Myung-Ju Ahn

Pembrolizumab for the Treatment of Non–Small-Cell Lung Cancer

BACKGROUND We assessed the efficacy and safety of programmed cell death 1 (PD-1) inhibition with pembrolizumab in patients with advanced non-small-cell lung cancer enrolled in a phase 1 study. We also sought to define and validate an expression level of the PD-1 ligand 1 (PD-L1) that is associated with the likelihood of clinical benefit. METHODS We assigned 495 patients receiving pembrolizumab (at a dose of either 2 mg or 10 mg per kilogram of body weight every 3 weeks or 10 mg per kilogram every 2 weeks) to either a training group (182 patients) or a validation group (313 patients). We assessed PD-L1 expression in tumor samples using immunohistochemical analysis, with results reported as the percentage of neoplastic cells with staining for membranous PD-L1 (proportion score). Response was assessed every 9 weeks by central review. RESULTS Common side effects that were attributed to pembrolizumab were fatigue, pruritus, and decreased appetite, with no clear difference according to dose or schedule. Among all the patients, the objective response rate was 19.4%, and the median duration of response was 12.5 months. The median duration of progression-free survival was 3.7 months, and the median duration of overall survival was 12.0 months. PD-L1 expression in at least 50% of tumor cells was selected as the cutoff from the training group. Among patients with a proportion score of at least 50% in the validation group, the response rate was 45.2%. Among all the patients with a proportion score of at least 50%, median progression-free survival was 6.3 months; median overall survival was not reached. CONCLUSIONS Pembrolizumab had an acceptable side-effect profile and showed antitumor activity in patients with advanced non-small-cell lung cancer. PD-L1 expression in at least 50% of tumor cells correlated with improved efficacy of pembrolizumab. (Funded by Merck; KEYNOTE-001 ClinicalTrials.gov number, NCT01295827.).

Clinical Experience With Crizotinib in Patients With Advanced ALK-Rearranged Non–Small-Cell Lung Cancer and Brain Metastases

PURPOSE Crizotinib is an oral kinase inhibitor approved for the treatment of ALK-rearranged non-small-cell lung cancer (NSCLC). The clinical benefits of crizotinib in patients with brain metastases have not been previously studied. PATIENTS AND METHODS Patients with advanced ALK-rearranged NSCLC enrolled onto clinical trial PROFILE 1005 or 1007 (randomly assigned to crizotinib) were included in this retrospective analysis. Patients with asymptomatic brain metastases (nontarget or target lesions) were allowed to enroll. Tumor assessments were evaluated every 6 weeks using RECIST (version 1.1). RESULTS At baseline, 31% of patients (275 of 888) had asymptomatic brain metastases; 109 had received no prior and 166 had received prior brain radiotherapy as treatment. Among patients with previously untreated asymptomatic brain metastases, the systemic disease control rate (DCR) at 12 weeks was 63% (95% CI, 54% to 72%), the intracranial DCR was 56% (95% CI, 46% to 66%), and the median intracranial time to progression (TTP) was 7 months (95% CI, 6.7 to 16.4). Among patients with previously treated brain metastases, the systemic DCR was 65% (95% CI, 57% to 72%), the intracranial DCR was 62% (95% CI, 54% to 70%), and the median intracranial TTP was 13.2 months (95% CI, 9.9 to not reached). Patients with systemic disease control were also likely to experience intracranial disease control at 12 weeks (correlation coefficient, 0.7652; P < .001). Among patients without baseline brain metastases who developed progressive disease (n = 253) after initiation of crizotinib, 20% were diagnosed with brain metastases. CONCLUSION Crizotinib was associated with systemic and intracranial disease control in patients with ALK-rearranged NSCLC who were ALK inhibitor naive and had brain metastases. However, progression of preexisting or development of new intracranial lesions while receiving therapy was a common manifestation of acquired resistance to crizotinib.

Metabolic Tumor Volume of [18F]-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Predicts Short-Term Outcome to Radiotherapy With or Without Chemotherapy in Pharyngeal Cancer

