The CLIP1-LTK fusion is an oncogenic driver in non-small-cell lung cancer.

Lung cancer is one of the most aggressive tumour types. Targeted therapies stratified by oncogenic drivers have substantially improved therapeutic outcomes in patients with non-small-cell lung cancer (NSCLC)1. However, such oncogenic drivers are not found in 25-40% of cases of lung adenocarcinoma, the most common histological subtype of NSCLC2. Here we identify a novel fusion transcript of CLIP1 and LTK using whole-transcriptome sequencing in a multi-institutional genome screening platform (LC-SCRUM-Asia, UMIN000036871). The CLIP1-LTK fusion was present in 0.4% of NSCLCs and was mutually exclusive with other known oncogenic drivers. We show that kinase activity of the CLIP1-LTK fusion protein is constitutively activated and has transformation potential. Treatment of Ba/F3 cells expressing CLIP1-LTK with lorlatinib, an ALK inhibitor, inhibited CLIP1-LTK kinase activity, suppressed proliferation and induced apoptosis. One patient with NSCLC harbouring the CLIP1-LTK fusion showed a good clinical response to lorlatinib treatment. To our knowledge, this is the first description of LTK alterations with oncogenic activity in cancers. These results identify the CLIP1-LTK fusion as a target in NSCLC that could be treated with lorlatinib.

First-line nivolumab plus ipilimumab with or without chemotherapy for Japanese patients with non-small cell lung cancer: LIGHT-NING study.

OBJECTIVE: As first-line treatment for stage IV or recurrent non-small cell lung cancer, combination immunotherapy with nivolumab and ipilimumab, with or without chemotherapy, had demonstrated survival benefits over chemotherapy; however, data on Japanese patients are limited. METHODS: LIGHT-NING was a multicenter, observational study and retrospectively collected data. In this interim analysis, we analyzed patients who received combination immunotherapy between 27 November 2020 and 31 August 2021 for the treatment status, safety objectives (treatment-related adverse events and immune-related adverse events incidences), and effectiveness objectives (objective response rate and progression-free survival) to determine the characteristics and early safety information. RESULTS: We analyzed 353 patients, with a median follow-up of 7.1 (interquartile range, 5.0-9.7) months. Overall, 60.1 and 39.9% received nivolumab plus ipilimumab with and without chemotherapy, respectively. In these cohorts, the median age was 67 and 72 years; 10.8 and 35.5% were aged ≥75 years; 80.2 and 79.4% were male; 5.2 and 13.5% had a performance score ≥ 2; 32.1 and 27.0% developed grade 3-4 immune-related adverse events; treatment-related deaths were observed in 6 (2.8%) and 5 (3.5%) patients, respectively. Grade 3-4 immune-related adverse event incidence was the highest within the first month of treatment in both cohorts, although the immune-related adverse event risk persisted throughout. No new safety signals were observed at this interim analysis. The median progression-free survival was 6.0 (95% confidence interval, 5.2-7.6) and 5.8 (4.3-7.0) months in nivolumab plus ipilimumab with and without chemotherapy cohorts, respectively. CONCLUSIONS: LIGHT-NING offers valuable insights into combination immunotherapy for untreated patients with stage IV or recurrent non-small cell lung cancer in Japanese real-world settings.

Detection of multiple druggable mutations of lung cancer from cytology specimens by MINtS: An advanced medicine A trial.

Most multigene mutation tests require tissue specimens. However, cytological specimens are easily obtained in the clinical practice and provide high-quality DNA and RNA. We aimed to establish a test that utilizes cytological specimens and performed a multi-institutional study to investigate the performance of MINtS, a test based on next-generation sequencing. A standard procedure for specimen isolation was defined. The specimens were considered suitable for the test if >100 ng DNA and >50 ng RNA could be extracted from them. In total, 500 specimens from 19 institutions were investigated. MINtS detected druggable mutations in 63% (136 of 222) of adenocarcinomas. Discordant results between MINtS and the companion diagnostics were observed in 14 of 310 specimens for the EGFR gene, and 6 of 339 specimens for the ALK fusion genes. Confirmation by other companion diagnostics for the EGFR mutations or the clinical response to an ALK inhibitor all supported the results obtained by MINtS. MINtS along with the isolation procedure presented in the current study will be a platform to establish multigene mutation tests that utilize cytological specimens. UMIN000040415.

