anti-EGFR Tyrosine Kinase Inhibitors Research Articles

Transformation of adenocarcinoma into small cell lung cancer as one of the mechanisms of acquired resistance to anti-EGFR tyrosine kinase inhibitors

Transformation of adenocarcinoma into small cell lung cancer (SCLC) is a rare and unique biological property of a cancer cell that is responsible for the mechanism of acquired resistance to EGFR tyrosine kinase inhibitors. There are very few clinical observations of phenotypic cellular transformation during metastatic progression of lung cancer in the literature. The aim of the work is to demonstrate clinical observation of phenotypic transformation of metastatic EGFR-mutated adenocarcinoma into small cell lung cancer with neuroendocrine differentiation during therapy with tyrosine kinase inhibitors. Case report. Due to the rarity of this biological phenomenon, we describe our own observation of the transformation of EGFR-mutated metastatic adenocarcinoma into DCLC with neuroendocrine differentiation, which occurred in a 42-year-old woman during treatment with gefitinib. Conclusions. Transformation and changes in cell phenotype during tyrosine kinase inhibitor therapy were the cause of resistance and failure of further treatment with osimertinib in the second line. It was concluded that it is necessary to consider this mechanism of resistance in clinical practice and to perform repeat biopsies during metastatic progression in patients with EGFR-mutated lung adenocarcinoma.

Epidermal growth factor receptor inhibitors in advanced cutaneous squamous cell carcinoma: A systematic review and meta-analysis.

Patients with advanced cutaneous squamous cell carcinoma (cSCC) who are not eligible for or who fail to respond to anti-PD1 immunotherapy have few treatment options. Epidermal growth factor receptor (EGFR) inhibitors have been investigated as a therapeutic option for advanced cSCC; however, data are limited to small single-arm trials or retrospective studies. A systematic review and meta-analysis was conducted to PRISMA guidelines (CRD42023394300). Studies reporting on outcomes of EGFR inhibition in advanced cSCC were identified. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and adverse event (AE) rate were pooled using a random effects model and the inverse variance method. Twelve studies (six prospective, six retrospective) were identified, representing 324 patients. Pooled ORR was 26% (95% confidence interval [CI] 18-36), median PFS was 4.8 months (95% CI 3.9-6.6) and median OS was 11.7 months (95% CI 9.2-14.1). Any grade AEs occurred in 93% of patients (95% CI 85-97) while grade 3 and higher AEs occurred in 30% (95% CI 14-54). These results were similar between anti-EGFR monoclonal antibodies (MAbs) and tyrosine kinase inhibitors (TKIs). EGFR inhibitors can be considered in patients with advanced cSCC who are contraindicated for or progress on first-line anti-PD1 immunotherapy. Future studies should evaluate their activity and safety following anti-PD1, identify predictive biomarkers for their efficacy and explore combination approaches.

Real-world outcomes of anti-EGFR therapy in advanced non-small cell lung cancer EGFR mutated in Peru.

Despite the advances in the management of advanced non-small cell lung cancer (NSCLC), the access to genetic profiling and target therapies remains a challenge in Latin America, even in countries with a higher rate of targetable mutations. The aim of this study is to evaluate the clinical outcomes of anti-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) treatment in a Peruvian real-world setting. This is a retrospective study of recurrent or advanced NSCLC EGFR mutated patients diagnosed and treated with anti-EGFR TKI at Instituto Nacional de Enfermedades Neoplásicas (INEN) between January 1, 2015 to December 31, 2020. The outcomes were objective response rate (ORR), progression free survival (PFS), and overall survival (OS). We identify 613 stage IV or recurrent NSCLC patients who were tested for EGFR mutations and found a pathogenic mutation in 39.5% of patients. Only 51.2% of them received anti-EGFR TKI as institutional treatment. ORR was 58%, after median follow-up of 32 months, the estimated median PFS was 13.9months (11.1-16.7months), and the estimated median OS was 21.7months (18.5-24.9months). No differences were found in PFS according to line of treatment or brain metastases at diagnosis (p=0.46 and p=0.07, respectively), respect to OS there were no differences line of treatment (p=0.12), significant difference were found in presence of brain metastases (p=0.006). Our study demonstrates that erlotinib for advanced NSCLC harboring EGFR-activating mutations is effective even in patients usually excluded from clinical trial, like those previously exposed to one or more lines of chemotherapy or with brain metastases.

