Surrogate Predictive Biomarkers for Response to Anti-EGFR Agents: State of the Art and Challenges

2007 ◽  
Vol 22 (1_suppl4) ◽  
pp. 10-23 ◽  
Author(s):  
F. Cappuzzo ◽  
L. Toschi ◽  
G. Finocchiaro ◽  
C. Ligorio ◽  
A. Santoro

The epidermal growth factor receptor (EGFR) plays a key role in cancer development and progression in several human malignancies including non-small cell lung cancer (NSCLC). Several strategies aimed at inhibiting the EGFR have been investigated in the last years, including the use of small tyrosine kinase inhibitors (TKIs) directed against the intracellular domain of the receptor and monoclonal antibodies targeting its extracellular portion. Subgroups of patients who are more likely to respond to TKIs have been identified based on both clincal and biological features. Never-smoking history has emerged as the most relevant clinical characteristic predictive of response to TKIs in NSCLC, while presence of drug-sensitive EGFR mutations and EGFR gene gain represent critical biological variables associated with an improved outcome for patients exposed to these agents. Recent studies have highlighted the existence of biological factors involved in intrinsic and acquired resistance to TKIs, including k-ras, HER-2 and EGFR exon 20 mutations. Increasing knowledge of EGFR biology and drug-receptor interactions will allow to identify individuals who are likely to derive a clinical benefit from the proposed targeted therapy, sparing refractory patients expensive and potentially toxic treatment.

Author(s):  
Christoforos Astaras ◽  
Adrienne Bettini ◽  
Daniel C. Betticher

In advanced non-small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) mutations are one of the most frequent oncogenic drivers. They confer a favorable prognosis and strongly predict sensitivity to EGFR tyrosine kinase inhibitors (TKIs). Over the last decades, several EGFR genetic alterations, common and uncommon mutations, have been described in exons 18−21. Common mutations are exon 19 deletions (most frequently E746-A750) and exon 21 L858R substitution. Uncommon mutations include exon 18 G719X, exon 20 S768l, exon 21 L861Q and many other rare ones. This report describes the case of a 55-year-old woman with a newly diagnosed metastatic lung adenocarcinoma harboring two rare EGFR mutations and showing sustained response to osimertinib.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e18095-e18095
Author(s):  
Rahul Peck ◽  
Elizabeth Connolly ◽  
Paul Taylor ◽  
Corinne Faivre-Finn ◽  
Fiona Hellen Blackhall ◽  
...  

e18095 Background: The presence of Epidermal Growth Factor Receptor (EGFR) activating mutations in patients with NSCLC was first described in 2005. Tumours exhibiting these mutations show sensitivity to treatment with an oral Tyrosine Kinase Inhibitor. Testing for EGFR mutations in patients with non-squamous NSCLC began in the Greater Manchester and Cheshire network in the last quarter of 2009. Methods: We audited the notes of consecutive patients who were identified with an activating EGFR mutation by the Central Manchester Genetics Laboratory between November 2009 and October 2011. Results: A total of 110 mutations were identified in tumour tissue from 98 patients. 13.6% were in exon 18, 38.2% in exon 19, 15.4% in exon 20 and 32.8% in exon 21. 65% of patients were female. The median age was 69 years (36-89). Notes were available for 85 patients, 59 of whom received treatment with an EGFR TKi. 7 had previously received radical treatment and 19 never received treatment. 7% were current smokers, 40% were ex-smokers, 30.6% had never smoked and smoking history was not documented in 22.4%. An initial response to treatment was seen in 55%, with stable disease in 15%.The mean duration of treatment was 7.6 months (2 weeks – 23 months), with 24 patients still receiving a TKi at the time of data analysis. The most commonly seen toxicities were diarrhoea and rash. Only 1 patient had no documented toxicity from their TKi. 17 patients (29%) had treatment discontinued or interrupted because of toxicity. In 8 of these, treatment was re-introduced at a reduced dose, and 3 patients went back to full dose. Conclusions: Our results confirm that treatment with a TKi is effective for those patients whose tumours harbour EGFR mutations, with a side effect profile consistent with published data.