Pembrolizumab plus chemotherapy in Japanese patients with metastatic squamous non-small-cell lung cancer in KEYNOTE-407.

The global phase III KEYNOTE-407 (NCT02775435) trial showed that pembrolizumab plus chemotherapy prolonged overall and progression-free survival (OS/PFS) versus placebo plus chemotherapy in patients with metastatic squamous non-small-cell lung cancer (NSCLC). We present outcomes of patients from Japan enrolled in KEYNOTE-407. Patients were randomized 1:1 to receive pembrolizumab 200 mg or placebo with paclitaxel 200 mg/m2 every 3 weeks (Q3W) or nab-paclitaxel 100 mg/m2 (weekly) plus carboplatin area under the concentration-time curve of 6 mg/mL/min Q3W for four cycles, followed by pembrolizumab or placebo Q3W for a total of 35 cycles. Primary end-points were OS and PFS per RECIST version 1.1 by blinded independent central review. Fifty patients were randomized at Japanese sites (pembrolizumab plus chemotherapy, n = 22; placebo plus chemotherapy, n = 28). Median follow-up time at data cut-off (May 9, 2019) was 15.1 (range, 0.5-24.0) months. Median OS (95% confidence interval [CI]) was 17.3 (12.5-not reached) versus 11.0 (8.6-19.5) months in the pembrolizumab plus chemotherapy versus placebo plus chemotherapy group (hazard ratio [HR] 0.56; 95% CI, 0.27-1.15). Median PFS (95% CI) was 8.3 (6.1-13.0) versus 7.2 (3.9-8.8) months (HR 0.65; 95% CI, 0.35-1.23). Grade 3-5 adverse events (AEs) occurred in 86% and 75% of patients, respectively. There were three fatal AEs, two of which were treatment-related (one from each treatment group, pneumonitis and pulmonary hemorrhage). Efficacy and safety outcomes were consistent with the global study and support the use of pembrolizumab plus chemotherapy in Japanese patients with metastatic squamous NSCLC.

First-line nivolumab plus ipilimumab in metastatic non-small cell lung cancer: 5-year outcomes in Japanese patients from CheckMate 227 Part 1.

BACKGROUND: In CheckMate 227 Part 1 (NCT02477826), first-line nivolumab plus ipilimumab demonstrated long-term durable overall survival (OS) benefit versus chemotherapy in patients with metastatic non-small cell lung cancer (NSCLC), regardless of tumor programmed death ligand 1 (PD-L1) expression. We report results in Japanese patients with ≥ 5-year follow-up. METHODS: Adults with stage IV/recurrent NSCLC without EGFR/ALK aberrations were randomized 1:1:1 to nivolumab plus ipilimumab, nivolumab alone, or chemotherapy (patients with tumor PD-L1 ≥ 1%), or nivolumab plus ipilimumab, nivolumab plus chemotherapy, or chemotherapy (patients with tumor PD-L1 < 1%). Five-year efficacy and safety were assessed in Japanese patients. RESULTS: At 62.1 months' minimum follow-up, 143 Japanese patients with PD-L1 ≥ 1% or < 1% were randomized to nivolumab plus ipilimumab (n = 66) or chemotherapy (n = 77). Five-year OS rates were 46% with nivolumab plus ipilimumab versus 34% with chemotherapy (PD-L1 ≥ 1%) and 36% versus 19% (PD-L1 < 1%). Median duration of response was 59.1 versus 7.1 months (PD-L1 ≥ 1%) and 17.3 versus 3.0 months (PD-L1 < 1%). Among 5-year survivors treated with nivolumab plus ipilimumab (PD-L1 ≥ 1% and < 1%; n = 27), 59% (95% CI, 39%-75%) were off treatment for ≥ 3 years without receiving subsequent therapy. No new safety signals were observed. CONCLUSIONS: At 5-year follow-up, nivolumab plus ipilimumab continued to show long-term durable clinical benefit versus chemotherapy, regardless of tumor PD-L1 expression. Consistent with findings for the global population, these data support the use of nivolumab plus ipilimumab as first-line treatment in Japanese patients with metastatic NSCLC.

Health Care Resource Use Among Patients with Advanced Non-Small Cell Lung Cancer in Japan, 2017-2019.

