3D layered co-culture model enhances Trastuzumab Deruxtecan sensitivity and reveals the combined effect with G007-LK in HER2-positive non-small cell lung cancer.

Human epidermal growth factor receptor 2 (HER2) aberrations are observed in various cancers. In non-small cell lung cancer, genetic alterations activating HER2, mostly exon 20 insertion mutations, occur in approximately 2-4% of cases. Trastuzumab deruxtecan (T-DXd), a HER2-targeted antibody-drug conjugate has been approved as the first HER2-targeted drug for HER2-mutant lung cancer. However, some cases are not responsive to T-DXd and the primary resistant mechanism remains unclear. In this study, we assessed sensitivity to T-DXd in JFCR-007, a patient-derived HER2-mutant lung cancer cell line. Although JFCR-007 was sensitive to HER2 tyrosine kinase inhibitors, it showed resistance to T-DXd in attachment or spheroid conditions. Accordingly, we established a three-dimensional (3D) layered co-culture model of JFCR-007, where it exhibited a lumen-like structure and became sensitive to T-DXd. In addition, an in-house inhibitor library screening revealed that G007-LK, a tankyrase inhibitor, was effective when combined with T-DXd. G007-LK increased the cytotoxicity of topoisomerase-I inhibitor, DXd, a payload of T-DXd and SN-38. This combined effect was also observed in H2170, an HER2-amplified lung cancer cell line. These results suggest that the proposed 3D co-culture system may help in evaluating the efficacy of T-DXd and may recapitulate the tumor microenvironment.

Soluble interleukin-2 receptor as a predictive biomarker for poor efficacy of combination treatment with anti-PD-1/PD-L1 antibodies and chemotherapy in non-small cell lung cancer patients.

Soluble interleukin-2 receptor (sIL-2R) suppresses effector T-cells. Few studies have assessed serum sIL-2R in patients receiving immunotherapy. We evaluated the association between serum sIL-2R levels and the efficacy of anti-programmed cell death 1/ programmed death-ligand 1 (anti-PD-1/PD-L1) antibody combined with chemotherapy in non-small cell lung cancer (NSCLC) patients. We prospectively enrolled NSCLC patients who received anti-PD-1/PD-L1 antibody combined with platinum-based chemotherapy between 8/2019 and 8/2020 and measured their serum sIL-2R. The patients were divided into high and low sIL-2R groups based on the median of sIL-2R levels at pretreatment. Progression-free survival (PFS) and overall survival (OS) of patients in the high and low sIL-2R groups were compared. The Kaplan-Meier curves of PFS and OS were evaluated using the log-rank test. The multivariate analysis of PFS and OS was performed using the Cox proportional hazard models. Among 54 patients (median age 65, range 34-84), 39 were male and 43 had non-squamous cell carcinoma. The sIL-2R cut-off value was 533 U/mL. Median PFS was 5.1 months (95% CI, 1.8-7.5 months) and 10.1 months (95% CI, 8.3-not reached [NR] months) in the high and low sIL-2R groups (P = 0.007), respectively. Median OS was 10.3 months (95% CI, 4.0-NR months) and NR (95% CI, 10.3-NR months) in the high and low sIL-2R groups (P = 0.005), respectively. Multivariate Cox regression analysis showed that high sIL-2R was significantly associated with shorter PFS and OS. SIL-2R may be a biomarker for the poor efficacy of anti-PD-1/PD-L1 antibody combined with chemotherapy.

EGFR-TKI re-administration after osimertinib failure in T790M mutation loss cases with re-biopsy.