Purpose: This study aimed to investigate whether metabolic tumor volume (MTV) measured from [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) predicts short-term outcome to radiotherapy with or without chemotherapy and disease-free survival (DFS) in patients with pharyngeal cancers. Experimental Design: The MTVs of primary sites with or without neck nodes were measured in 82 patients. Short-term outcome was assessed using the treatment response evaluation by the Response Evaluation Criteria in Solid Tumors and recurrence events during follow-up (complete response/no recurrence or residual disease/recurrence). Results: A total of 64 patients had complete response/no recurrence as of the last follow-up. A cutoff of 40 mL for the MTV was the best discriminative value for predicting treatment response. By univariate analyses, patients with MTV >40 mL showed a significantly lower number of complete response/no recurrence than did patients with MTV ≤40 mL [68.2% versus 87.8%; hazard ratio (HR), 3.34; 95% confidence interval (95% CI), 1.09-10.08; P = 0.03], as is the same in tumor-node-metastasis stage (87.5% for I-II versus 90% for III versus 63.8% for IV; P = 0.02). However, MTV was only a significant predictor of short-term outcome by multivariate analyses (HR, 4.09; 95% CI, 1.02-16.43; P = 0.04). MTV >40 mL indicated a significantly worse DFS than MTV ≤40 mL (HR, 3.42; 95% CI, 1.04-11.26;P = 0.04). The standardized uptake value for the primary tumor did not show any correlation with treatment outcome or DFS. Conclusion: MTV has a potential value in predicting short-term outcome and DFS in patients with pharyngeal cancers. (Clin Cancer Res 2009;15(18):5861–8)

The EGFR T790M Mutation in Acquired Resistance to an Irreversible Second-Generation EGFR Inhibitor

Molecular target therapies using first-generation, reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), such as gefitinib or erlotinib, have been shown to be effective for patients with non-small cell lung cancer (NSCLC) who harbor activating mutations in EGFR. However, these patients eventually develop resistance to the reversible TKIs, and this has led to the development of second-generation, irreversible EGFR inhibitors. Currently, the mechanism of acquired resistance to irreversible EGFR inhibitors is not clear. Using an in vitro cell culture system, we modeled the acquired resistance to first-line treatment with second-generation EGFR-TKIs using an EGFR-mutant NSCLC cell line. Here, we report a mechanism of resistance involving T790M secondary mutation as well as a corresponding clinical case. The results of these findings suggest that inhibition of EGFR by currently available second-generation EGFR-TKIs may not be sufficient to physiologically prevent the emergence of cells that are still dependent on EGFR signaling. This finding bears important implications on the limitations of currently available second-generation EGFR-TKIs. Mol Cancer Ther; 11(3); 784–91. ©2012 AACR.

Brigatinib in Patients With Crizotinib-Refractory Anaplastic Lymphoma Kinase–Positive Non–Small-Cell Lung Cancer: A Randomized, Multicenter Phase II Trial

Purpose Most crizotinib-treated patients with anaplastic lymphoma kinase gene ( ALK)-rearranged non-small-cell lung cancer (ALK-positive NSCLC) eventually experience disease progression. We evaluated two regimens of brigatinib, an investigational next-generation ALK inhibitor, in crizotinib-refractory ALK-positive NSCLC. Patients and Methods Patients were stratified by brain metastases and best response to crizotinib. They were randomly assigned (1:1) to oral brigatinib 90 mg once daily (arm A) or 180 mg once daily with a 7-day lead-in at 90 mg (180 mg once daily [with lead-in]; arm B). Investigator-assessed confirmed objective response rate (ORR) was the primary end point. Results Of 222 patients enrolled (arm A: n = 112, 109 treated; arm B: n = 110, 110 treated), 154 (69%) had baseline brain metastases and 164 of 222 (74%) had received prior chemotherapy. With 8.0-month median follow-up, investigator-assessed confirmed ORR was 45% (97.5% CI, 34% to 56%) in arm A and 54% (97.5% CI, 43% to 65%) in arm B. Investigator-assessed median progression-free survival was 9.2 months (95% CI, 7.4 to 15.6) and 12.9 months (95% CI, 11.1 to not reached) in arms A and B, respectively. Independent review committee-assessed intracranial ORR in patients with measurable brain metastases at baseline was 42% (11 of 26 patients) in arm A and 67% (12 of 18 patients) in arm B. Common treatment-emergent adverse events were nausea (arm A/B, 33%/40%), diarrhea (arm A/B, 19%/38%), headache (arm A/B, 28%/27%), and cough (arm A/B, 18%/34%), and were mainly grades 1 to 2. A subset of pulmonary adverse events with early onset (median onset: day 2) occurred in 14 of 219 treated patients (all grades, 6%; grade ≥ 3, 3%); none occurred after escalation to 180 mg in arm B. Seven of 14 patients were successfully retreated with brigatinib. Conclusion Brigatinib yielded substantial whole-body and intracranial responses as well as robust progression-free survival; 180 mg (with lead-in) showed consistently better efficacy than 90 mg, with acceptable safety.

