EGFR Mutation-positive NSCLC Research Articles

189TiP Phase IV trial of afatinib followed by osimertinib versus osimertinib alone as first-line treatment in patients (pts) with advanced EGFR mutation-positive (EGFRm+) NSCLC

189TiP Phase IV trial of afatinib followed by osimertinib versus osimertinib alone as first-line treatment in patients (pts) with advanced EGFR mutation-positive (EGFRm+) NSCLC

145P UpSwinG: Real-world, non-interventional cohort study on TKI activity in patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC with uncommon mutations

Background: EGFR TKIs are established as an effective treatment (tx) option for pts with EGFRm+ NSCLC with common (Del19 or L858R) mutations, but limited clinical data exist for EGFR TKI use in the 7–23% of NSCLC tumours with uncommon EGFR mutations.

P03.02 Neoadjuvant Osimertinib with/without Chemotherapy vs Chemotherapy for EGFR Mutated Resectable NSCLC: NeoADAURA

Background: Approximately 30% of patients with NSCLC present with resectable disease. Primary treatment for resectable NSCLC is curative surgery; patient prognosis following surgery alone remains poor. Neoadjuvant chemotherapy is recommended in resectable stage-III NSCLC, regardless of EGFR mutation status, and has demonstrated clinical benefit. However, improved treatment options for stage II/III are needed. Recent studies indicate that EGFR-TKI therapy could potentially achieve tumour size reduction and clearance of micrometastases in the neoadjuvant setting; treatment effect can be assessed in resected specimens. Osimertinib is a third-generation, CNS-active EGFR-TKI, with superior efficacy to comparator EGFR-TKI in treatment-naïve EGFR mutation-positive (EGFRm) advanced NSCLC. In the Phase III ADAURA study (NCT02511106), osimertinib showed statistically significant DFS improvement (hazard ratio: 0.20 [99.12% confidence interval 0.14, 0.30; p<0.001) in resected stage IB—IIIA EGFRm NSCLC following adjuvant chemotherapy, when indicated. A recent study (NCT03433469) found neoadjuvant osimertinib was well tolerated in patients with Stage I—IIIA NSCLC. Efficacy and tolerability of osimertinib in advanced and adjuvant settings support its investigation as neoadjuvant treatment in resectable disease. NeoADAURA (NCT04351555) is a Phase III, controlled, randomised study assessing efficacy and safety of osimertinib (with/without chemotherapy) versus chemotherapy plus placebo as neoadjuvant treatment in resectable stage II—IIIB EGFRm NSCLC. Trial Design: Eligible patients: ≥18 years (≥20 years, Japan), ECOG PS 0/1, primary non-squamous stage II—IIIB (IASLC Cancer Staging Manual v8) NSCLC and confirmed EGFRm (Ex19del/L858R), deemed completely resectable. Prior treatment with systemic anti-cancer therapy for NSCLC is not allowed. Approximately 351 patients will be randomised 1:1:1 (Figure) to receive platinum-based chemotherapy (pemetrexed 500 mg/m2 plus carboplatin AUC5 or cisplatin 75 mg/m2) plus placebo (Arm 1; double-blind), platinum-based chemotherapy plus osimertinib 80 mg once-daily (Arm 2; double-blind) or osimertinib 80 mg once-daily alone (Arm 3; open-label). Patients will be stratified by disease stage (II/III), race (non-Asian/Chinese/other Asian) and EGFR mutation (Ex19del/L858R). Following three cycles of chemotherapy (Arms 1 and 2) or nine weeks of osimertinib (Arm 3), patients will undergo complete surgical resection of primary NSCLC. Treatment with osimertinib or placebo may continue until surgery, unless unacceptable toxicity/withdrawn consent/other discontinuation criterion. Post-surgery, patients will receive optimal care (investigator-defined); this may include adjuvant osimertinib treatment for three years (maximum)/until disease recurrence or unmanageable toxicity. The primary endpoint is MPR, (≤10% residual cancer cells in surgical specimen post-surgery) centrally assessed. Secondary endpoints include pCR, EFS, downstaging, DFS, OS and safety. MPR and EFS will be tested using hierarchal testing procedure at MPR primary analysis. osimertinib, Stage II—IIIB NSCLC, Neoadjuvant