Data on the re-administration of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) after osimertinib failure in patients with T790M-positive non-small cell lung cancer (NSCLC) is limited. EGFR-TKI re-administration efficacy may vary between patients with T790M loss and those with T790M persistent with re-biopsy after osimertinib treatment. Patients who received EGFR-TKI re-administration (gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib) after osimertinib failure were identified from our database. T790M mutation status before EGFR-TKI re-administration was analyzed via repeat biopsy. We retrospectively evaluated the efficacy of EGFR-TKI re-administration, especially differences according to the T790M mutation status, via repeat biopsy. Until June 2020, 28 patients received EGFR-TKI re-administration and 17 underwent repeat biopsy after osimertinib failure. Patients were divided into three groups, including the T790M loss group, where active mutation persisted and T790M was lost (13/17); T790M remaining group, where both the active mutation and T790M persisted (3/17); and active mutation loss group where both the active mutation and T790M were lost (1/17). The overall response rate (ORR) of EGFR-TKI re-administration in the T790M loss group was 31% and the disease control rate (DCR) was 54%, which were higher than the ORR of 21% and DCR of 43% in the entire patient population. ORR and DCR of the not re-biopsy group were low (9% and 27%, respectively). The therapeutic effect of EGFR-TKI re-administration in patients with T790M-positive NSCLC after osimertinib failure is limited. EGFR-TKI re-administration may be considered in cases of T790M loss after repeat biopsy.

Monitoring epidermal growth factor receptor C797S mutation in Japanese non-small cell lung cancer patients with serial cell-free DNA evaluation using digital droplet PCR.

Osimertinib is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that is effective in treating both naïve and T790M-mutated EGFR-TKI-resistant non-small cell lung cancer patients. The EGFR C797S mutation is the major osimertinib resistance mechanism. The present study monitored the EGFR C797S mutation during osimertinib treatment in Japanese patients using droplet digital PCR (ddPCR). In our first cohort, C797S detection was validated with tumor specimens and/or plasma samples from 26 patients using ddPCR with custom-designed probes detecting and discriminating T790M and C797S in cis and trans positions. In our second cohort, 18 patients with EGFR-T790M who were going to start osimertinib were analyzed using ddPCR by collecting the plasma samples every month from the beginning of the course of osimertinib. In the first cohort, C797S was detected in 15.4% of patients. C797S and T790M in cis and trans positions were distinguished using ddPCR. In the second cohort, serial cfDNA evaluation revealed that the rate of EGFR mutation changes with disease state. Increases of EGFR mutation were detected, including C797S several months before the diagnosis of disease progression. As with the first cohort, C797S and T790M in cis and trans position were distinguished by ddPCR at disease progression. Coincidentally, in the first cohort, next generation sequencing detected NRAS Q61K mutation and the resistance with NRAS Q61K mutation was overcome by trametinib. In the second cohort, serial cfDNA analysis was useful for evaluating bone oligo-progression and local radiation therapy.

Phase II study of the combination of S-1 with bevacizumab for patients with previously treated advanced non-squamous non-small-cell lung cancer.

BACKGROUND: We assessed the efficacy and safety of bevacizumab and S-1 chemotherapy for patients with previously treated advanced non-squamous non-small-cell lung cancer (NSCLC). METHODS: This was a prospective single-arm study, including patients with non-squamous NSCLC who had received at least one chemotherapy regimen along with a platinum-based regimen. Bevacizumab 15 mg/kg was intravenously administered every 3 weeks, and S-1 40 mg/m2 was orally administered twice daily from day 1 (evening) through day 15 (morning). The treatment continued for 3 weeks/cycle until disease progression or until unacceptable toxicities occurred. During the lead-in part, six patients were evaluated for dose-limiting toxicity (DLT) rate. In phase II, the primary endpoint was objective response rate (ORR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. RESULTS: In the lead-in part, we evaluated the safety in the first six patients and observed no DLT. In phase II, a total of 46 patients were enrolled from September 2012 to December 2018. The median follow-up duration was 13.7 months [95% confidence interval (CI) 1.4-72.0]. The ORR was 28.3%. The median PFS and OS were 4.3 (95% CI 2.9-5.9) and 15.0 months (95% CI 9.8-30.3), respectively. The most common adverse events were hypertension (65.2%), diarrhea (47.8%), mucositis oral (45.7%), and proteinuria (43.5%), and the most common grade 3 adverse events were hypertension (23.9%) and proteinuria (6.5%). Grade 4/5 adverse events were not observed. CONCLUSION: Bevacizumab and S-1 combination chemotherapy showed high activity and were well tolerated in patients with previously treated advanced non-squamous NSCLC.