Retrospective Evaluation of the Analgesic Effects of Molecular Target Agents Against Cancer Pain and Oxaliplatin-Induced Chronic Peripheral Neuropathy

Epidermal growth factor receptor (EGFR) has received significant attention for its therapeutic potential for pain relief. The relief of neuropathic pain after treatment with anti-EGFR antibodies or tyrosine kinase inhibitors has been previously described. However, few reports have investigated the association of cancer-related nociceptive pain or chronic chemical induced peripheral neuropathy with the analgesic effects of EGFR inhibition.
 Therefore, we conducted a retrospective survey of 191 patients with colorectal cancer receiving chemotherapy plus molecular targeting drugs to examine the analgesic effects of anti-EGFR antibodies against either cancer pain or oxaliplatin-induced peripheral neuropathy. We identified a significant difference in the improvement rates of nociceptive pain between panitumumab- and bevacizumab-treated patients (100% vs. 9.1%; p < 0.01), but not oxaliplatin-induced peripheral neuropathy.
 In conclusion, panitumumab may be effective at reducing cancer-related nociceptive pain.

Abstract 75: Highly multiplexed EGFR mutation detection from liquid biopsy samples using the 6-color Crystal Digital PCR™

Abstract Liquid biopsies are a minimally invasive sampling approach to overcome the heterogeneity of tumors and represent a valuable source of circulating tumor DNA (ctDNA) for oncological biomarker analysis. ctDNA measurements require a highly sensitive and reliable detection technology to quantify often low-level genetic aberrations within a high background of wild-type sequences. Digital PCR emerged as a powerful technology for the next-generation analysis of liquid biopsies. Stilla Technologies' 6-color naica® system is an ultrasensitive, easy-to-use digital PCR platform capable of simultaneously and precisely quantifying high numbers of biomarkers in a single reaction. Non-small cell lung cancer (NSCLC) is a leading cause of cancer mortality worldwide. Epidermal growth factor receptor (EGFR) is frequently mutated in NSCLC. A handful of anti-EGFR Tyrosine Kinase Inhibitor therapies are approved by the FDA; however, most patients develop resistance over time to these treatments. Both monitoring primary EGFR mutations to predict treatment response and precociously detecting resistance mutations to adapt treatments promptly through ctDNA analysis stand to improve the effectiveness of NSCLC patient management. Stilla has developed a highly multiplexed 6-color Crystal Digital PCR EGFR kit detecting more than 90% of EGFR mutations described in NSCLC from ctDNA. The assay detects 32 common and rare somatic EGFR mutations in exons 18, 19, 20, and 21, including both activating and resistant mutations. In this work, we evaluated the sensitivity, precision and specificity of the EGFR 6-color Crystal Digital PCR assay highly specific and sensitive for the detection of EGFR mutations, with a Limit of Detection in a high background of wild-type DNA ranging from 0.30 to 0.46 cp/μL (with observed MAFs ranging from 0.06 to 0.09%). Moreover, a high concordance was observed between those EGFR results obtained for NSCLC ctDNA samples using 6-color Crystal Digital PCR and other technologies. With a rapid time to results and straightforward ctDNA analysis workflow, Crystal Digital PCR on the naica system promises ultrasensitive, highly multiplexed 6-color mutation detection, maximizing the information obtained from precious samples. Citation Format: Cécile Jovelet, Myrtille Remy, Noémie Pata-Merci, Damien Vasseur, Ludovic Lacroix, Claudia Labrador-Rached, Allison C. Mallory. Highly multiplexed EGFR mutation detection from liquid biopsy samples using the 6-color Crystal Digital PCR™ [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 75.

P-156 MOUNTAINEER-02: Phase 2/3 study of tucatinib, trastuzumab, ramucirumab, and paclitaxel in previously treated HER2+ gastric or gastroesophageal junction adenocarcinoma: Trial in progress

