Byoung Chul Cho

Acquired EGFR C797S mutation mediates resistance to AZD9291 in non–small cell lung cancer harboring EGFR T790M

Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired EGFR C797S mutation in one; expression of this mutant EGFR construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA specimens collected from 15 AZD9291-treated subjects. All were positive for the T790M mutation before treatment, but upon developing AZD9291 resistance three molecular subtypes emerged: six cases acquired the C797S mutation, five cases maintained the T790M mutation but did not acquire the C797S mutation and four cases lost the T790M mutation despite the presence of the underlying EGFR activating mutation. Our findings provide insight into the diversity of mechanisms through which tumors acquire resistance to AZD9291 and highlight the need for therapies that are able to overcome resistance mediated by the EGFR C797S mutation.

Durvalumab after Chemoradiotherapy in Stage III Non–Small-Cell Lung Cancer

Background Most patients with locally advanced, unresectable, non–small‐cell lung cancer (NSCLC) have disease progression despite definitive chemoradiotherapy (chemotherapy plus concurrent radiation therapy). This phase 3 study compared the anti–programmed death ligand 1 antibody durvalumab as consolidation therapy with placebo in patients with stage III NSCLC who did not have disease progression after two or more cycles of platinum‐based chemoradiotherapy. Methods We randomly assigned patients, in a 2:1 ratio, to receive durvalumab (at a dose of 10 mg per kilogram of body weight intravenously) or placebo every 2 weeks for up to 12 months. The study drug was administered 1 to 42 days after the patients had received chemoradiotherapy. The coprimary end points were progression‐free survival (as assessed by means of blinded independent central review) and overall survival (unplanned for the interim analysis). Secondary end points included 12‐month and 18‐month progression‐free survival rates, the objective response rate, the duration of response, the time to death or distant metastasis, and safety. Results Of 713 patients who underwent randomization, 709 received consolidation therapy (473 received durvalumab and 236 received placebo). The median progression‐free survival from randomization was 16.8 months (95% confidence interval [CI], 13.0 to 18.1) with durvalumab versus 5.6 months (95% CI, 4.6 to 7.8) with placebo (stratified hazard ratio for disease progression or death, 0.52; 95% CI, 0.42 to 0.65; P<0.001); the 12‐month progression‐free survival rate was 55.9% versus 35.3%, and the 18‐month progression‐free survival rate was 44.2% versus 27.0%. The response rate was higher with durvalumab than with placebo (28.4% vs. 16.0%; P<0.001), and the median duration of response was longer (72.8% vs. 46.8% of the patients had an ongoing response at 18 months). The median time to death or distant metastasis was longer with durvalumab than with placebo (23.2 months vs. 14.6 months; P<0.001). Grade 3 or 4 adverse events occurred in 29.9% of the patients who received durvalumab and 26.1% of those who received placebo; the most common adverse event of grade 3 or 4 was pneumonia (4.4% and 3.8%, respectively). A total of 15.4% of patients in the durvalumab group and 9.8% of those in the placebo group discontinued the study drug because of adverse events. Conclusions Progression‐free survival was significantly longer with durvalumab than with placebo. The secondary end points also favored durvalumab, and safety was similar between the groups. (Funded by AstraZeneca; PACIFIC ClinicalTrials.gov number, NCT02125461.)

Phase II Study of Erlotinib in Advanced Non–Small-Cell Lung Cancer After Failure of Gefitinib