P76.44 Application of Longitudinal Exposure-Response Modelling to Support Dacomitinib Starting Dose in Patients with EGFR Mutation-Positive NSCLC

P76.44 Application of Longitudinal Exposure-Response Modelling to Support Dacomitinib Starting Dose in Patients with EGFR Mutation-Positive NSCLC

P35.05 The Monitoring of Mutated EGFR Levels in Liquid Biopsy from Patients on EGFR-TKIs – Early Detection of NSCLC Progression

Non-invasive evaluation of circulating tumor DNA (ctDNA) enables the real-time monitoring of the status and quantitate expression level of mutated EGFR gene (mEGFR) in the blood from NSCLC patients (pts) on EGFR TKIs. We evaluated the feasibility of the longitudinal analysis of mEGFR level in plasma and its effectiveness in early detection of NSCLC progression in pts treated with EGFR TKIs in the first line. Peripheral blood was prospectively collected from 64 advanced, EGFR mutation-positive NSCLC pts at the time of diagnosis (baseline) and then every month during the first line EGFR-TKI treatment (erlotinib, gefitinib, afatinib) until clinical progression. The mutated EGFR ctDNA was analyzed using Cobas EGFR Mutation Test v2 (Roche, Germany). The level of mEGFR in plasma was measured as the Semi-Quantitative Index (SQI). At baseline, 46 out of 64 (72%) pts demonstrated the same activating EGFR mutation in liquid biopsy and tumor tissue (there were no discrepant results). In the remaining 28% pts the mEGFR ctDNA was undetectable in plasma. To date, 33 pts completed the first line EGFR TKI treatment with complete set of plasma samples analyzed for mEGFR ctDNA. The median (min-max) PFS was 10 (2-25) months. In the subgroup of long-term responders to first line EGFR TKIs (PFS≥11 months, n=14, 42%) the complete clearance of baseline mEGFR levels in plasma was observed within 1-2 months of treatment regardless the type of mutation; mEGFR ctDNA remained undetectable during the following months. This phenomenon was not observed in short-term responders (PFS<5.5 months, n=8, 24%). In 17 pts, a rapid raise to or above mEGFR baseline preceded clinical progression by 4-20 weeks, with mean SQI of mEGFR in plasma at baseline 8.59, after first month of treatment 1.69, and 6.73 upon progression. In 8 (24%) pts the T790M resistance mutation was detected upon progression in plasma ctDNA alongside with the primary activating EGFR mutation (mean SQI for T790M was 7.87). In 12 (28%) pts the plasma mEGFR levels were undetectable at diagnosis and throughout the treatment. The dynamic changes of mEGFR ctDNA levels in plasma of NSCLC pts reflect well their response to the first line EGFR TKIs. The longitudinal monitoring of mEGFR levels in plasma allows to observe the disease progression on EGFR TKIs much earlier than conventional imaging techniques. The dynamics of mEGFR ctDNA level in plasma during the first 2 months of treatment may present a predictive value for EGFR TKI therapy. In 28% pts the plasma mEGFR level remains undetectable at diagnosis and during treatment. The study is ongoing.

Safety and efficacy of first-line dacomitinib in Asian patients with EGFR mutation-positive non-small cell lung cancer: Results from a randomized, open-label, phase 3 trial (ARCHER 1050)