Differential gene expression in retinoic acid-induced differentiation of acute promyelocytic leukemia cells, NB4 and HL-60 cells

Acute promyelocytic leukemia (APL) is characterized by a specific chromosome translocation t(15;17), which results in the fusion of the promyelocytic leukemia gene (PML) and retinoic acid receptor alpha gene (RARalpha). APL can be effectively treated with the cell differentiation inducer all-trans retinoic acid (ATRA). NB4 cells, an acute promyelocytic leukemia cell line, have the t(15;17) translocation and differentiate in response to ATRA, whereas HL-60 cells lack this chromosomal translocation, even after differentiation by ATRA. To identify changes in the gene expression patterns of promyelocytic leukemia cells during differentiation, we compared the gene expression profiles in NB4 and HL-60 cells with and without ATRA treatment using a cDNA microarray containing 10,000 human genes. NB4 and HL-60 cells were treated with ATRA (10(-6)M) and total RNA was extracted at various time points (3, 8, 12, 24, and 48h). Cell differentiation was evaluated for cell morphology changes and CD11b expression. PML/RARalpha degradation was studied by indirect immunofluoresence with polyclonal PML antibodies. Typical morphologic and immunophenotypic changes after ATRA treatment were observed both in NB4 and HL-60 cells. The cDNA microarray identified 119 genes that were up-regulated and 17 genes that were down-regulated in NB4 cells, while 35 genes were up-regulated and 36 genes were down-regulated in HL60 cells. Interestingly, we did not find any common gene expression profiles regulated by ATRA in NB4 and HL-60 cells, even though the granulocytic differentiation induced by ATRA was observed in both cell lines. These findings suggest that the molecular mechanisms and genes involved in ATRA-induced differentiation of APL cells may be different and cell type specific. Further studies will be needed to define the important molecular pathways involved in granulocytic differentiation by ATRA in APL cells.

Randomized phase II study of gefitinib versus erlotinib in patients with advanced non-small cell lung cancer who failed previous chemotherapy ☆

PURPOSE Gefitinib and erlotinib are potent EGFR TKIs, with antitumor activity. In this randomized, single-center, non-comparative phase II trial, the efficacy and safety of gefitinib and erlotinib was evaluated as the second-line therapy for advanced non-small cell lung cancer (NSCLC). PATIENTS AND METHODS Patients with locally advanced, metastatic stage IIIB/IV NSCLC who failed first-line chemotherapy and had either EGFR mutation or at least two out of three clinical factors associated with higher incidence of EGFR mutations (female, adenocarcinoma histology, and never-smoker) were eligible. RESULTS A total of 96 (48 per arm) patients were randomly assigned to gefitinib- or erlotinib-arm, respectively. Baseline characteristics were well-balanced between the two arms. The response rates (RR) were 47.9% in the gefitinib arm and 39.6% in the erlotinib arm. Median PFS was 4.9 months (95% CI, 1.3-8.5) in the gefitinib arm and 3.1 months (95% CI, 0.0-6.4) in the erlotinib arm. The most common grade 3/4 toxicity was skin rash. Exploratory analyses showed that there was no significant difference in RR and PFS in the gefitinib arm compared to the erlotinib arm (RR (%) 47.9 vs. 39.6, p=0.269; median survival (months) 4.9 vs. 3.1, p=0.336). There was no significant difference in QOL between the two arms. CONCLUSION Both gefitinib and erlotinib showed effective activity and tolerable toxicity profiles as second-line treatment for the selected population of NSCLC. We may consider conducting a phase III trial to directly compare the efficacy and toxicity between gefitinib and erlotinib in an enriched patient population.

Significance of thymidylate synthase and thyroid transcription factor 1 expression in patients with nonsquamous non-small cell lung cancer treated with pemetrexed-based chemotherapy.