PURPOSE This study was designed to evaluate the efficacy and toxicity of erlotinib in patients with advanced non-small-cell lung cancer (NSCLC) who experienced disease progression after treatment with gefitinib. PATIENTS AND METHODS The study included stage IIIB/IV recurrent or metastatic NSCLC patients who received two or three prior chemotherapy regimens and showed progressive disease within 4 months of gefitinib therapy discontinuation. Patients received erlotinib 150 mg/d until disease progression or unacceptable toxicity. Epidermal growth factor receptor (EGFR) mutations and other genetic abnormalities were analyzed from available tumor samples. RESULTS Patient and disease characteristics (N = 21) included median age 56 years; number of prior chemotherapy regimens (three; n = 11); female sex (n = 11); adenocarcinoma (n = 15); and never-smoker status (n = 11). Among the 17 patients with tumor samples available, EGFR mutations were detected in five. The disease control rate (DCR) and response rate (RR) for all patients were 28.6% and 9.5%, respectively. The median duration of disease control was 125 days. The median time to progression and overall survival were 60 days and 158 days, respectively. Patients who had stable disease (SD) while receiving gefitinib showed significantly higher DCR (75% v 17.6% in non-SD patients; P = .050) and RR (50.0% v 0% in non-SD patients; P = .029). Among 17 patients with biomarker results available, those lacking EGFR mutations who had SD while receiving gefitinib showed significantly higher DCR and RR. CONCLUSION Erlotinib seems to be a potential therapeutic option for the treatment of advanced NSCLC patients with wild-type EGFR who had SD while receiving gefitinib.

Effects of Erlotinib in EGFR Mutated Non-Small Cell Lung Cancers with Resistance to Gefitinib

Purpose: Most lung cancers with activating epidermal growth factor receptor (EGFR) mutations respond to gefitinib; however, resistance to this tyrosine kinase inhibitor (TKI) invariably ensues. The T790M mutation occurs in 50% and MET amplification in 20% of TKI-resistant tumors. Other secondary mutations (D761Y and L747S) are rare. Our goal was to determine the effects of erlotinib 150 mg/d in EGFR mutated patients resistant to gefitinib 250 mg/d, because the EGFR TKI erlotinib is given at a higher biologically active dose than gefitinib. Experimental Design: Retrospective review of 18 EGFR mutated (exon 19 deletions, L858R, and L861Q) patients that were given gefitinib and subsequently erlotinib. Seven patients had tumor resampling after TKI therapy and were analyzed for secondary EGFR mutations and MET amplification. Results: Most patients (14 of 18) responded to gefitinib with median progression-free survival of 11 months (95% confidence interval, 4-16). After gefitinib resistance (de novo or acquired), 78% (14 of 18) of these patients displayed progressive disease while on erlotinib with progression-free survival of 2 months (95% confidence interval, 2-3). Six of 7 resampled patients acquired the T790M mutation, and 0 of 3 had MET amplification. Only 1 gefitinib-resistant patient with the acquired L858R-L747S EGFR, which in vitro is sensitive to achievable serum concentrations of erlotinib 150 mg/d, achieved a partial response to erlotinib. Conclusions: In EGFR mutated tumors resistant to gefitinib 250 mg/d, a switch to erlotinib 150 mg/d does not lead to responses in most patients. These findings are consistent with preclinical models, because the common mechanisms of TKI resistance (T790M and MET amplification) in vitro are not inhibited by clinically achievable doses of gefitinib or erlotinib. Alternative strategies to overcome TKI resistance must be evaluated.