Drug resistance mechanisms in Japanese anaplastic lymphoma kinase-positive non-small cell lung cancer and the clinical responses based on the resistant mechanisms.

The treatment for anaplastic lymphoma kinase (ALK)-positive lung cancer has been rapidly evolving since the introduction of several ALK tyrosine kinase inhibitors (ALK-TKI) in clinical practice. However, the acquired resistance to these drugs has become an important issue. In this study, we collected a total of 112 serial biopsy samples from 32 patients with ALK-positive lung cancer during multiple ALK-TKI treatments to reveal the resistance mechanisms to ALK-TKI. Among 32 patients, 24 patients received more than two ALK-TKI. Secondary mutations were observed in 8 of 12 specimens after crizotinib failure (G1202R, G1269A, I1171T, L1196M, C1156Y and F1245V). After alectinib failure, G1202R and I1171N mutations were detected in 7 of 15 specimens. G1202R, F1174V and G1202R, and P-gp overexpression were observed in 3 of 7 samples after ceritinib treatment. L1196M + G1202R, a compound mutation, was detected in 1 specimen after lorlatinib treatment. ALK-TKI treatment duration was longer in the on-target treatment group than that in the off-target group (13.0 vs 1.2 months). In conclusion, resistance to ALK-TKI based on secondary mutation in this study was similar to that in previous reports, except for crizotinib resistance. Understanding the appropriate treatment matching resistance mechanisms contributes to the efficacy of multiple ALK-TKI treatment strategies.

Dissociated responses at initial computed tomography evaluation is a good prognostic factor in non-small cell lung cancer patients treated with anti-programmed cell death-1/ligand 1 inhibitors.

BACKGROUND: Dissociated responses (DR) are phenomena in which some tumors shrink, whereas others progress during treatment of patients with cancer. The purpose of the present study was to evaluate the frequency and prognosis of DR in non-small cell lung cancer (NSCLC) patients treated with anti-programmed cell death-1/ligand 1 (anti-PD-1/L1) inhibitors. METHODS: This retrospective study included NSCLC patients who received anti-PD-1/L1 inhibitor as second- or later-line treatment. We excluded patients without radiological evaluation. In patients who showed progressive disease (PD) according to the RECIST 1.1 at the initial CT evaluation, we evaluated all measurable lesions in each organ to identify DR independently of RECIST 1.1. We defined DR as a disease with some shrinking lesions as well as growing or emerging new lesions. Cases not classified as DR were defined as 'true PD'. Overall survival was compared between patients with DR and those with true PD using Cox proportional hazards models. RESULTS: The present study included 62 NSCLC patients aged 27-82 years (median: 65 years). DR and true PD were observed in 11 and 51 patients, respectively. The frequency of DR in NSCLC patients who showed PD to anti-PD-1/L1 was 17.7%. Median overall survival was significantly longer in patients with DR versus true PD (14.0 vs. 6.6 months, respectively; hazard ratio for death: 0.40; 95% confidence interval: 0.17-0.94). CONCLUSIONS: Patients with DR exhibited a relatively favorable prognosis.

Efficacy of anti-PD-1 therapy for recurrence after chemoradiotherapy in locally advanced NSC LC.

PURPOSE: Chemoradiotherapy (CRT) is the standard treatment for locally advanced non-small cell lung cancer (NSCLC). Recently, anti-PD-1 antibody therapy became a key treatment for stage IV NSCLC as the combination of immune checkpoint inhibitors (ICIs) and platinum doublet chemotherapy. However, the efficacy and toxicity of anti-PD-1 therapy for recurrence after CRT in stage III NSCLC are not well examined. METHODS: Patients who received anti-PD-1 therapy for recurrence after CRT were identified in our clinical database. The safety and efficacy of anti-PD-1 therapy were retrospectively analyzed. RESULTS: From March 1, 2013 to April 30, 2018, there were 20 patients who received anti-PD-1 therapy for recurrence after CRT. The median duration from CRT to initial anti-PD-1 therapy was 9.3 months. 12 patients (60%) were alive and 7 patients (35%) were still receiving anti-PD-1 therapy at the data cutoff point (median follow-up, 13.5 months). The ORR for anti-PD-1 therapy was 45.0%. Median progression-free survival (PFS) and overall survival (OS) from initiation of anti-PD-1 therapy was 8.4 months and 26.2 months, respectively. PFS in patients who had a short interval from last CRT to initial anti-PD-1 therapy seemed to have better outcomes (duration from last CRT to initial anti-PD-1 therapy < 9.3 months vs. ≥ 9.3 months; median PFS, 17.0 months vs. 4.9 months). Grade 3 or 4 immune-related adverse events occurred in 5% of patients. Only grade 1 pneumonitis was observed. CONCLUSION: The efficacy of anti-PD-1 therapy for recurrence after CRT in stage III NSCLC might better than in stage IV NSCLC. The duration from CRT to initial anti-PD-1 therapy might be related to efficacy.