Introduction: This study is to evaluate whether thymidylate synthase (TS) or thyroid transcription factor 1 (TTF1) protein expression can predict clinical outcomes for pemetrexed-based chemotherapy in patients with nonsquamous non-small cell lung cancer (NSCLC). Methods: Two hundred eighty-five consecutive patients with nonsquamous NSCLC treated with pemetrexed-based chemotherapy were immunohistochemically analyzed for the expressions of TS and TTF1. Results: TS and TTF1 expression were successfully analyzed in 193 and 284 cases, respectively. Tumors with TS-negativity or TTF1-positivity were more frequent in patients who were female, younger, had adenocarcinoma, or had never smoked. Higher response rates for pemetrexed-based chemotherapy were associated with TS-negativity (33.7% versus 14.1%, p = 0.002) and TTF1-positivity (28.1% versus 9.8%, p < 0.001). In univariate analysis, progression-free survival for pemetrexed-based chemotherapy was significantly longer in groups with adenocarcinoma (2.9 versus 1.4 months, p = 0.001), TS-negativity (4.1 versus 2.0 months, p = 0.001), and TTF1-positivity (3.8 versus 1.3 months, p < 0.001). In multivariate analysis, TS-negativity (hazard ratio [HR] = 0.70; 95% confidence interval [CI], 0.51–0.97) and TTF1-positivity (HR = 0.51; 95% CI, 0.35–0.73) were associated with longer progression-free survival. Patients with TTF1-positive tumors also had significantly longer overall survival times than patients with TTF1-negative tumors (25.4 versus 14.2 months, HR = 0.55; 95% CI, 0.39–0.77). Conclusions: Low TS or high TTF1 protein expression was significantly associated with better clinical outcomes in nonsquamous NSCLC patients who were treated with pemetrexed-based chemotherapy. The predictive role of TS or TTF1 expression should be further validated in a prospective randomized study.

A Dramatic Response to Crizotinib in a Non–Small-Cell Lung Cancer Patient with IHC-Positive and FISH-Negative ALK

Journal of Thoracic Oncology • Volume 7, Number 12, December 2012 A 54-year-old woman presented with locally advanced pulmonary adenocarcinoma in December 2011. During the workup, lung mass increased rapidly and a large amount of pleural effusion was newly developed. The analysis of pleural effusion indicated malignant hemothorax, and more than 1 liter of bloody pleural effusion was drained daily through a chest tube. In the biomarker analysis, immunohistochemistry (IHC) with an antibody (clone 5A4, Novocastra, Newcastle, United Kingdom) for anaplastic lymphoma kinase (ALK) protein showed moderately positive staining (Fig. 1A). However, fluorescent in situ hybridization (FISH) using a probe specific to the ALK locus (Vysis LSI ALK dual-color, break-apart rearrangement probe; Abbott Molecular, Abbott Park, IL) did not show ALK translocation (Fig. 1B). There was neither ROS1 rearrangement nor MET amplification. We started chemotherapy with gemcitabine plus cisplatin. The follow-up chest radiograph and computed tomography, performed on the 17th day after starting chemotherapy, showed an unresolved primary lung mass and a mediastinal lymph node compressing the right main bronchus (Fig. 2A). We prescribed crizotinib (250 mg twice a day), starting February 16, 2012. The pleural effusion decreased rapidly, and the chest tube was removed 6 days after the initiation of crizotinib therapy. At day 32, chest images showed a great decrease in the cancerous lesions (Fig. 2B). The patient did not experience any noticeable hematologic or nonhematologic adverse events. At day 83, the lesions decreased further; this partial response was confirmed with chest images (Fig. 2C). At 27 weeks, the patient is still on crizotinib and is in good general condition.

Volume-based assessment by (18)F-FDG PET/CT predicts survival in patients with stage III non-small-cell lung cancer.

PurposeWe evaluated the prognostic impact of volume-based assessment by 18F-FDG PET/CT in patients with stage III non-small-cell lung cancer (NSCLC).MethodsWe reviewed 194 consecutive patients with stage IIIA NSCLC treated with surgical resection (surgical group) and 115 patients treated with nonsurgical therapy (nonsurgical group: 50 stage IIIA, 65 stage IIIB). Metabolic tumour volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) of primary tumours were measured using pretreatment 18F-FDG PET/CT. Overall survival was assessed using the Kaplan-Meier method. The prognostic significance of PET parameters and other clinical variables was assessed using Cox proportional hazards regression analyses. To evaluate and compare the predictive performance of PET parameters, time-dependent receiver operating characteristic (ROC) curve analysis was used.ResultsIn the Cox proportional hazards models, MTV (HR = 1.27 for a doubling of MTV, P = 0.008) and TLG (HR = 1.22 for a doubling of TLG, P = 0.035) were significantly associated with an increased risk of death after adjusting for age, gender, histological cell type, T stage, N stage, and treatment variables in the surgical group. SUVmax was not a significant prognostic factor in either the surgical or nonsurgical group. In the time-dependent ROC curve analysis, volume-based PET parameters predicted survival better than SUVmax.ConclusionThe volume-based PET parameters (MTV and TLG) are significant prognostic factors for survival independent of tumour stage and better prognostic imaging biomarkers than SUVmax in patients with stage IIIA NSCLC after surgical resection.