ObjectivesTo compare efficacy and safety of dacomitinib versus gefitinib as first-line therapy for EGFR mutation-positive advanced NSCLC in Asian patients enrolled in the ongoing ARCHER 1050 trial. Materials and methodsIn this ongoing, randomized, open-label, phase 3 trial (NCT01774721), eligible patients with newly diagnosed advanced EGFR mutation-positive NSCLC were randomized (1:1) to receive oral dacomitinib 45 mg/day or oral gefitinib 250 mg/day. Randomization, by a central computer system, was stratified by race and EGFR mutation type (exon 19 deletion mutation/exon 21 L858R substitution mutation). The primary endpoint was PFS by blinded independent review. ResultsOf 346 Asian patients, 170 were randomized to dacomitinib and 176 to gefitinib. The hazard ratio (HR) for PFS with dacomitinib versus gefitinib was 0.509 (95 % confidence interval [CI]: 0.391–0.662; 1-sided p < 0.0001; median 16.5 months [95 % CI: 12.9–18.4] vs. 9.3 months [95 % CI: 9.2–11.0]). HR for OS with dacomitinib versus gefitinib was 0.759 (95 % CI: 0.578–0.996; median 37.7 months [95 % CI: 30.2–44.7] vs. 29.1 months [95 % CI: 25.6–36.0]). The OS benefit was still maintained in those patients who had a stepwise dose reduction of dacomitinib (to 30 and 15 mg/day). The most common adverse events (AEs) were diarrhea (154 [90.6 %] patients), paronychia (110 [64.7 %]), dermatitis acneiform (96 [56.5 %]), and stomatitis (87 [51.2 %]) with dacomitinib, and diarrhea (100 [56.8 %]), alanine aminotransferase increased (81 [46.0 %]), and aspartate aminotransferase increased (75 [42.6 %]) with gefitinib. Treatment-related serious AEs were reported in 16 (9.4 %) and 8 (4.5 %) patients treated with dacomitinib and gefitinib, respectively. ConclusionFirst-line dacomitinib was associated with significant prolongation of PFS and improved OS compared with gefitinib in Asian patients with EGFR mutation-positive advanced NSCLC. The AE profiles of dacomitinib and gefitinib in Asian patients were consistent with the overall ARCHER 1050 population.

RELAY, ramucirumab plus erlotinib versus placebo plus erlotinib in patients with untreated, EGFR-mutated, metastatic non-small cell lung cancer: Europe/United States subset analysis

BackgroundIn EGFR mutation-positive NSCLC, dual EGFR/VEGFR inhibition compared to EGFR alone increases anti-tumor efficacy. The Phase III RELAY trial demonstrated superior PFS for ramucirumab plus erlotinib (RAM + ERL) over placebo plus erlotinib (PBO + ERL) (HR 0.591 [95% CI 0.461–0.760], p<0.0001). EGFR mutated NSCLC is less prevalent in Western versus Asian patients. This prespecified analysis evaluates efficacy and safety of RAM + ERL in EU and US patients enrolled in RELAY. Patients and MethodsPatients were randomized 1:1 to ERL + RAM (10 mg/kg IV) or PBO Q2W. Treatment continued until unacceptable toxicity or progressive disease. Patients were stratified by geographic region (East Asia vs “other” [EU/US and Canada (EU/US)]). Objectives included PFS, ORR, DoR, OS, PFS2, safety and biomarker analysis. ResultsEU/US subset included 113/449 (25.9%) patients (58 RAM + ERL, 55 PBO + ERL). RAM + ERL improved PFS (20.6 vs 10.9 months, HR 0.605 [95% CI: 0.362–1.010]). ORR and DCR were similar, but median DoR was longer with RAM + ERL (18.0 vs 10.1 months, HR 0.527 [95% CI: 0.296–0.939]). OS and PFS2 were immature at data cut-off (censoring rates 81.0–81.8% and 67.3–79.3%, respectively). Most commonly reported Grade ≥3 TEAE for RAM + ERL was hypertension (17 [29.8%]) and for PBO + ERL, dermatitis acneiform (5 [9.1%]). ConclusionEU/US subset analysis showed improved efficacy outcomes for RAM + ERL and a safety profile consistent with the overall population. Ramucirumab is a safe and effective addition to standard-of-care EGFR-TKI for EGFR mutation-positive metastatic NSCLC.