Background: First-line immune checkpoint inhibitor (ICI) monotherapy for advanced non-small cell lung cancer (NSCLC) was introduced in Japan in February 2017. Limited information is available since that time regarding health care resource use for NSCLC in Japan, where the hospitalization burden is high. Objective: We evaluated health care resource use from first- through third-line systemic anticancer therapy for patients with advanced NSCLC included in a multicenter, retrospective chart review study. Methods: Eligible patients were aged 20 years or older with unresectable locally advanced/metastatic NSCLC with no known actionable genomic alteration who initiated first-line systemic anticancer therapy from July 1, 2017, to December 20, 2018, at 23 Japanese hospitals. We calculated the percentage of patients with a record of each resource used, the total number of each resource, and the resource use per 100 patient-weeks of follow-up from initiation of first-, second-, and third-line therapy, overall and by the 3 most common regimen categories, namely, ICI monotherapy, platinum-doublet chemotherapy (without concomitant ICI), and nonplatinum cytotoxic regimens (nonplatinum). Study follow-up ended September 30, 2019. Results: Among 1208 patients (median age = 70 years; 975 [81%] men), 463 patients (38%) received ICI monotherapy, 647 (54%) received platinum-doublet chemotherapy, and 98 (8%) received nonplatinum regimens as first-line therapy. During the study, 621 (51%) patients initiated second-line, and 281 (23%) initiated third-line therapy. The majority of patients experienced ≥1 hospitalization (76%-94%) and ≥1 outpatient visit (85%-90%) during each therapy line. The number of hospitalizations increased from 6.5 per 100 patient-weeks in first-line to 8.0 per 100 patient-weeks in third-line. During first-line therapy, the number of hospitalizations per 100 patient-weeks were 4.8, 8.4, and 6.5 for patients receiving ICI monotherapy, platinum-doublet chemotherapy, and nonplatinum regimens, respectively, and the percentages of hospitalizations categorized as attributable to NSCLC treatment administration (no surgery, procedure, treatment of metastasis, or palliative lung radiation) were 64%, 77%, and 73%, respectively. The number of outpatient visits increased from 43.0 per 100 patient-weeks in first-line to 51.4 per 100 patient-weeks in third-line therapy. During first-line therapy, outpatient visits per 100 patient-weeks were 41.0, 46.7, and 33.0 for patients receiving ICI monotherapy, platinum-doublet chemotherapy, and nonplatinum regimens, respectively, and the percentages of outpatient visits for infusion therapy were 48%, 34%, and 36%, respectively. Conclusions: The results of this study, although solely descriptive, showed differing patterns of health care resource use during first-line therapy among the 3 common systemic anticancer therapy regimens for advanced NSCLC in Japan and suggest that further research is needed to investigate these apparent differences by treatment regimen.

Phase II study of carboplatin-paclitaxel alone or with bevacizumab in advanced sarcomatoid carcinoma of the lung: HOT1201/NEJ024.

OBJECTIVES: Only a few prospective studies have been conducted to examine the efficacy and safety of systemic chemotherapy for patients with pulmonary sarcomatoid carcinomas (PSCs). There is, thus, a crucial need to develop novel treatment strategies for this rare tumor. PATIENTS AND METHODS: Chemotherapy-naïve patients with histologically confirmed PSCs were assigned to receive either carboplatin/paclitaxel alone (CP) or with bevacizumab (CPB) followed by bevacizumab maintenance. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. RESULTS: This study was closed before accumulating the expected number of cases due to slow patient accrual. Eventually, 16 patients were enrolled. The ORR was 25.0% and disease control rate was 56.3%. CPB was administered in all four patients with an objective response [partial response (PR)]; among the four PR cases, two patients had pleomorphic carcinoma, and two had carcinosarcoma. Median PFS and median survival time (MST) in all the enrolled patients were 2.6 months and 8.8 months, respectively. Median PFS was 1.2 months in the CP group and 4.2 months in the CPB group. In addition, MST was 7.9 months in the CP group and 11.2 months in the CPB group. Hematological and non-hematological adverse events were common and reversible, although ileus (grade 4) and nasal bleeding (grade 3) occurred in one case each in the CPB group. CONCLUSIONS: CPB might be effective as first-line treatment for PSCs. Further study is warranted to clarify the role of cytotoxic chemotherapy for this rare and aggressive tumor. CLINICAL TRIALS REGISTRATION: University Hospital Medical Information Network (UMIN) Clinical Trial Registry (UMIN000008707).

MK-6, a novel not-α IL-2, elicits a potent antitumor activity by improving the effector to regulatory T cell balance.