Barcode sequencing identifies resistant mechanisms to epidermal growth factor receptor inhibitors in circulating tumor DNA of lung cancer patients.

Most patients with epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) will inevitably develop acquired resistance induced by treatment with EGFR tyrosine kinase inhibitors (EGFR-TKI). The mechanisms of resistance to EGFR-TKI are multifactorial, and the detection of these mechanisms is critical for treatment choices in patients who have progressed after EGFR-TKI therapy. We evaluated the feasibility of a molecular barcode method using next-generation sequencing to detect multifactorial resistance mechanisms in circulating tumor DNA and compared the results with those obtained using other technologies. Plasma samples were collected from 25 EGFR mutation-positive NSCLC patients after the development of EGFR-TKI resistance. Somatic mutation profiles of these samples were assessed using two methods of next-generation sequencing and droplet digital PCR (ddPCR). The positive rate for EGFR-sensitizing mutations was 18/25 (72.0%) using ddPCR, 17/25 (68.0%) using amplicon sequencing, and 19/25 (76.0%) using molecular barcode sequencing. Rate of the EGFR T790M resistance mutation among patients with EGFR-sensitizing mutations was shown to be 7/18 (38.9%) using ddPCR, 6/17 (35.3%) using amplicon sequencing, and 8/19 (42.1%) using molecular barcode sequencing. Copy number gain in the MET gene was detected in three cases using ddPCR. PIK3CA, KRAS and TP53 mutations were detected using amplicon sequencing. Molecular barcode sequencing detected PIK3CA, TP53, KRAS, and MAP2K1 mutations. Results of the three assays were comparable; however, in cell-free DNA, molecular barcode sequencing detected mutations causing multifactorial resistance more sensitively than did the other assays.

Distinction of ALK fusion gene- and EGFR mutation-positive lung cancer with tumor markers.

BACKGROUND: It is difficult to predict gene mutations individually based on clinical background alone. Tumor markers may help to predict each gene mutation. Identifying tumor markers that can predict gene mutation will facilitate timely genetic testing and intervention. METHODS: We selected 134 cases of advanced or recurrent ALK-positive and 172 cases of advanced or recurrent EGFR-positive lung cancer from our clinical database. The cutoff values for the tumor markers were defined as 5.0 ng/mL or higher for carcinoembryonic antigen (CEA) and 3.5 ng/mL or higher for soluble fragment of cytokeratin 19 (CYFRA21-1) in accordance with the institutional standards. A positive CYFRA21-1:CEA ratio was defined as 0.7 or higher. RESULTS: The CEA-positivity rate was 49% for ALK-positive lung cancers and 73% for EGFR-positive lung cancers, which was significantly different (p < 0.001). The CYFRA21-1 positivity rate was significantly higher in ALK-positive lung cancer (36%) compared with EGFR-positive lung cancer (23%) (p = 0.034). The median CYFRA21-1:CEA ratio was 0.395 for the ALK group, which was significantly higher compared with 0.098 for the EGFR group (p < 0.001). These trends were similar when excluding histology other than adenocarcinoma. The median time-to-treatment failure (TTF) for initial tyrosine kinase inhibitor (TKI) therapy was 308 days for the high CYFRA21-1:CEA ratio group and 617 days for the low CYFRA21-1:CEA ratio group for ALK-positive lung cancer (p = 0.100). CONCLUSIONS: A higher proportion of patients with ALK-positive lung cancer were CYFRA21-1 positive and had higher CYFRA21-1:CEA ratios compared with EGFR-positive lung cancer patients.