Tucatinib (TUC), a highly selective HER2-directed tyrosine kinase inhibitor (TKI) approved in multiple regions for HER2+ metastatic breast cancer, is being developed as a novel therapy for patients with GI tumors including gastric or gastroesophageal junction adenocarcinoma (GEC). While trastuzumab (Tras) with chemotherapy is standard in the first-line setting for metastatic HER2+ GEC, no anti-HER2 therapy has demonstrated an OS benefit over chemotherapy as second-line therapy, possibly due to loss of HER2 expression following Tras-based therapy. In GEC xenograft models, dual targeting of HER2 with TUC and Tras showed superior activity to either agent alone. (Kulukian 2020) Interim results from the MOUNTAINEER study have shown promising activity for TUC and Tras for HER2+ mCRC.(Strickler 2019) The MOUNTAINEER-02 study (NCT04499924) is evaluating the efficacy and safety of TUC with Tras, ramucirumab (Ram), and paclitaxel (Pac) in patients with HER2+ GEC in the second-line setting. MOUNTAINEER-02 is a phase 2/3 study evaluating TUC + Tras with Ram and Pac. Eligible patients have locally-advanced unresectable or metastatic HER2+ GEC and have received a HER2-directed antibody and 1 prior line of therapy for advanced disease. Patients are ≥18 years of age; have an ECOG ≤1; and have had no prior exposure to Ram, an anti-HER2 or anti-EGFR TKI, HER2-directed antibody-drug conjugates, or taxanes ≤12 months before enrollment. Patients receive TUC 300 mg or placebo PO BID and Tras or placebo (IV on Days 1 and 15 of each 28-day cycle) in combination with Pac (IV on Days 1, 8, and 15) and Ram (IV on Days 1 and 15). The study includes an initial Pac-dose optimization stage because of the potential impact of TUC on Pac metabolism. The open-label phase 2 part determines the recommended dose of Pac (60 or 80 mg/m2) combined with TUC, Tras, and Ram in 6–18 patients and evaluates safety and activity of the regimen in Cohorts 2A and 2B (30 patients each). The randomized, double-blind, phase 3 part compares the efficacy and safety of TUC and Tras (Arm 3A, ∼235 patients) vs placebo (Arm 3B, ∼235 patients), both in combination with Ram and Pac, and evaluates activity of TUC with Ram and Pac (Arm 3C, ∼30 patients). The coprimary phase 3 endpoints are OS and PFS per investigator, and secondary endpoints include DOR, confirmed ORR, and DCR. Secondary objectives include patient-reported outcomes. HER2 status is determined by blood-based NGS assay or IHC/ISH assay of a tumor tissue sample (IHC3+ or IHC2+/ISH+) at screening. In Cohort 2A and phase 3, patients must be HER2+ by blood-based NGS. In Cohort 2B, patients must be HER2+ by biopsy but HER2 negative by blood-based NGS after progression in first-line or subsequent therapy. Disease assessments per RECIST v1.1 occur q6 weeks for 36 weeks, then q9 weeks. The pharmacokinetics of TUC, Pac, and their metabolites are evaluated in a subset of patients, including a cohort with gastrectomies. Enrollment in phase 2 is ongoing. NCT04499924. The authors thank Joseph Giaconia of MMS Holdings, Michigan, USA for providing medical writing support/editorial support, which was funded by Seagen Inc., Bothell, WA, USA in accordance with Good Publication Practice (GPP3) guidelines. Seagen Inc.

MOUNTAINEER-02: Phase 2/3 study of tucatinib, trastuzumab, ramucirumab, and paclitaxel in previously treated HER2+ gastric or gastroesophageal junction adenocarcinoma—Trial in progress.