IL-2 is a pleiotropic cytokine that regulates immune cell homeostasis. Its immunomodulatory function has been used clinically as an active immunotherapy agent for metastatic cancers. However, severe adverse effects, including the vascular leak syndrome and the preferential stimulation of anti-immunogenic Treg rather than effector T cells, have been obstacles. We newly designed a mutein IL-2, Mutakine-6 (MK-6), with reduced IL-2Rα-binding capability. MK-6 induced comparable cell growth potential toward IL-2Rßγ-positive T cells but was far less efficient in in vitro Treg proliferation and STAT5 activation. Unlike IL-2, in vivo administration of MK-6 produced minimal adverse effects. Using CT26 and B16F10-syngeneic tumor models, we found MK-6 was highly efficacious on tumor regression. Serum albumin conjugation to MK-6 prolonged in vivo half-life and accumulated in CT26 tumors, showing enhanced antitumor effect. Tumor-infiltrating leukocytes analysis revealed that albumin-fused MK-6 increased the ratio of effector CD8+ T cells to CD4+ Treg cells. These results demonstrated that MK-6 is an efficient immunomodulator potentially used for improved immunotherapy with decreased adverse effects and attenuated Treg stimulation.

First-line pembrolizumab vs chemotherapy in metastatic non-small-cell lung cancer: KEYNOTE-024 Japan subset.

This prespecified subanalysis of the global, randomized controlled phase III KEYNOTE-024 study of pembrolizumab vs chemotherapy in previously untreated metastatic non-small-cell lung cancer without EGFR/ALK alterations and a programmed death-ligand 1 (PD-L1) tumor proportion score of 50% or greater evaluated clinical outcomes among patients enrolled in Japan. Treatment consisted of pembrolizumab 200 mg every 3 weeks (35 cycles) or platinum-based chemotherapy (four to six cycles). The primary end-point was progression-free survival; secondary end-points included overall survival and safety. Of 305 patients randomized in KEYNOTE-024 overall, 40 patients were enrolled in Japan (all received treatment: pembrolizumab, n = 21; chemotherapy, n = 19). The hazard ratio (HR) for progression-free survival by independent central review (data cut-off date, 10 July 2017) was 0.25 (95% confidence interval [CI], 0.10-0.64; one-sided, nominal P = .001). The HR for overall survival (data cut-off date, 15 February 2019) was 0.39 (95% CI, 0.17-0.91; one-sided, nominal P = .012). Treatment-related adverse events occurred in 21/21 (100%) pembrolizumab-treated and 18/19 (95%) chemotherapy-treated patients; eight patients (38%) and nine patients (47%), respectively, had grade 3-5 events. Immune-mediated adverse events and infusion reactions occurred in 11 patients (52%) and four patients (21%), respectively; four patients (19%) and one patient (5%), respectively, had grade 3-5 events. Consistent with results from KEYNOTE-024 overall, first-line pembrolizumab improved progression-free survival and overall survival vs chemotherapy with manageable safety among Japanese patients with metastatic non-small-cell lung cancer without EGFR/ALK alterations and a PD-L1 tumor proportion score of 50% or greater. The trial is registered with ClinicalTrials.gov: NCT02142738.

First-line pembrolizumab vs chemotherapy in metastatic non-small-cell lung cancer: KEYNOTE-024 Japan subset.

This prespecified subanalysis of the global, randomized controlled phase III KEYNOTE-024 study of pembrolizumab vs chemotherapy in previously untreated metastatic non-small-cell lung cancer without EGFR/ALK alterations and a programmed death ligand 1 (PD-L1) tumor proportion score of 50% or higher evaluated clinical outcomes among patients enrolled in Japan. Treatment consisted of pembrolizumab 200 mg every 3 weeks (35 cycles) or platinum-based chemotherapy (four to six cycles). The primary end-point was progression-free survival; secondary end-points included overall survival and safety. Of 305 patients randomized in KEYNOTE-024 overall, 40 patients were enrolled in Japan (all received treatment: pembrolizumab, n = 21; chemotherapy, n = 19). Median progression-free survival was 41.4 (95% confidence interval [CI], 4.2-42.5) months with pembrolizumab and 4.1 (95% CI, 2.8-8.3) months with chemotherapy (hazard ratio [HR], 0.27 [95% CI, 0.11-0.65]; one-sided, nominal P = .001). Median overall survival was not reached (NR) (95% CI, 22.9-NR) and 21.5 (95% CI, 5.2-35.0) months, respectively (HR, 0.39 [95% CI, 0.17-0.91]; one-sided, nominal P = .012). Treatment-related adverse events occurred in 21/21 (100%) pembrolizumab-treated and 18/19 (95%) chemotherapy-treated patients; eight patients (38%) and nine patients (47%), respectively, had grade 3-5 events. Immune-mediated adverse events and infusion reactions occurred in 11 pembrolizumab-treated patients (52%) and four chemotherapy-treated patients (21%), respectively; four patients (19%) and one patient (5%), respectively, had grade 3-5 events. Consistent with results from KEYNOTE-024 overall, first-line pembrolizumab improved progression-free survival and overall survival vs chemotherapy with manageable safety among Japanese patients with metastatic non-small-cell lung cancer without EGFR/ALK alterations and a PD-L1 tumor proportion score of 50% or higher. The trial is registered with Clinicaltrials.gov: NCT02142738.