Author(s):  
Alessandro Pancrazzi ◽  
Agostino Ognibene ◽  
Alice Moncada ◽  
Valerio Torre

Abstract Background The quality programs can be considered to be a valuable tool for global and individual growth. Each result, obtained by a single laboratory, contributes to define the standardization of the response. In the case of the uncommon epidermal growth factor receptor (EGFR) mutations, the molecular result is sometimes difficult to interpret in terms of biological significance and therapy choosing. The standardization effort in the diagnostic lung setting also consists of active quality program participation. Materials and Methods The quality control analysis, which is defined as a clinical case, was performed by the extraction of DNA from FFPE sections and by RT-PCR on the EGFR (exons 19, 20, 21), BRAF, and KRAS genes. The laboratory performed a validation sequencing of EGFR exon 20 with the help of the Sanger method. Results The laboratory reported positivity for EGFR exon 20 insertions and negative results for BRAF and KRAS. The quality test finished with the redaction of a report containing the recommendation to consider the efficacy of therapy with tyrosine kinase inhibitors (TKI). This specific interpretation has determined poor performance judgment by the quality provider, which explained why most of these mutations are TKI-resistant. Conclusions This experience provides an opportunity to reflect on the critical aspects of this diagnostic setting. The detection of some uncommon EGFR mutations should entail the mutation characterization, especially for the rare exon 20 insertions, of which are not classifiable as “resistant.” Moreover, this experience allows reflecting on the quality program design, mandatory actions for the laboratory, and routine activity in the oncologic multidisciplinary team.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xia Wang ◽  
Zhimin Zeng ◽  
Jing Cai ◽  
Peng Xu ◽  
Pingan Liang ◽  
...  

Abstract Background This retrospective study aimed to evaluate the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) with stereotactic body radiation therapy (SBRT) and to elucidate potential mechanisms of acquired resistance. Methods Patients with advanced NSCLC harboring positive EGFR mutations after initial TKI therapy for at least 8 weeks were eligible for SBRT between August 2016 and August 2019. Eligible patients were treated with thoracic SBRT, and TKI was continued after SBRT until it was considered ineffective. The control group was treated with TKIs monotherapy. Propensity score matching (PSM, ratio of 1:2) was used to account for differences in baseline characteristics. Overall survival (OS), progression-free survival (PFS), treatment safety and resistance mechanisms were evaluated. Results Three hundred eight patients were included in the study population. Among them, 262 patients received TKIs alone, and 46 patients received TKIs with SBRT. Baseline characteristics were not significantly different between the two cohorts after PSM. The median PFS was 19.4 months in the TKIs +SBRT group compared to 13.7 months in the TKIs group (p = 0.034). An influence on OS has not yet been shown (p = 0.557). Of the 135 patients evaluated after PSM, 28 and 71 patients in the TKIs and TKIs +SBRT cohorts, respectively, had plasma cell-free DNA (cfDNA) next-generation sequencing (NGS) performed at baseline and disease progression. In the TKIs +SBRT cohort, the NGS results showed that T790M mutations were detected in 64.3% (18/28) of patients. Patients in the TKIs cohort exhibited fewer T790M-positive mutations (40.8%, p = 0.035) compared to patients in the TKIs +SBRT cohort. Conclusion Real world data prove that TKIs plus thoracic SBRT significantly extend PFS with tolerable toxicity. The mutation ratio of T790M was increased in the TKIs +SBRT group compared to the TKIs only group. Further randomized studies are warranted.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 7177-7177
Author(s):  
L. V. Sequist ◽  
V. A. Joshi ◽  
P. A. Jänne ◽  
P. Fidias ◽  
A. Muzikansky ◽  
...  

7177 Background: Somatic mutations in EGFR are associated with response to therapy and prolonged overall survival (OS) of NSCLC pts treated with tyrosine kinase inhibitors (TKI). We began EGFR mutation screening in 2004 with a CLIA certified test. We determined the characteristics of pts tested, EGFR mutations identified, and analyzed response to therapy and OS. Methods: We performed a retrospective cohort study of all NSCLC pts referred for EGFR testing over 1 year. Samples underwent direct sequence analysis of EGFR exons 18–24. We used multivariable logistic regression models to examine associations between mutation and pt characteristics. We used chi-square tests to assess differences in response to therapy by EGFR status and analyzed OS with Cox proportional hazard models, adjusting for age, gender and stage. Results: We screened 269 NSCLC pts for EGFR mutations, including 188 (71%) with unresectable disease and 245 (91%) with adenocarcinoma. Mutations were identified in 62 (23%) pts. 15 samples (6%) yielded insufficient DNA for testing. Mutation was more likely in the 59 never-smokers compared to the 185 ever-smokers [odds ratio (OR) 4.8, 95% confidence interval (CI) 2.5–9.2]. Each added pack-year of smoking history lowered the odds of mutation by 5% (OR 0.95, 95% CI 0.94–0.97). Mutation was more likely in the 12 Asians than in the 212 of all other races (OR 3.7, 95% CI 1.1–12.0). In multivariable analyses, pack-years of smoking remained predictive of mutation (OR 0.96, 95% CI 0.94–0.99). Among 44 pts with unresectable disease undergoing subsequent TKI therapy, the 20 EGFR positive pts had an increased response rate (RR) compared to the 24 EGFR negative pts (60% v. 4%, p < 0.0001). In 27 pts given subsequent chemotherapy, RR was 33% and did not differ by EGFR status. Median follow-up was 9.8 months (mo) (range 0.2–135.8 mo). Among pts with unresectable disease, median OS is estimated to be 22.7 mo in EGFR negative pts and is not reached in EGFR positive pts (HR 0.22, 95% CI 0.80–0.63). Conclusions: Sequencing EGFR for somatic mutations is feasible in routine care of NSCLC pts. 23% of screened pts tested positive, and never smoking was the strongest predictor of mutation. Among patients with unresectable disease, EGFR mutation was associated with an increased RR to TKI therapy and OS. [Table: see text]