TPS371 Background: Tucatinib (TUC), a highly selective HER2-directed tyrosine kinase inhibitor (TKI) approved in multiple regions for HER2+ metastatic breast cancer, is being developed as a novel therapy for patients (pts) with GI tumors including gastric or gastroesophageal junction adenocarcinoma (GEC). While trastuzumab (Tras) with chemotherapy is standard in the 1st-line setting for metastatic HER2+ GEC, no anti-HER2 therapy has demonstrated an OS benefit over chemotherapy as 2nd-line therapy, possibly due to loss of HER2 expression following Tras-based therapy. In GEC xenograft models, dual targeting of HER2 with TUC and Tras showed superior activity to either agent alone.(Kulukian 2020) Interim results from the MOUNTAINEER study have shown promising activity for TUC and Tras for HER2+ mCRC.(Strickler 2019) The MOUNTAINEER-02 study is evaluating the efficacy and safety of TUC with Tras, ramucirumab (Ram), and paclitaxel (Pac) in pts with HER2+ GEC in the 2nd-line setting. Methods: MOUNTAINEER-02 (NCT04499924) is a phase 2/3 study evaluating TUC + Tras with Ram and Pac. Pts receive TUC 300 mg or placebo PO BID, Tras (6 then 4 mg/kg) or placebo (IV on Days 1 and 15 of each 28-day cycle), Pac (IV on Days 1, 8, 15), and Ram (IV on Days 1 and 15). Eligible pts have locally-advanced unresectable or metastatic HER2+ GEC and have received a HER2-directed antibody and 1 prior line of therapy for advanced disease. Pts must be ≥18 years of age, with an ECOG ≤1, and have had no prior exposure to Ram, anti-HER2 or anti-EGFR TKI, HER2-directed antibody-drug conjugates, or taxanes ≤12 months before enrollment. Due to the potential impact of TUC on Pac metabolism, the study will include an initial Pac dose optimization stage. The open-label phase 2 part will determine the recommended dose of Pac (60 or 80 mg/m²) combined with TUC, Tras, and Ram in 6-18 pts, and evaluate safety and activity of the regimen in Cohorts 2A and 2B (30 pts each). The randomized, double-blind, phase 3 part will compare the efficacy and safety of TUC and Tras (Arm 3A; ̃235 pts) vs. placebo (Arm 3B; ̃235 pts), both in combination with Ram and Pac, and also evaluate activity of TUC with Ram and Pac (Arm 3C; ̃30 pts). The dual primary phase 3 endpoints are OS and PFS per investigator, with confirmed ORR as a key secondary endpoint. HER2 status is determined at baseline using a blood-based NGS assay, and IHC/ISH of fresh or archival tumor biopsies, if available. Pts must be HER2+ by blood-based NGS in Cohort 2A and phase 3; in Cohort 2B, pts must be HER2+ in a biopsy taken post-progression during/after 1st-line therapy, but HER2-negative by blood-based NGS. Disease assessments per RECISTv1.1 will occur q6 weeks for 36 weeks, then q9 weeks. The pharmacokinetics of TUC, Pac, and their metabolites will be evaluated in a subset of pts, including a cohort with gastrectomies. Enrollment in phase 2 is ongoing. Clinical trial information: NCT04499924.

Global prognostic impact of driver genetic alterations in patients with lung adenocarcinoma: a real-life study

BackgroundAdvanced lung adenocarcinoma (LAC) is one of the most lethal malignancies worldwide. The aim of this study was to evaluate the global survival in a real-life cohort of patients with LAC harboring driver genetic alterations.MethodsA series of 1282 consecutive Sardinian LAC patients who underwent genetic testing from January 2011 through July 2016 was collected. Molecular tests were based on the clinical needs of each single case (EGFR-exon18/19/21, ALK, and, more recently, BRAF-exon15), and the availability of tissue (KRAS, MET, and presence of low-frequency EGFR-T790M mutated alleles at baseline).ResultsThe mean follow-up time of the patients was 46 months. EGFR, KRAS, and BRAF mutations were detected in 13.7%, 21.3%, and 3% of tested cases, respectively; ALK rearrangements and MET amplifications were found respectively in 4.7% and 2% of tested cases. As expected, cases with mutations in exons 18–21 of EGFR, sensitizing to anti-EGFR tyrosine kinase inhibitors (TKIs) agents, had a significantly longer survival in comparison to those without (p < 0.0001); conversely, KRAS mutations were associated with a significantly lower survival (p = 0.0058). Among LAC patients with additional tissue section available for next-generation sequencing (NGS)-based analysis, 26/193 (13.5%) patients found positive for even low-rate EGFR-T790M mutated alleles at baseline were associated with a highly significant lower survival in comparison to those without (8.7 vs. 47.4 months, p < 0.0001).ConclusionsIn addition to its predictive value for addressing targeted therapy approaches, the assessment of as more inclusive mutation analysis at baseline may provide clues about factors significantly impacting on global survival in advanced LAC patients.

Prevention and treatment of mucocutaneous adverse reactions associated with epidermal growth factor receptor inhibitors

The epidermal growth factor receptor (EGFR) signaling is aberrantly overexpressed in many solid malignancies, making it an important target for anti-cancer biologic agents. Among them, epidermal growth factor receptor inhibitors (EGFRIs), which have been widely used in clinical practice, include anti-EGFR monoclonal antibodies and tyrosine kinase inhibitors. A proportion of patients treated with EGFRIs develop specific, dose-dependent skin toxicity such as papulopustular rash, paronychia, xerosis and itch. These side effects can cause physical and psychosocial discomfort that may result in dose reduction, discontinuance, or replacement of the current EGFRIs treatment. Correct diagnosis and treatment of these skin and mucosal adverse effects associated with EGFRIs is of great significance for the tertiary prevention of malignant tumors. A review on EGFRI-related mucocutaneous adverse reactions is presented here, focusing on the pathogenesis, the various clinical manifestations, the strategies for prevention and treatment of these conditions.