Erlotinib plus bevacizumab versus erlotinib alone in patients with EGFR-positive advanced non-squamous non-small-cell lung cancer (NEJ026): interim analysis of an open-label, randomised, multicentre, phase 3 trial.

BACKGROUND: Resistance to first-generation or second-generation EGFR tyrosine kinase inhibitor (TKI) monotherapy develops in almost half of patients with EGFR-positive non-small-cell lung cancer (NSCLC) after 1 year of treatment. The JO25567 phase 2 trial comparing erlotinib plus bevacizumab combination therapy with erlotinib monotherapy established the activity and manageable toxicity of erlotinib plus bevacizumab in patients with NSCLC. We did a phase 3 trial to validate the results of the JO25567 study and report here the results from the preplanned interim analysis. METHODS: In this prespecified interim analysis of the randomised, open-label, phase 3 NEJ026 trial, we recruited patients with stage IIIB-IV disease or recurrent, cytologically or histologically confirmed non-squamous NSCLC with activating EGFR genomic aberrations from 69 centres across Japan. Eligible patients were at least 20 years old, and had an Eastern Cooperative Oncology Group performance status of 2 or lower, no previous chemotherapy for advanced disease, and one or more measurable lesions based on Response Evaluation Criteria in Solid Tumours (1.1). Patients were randomly assigned (1:1) to receive oral erlotinib 150 mg per day plus intravenous bevacizumab 15 mg/kg once every 21 days, or erlotinib 150 mg per day monotherapy. Randomisation was done by minimisation, stratified by sex, smoking status, clinical stage, and EGFR mutation subtype. The primary endpoint was progression-free survival. This study is ongoing; the data cutoff for this prespecified interim analysis was Sept 21, 2017. Efficacy was analysed in the modified intention-to-treat population, which included all randomly assigned patients who received at least one dose of treatment and had at least one response evaluation. Safety was analysed in all patients who received at least one dose of study drug. The trial is registered with the University Hospital Medical Information Network Clinical Trials Registry, number UMIN000017069. FINDINGS: Between June 3, 2015, and Aug 31, 2016, 228 patients were randomly assigned to receive erlotinib plus bevacizumab (n=114) or erlotinib alone (n=114). 112 patients in each group were evaluable for efficacy, and safety was evaluated in 112 patients in the combination therapy group and 114 in the monotherapy group. Median follow-up was 12·4 months (IQR 7·0-15·7). At the time of interim analysis, median progression-free survival for patients in the erlotinib plus bevacizumab group was 16·9 months (95% CI 14·2-21·0) compared with 13·3 months (11·1-15·3) for patients in the erlotinib group (hazard ratio 0·605, 95% CI 0·417-0·877; p=0·016). 98 (88%) of 112 patients in the erlotinib plus bevacizumab group and 53 (46%) of 114 patients in the erlotinib alone group had grade 3 or worse adverse events. The most common grade 3-4 adverse event was rash (23 [21%] of 112 patients in the erlotinib plus bevacizumab group vs 24 [21%] of 114 patients in the erlotinib alone group). Nine (8%) of 112 patients in the erlotinib plus bevacizumab group and five (4%) of 114 patients in the erlotinib alone group had serious adverse events. The most common serious adverse events were grade 4 neutropenia (two [2%] of 112 patients in the erlotinib plus bevacizumab group) and grade 4 hepatic dysfunction (one [1%] of 112 patients in the erlotinib plus bevacizumab group and one [1%] of 114 patients in the erlotinib alone group). No treatment-related deaths occurred. INTERPRETATION: The results of this interim analysis showed that bevacizumab plus erlotinib combination therapy improves progression-free survival compared with erlotinib alone in patients with EGFR-positive NSCLC. Future studies with longer follow-up, and overall survival and quality-of-life data will be required to further assess the efficacy of this combination in this setting. FUNDING: Chugai Pharmaceutical.