Osimertinib in Untreated EGFR-Mutated Advanced Non–Small-Cell Lung Cancer

Background Osimertinib is an oral, third‐generation, irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR‐TKI) that selectively inhibits both EGFR‐TKI–sensitizing and EGFR T790M resistance mutations. We compared osimertinib with standard EGFR‐TKIs in patients with previously untreated, EGFR mutation–positive advanced non–small‐cell lung cancer (NSCLC). Methods In this double‐blind, phase 3 trial, we randomly assigned 556 patients with previously untreated, EGFR mutation–positive (exon 19 deletion or L858R) advanced NSCLC in a 1:1 ratio to receive either osimertinib (at a dose of 80 mg once daily) or a standard EGFR‐TKI (gefitinib at a dose of 250 mg once daily or erlotinib at a dose of 150 mg once daily). The primary end point was investigator‐assessed progression‐free survival. Results The median progression‐free survival was significantly longer with osimertinib than with standard EGFR‐TKIs (18.9 months vs. 10.2 months; hazard ratio for disease progression or death, 0.46; 95% confidence interval [CI], 0.37 to 0.57; P<0.001). The objective response rate was similar in the two groups: 80% with osimertinib and 76% with standard EGFR‐TKIs (odds ratio, 1.27; 95% CI, 0.85 to 1.90; P=0.24). The median duration of response was 17.2 months (95% CI, 13.8 to 22.0) with osimertinib versus 8.5 months (95% CI, 7.3 to 9.8) with standard EGFR‐TKIs. Data on overall survival were immature at the interim analysis (25% maturity). The survival rate at 18 months was 83% (95% CI, 78 to 87) with osimertinib and 71% (95% CI, 65 to 76) with standard EGFR‐TKIs (hazard ratio for death, 0.63; 95% CI, 0.45 to 0.88; P=0.007 [nonsignificant in the interim analysis]). Adverse events of grade 3 or higher were less frequent with osimertinib than with standard EGFR‐TKIs (34% vs. 45%). Conclusions Osimertinib showed efficacy superior to that of standard EGFR‐TKIs in the first‐line treatment of EGFR mutation–positive advanced NSCLC, with a similar safety profile and lower rates of serious adverse events. (Funded by AstraZeneca; FLAURA ClinicalTrials.gov number, NCT02296125.)

Fibroblast Growth Factor Receptor 1 Gene Amplification Is Associated With Poor Survival and Cigarette Smoking Dosage in Patients With Resected Squamous Cell Lung Cancer

PURPOSE To investigate the frequency and the prognostic role of fibroblast growth factor receptor 1 (FGFR1) amplification in patients with surgically resected squamous cell carcinoma of the lung (SCCL) and the association between smoking and FGFR1 amplification. PATIENTS AND METHODS Gene copy number of FGFR1 was investigated in microarrayed tumors from 262 patients with SCCL who had tumor tissue as well as smoking and survival data available. Gene copy number was evaluated by fluorescent in situ hybridization, and an FGFR1-amplified tumor (FGFR1 amp(+)) was prespecified as a tumor with nine or more copies of FGFR1. RESULTS Among 262 patients, the frequency of FGFR1 amp(+) was 13.0%. Patients with FGFR1 amp(+) had significantly shorter disease-free survival (DFS; 26.9 v 94.6 months; P < .001) as well as shorter overall survival (OS; 51.2 v 115.0 months; P = .002) than those without FGFR1 amp(+). Multivariate modeling confirmed that patients with FGFR1 amp(+) had a significantly greater risk of recurrence and death than those without FGFR1 amp(+) after adjusting for sex, smoking status, pathologic stage, and adjuvant chemotherapy (DFS: adjusted hazard ratio [AHR], 2.24; 95% CI, 1.45 to 3.45; P < .001; OS: AHR, 1.83; 95% CI, 1.15 to 2.89; P = .01). The frequency of FGFR1 amp(+) was significantly higher in current smokers than in former smokers and never-smokers (28.9% v 2.5% v 0%; P(trend) < .001). As the smoking dosage increased, so did the incidence of FGFR1 amp(+) (P(trend) = .002). CONCLUSION FGFR1 amplification is an independent negative prognostic factor in surgically resected SCCL and is associated with cigarette smoking in a dose-dependent manner. FGFR1 amplification is a relevant therapeutic target in Asian patients with SCCL.