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e18021-e18021
Author(s):  
Nicola Normanno ◽  
Carmine Pinto ◽  
Gian Luigi Taddei ◽  
Giancarlo Troncone ◽  
Paolo Graziano ◽  
...  

e18021 Background: Gefitinib was approved in Italy for treatment of pts with advanced NSCLC carrying mutant EGFR in May 2010. Methods: The EGFR FASTnet program was designed to facilitate the exchange of biological material, clinico-pathological data and reports between medical oncologists, primary pathologists and referral laboratories. EGFR mutational analysis was carried by Sanger sequencing, Real Time PCR, Pyrosequencing, Fragment Analysis and High resolution melting. The Italian Association of Medical Oncology (AIOM) and the Italian Society of Surgical Pathology and Cytopathology (SIAPEC-IAP) have full access to the anonymous EGFR FASTnet database. Results: As of December 31, 2011, 503 oncologists, 135 pathologists and 38 referral laboratories joined the EGFR FASTnet program. The enrolled cohort of 3819 pts with advanced NSCLC was significantly enriched for adenocarcinoma histology (3172 [83%]), female sex (1361 [36%]) and smoking history (never smoker 911 [24%], former smoker>15 yrs 880 [23%], light smoker 194 [5%]). Mutational analysis was feasible in 3567 pts (93%). At registration, 72% of the pts had not received yet treatment for advanced disease. Mutational analysis was carried by Sanger sequencing in 2021 cases (57%), Real Time PCR in 174 (5%), Pyrosequencing in 636 (18%) and other techniques in 736 (21%). EGFR mutations were found in 520 cases (14.6%): 334 in exon 19 (9.4%), 163 in exon 21 (4.6%), 7 in exon 18 (0.2%) and 16 in exon 20 (0.4%). Proportion of mutated cases was slightly higher with Real time PCR compared to other techniques: Sanger 14.8%, Real time PCR 21.3%, Pyrosequencing 13.5%, other 13.3% (p = 0.049). A higher mutation rate was found in never smokers (32.0%), light smokers (18.7%) and former smokers >15 yrs (12.4%), as well as in adenocarcinoma (15.7%) and females (25.2%). Conclusions: The pts for EGFR mutational screening are spontaneously selected by medical oncologists according to known predictive factors. The results of the mutational analysis from clinical practice in Italy are consistent with data from literature.


Author(s):  
Tanushree Mukherjee

The type of lung cancer as per histology is small cell and non-small cell carcinoma which includes adenocarcinoma with variants, squamous carcinoma. Biomolecular testing[1-3] includes tests of genes or proteins required to analyze which can be targeted with therapy to treat the patients. Molecular diagnostics-guided targeted therapies have become a standard treatment for patients with lung cancer. Driver genetic alterations such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements are currently used as predictive biomarkers for EGFR tyrosine kinase inhibitors and ALK inhibitors, respectively.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e23033-e23033
Author(s):  
Veena M. Singh ◽  
Anthony J. Daher ◽  
Jeffery J. Chen ◽  
Lyle Arnold ◽  
Cecile Rose T. Vibat