MO01.36 Afatinib in Asian and Non-Asian Patients (pts) with EGFR Mutation-Positive (EGFRm+) NSCLC Harboring Major Uncommon Mutations

MO01.36 Afatinib in Asian and Non-Asian Patients (pts) with EGFR Mutation-Positive (EGFRm+) NSCLC Harboring Major Uncommon Mutations

BEBT-109, a pan-mutant-selective EGFR inhibitor with potent antitumor activity in EGFR-mutant non-small cell lung cancer

EGFR mutation-positive NSCLC tumors are highly heterogeneous, therefore, exploring an agent simultaneously targeting multiple EGFR mutations may be valuable for clinical practice. Compared with osimertinib, BEBT-109 shows more sensitive and extensive antitumor activity in EGFR mutant NSCLC, while sparing wild-type EGFR cell lines. Meanwhile, unlike the metabolite of osimertinib AZ5104, the main metabolites of BEBT-109 are found lacking in activity against wild-type EGFR cell lines. Preclinical and clinical studies demonstrate a unique pharmacokinetic profiles of BEBT-109 with rapid absorption and quick in vivo clearance without accumulation, which are conducive to minimizing the off-target toxicity of the covalent irreversible EGFR inhibitor. Oral administration of BEBT-109 induces tumor regression in EGFR exon 20 insertion xenografts, and even tumor disappearance in PC-9, HCC827 and H1975 xenograft models. Furthermore, in clinical trials, the objective responses were observed in NSCLC patients with EGFR T790M mutation in the first and second dosing cohorts. These findings demonstrate that BEBT-109, a potent pan-mutant-selective EGFR inhibitor with improved pharmacokinetic properties, might offer a promising new option for the treatment of multiple mutant-EGFR-driven NSCLC.

400P Sequential afatinib and osimertinib in real-world EGFR mutation positive (EGFRm+) NSCLC: Final analysis of Asian patients in the GioTag study

400P Sequential afatinib and osimertinib in real-world EGFR mutation positive (EGFRm+) NSCLC: Final analysis of Asian patients in the GioTag study

420TiP UpSwinG: Real-world study of TKI activity in patients with EGFR mutation-positive (EGFRm+) NSCLC with uncommon mutations, and sequencing of afatinib followed by osimertinib

420TiP UpSwinG: Real-world study of TKI activity in patients with EGFR mutation-positive (EGFRm+) NSCLC with uncommon mutations, and sequencing of afatinib followed by osimertinib

395P Afatinib in Asian and non-Asian patients (pts) with EGFR mutation positive (EGFRm+) NSCLC harboring major uncommon mutations

395P Afatinib in Asian and non-Asian patients (pts) with EGFR mutation positive (EGFRm+) NSCLC harboring major uncommon mutations

Real-World Evaluation of Factors for Interstitial Lung Disease Incidence and Radiologic Characteristics in Patients With EGFR T790M–positive NSCLC Treated With Osimertinib in Japan

Using real-world Japanese postmarketing data, we characterized interstitial lung disease (ILD) development during the second- or later-line osimertinib treatment for EGFR mutation-positive NSCLC. Retrospective radiologic image evaluation of patients developing ILD was also performed. Patients who had ILD events reported as an adverse drug reaction by their physicians and who were assessed as having developed ILD as assessed by an ILD expert committee in Japan were included. Among 3578 patients, 252 ILD events were reported in 245 patients (6.8%) by their attending physicians. The median (range) time to the first onset of ILD after osimertinib treatment initiation was 63.0 (5-410) days, and 29 patients with a fatal outcome were reported. The ILD expert committee assessed 231 of 3578 patients (6.5%) as having ILD. A previous history of nivolumab therapy (adjusted OR: 2.84; 95% confidence interval: 1.98-4.07) and a history or concurrence of ILD (3.51; 2.10-5.87) were identified as factors potentially associated with ILD onset during osimertinib treatment. In patients who had received a previous nivolumab treatment, the number and proportion of patients developing ILD were highest for patients who discontinued nivolumab treatment within the first month before initiating osimertinib; trends for decreasing incidence and proportion were observed, with an increasing duration between the end of nivolumab treatment and the initiation of osimertinib treatment. The frequency of ILD was consistent with the known osimertinib safety profile in the Japanese population. A history or concurrence of ILD and history of previous nivolumab therapy are factors potentially associated with ILD onset during osimertinib treatment.