1226P Efficacy and safety of Anti-EGFR TKIs combined with bevacizumab or ramucirumab in the first-line treatment of non-small cell lung cancer: Meta-analysis of randomized controlled trials

Anti-EGFR tyrosine kinase inhibitors (TKIs) are the standard therapy in the first-line treatment of EGFR mutant non-small cell lung cancer (NSCLC). It was aimed to increase the efficacy by adding anti-angiogenic antibodies to these agents, and several randomized controlled trials (RCTs)have been conducted in this area in recent years. Here, we performed an efficacy and safety analysis of RCTs investigating the addition of bevacizumab or ramucirumab to EGFR-TKIs in EGFR mutant advanced NSCLC.

Generation and Characterization of a New Preclinical Mouse Model of EGFR-Driven Lung Cancer with MET-Induced Osimertinib Resistance.

Simple SummaryThe use of targeted therapy has changed the clinical management of lung cancer patients, increasing both their life quality and expectancy. Conversely, the appearance of resistance occurs in almost all patients receiving this therapy. In this regard, new strategies combining different therapies could delay or even eliminate the appearance of resistance. However, in order to develop new therapeutic treatments, we need preclinical mouse models that recapitulate human disease. In the present study, we developed a new state-of-the-art mouse model that summarizes all features occurring in EGFR-mutated patients that relapse after osimertinib after acquisition of MET amplification.Despite the introduction of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) to treat advanced lung cancer harboring EGFR-activating mutations, the prognosis remains unfavorable because of intrinsic and/or acquired resistance. We generated a new state-of-the-art mouse strain harboring the human EGFRT790M/L858R oncogene and MET overexpression (EGFR/MET strain) that mimics the MET amplification occurring in one out of five patients with EGFR-mutated lung cancer that relapsed after treatment with osimertinib, a third-generation anti-EGFR TKI. We found that survival was reduced in EGFR/MET mice compared with mice harboring only EGFRT790M/L858R (EGFR strain). Moreover, EGFR/MET-driven lung tumors were resistant to osimertinib, recapitulating the phenotype observed in patients. Conversely, as also observed in patients, the crizotinib (anti-MET TKI) and osimertinib combination improved survival and reduced tumor burden in EGFR/MET mice, further validating the model’s value for preclinical studies. We also found that in EGFR/MET mice, MET overexpression negatively regulated EGFR activity through MIG6 induction, a compensatory mechanism that allows the coexistence of the two onco-genic events. Our data suggest that single EGFR or MET inhibition might not be a good therapeutic option for EGFR-mutated lung cancer with MET amplification, and that inhibition of both pathways should be the best clinical choice in these patients.

Detection of EGFR Mutations in Plasma Cell-Free Tumor DNA of TKI-Treated Advanced-NSCLC Patients by Three Methodologies: Scorpion-ARMS, PNAClamp, and Digital PCR.

Analysis of circulating cell-free tumor DNA (cftDNA) has emerged as a specific and sensitive blood-based approach to detect epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients. Still, there is some debate on what should be the preferential clinical method for plasma-derived cftDNA analysis. We tested 31 NSCLC patients treated with anti-EGFR tyrosine kinase inhibitors (TKIs), at baseline and serially during therapy, by comparing three methodologies in detecting EGFR mutations (L858R, exon 19 deletion, and T790M) from plasma: scorpions-amplification refractory mutation system (ARMS) methodology by using EGFR Plasma RGQ PCR Kit-QIAGEN, peptide nucleic acid (PNA) clamp and PANA RealTyper integration by using PNAClamp EGFR-PANAGENE, and digital real time PCR by using QuantStudio 3D Digital PCR System-Thermo Fisher Scientific. Specificity was 100% for all three mutations, independently from the platform used. The sensitivity for L858R (42.86%) and T790M (100%) did not change based on the method, while the sensitivity for Del 19 differed markedly (Scorpion-ARMS 45%, PNAClamp 75%, and Digital PCR 85%). The detection rate was also higher (94.23%) as measured by Digital PCR, and when we monitored the evolution of EGFR mutations over time, it evidenced the extreme inter-patient heterogeneity in terms of levels of circulating mutated copies. In our study, Digital PCR showed the best correlation with tissue biopsy and the highest sensitivity to attain the potential clinical utility of monitoring plasma levels of EGFR mutations.