e23033 Background: Targeted cancer therapy relies on identifying specific DNA mutations from a patient’s tumor. Tyrosine kinase inhibitors (TKIs) tend to be effective for non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) activating mutations, of which exon 19 deletions (Del19) and L858R are most common. Acquired resistance to TKI therapy is associated with a T790M mutation. Standard biomarker analyses may not reflect tumor heterogeneity; they entail tissue biopsies often with surgical complications. To address these limitations, Biocept developed a minimally invasive method to characterize cancer biomarkers in blood. Biocept's proprietary TargetSelector assays selectively amplify relevant mutations from circulating tumor DNA (ctDNA). Clinical validations demonstrated high concordances between molecular tests in blood vs tissue. As further validation, EGFR mutation detection frequencies were compared to US averages (mycancergenome.org). Here we analyze 2000 blood samples received at Biocept from 1Mar 2016 to 4Jan 2017 from late stage NSCLC patients. Methods: Blood was collected in Biocept OncoCEE BCT validated to preserve DNA ≤ 8 days. TargetSelector was used to detect ctDNA L858R, Del19 and T790M.EGFR allele copy numbers for wild type and each mutant were calculated. The prevalence of each mutation was compared to US averages. Results: Del19, L858R, and T790M mutations were detected in 12.9%, 8.5%, and 9.9% of the analyzed blood samples, respectively. This is concordant with US averages, which are 10% for each mutation. Median copy numbers/ml of blood were 30 for Del19 (range: 1 – 91974), 15 for L858R (range: 1 – 91200), and 10 for T790M (range: 1 – 137360). The median wild type EGFR copy number detected/ml blood was 2304 (range: 8 – 2498725). In ~80% of T790M cases, ≥ 1 concomitant activating mutation was detected. Conclusions: Biocept's TargetSelector detects EGFR mutations (Del19, L585R, and T790M) at a very high level of sensitivity down to 1 mutant copy/ml in advanced NSCLC patients at frequencies consistent with cited US rates. Moreover, the underlying activating mutation was detected in ~80% of T790M cases.


Author(s):  
Jing Sun

Traditional treatments for non-small cell lung adenocarcinomas do produce impressive improvements in patient health. Newly developed biologically based treatments exploit the drug-sensitivity conferred by mutations in the epidermal growth factor receptor (EGFR). In adenocarcinomas, cell proliferation and survival depend on mutant EGFR activity. For patients with certain EGFR mutations, treatment with tyrosine kinase inhibitors (TKIs) rather than chemotherapy improves patient survival. However, almost every patient acquires resistance to TKI treatment. About 50% of acquired resistance is because of a secondary mutation in EGFR. MET gene amplification, which allows cells to use MET to activate downstream signals, is another established mechanism. A third known mechanism is epithelial to mesenchymal transition (EMT). About 30% of all resistance mechanisms still remain unknown. This semester, the HCC2279 EGFR-mutant human adenocarcinoma line was characterized in hopes of discovering new models of resistance. Growth inhibition assays and immunoblotting were used to analyze the effects of treatments and to examine the status of signaling molecules. The HCC2279 resistant line appeared to have an EGFR-independent mechanism and did not seem to use MET as a major mechanism of resistance. The resistant cells continued to grow in the presence of TKI and TKI plus MET inhibitor, and immunoblotting showed that TKIs were capable of completely inhibiting the activation and phosphorylation of EGFR and MET. Signs of EMT were detected via immunoblotting due to a loss of E-cadherin and gain of vimentin, and EMT was corroborated by histological changes such as a loss in resistant cell polarity.


2020 ◽  
Author(s):  
Pedro E. N. S. Vasconcelos ◽  
Ikei S. Kobayashi ◽  
Susumu S. Kobayashi ◽  
Daniel B. Costa

AbstractBackgroundEpidermal growth factor receptor (EGFR) exon 20 insertion mutations account for 10% of all EGFR mutations and are mostly insensitive to approved EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Novel EGFR-TKIs have been developed or repurposed for these mutants. A limited number of preclinical studies have detailed these EGFR-TKIs. We sought to use commercially available mobocertinib (TAK-788) to characterize the preclinical therapeutic window of this EGFR-TKI against EGFR mutations and to probe possible on-target mechanisms of resistance (EGFR-C797S).MethodsWe used models of EGFR mutations to probe representative 1st, 2nd, 3rd generation, and in-development EGFR exon 20-active (poziotinib, mobocertinib) TKIs. We also introduced EGFR-C797S to these models to identify mechanisms of resistance.ResultsCells driven by the most common EGFR exon 20 insertion mutations (A767_V769dupASV, D770_N771insSVD, H773_V774insH and others) were inhibited by in-development EGFR TKIs at doses below those affecting EGFR-wildtype; albeit more common EGFR mutations (exon 19 deletions and L858R) were inhibited more readily by mobocertinib and poziotinib. Mobocertinib was able to inhibit phosphorylation of EGFR in multiple preclinical models. The presence of EGFR-C797S led to >200-fold resistance in proliferation assays probing mobocertinib and osimertinib. Review of clinical studies of mobocertinib disclosed responses that could be lasting.ConclusionsThis is one of the initial reports to characterize the novel EGFR TKI mobocertinib and highlights its broad activity against EGFR mutants plus the therapeutic window to EGFR exon 20 insertion mutations; as well as EGFR-C797S as a possible mechanism of resistance. Further clinical development of mobocertinib merits continuation.


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