1341P Afatinib in Asian and non-Asian patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC harboring uncommon mutations

1341P Afatinib in Asian and non-Asian patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC harboring uncommon mutations

1356P Disease monitoring and TKI resistance mutations of EGFR mutation-positive NSCLC patients via circulating tumour DNA

1356P Disease monitoring and TKI resistance mutations of EGFR mutation-positive NSCLC patients via circulating tumour DNA

Abstract CT215: RELAY, ramucirumab plus erlotinib (RAM+ERL) versus placebo plus erlotinib (PBO+ERL) in previously untreated EGFR mutation-positive metastatic NSCLC: Next generation sequencing (NGS) results

Abstract RELAY (NCT02411448) showed a superior progression free survival benefit with RAM+ERL versus (v) PBO+ ERL (mPFS 19.4 vs 12.4mo, HR 0.59, p-value &amp;lt;0.0001). We investigated the mutational landscape for potential a) baseline biomarkers and b) treatment emergent (TE) alterations. Eligible patients (untreated metastatic NSCLC, EGFR exon 19 deletion or exon 21 L858R mutation-positive by local testing, ECOG PS of 0 or 1, and without CNS metastases) were randomized to receive ERL (150 mg oral) daily with either RAM (10 mg/kg iv) or PBO Q2W until progressive disease, unacceptable toxicity, withdrawal, non-compliance, or investigator decision. Liquid biopsies (baseline, cycle 4 (C4), and post-treatment discontinuation 30-day follow-up) underwent Guardant360® NGS for pre-specified exploratory biomarker analyses. For baseline analyses, alterations (single nucleotide variants, gene fusions, or copy number changes) in ALK, MET, and TP53 were among the 69 genes with alterations co-occurring at baseline with ex19del or ex21.L858R (not shown). Baseline ALK and MET alterations did not appear to impact the observed PFS or DOR. However, altered baseline TP53 associated with a worse prognosis (p&amp;lt;0.001), and had a trend for better ram efficacy. For evaluating TE alterations, two populations were assessed to address factors like disease progression and ctDNA shedding (footnote). The distribution of TE alterations in the 30-day follow-up samples was similar for RAM+ERL v PBO+ERL (TABLE). Additional results, including associations with baseline characteristics, C4, 30-day follow-up, and PFS will be presented. Understanding the potential clinical impact of co-occurring baseline alterations provides important information to evaluate treatment options. Sample size was limited, but the types and frequency of TE alterations appeared similar between treatment arms. TablePts (≥2 in either treatment group) with treatment emergent alterationsaPop1bPop2bGene NameRAM+ERL (n=36)PBO+ERL (n=60)p-valuecRAM+ERL (n=98)PBO+ERL (n=129)p-valuecEGFRd16 (44)33 (55).3227 (28)47 (36).16TP538 (22)7 (12).1717 (17)16 (12).30NF15 (14)1 (2).027 (7)3 (2).08APC4 (11)1 (2).055 (5)3 (2).26MET3 (8)5 (8)1.006 (6)7 (5).82KRAS2 (6)3 (5).917 (7)3 (2).08FGFR22 (6)2 (3).603 (3)3 (2).73GNAS2 (6)0.052(2)1 (1).41BRAF1 (3)6 (10).163 (3)6 (5).54PI3KA1 (3)4 (7).391 (1)7 (5).06BRCA203 (5).094 (4)6 (5).84ERBB21 (3)3 (5).594 (4)4 (3).69AR02 (3).171 (1)2 (2).73CDK61 (3)2 (3).881 (1)2 (2).73RB11 (3)1 (2).722 (2)3 (2).88CDK41 (3)1 (2).721 (1)2 (2).73SMAD41 (3)1 (2).721 (1)2 (2).73KIT1 (3)1 (2).723 (3)1 (1).19PTEN1 (3)2 (3).882 (2)2 (2).78ARID1A1 (3)1 (2).723 (3)3 (2).73FGFR11 (3)0.162 (2)1 (1).41MAP2K11 (3)0.162 (2)0.07MAPK31 (3)0.162 (2)0.07MTOR01 (2).332 (2)1 (1).41MYC1 (3)0.162 (2)2 (2).78RET00–2 (2)0.07ROS100–2 (2)0.07STK1100–1 (1)2 (2).73Evaluable baseline NGS results were obtained for 390 out of 449 ITT patients (87%).aPts are included in more than one row if alterations arose in more than one gene.bAnalysis population 1 (Pop1, N=96) had disease progression by the 30-day post treatment discontinuation follow-up and had detectable EGFR ex19del or ex21.L858R mutation in baseline and 30 day follow-up blood samples. There is a greater confidence that alterations related to mechanisms of resistance would be detectable in this population since the patients had all progressed by 30-day follow-up and since the EGFR ex19del and ex21.L858R were detectable as shed circulating tumor DNA in the blood. Analysis population 2 (Pop2, N=227) had discontinued study treatment for any reason by the 30-day post treatment discontinuation follow-up and had any alteration detectable at baseline and at 30 day follow-up. Pop2 is a larger population (includes all Pop1 pts) and offers the opportunity to detect less common TE alterations that may not be found in the smaller Pop1. Seven (19%) RAM+ERL v 19 (32%) PBO+ERL of Pop1 and 33 (34%) v 59 (46%) of Pop2 pts had not acquired any of the evaluated alterations.cFisher's exact testdIncludes T790M; the frequencies of TE T790M in RAM+ERL v PBO+ERL for Pop1 were 42% v 50%, respectively, and for Pop2, 19% v 25% Citation Format: Edward Garon, Martin Reck, Kazuto Nishio, John Victor Heymach, Makoto Nishio, Silvia Novello, Luis Paz-Ares, Sanjay Popat, Santiago Ponce Aix, Sameera Wijayawardana, Rebecca R. Hozak, Carla Visseren-Grul, Kazuhiko Nakagawa. RELAY, ramucirumab plus erlotinib (RAM+ERL) versus placebo plus erlotinib (PBO+ERL) in previously untreated EGFR mutation-positive metastatic NSCLC: Next generation sequencing (NGS) results [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT215.