KEYNOTE-025: Phase 1b study of pembrolizumab in Japanese patients with previously treated programmed death ligand 1-positive advanced non-small-cell lung cancer.

Pembrolizumab, a humanized monoclonal antibody against programmed death 1 (PD-1), has been shown to improve overall survival (OS) in patients with previously treated advanced non-small-cell lung cancer (NSCLC) with programmed death ligand 1 (PD-L1) tumor proportion score (TPS) ≥1%. We report safety and efficacy results from the phase 1b KEYNOTE-025 study, which evaluated pembrolizumab in Japanese patients with previously treated NSCLC. Eligible patients had histologically/cytologically confirmed advanced NSCLC with PD-L1 TPS ≥1% and had received ≥1 platinum-doublet chemotherapy. Patients received pembrolizumab 10 mg/kg once every 3 weeks for 2 years or until disease progression/unacceptable toxicity. Primary objectives were to evaluate the safety of pembrolizumab in patients with PD-L1 TPS ≥1% and the objective response rate (ORR) per RECIST version 1.1 in patients with PD-L1 TPS ≥50%. Thirty-eight patients were enrolled and received ≥1 pembrolizumab dose. The median (range) age was 66.0 (41-78) years, and 61% had received ≥2 prior systemic therapies. Eleven patients (29%) experienced grade 3-5 treatment-related adverse events (AE); 9 patients (24%) experienced immune-mediated AE and infusion reactions, with pneumonitis (11%; any grade) being most common. Among evaluable patients with PD-L1 TPS ≥50% (n = 11), ORR was 27% (95% CI, 6-61). Among evaluable patients with PD-L1 TPS ≥1% (n = 37), ORR was 22% (95% CI, 10-38). Median (95% CI) progression-free survival and OS were 3.9 (2.0-6.2) months and 19.2 (8.0-26.7) months, respectively. In summary, pembrolizumab was generally well tolerated and showed promising antitumor activity in Japanese patients with previously treated PD-L1-expressing NSCLC. Outcomes were consistent with those from the phase 3 KEYNOTE-010 study. (Trial registration number: ClinicalTrials.gov, NCT02007070.).

Exploration of resistance mechanisms for epidermal growth factor receptor-tyrosine kinase inhibitors based on plasma analysis by digital polymerase chain reaction and next-generation sequencing.

Liquid biopsy offers a potential alternative to tissue biopsy for detection of genetic alterations in cancer, and it has been introduced into clinical practice to detect the tyrosine kinase inhibitor (TKI) resistance-conferring T790M mutation of epidermal growth factor receptor (EGFR) in patients with non-small-cell lung cancer (NSCLC). We prospectively collected tumor and plasma samples from 25 NSCLC patients who harbored activating mutations of EGFR and experienced failure of treatment with afatinib. The samples were analyzed by digital PCR (dPCR) and next-generation sequencing (NGS). T790M was detected in plasma with a respective sensitivity and specificity of 83.3% and 70.0% by dPCR and 50.0% and 70.0% by NGS relative to analysis of corresponding tumor samples. Quantitation of T790M based on the ratio of the number of T790M alleles to that of activating mutation alleles (T/A ratio) improved the specificity of plasma analysis to 100% for both dPCR and NGS without a reduction in sensitivity. Although several afatinib resistance mechanisms other than T790M-including copy number gain of NRAS or MET-were identified in tumor samples, the corresponding genetic alterations were not detected in plasma. TP53 mutations were frequently identified in plasma and tumor samples, with most such mutations also having been detected before afatinib treatment. The presence of de novo TP53 mutations was associated with reduced progression-free survival. Quantitation of T790M in plasma is thus a clinically relevant approach to determine the T790M status of tumors. In addition, genetic alterations coexisting with EGFR mutations can affect the efficacy of EGFR-TKI treatment.

Secretory leukocyte protease inhibitor modulates urethane-induced lung carcinogenesis.