Effective tyrosine kinase inhibitor re-treatment in epidermal growth factor receptor-mutated non-small-cell lung cancer patient: a case report

: The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) represent the standard of care as first-line treatment for patients with non-small-cell lung cancer (NSCLC) harbouring EGFR mutation. There are few treatment options after progression from TKI. In the absence of targetable mutations, patients who develop resistance are usually treated with chemotherapy. There are limited data focusing the role of TKI re-treatment. We present the case of a patient who achieved clinical benefit and objective response upon re-treatment with a first-generation anti-EGFR TKI.

Potential life years not saved due to lack of access to anti-EGFR tyrosine kinase inhibitors for lung cancer treatment in the Brazilian public healthcare system: Budget impact and strategies to improve access. A pharmacoeconomic study.

Lung cancer is the fourth most common cancer in Brazil. In the 2000s, better understanding of molecular pathways led to development of epidermal growth factor receptor (EGFR)-targeted treatments that have improved outcomes. However, these treatments are unavailable in most Brazilian public healthcare services (Sistema Único de Saúde, SUS). To assess the potential number of years of life not saved, the budget impact of the treatment and strategies to improve access. Pharmacoeconomic study assessing the potential societal and economic impact of adopting EGFR-targeted therapy within SUS. We estimated the number of cases eligible for treatment, using epidemiological data from the National Cancer Institute. We used data from a single meta-analysis and from the Lung Cancer Mutation Consortium (LCMC) study as the basis for assessing differences in patients' survival between use of targeted therapy and use of chemotherapy. The costs of targeted treatment were based on the national reference and were compared with the amount reimbursed for chemotherapy through SUS. There was no life-year gain with EGFR-targeted therapy in the single meta-analysis (hazard ratio, HR, 1.01). The LCMC showed that 1,556 potential life-years were not saved annually. We estimated that the annual budget impact was 125 million Brazilian reais (BRL) with erlotinib, 48 million BRL with gefitinib and 52 million BRL with afatinib. Their incremental costs over chemotherapy per life-year saved were 80,329 BRL, 31,011 BRL and 33,225 BRL, respectively. A drug acquisition discount may decrease the budget impact by 30% (with a 20% discount). A fixed cost of 1,000 BRL may decrease the budget impact by 95%. Reducing drug acquisition costs may improve access to EGFR-targeted therapy for lung cancer.

EGFR-Specific Tyrosine Kinase Inhibitor Modifies NK Cell-Mediated Antitumoral Activity against Ovarian Cancer Cells.

The adverse prognosis of most patients with ovarian cancer is related to recurrent disease caused by resistance to chemotherapeutic and targeted therapeutics. Besides their direct activity against tumor cells, monoclonal antibodies and tyrosine kinase inhibitors (TKIs) also influence the antitumoral activity of immune cells, which has important implications for the design of immunotherapies. In this preclinical study, we treated different ovarian cancer cell lines with anti-epidermal growth factor receptor (EGFR) TKIs and co-incubated them with natural killer (NK) cells. We studied treatment-related structural and functional changes on tumor and immune cells in the presence of the anti-EGFR antibody cetuximab and investigated NK-mediated antitumoral activity. We show that long-term exposure of ovarian cancer cells to TKIs leads to reduced responsiveness of intrinsically sensitive cancer cells over time. Inversely, neither long-term treatment with TKIs nor cetuximab could overcome the intrinsic resistance of certain ovarian cancer cells to anti-EGFR agents. Remarkably, tumor cells pretreated with anti-EGFR TKIs showed increased sensitivity towards NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC). In contrast, the cytokine secretion of NK cells was reduced by TKI sensitization. Our data suggest that sensitization of tumor cells by anti-EGFR TKIs differentially modulates interactions with NK cells. These data have important implications for the design of chemo-immuno combination therapies in this tumor entity.

Retrospective Analysis of Skin Toxicity in Patients under Anti-EGFR Tyrosine Kinase Inhibitors: Our Experience in Lung Cancer.