Abstract 528: EMB-01: An innovative bispecific antibody targeting EGFR and cMet on tumor cells mediates a novel mechanism to improve anti-tumor efficacy

Abstract Interruption of EGFR signaling, either by blocking EGFR binding sites on the extracellular domain of the receptor or by inhibiting intracellular tyrosine kinase activity, can prevent the growth of EGFR-expressing tumors. EGFR tyrosine kinase inhibitors (TKIs) provide a favorable treatment outcome in EGFR mutation positive NSCLC patients. However, many patients eventually develop progressive disease after treatment. Such acquired resistance limits the long-term efficacy of these EGFR TKIs in the clinic. The mechanisms of acquired resistance include a variety of mutations of the EGFR and crosstalk with the adjacent cMet receptors that allow the tumor to partially compensate the EGFR activity. EMB-01 is an innovative bispecific antibody developed based on EpimAb's proprietary FIT-Ig® platform to target EGFR and cMET on tumor cells simultaneously. The anti-EGFR and anti-cMet Fab-domains in each EMB-01 arm are fused directly in-tandem in a unique crisscross orientation without any mutations or use of peptide linkers to form a final tetravalent binding complex with the corresponding receptors on cell surface. We have demonstrated that EMB-01 can maintain all the biological activity from parental monoclonal antibody (mAb) to block ligand binding and the downstream signal pathway. In addition, such tetravalent binding feature is found to induce significant co-degradation of EGFR and cMET in various tumor cells, and such effect is unattainable by either mAb alone or in combination, demonstrating a unique synergistic function of EMB-01. At equivalent doses, EMB-01 induces significantly stronger anti-tumor activity in PDX and CDX tumor models than that of anti-EGFR mAb or anti-cMet mAb alone. Furthermore, EMB-01 shows significant anti-tumor activity in anti-EGFR mAb resistant tumor model. These results demonstrate the potential benefit of EMB-01 in treating EGFR and/or cMET driven cancers, particularly in cases where patients develop acquired resistance due to secondary EGFR mutations in the kinase domain or cMET activation. Currently, EMB-01 has initiated a Phase I/II clinical trial with advanced/metastatic solid tumors. Citation Format: Fang Ren, Xuan Wu, Dandan Yang, Danqing Wu, Shiyong Gong, Yingxi Zhang, Stephan Lensky, Chengbin Wu. EMB-01: An innovative bispecific antibody targeting EGFR and cMet on tumor cells mediates a novel mechanism to improve anti-tumor efficacy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 528.