Secretory leukocyte protease inhibitor (SLPI), 11.7 kDa serine protease inhibitor, is produced primarily in the respiratory tract, but it is often elevated in lung, head/neck and ovarian cancers. SLPI expression in relation to cancer progression, metastasis and invasion has been studied extensively in non-small cell lung cancer. However, the role of SLPI during the early stages of carcinogenesis remains unknown. We hypothesized that SLPI is required from the initiation and promotion to the progression of lung carcinogenesis. A skin allograft model using SLPI-knockout (SLPI-KO) mice and short hairpin RNA-treated cells was used to demonstrate that SLPI expression in tumor cells is crucial for tumor formation. Moreover, lung tumorigenesis induced by urethane, a chemical lung carcinogen, was significantly suppressed in SLPI-KO mice in association with decreased nuclear factor-kappaB (NF-κB) activity. SLPI deficiency also resulted in decreased cell numbers and decreased production of inflammatory cytokines in bronchoalveolar lavage fluids. The suppression of NF-κB activation in SLPI-KO mice was associated with lower expression of NF-κB-related survival genes and DNA repair genes. Our findings demonstrate that SLPI plays an important role from the initial stages of lung carcinogenesis to the progression of lung cancer in an NF-κB-dependent manner.

Synergistic cytotoxicity of afatinib and cetuximab against EGFR T790M involves Rab11-dependent EGFR recycling.

EGFR is an important therapeutic target for non-small cell lung cancers (NSCLCs). Tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib, are effective in cases with EGFR-activating mutations. However, most such cases become resistant through a secondary EGFR mutation, T790M. While the second-generation TKI afatinib has a higher affinity for double-mutant EGFRs, better efficacy is needed. Combining afatinib with the anti-EGFR monoclonal antibody cetuximab improves clinical outcomes, but the mechanism is unclear. Here we examined this effect using erythroleukemic K562 cells. The activating EGFR mutation L858R is sensitive to first-generation TKIs, and adding T790M confers resistance to these drugs. This double-mutant EGFR was moderately sensitive to afatinib, but responded weakly to cetuximab. Combined afatinib and cetuximab synergistically increased their cytotoxicity for K562 cells expressing the double-mutant EGFR. Apoptosis in these cells followed induction of the pro-apoptotic protein BIM. Unexpectedly, afatinib caused redistribution of EGFR to the cell surface through Rab11a-dependent recycling. Cetuximab reduced cell-surface EGFR, and total EGFR decreased synergistically when cetuximab was combined with afatinib. Our results suggest that the synergistic effect exerted by afatinib and cetuximab on NSCLCs is associated with BIM induction and alterations in EGFR status.

Monitoring of Plasma EGFR Mutations during Osimertinib Treatment for NSCLC Patients with Acquired T790M Mutation.

BACKGROUND: Osimertinib was first approved for the treatment of non-small cell lung cancer (NSCLC) in patients who have developed the epidermal growth factor receptor (EGFR) T790M mutation after treatment with EGFR tyrosine kinase inhibitors (TKIs). We routinely evaluated the plasma of NSCLC patients with the T790M mutation to more rapidly detect an increase in disease activity and resistance to treatment. METHODS: Eligible patients received osimertinib after resistance to the first- or second-generation of EGFR-TKIs in NSCLC harboring T790M mutation detectable in tumor tissue or plasma. Plasma samples were collected every 8 weeks during osimertinib treatment. The plasma analysis was performed using an improved PNA-LNA PCR clamp method. We tested samples for a resistance mechanism, including EGFR-activating, T790M, and C797S mutations, and assessed the association between the mutations and osimertinib treatment. RESULTS: Of the 60 patients enrolled in the study, 58 were eligible for this analysis. In plasma collected before osimertinib treatment, activating mutations were detected in 47 of 58 patients (81.0%) and T790M was detected in 44 patients (75.9%). Activating mutations were cleared in 60.9% (28/46) and T790M was cleared in 93.0% (40/43). Of these, 71.4% (20/28) of activating mutations and 87.5% (35/40) of T790M mutation were cleared within 8 weeks of treatment. The total response rate (RR) was 53.4% (31/58). The median duration of treatment was 259 days, with a trend toward longer treatment duration in patients who experienced the clearance of activating mutations with osimertinib. At the time of disease progression during osimertinib treatment, C797S was detected in 3 of 37 patients (8.1%). CONCLUSION: Plasma EGFR mutation analysis was effective in predicting the effect of osimertinib treatment.