Enhanced Antitumor Effect of Oncolytic Adenovirus Expressing Interleukin-12 and B7-1 in an Immunocompetent Murine Model

Purpose: We investigated whether an armed viral platform, where lytic property of a viral infection is coupled to viral-mediated delivery of therapeutic genes, could increase the therapeutic potential of a viral-based therapy. Experimental Design: We generated interleukin (IL)-12-expressing oncolytic adenovirus (YKL-IL-12) and IL-12- and B7-1-expressing (YKL-IL12/B7) oncolytic adenovirus. Therapeutic efficacy of these newly engineered adenoviruses was then evaluated in vivo using an immunocompetent mouse bearing murine melanoma B16-F10 tumors. Overall survival was assessed with the Kaplan-Meier method. The induction of immune cell cytotoxicity was assessed by CTL assay, IFN-γ enzyme-linked immunospot assay, and immunohistochemical studies. Results: YKL-IL12/B7 oncolytic adenovirus, expressing both IL-12 and B7-1, showed a higher incidence of complete tumor regression compared with the analogous oncolytic adenovirus, YKL-1, or IL-12-expressing, YKL-IL12. Significant survival advantage was also seen in response to YKL-IL12/B7. Moreover, IL-12 and IFN-γ levels produced in tumors treated with YKL-IL12/B7 was significantly greater than those treated with YKL-IL12. The enhanced survival advantage was mediated by the induction of immune cell cytotoxicity. In agreement with these results, massive infiltration of CD4+ and CD8+ T cells into tissues surrounding the necrotic area of the tumor was observed following in situ delivery of YKL-IL12/B7. Conclusion: Combination of oncolysis and the enhancement of antitumor immune response by oncolytic adenovirus expressing both IL-12 and B7-1 elicits potent antitumor effect and survival advantage.

Activation of IL-6R/JAK1/STAT3 Signaling Induces De Novo Resistance to Irreversible EGFR Inhibitors in Non–Small Cell Lung Cancer with T790M Resistance Mutation

The secondary T790M mutation in epidermal growth factor receptor (EGFR) is the major mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (TKI) in non–small cell lung cancer (NSCLC). Although irreversible EGFR TKIs, such as afatinib or dacomitinib, have been introduced to overcome the acquired resistance, they showed a limited efficacy in NSCLC with T790M. Herein, we identified the novel de novo resistance mechanism to irreversible EGFR TKIs in H1975 and PC9-GR cells, which are NSCLC cells with EGFR T790M. Afatinib activated interleukin-6 receptor (IL-6R)/JAK1/STAT3 signaling via autocrine IL-6 secretion in both cells. Inhibition of IL-6R/JAK1/STAT3 signaling pathway increased the sensitivity to afatinib. Cancer cells showed stronger STAT3 activation and enhanced resistance to afatinib in the presence of MRC5 lung fibroblasts. Blockade of IL-6R/JAK1 significantly increased the sensitivity to afatinib through inhibition of afatinib-induced STAT3 activation augmented by the interaction with fibroblasts, suggesting a critical role of paracrine IL-6R/JAK1/STAT3 loop between fibroblasts and cancer cells in the development of drug resistance. The enhancement of afatinib sensitivity by inhibition of IL-6R/JAK1/STAT3 signaling was confirmed in in vivo PC9-GR xenograft model. Similar to afatinib, de novo resistance to dacomitinib in H1975 and PC9-GR cells was also mediated by dacomitinib-induced JAK1/STAT3 activation. Taken together, these findings suggest that IL-6R/JAK1/STAT3 signaling can be a potential therapeutic target to enhance the efficacy of irreversible EGFR TKIs in patients with EGFR T790M. Mol Cancer Ther; 11(10); 2254–64. ©2012 AACR.