Osimertinib as adjuvant therapy in patients (pts) with stage IB–IIIA EGFR mutation positive (EGFRm) NSCLC after complete tumor resection: ADAURA.

LBA5 Background: Osimertinib is a 3rd-generation, CNS-active, EGFR-TKI with superior efficacy to comparator EGFR-TKI (gefitinib/erlotinib) in treatment-naïve EGFRm advanced NSCLC. Approx. 30% of pts with NSCLC present with early stage (I–IIIA) disease; surgery is the primary treatment. Adjuvant chemotherapy is standard of care in pts with resected stage II–III NSCLC and select stage IB pts; however, recurrence rates are high and other therapies are needed. ADAURA (NCT02511106) is a Ph III, double-blind, randomized study assessing the efficacy and safety of osimertinib vs placebo (PBO) in pts with stage IB–IIIA EGFRm NSCLC after complete tumor resection and adjuvant chemotherapy, when indicated. Following Independent Data Monitoring Committee recommendation, the trial was unblinded early due to efficacy; we report an unplanned interim analysis. Methods: Eligible pts: ≥18 years (Japan/Taiwan: ≥20), WHO PS 0/1, primary non-squamous stage IB/II/IIIA NSCLC, confirmed EGFRm (ex19del/L858R), complete resection of primary NSCLC with full recovery from surgery; postoperative chemotherapy was allowed. Pts were randomized 1:1 to osimertinib 80 mg once daily orally or PBO to receive treatment for up to 3 years and stratified by stage (IB/II/IIIA), mutation type (ex19del/L858R), and race (Asian/non-Asian). Primary endpoint: disease-free survival (DFS) by investigator in stage II–IIIA pts. Secondary endpoints: overall survival (OS) and safety. Data cutoff (DCO): 17 Jan 2020. Results: Globally, 682 pts were randomized to treatment: osimertinib n=339, PBO n=343. Baseline characteristics were balanced across arms (osimertinib/PBO): stage IB 31/31%, stage II/IIIA 69/69%, female 68/72%, ex19del 55/56%, L858R 45/44%. In stage II–IIIA pts, DFS hazard ratio (HR) was 0.17 (95% CI 0.12, 0.23); p&lt;0.0001 (156/470 events); 2-year DFS rate was 90% with osimertinib vs 44% with PBO. In the overall population, DFS HR was 0.21 (0.16, 0.28); p&lt;0.0001 (196/682 events); 2-year DFS rate was 89% with osimertinib vs 53% with PBO. OS was immature (4% maturity) with 29/682 deaths (osimertinib n=9, PBO n=20) at DCO. The safety profile was consistent with the known safety profile of osimertinib. Conclusions: Adjuvant osimertinib is the 1st targeted agent in a global trial to show a statistically significant and clinically meaningful improvement in DFS in pts with stage IB/II/IIIA EGFRm NSCLC after complete tumor resection and adjuvant chemotherapy, when indicated. Adjuvant osimertinib provides an effective new treatment strategy for these pts. Clinical trial information: NCT02511106 .