Multi-gene Liquid Biopsy to Detect Resistance to First-line Osimertinib in Patients With EGFR-mutated Lung Adenocarcinoma.

BACKGROUND/AIM: Osimertinib is currently used as a first-line treatment for EGFR-mutated non-small cell lung cancer, and the emergence of drug resistance poses a substantial challenge. Liquid biopsy with a multi-gene panel can examine both the molecular mechanisms and possibility of early resistance diagnosis. PATIENTS AND METHODS: We used a molecular barcode library construction kit (Archer® LiquidPlex™) that allowed the analysis of multiple cancer-related genes using cell-free DNA from the plasma samples of patients. We collected plasma from 17 consecutive patients with lung adenocarcinoma at our hospital at various time points and cell-free DNA was extracted and subjected to LiquidPlex analysis. RESULTS: Plasma DNA concentration was not associated with the presence or absence of resistance to osimertinib. The pathological mutations detected using next-generation sequencing in the resistant specimens were in MAP2K1, PIK3CA, TP53, BRAF, and EGFR. Among the recurrent cases, EGFR mutations identified at the initial diagnosis were detected within 6 months before relapse confirmation in four cases (average 88 days). Many of the recurrent cases without detection of known EGFR mutations in the liquid biopsy showed a longer interval between the detection of relapse and the last blood draw for the liquid biopsy (average 255 days). CONCLUSION: Frequent liquid biopsies are useful for identifying known EGFR mutations as markers for early detection of relapse. Several cancer driver mutations were observed, suggesting a variety of mechanisms of resistance in first-line osimertinib-treated lung adenocarcinoma.

A Prospective Cohort Study Assessing the Relationship between Plasma Levels of Osimertinib and Treatment Efficacy and Safety.

Osimertinib is a standard treatment for patients with EGFR-mutated non-small cell lung carcinoma (NSCLC). We evaluated the relationship between plasma osimertinib concentrations and treatment outcome in patients with NSCLC for this cohort study. The plasma levels of osimertinib and its metabolite AZ5104 were measured a week after the start of treatment (P1). The primary endpoint was to evaluate the correlation between plasma concentration and adverse events (AEs). The correlation with treatment efficacy was one of the secondary endpoints. In patients with CNS metastases, the concentration in the cerebrospinal fluid was also measured. Forty-one patients were enrolled. The frequency of AEs was highest for rash, followed by anorexia and thrombocytopenia. Thirty-eight cases provided measurements for P1. The median plasma concentration of osimertinib was 227 ng/mL, and that of AZ5104 was 16.5 ng/mL. The mean CNS penetration rate of two cases was 3.8%. The P1 in the group with anorexia was significantly higher than that in the group without anorexia (385.0 ng/mL vs. 231.5 ng/mL, p = 0.009). Divided into quartiles by P1 trough level, Q2 + Q3 (164-338 ng/mL) had longer PFS, while Q1 and Q4 had shorter PFS. An appropriate plasma level of osimertinib may avoid some adverse events and induce long PFS. Further large-scale trials are warranted.

Niacin restriction with NAMPT-inhibition is synthetic lethal to neuroendocrine carcinoma.

Nicotinamide phosphoribosyltransferase (NAMPT) plays a major role in NAD biosynthesis in many cancers and is an attractive potential cancer target. However, factors dictating therapeutic efficacy of NAMPT inhibitors (NAMPTi) are unclear. We report that neuroendocrine phenotypes predict lung and prostate carcinoma vulnerability to NAMPTi, and that NAMPTi therapy against those cancers is enhanced by dietary modification. Neuroendocrine differentiation of tumor cells is associated with down-regulation of genes relevant to quinolinate phosphoribosyltransferase-dependent de novo NAD synthesis, promoting NAMPTi susceptibility in vitro. We also report that circulating nicotinic acid riboside (NAR), a non-canonical niacin absent in culture media, antagonizes NAMPTi efficacy as it fuels NAMPT-independent but nicotinamide riboside kinase 1-dependent NAD synthesis in tumors. In mouse transplantation models, depleting blood NAR by nutritional or genetic manipulations is synthetic lethal to tumors when combined with NAMPTi. Our findings provide a rationale for simultaneous targeting of NAR metabolism and NAMPT therapeutically in neuroendocrine carcinoma.