BACKGROUND:Tyrosine kinase inhibitors (TKIs) have been introduced for the treatment of lung cancer, improving progression-free survival, objective response rate, and quality of life. However, TKIs can lead to cutaneous toxicities, including papulopustular rash, xerosis, paronychia with/without pyogenic granulomas, scalp disorders, facial hair and/or eyelash growth.AIM:In this study, we describe retrospectively all cases of mucocutaneous side effects in patients with lung cancer under TKIs referring to our outpatient for the skin care of oncological patients.METHODS:We included patients referring from January 2016 to January 2018 affected by lung cancer and under TKIs. We collected data about the clinical exam, clinical photography, dermoscopy, histology and direct microscopic examination for each patient and we performed retrospectively descriptive analyses to assess whether a specific TKIs is linked significantly to particular cutaneous toxicity.RESULTS:The majority of skin toxicities were due to afatinib, and the most common skin reaction was rash. We selected 60 patients with skin reactions, treated by TKIs for lung cancer. The majority of skin toxicities were due to afatinib (47/102 adverse reactions) and erlotinib (39/102). The most common skin reaction was rash (63% of patients), followed by xerosis (30%) and granulomas (30%). There was no significant relationship between a specific type of cutaneous reaction and specific EGFRi except for granulomas, developed more frequently in patients under afatinib (p < 0.05).CONCLUSION:Most of our patients (63%) developed a cutaneous rash under TKIs. Most commonly afatinib was the drug involved, although it wasn’t the most used EGFRi. Moreover, we noticed a significant correlation between afatinib therapy and appearance of granulomas.

From Biology to Therapy: Improvements of Therapeutic Options in Lung Cancer.

Lung cancer is the leading cause of cancer-related mortality around the world, despite effective chemotherapeutic agents, the prognosis has remained poor for a long time. The discovery of molecular changes that drive lung cancer has led to a dramatic shift in the therapeutic landscape of this disease. In "in vitro" and "in vivo" models of NSCLC (Non-Small Cell Lung Cancer), angiogenesis blockade has demonstrated an excellent anti-tumor activity, thus, a number of anti-angiogenic drugs have been approved by regulatory authorities for use in clinical practice. Much more interesting is the discovery of EGFR (Epithelial Growth Factor Receptor) mutations that predict sensitivity to the anti-EGFR Tyrosine Kinase Inhibitors (TKIs), a class of drugs that has shown to significantly improve survival when compared with standard chemotherapy in the first-line treatment of metastatic NSCLC. Nevertheless, after an initial response, resistance often occurs and prognosis becomes dismal. Biomolecular studies on cell line models have led to the discovery of mutations (e.g., T790M) that confer resistance to anti-EGFR inhibitors. Fortunately, drugs that are able to circumvent this mechanism of resistance have been developed and have been recently approved for clinical use. The discovery of robust intratumor lymphocyte infiltration in NSCLC has paved the way to several strategies able to restore the immune response. Thus, agents interfering with PD-1/PD-L1 (Programmed Death) pathways make up a significant portion of the armamentarium of cancer therapies for NSCLC. In all the above-mentioned situations, the basis of the success in treating NSCLC has started from understanding of the mutational landscape of the tumor.

Crystal structure of EGFR T790M/C797S/V948R in complex with EAI045

Lung cancer is the leading cause of cancer deaths. Epidermal growth factor receptor (EGFR) kinase domain mutations are a common cause of non-small cell lung cancers (NSCLCs), a major subtype of lung cancers. Patients harboring most of these mutations respond well to the anti-EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib initially, but soon develop resistance to them in about half of the cases due to the emergence of the gatekeeper mutation T790M. The third-generation TKIs such as AZD9291, HM61713, CO-1686 and WZ4002 can overcome T790M through covalent binding to the EGFR kinase through Cys 797, but ultimately lose their efficacy upon emergence of the C797S mutation that abolishes the covalent bonding. Therefore to develop new TKIs to overcome EGFR drug-resistant mutants harboring T790M/C797S is urgently demanded. EAI001 and EAI045 are a new type of EGFR TKIs that bind to EGFR reversibly and not relying on Cys 797. EAI045 in combination with cetuximab is effective in mouse models of lung cancer driven by EGFR L858R/T790M and L858R/T790M/C797S. Here we report the crystal structure of EGFR T790M/C797S/V948R in complex with EAI045, and compare it to EGFR T790M/V948R in complex with EAI001. The complex structure reveals why EAI045 binds tighter to EGFR than does EAI001, and why EAI001 and EAI045 prefer binding to EGFR T790M. The knowledge may facilitate future drug development studies targeting this very important cancer target.