Disease monitoring and TKI resistance mutations of EGFR mutation-positive NSCLC patients via circulating tumor DNA.

e21627 Background: 15–40% of NSCLC adenocarcinoma patients harbor EGFR sensitizing mutations. Tyrosine kinase inhibitors (TKI) provide significant clinical benefit in this population, yet all patients will develop resistance. Liquid biopsy has been demonstrated to reliably identify tumor associated somatic EGFR mutations. Quantitative assessment of mutated EGFR driven tumors could potentially be used to monitor disease progression, to assess therapeutic response, and to identify resistance mechanisms. Methods: 106 longitudinal plasma samples from 16 NSCLC patients who were treated with osimertinib as either first line or second line therapy were collected. A series of plasma samples collected during treatment and at the time of disease progression were analyzed with the AVENIO ctDNA Surveillance kit*. Mutations at each time point were identified and reported by the AVENIO software v2.0*. The mutation profile of each patient at different timepoints along with the treatment journey was examined in combination with clinical outcome data. Results: EGFR sensitizing mutations were detected in all plasma samples by sequencing except in 3 cases. Patients responsive to anti-EGFR therapy showed a rapid decrease of EGFR driver mutations to non-detectable levels. Meanwhile, patients who had stable disease or rapid disease progression had stable or slightly decreasing ctDNA levels after receiving the treatment. One patient had a MET amplification, FBXL7 SNV, and EGFR T790M detected at the time of disease progression which were not detected at baseline. One patient had both EGFR L858R and T790M mutations. This patient progressed very quickly on erlotinib. Detection of the T790M mutation decreased upon osimertinib administration, however, the L858R mutation level stayed the same. TP53 mutations were elevated in 3 patients at the time of progression, and could potentially be related to anti-EGFR resistance. Conclusions: This study clearly demonstrated that liquid biopsy could identify resistance mutations beyond EGFR prior to clinical progression. Plasma samples collected prior to or at disease progression could facilitate identification of novel resistant mutations to TKI therapy. Further studies to demonstrate the clinical utility of serial blood EGFR testing in NSCLC management are necessary. *For Research Use Only. Not for use in diagnostic procedures.

A phase II study of osimertinib for patients with radiotherapy-naïve CNS metastasis of non-small cell lung cancer harboring EGFR mutations: The OCEAN study (LOGIK 1603/WJOG 9116L).

9597 Background: Approximately 15%–30% of patients treated with EGFR-TKIs experience central nervous system (CNS) progression. Although radiotherapy is a standard treatment for CNS metastasis, the efficacy of radiotherapy against CNS is poor. The aim of OCEAN study was to assess the efficacy of osimertinib for patients with radiotherapy-naïve CNS metastasis of NSCLC harboring EGFR mutations. Methods: OCEAN study was two-cohort phase II trial, 65 patients (T790M cohort; 40 patients and first-line cohort; 25 patients) with radiotherapy-naïve CNS metastasis of EGFR mutation-positive NSCLC was included. Patients were treated with osimertinib 80 mg once daily. The primary endpoint was the response rate of brain metastasis (BMRR) assessed by the PAREXEL criteria. We set a threshold value of 50% and an expected value of 70% based on the overall response rate (ORR) of AURA trial. Based on one-sided alpha = 0.05 and power = 0.8, the sample size of T790M cohort was calculated to be 40. Key secondary endpoints were progression-free survival (PFS), and ORR, BMRR assessed by the RECIST criteria. We are exploratorily assessing the blood concentration of osimertinib at day 22, which considered to represent steady state. In this report, we present the results of T790M cohort. Results: Between October 2016 to July 2019, 40 participants were recruited in the T790M cohort. The median age was 66.5 with 30.0% male. Eight patients had symptomatic CNS metastasis and most patient had multiple CNS metastasis (77.5%). BMRR assessed by PAREXEL criteria was 66.7% (95%CI: 54.3 – 79.1%) and BMRR assessed by RECIST was 70.0% (95%CI, 49.9 – 90.1%). Median PFS was 7.1 months (95%CI, 3.4 – 13.6 months) and ORR assessed by RECIST was 40.5% (95%CI, 24.7 – 57.9%). Treatment related pneumonitis was observed in 4 patients (10.0%). There was no grade 3 or higher toxicities that were found in more than 10%. Conclusions: This first study assessed the efficacy of osimertinib for patients with radiotherapy-naïve CNS metastasis of EGFR T790M mutation-positive NSCLC. The OCEAN study met primary endpoint. The results of this study suggested that patients with brain metastasis harboring EGFR T790M mutations had better to receive osimertinib prior to brain radiotherapy. Clinical trial information: 071180017 .