Efficacy of the MAGE-A3 cancer immunotherapeutic as adjuvant therapy in patients with resected MAGE-A3-positive non-small-cell lung cancer (MAGRIT): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND Fewer than half of the patients with completely resected non-small-cell lung cancer (NSCLC) are cured. Since the introduction of adjuvant chemotherapy in 2004, no substantial progress has been made in adjuvant treatment. We aimed to assess the efficacy of the MAGE-A3 cancer immunotherapeutic in surgically resected NSCLC. METHODS In this randomised, double-blind, placebo-controlled trial, we recruited patients aged at least 18 years with completely resected stage IB, II, and IIIA MAGE-A3-positive NSCLC who did or did not receive adjuvant chemotherapy from 443 centres in 34 countries (Europe, the Americas, and Asia Pacific). Patients were randomly assigned (2:1) to receive 13 intramuscular injections of recMAGE-A3 with AS15 immunostimulant (MAGE-A3 immunotherapeutic) or placebo during 27 months. Randomisation and treatment allocation at the investigator site was done centrally via internet with stratification for chemotherapy versus no chemotherapy. Participants, investigators, and those assessing outcomes were masked to group assignment. A minimisation algorithm accounted for the number of chemotherapy cycles received, disease stage, lymph node sampling procedure, performance status score, and lifetime smoking status. The primary endpoint was broken up into three co-primary objectives: disease-free survival in the overall population, the no-chemotherapy population, and patients with a potentially predictive gene signature. The final analyses included the total treated population (all patients who had received at least one treatment dose). This trial is registered with ClinicalTrials.gov, number NCT00480025. FINDINGS Between Oct 18, 2007, and July 17, 2012, we screened 13 849 patients for MAGE-A3 expression; 12 820 had a valid sample and of these, 4210 (33%) had a MAGE-A3-positive tumour. 2312 of these patients met all eligibility criteria and were randomly assigned to treatment: 1515 received MAGE-A3 and 757 received placebo and 40 were randomly assigned but never started treatment. 784 patients in the MAGE-A3 group also received chemotherapy, as did 392 in the placebo group. Median follow-up was 38·1 months (IQR 27·9-48·4) in the MAGE-A3 group and 39·5 months (27·9-50·4) in the placebo group. In the overall population, median disease-free survival was 60·5 months (95% CI 57·2-not reached) for the MAGE-A3 immunotherapeutic group and 57·9 months (55·7-not reached) for the placebo group (hazard ratio [HR] 1·02, 95% CI 0·89-1·18; p=0·74). Of the patients who did not receive chemotherapy, median disease-free survival was 58·0 months (95% CI 56·6-not reached) in those in the MAGE-A3 group and 56·9 months (44·4-not reached) in the placebo group (HR 0·97, 95% CI 0·80-1·18; p=0·76). Because of the absence of treatment effect, we could not identify a gene signature predictive of clinical benefit to MAGE-A3 immunotherapeutic. The frequency of grade 3 or worse adverse events was similar between treatment groups (246 [16%] of 1515 patients in the MAGE-A3 group and 122 [16%] of 757 in the placebo group). The most frequently reported grade 3 or higher adverse events were infections and infestations (37 [2%] in the MAGE-A3 group and 19 [3%] in the placebo group), vascular disorders (30 [2%] vs 17 [3%]), and neoplasm (benign, malignant, and unspecified (29 [2%] vs 16 [2%]). INTERPRETATION Adjuvant treatment with the MAGE-A3 immunotherapeutic did not increase disease-free survival compared with placebo in patients with MAGE-A3-positive surgically resected NSCLC. Based on our results, further development of the MAGE-A3 immunotherapeutic for use in NSCLC has been stopped. FUNDING GlaxoSmithKline Biologicals SA.

Nivolumab in NSCLC: Latest evidence and clinical potential

New insight on the interaction between the immune system and tumor has identified the programmed death-1/programmed death-1 ligand pathway to be a key player in evading host immune response. The immune checkpoint modulator, nivolumab (BMS-936558/ONO-4538), is the first PD-1 inhibitor to gain regulatory approval, for the treatment of patients with unresectable melanoma. This review will discuss results from early phase studies of nivolumab in solid tumors including non-small cell lung cancer (NSCLC) as well as studies of nivolumab in combination with chemotherapy, other immune modulators and molecular targeted therapy in patients with NSCLC.