrosine kinase inhibitors (TKIs).This is a literature overview on the state-of-the-art of EGFR oncogenic mutation in NSCLC. It is designed to highlight the preclinical rationale driving the molecular footprint assessment, the progressive development of a specific pharmacological treatment and the best method to identify those NSCLC who would most likely benefit from treatment with EGFR-targeted therapy. This is supported by the belief that a rationale for the prioritization of specific regimens based on patient-tailored therapy could be closer than commonly expected.
Project description:IntroductionIn Chinese patients with NSCLC, prevalence of EGFR-mutated (EGFRm) disease is high. In the global phase 3 ADAURA study (NCT02511106), adjuvant osimertinib was found to have a statistically significant and clinically meaningful improvement in disease-free survival (DFS) versus placebo in resected stage IB to IIIA EGFRm NSCLC. We present efficacy and safety data from a subgroup analysis of 159 Chinese patients enrolled in the People's Republic of China from ADAURA.MethodsIn ADAURA, patients with completely resected stage IB to IIIA EGFRm (exon 19 deletion/exon 21 L858R) NSCLC were randomized 1:1 to receive osimertinib (80 mg once daily) or placebo for 3 years or until disease recurrence/discontinuation. Adjuvant chemotherapy was permitted before randomization, per physician/patient choice. Primary end point was investigator-assessed DFS in stage II to IIIA disease; secondary end points included DFS in stage IB to IIIA (overall population), overall survival, health-related quality of life (HRQoL), and safety.ResultsOf 682 patients enrolled globally, 159 patients in the People's Republic of China were included in this subgroup analysis (osimertinib n = 77; placebo n = 82). Baseline characteristics were balanced across the treatment arms. At data cutoff, stage II to IIIA DFS hazard ratio (HR) was 0.23 (95% confidence interval [CI]: 0.13-0.42; maturity 59%); stage IB to IIIA DFS HR was 0.29 (95% CI: 0.17-0.48; maturity 42%). At 13% maturity (21 deaths), HR for overall survival in the stage IB to IIIA population was 0.51 (95% CI: 0.21-1.20). HRQoL was maintained from baseline, and safety was consistent with the global population.ConclusionsIn this population of Chinese patients from ADAURA, adjuvant osimertinib was found to have a clinically meaningful improvement in DFS versus placebo, with maintained HRQoL and a safety profile consistent with the global study population.
Project description:Osimertinib, a third-generation EGFR tyrosine kinase inhibitor, shows significant benefit among patients with EGFR T790M mutation at disease progression. We analyzed the whole exome sequence of 48 samples obtained from 16 lung cancer patients with a longitudinal follow-up: treatment-naïve-baseline primary tumors positive for EGFR activating-mutations, paired re-biopsies upon disease progression but negative for EGFR T790M mutation based on qPCR, and their matched normal blood samples. Our Next generation sequencing (NGS) analysis identified an additional set of 25% re-biopsy samples to harbor EGFR T790M mutation occurring at a low-allele frequency of 5% or less, undetectable by conventional qPCR-based assays. Notably, the clinical utility of osimertinib among patients harboring low-allele frequency of EGFR T790M in tissue biopsy upon disease progression remains less explored. We established erlotinib-resistant PC-9R cells and twenty single-cell sub-clones from erlotinib-sensitive lung cancer PC-9 cells using in vitro drug-escalation protocol. NGS and allele-specific PCR confirmed the low-allele frequency of EGFR T790M present at 5% with a 100-fold higher resistance to erlotinib in the PC-9R cells and its sub-clones. Additionally, luciferase tagged PC-9, and PC-9R cells were orthotopically injected through the intercostal muscle into NOD-SCID mice. The orthotopic lung tumors formed were observed by non-invasive bioluminescence imaging. Consistent with in vitro data, osimertinib, but not erlotinib, caused tumor regression in mice injected with PC-9R cells, while both osimertinib and erlotinib inhibited tumors in mice injected with PC-9 cells. Taken together, our findings could extend the benefit of osimertinib treatment to patients with low EGFR T790M mutation allele frequency on disease progression.