Abstract B168: Monitoring acquired resistance to EGFR-TKIs and clonal evolution in metastatic NSCLC patients using liquid biopsies

Abstract Epidermal Growth Factor Receptor (EGFR) activating mutations predict sensitivity to first- and second-generation anti-EGFR tyrosine kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). However, NSCLC invariably develops acquired resistance (AR) to these agents, leading to disease progression. EGFR-T790M secondary mutation is the most frequent AR mechanism in this setting. Patients with EGFR-T790M positive tumors demonstrate impressive response rate to osimertinib, a third-generation EGFR-TKI, but disease progression also occurs. Intratumor heterogeneity and selection of genetic alterations that confer resistance to target therapy have been recognized as crucial in the development of AR to EGFR-TKIs. In the present study, we used liquid biopsies to monitor the appearance and dynamics of genetic alterations known to be associated with EGFR-TKIs AR in circulating tumor DNA (ctDNA) of patients with metastatic NSCLC treated with EGFR-TKIs. A total of 21 patients were recruited for this study, of whom 17 were initially treated with erlotinib, 2 with gefitinib, and 2 with afatinib. Disease progression was observed in 9 patients using erlotinib, 2 patient using gefitinib, and 1 patient using afatinib. The detection of EGFR mutations in these patients was carried out in serial liquid biopsies using droplet digital PCR (ddPCR) at a sensitivity between 0.1-0.5%. Of the 12 patients with disease progression, 7 (58.3%) were positive for the EGFR-T790M mutation in tissue biopsy and for 4 (57.1%) of these patients the EGFR-T790M was also detected by liquid biopsy at disease progression. Of the 7 EGFR-T790M positive patients, 5 received osimertinib, including 2 patients with EGFR-T790M positive liquid biopsy. Patients with EGFR-T790M positive liquid biopsies were followed closely using serial liquid biopsies to monitor the levels of the original EGFR mutation and of the EGFR-T790M resistance mutation. In general, plasma levels of the activating EGFR mutation and of the EGFR-T790M mutation accurately paralleled the clinical and radiologic evolution of the disease. Patients showing sequential increase in both EGFR mutations showed marked disease progression while those with stable levels presented indolent disease. EGFR-T790M plasma levels became undetectable within 1-2 weeks after the start of osimertinib, anticipating radiologic response to the drug. Of note, increases in T790M levels during treatment anticipated AR to osimertinib in one of our patients. This was accompanied by the emergence of a second EGFR resistance mutation (C797S) and a selective amplification of the EGFR-exon19del allele. In conclusion, liquid biopsies for EGFR genotyping can be used as a complementary strategy to tissue biopsies and should be considered the initial approach to identify both EGFR-TKI sensitizing and resistance mutations due to its minimally invasive nature. Also, plasma levels of EGFR mutations accurately paralleled the clinical and radiologic evolution of disease for these patients, allowing early detection of AR to TKIs. Finally, liquid biopsies can also be used to study novel mechanisms of AR to EGFR-TKIs. Citation Format: Franciele Knebel, Fabiana Bettoni, Andrea Shimada, Manoel Cruz, João Victor Alessi, Marcelo Negrao, David Muniz, Luiz Fernando Reis, Artur Katz, Olavo Feher, Daniel Saragiotto, Anamaria Camargo. Monitoring acquired resistance to EGFR-TKIs and clonal evolution in metastatic NSCLC patients using liquid biopsies [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B168.

P2.03-006 How Many Years of Life Have We Lost in Brazil Due to the Lack of Access to Anti-EGFR TKIs in the National Public Health System?

Lung cancer is the fourth most common cancer in Brazil with 28,220 new cases in 2017. It is the main cause of cancer-related deaths with 23,393 deaths in 2013. In the 2000s, better understanding of molecular pathways led to the development of targeted treatments. The introduction of EGFR tyrosine kinase inhibitors (TKI) led to significant improvements in Response Rate and Progression-Free Survival for patients with activating mutations. Nevertheless, this treatment is not available in the Brazilian Public Health System based upon its costs and the absence of Overall Survival gain in randomized clinical trials.