Efficacy of osimertinib in patients with EGFR-mutation positive non-small cell lung cancer with malignant pleural effusion.

BACKGROUND: As an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), osimertinib has emerged as a standard EGFR-mutation positive treatment for non-small cell lung cancer (NSCLC). However, the efficacy of osimertinib for malignant pleural effusion (MPE) remains understudied. This study aimed to evaluate the impact of osimertinib on time to treatment failure (TTF) and overall survival (OS) in patients with EGFR-mutation positive NSCLC, comparing those with and without MPE. METHODS: This retrospective analysis included patients with advanced or recurrent NSCLC treated with osimertinib at our hospital between April 2016 and June 2021. TTF was defined as the duration from osimertinib initiation to discontinuation, and OS as the duration until death, irrespective of the reason. RESULTS: Among 229 patients receiving osimertinib, 84 had MPE before administration, 39 acquired EGFR exon20 T790M mutation following previous EGFR-TKI therapy, and 45 were EGFR-TKI-naive. Among EGFR-TKI-naive patients, median TTF was 14.8 and 19.8 months for those with and without MPE, respectively (hazard ratio [HR] 1.40; 95% confidence interval [CI]: 0.90-2.18; p = 0.12). Median OS was 32.0 and 42.0 months for patients with and without MPE, respectively (HR 1.43; 95% CI: 0.86-2.38; p = 0.16). Among patients with T790M mutation, median TTF was 12.3 and 13.1 months for patients with and without MPE, respectively (HR 1.03; 95% CI: 0.69-1.55; p = 0.88). Median OS for patients with and without MPE was 23.2 and 24.7 months, respectively (HR 1.09; 95% CI: 0.72-1.67; p = 0.68). CONCLUSION: Among patients with EGFR-mutation positive NSCLC, the evidence of MPE has little effect on survival with osimertinib.

A macrocyclic kinase inhibitor overcomes triple resistant mutations in EGFR-positive lung cancer.

Brigatinib-based therapy was effective against osimertinib-resistant EGFR C797S mutants and is undergoing clinical studies. However, tumor relapse suggests additional resistance mutations might emerge. Here, we first demonstrated the binding mode of brigatinib to the EGFR-T790M/C797S mutant by crystal structure analysis and predicted brigatinib-resistant mutations through a cell-based assay including N-ethyl-N-nitrosourea (ENU) mutagenesis. We found that clinically reported L718 and G796 compound mutations appeared, consistent with their proximity to the binding site of brigatinib, and brigatinib-resistant quadruple mutants such as EGFR-activating mutation/T790M/C797S/L718M were resistant to all the clinically available EGFR-TKIs. BI-4020, a fourth-generation EGFR inhibitor with a macrocyclic structure, overcomes the quadruple and major EGFR-activating mutants but not the minor mutants, such as L747P or S768I. Molecular dynamics simulation revealed the binding mode and affinity between BI-4020 and EGFR mutants. This study identified potential therapeutic strategies using the new-generation macrocyclic EGFR inhibitor to overcome the emerging ultimate resistance mutants.

Real-World Outcome Analysis of Patients With Stage IV NSCLC Treated With Tyrosine Kinase and Immune Checkpoint Inhibitors.

Introduction: Only a few reports have determined whether recently advanced anticancer drugs, particularly next-generation tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs), prolong the survival of patients with NSCLC in the real world. Methods: To evaluate the association between recently advanced drugs and patient survival, survival data of 2078 patients with stage IV NSCLC from 1995 to 2022 were analyzed in the present study. The patients were classified into the following six groups in terms of the date of diagnosis: period A, 1995 to 1999; period B, 2000 to 2004; period C, 2005 to 2009; period D, 2010 to 2014; period E, 2015 to 2019; and period F, 2000 to 2022. They were further grouped in terms of EGFR mutation and ALK fusion. Results: The median overall survival (mOS) times were 8.9, 11.0, 13.6, 17.9, and 25.2 months in periods A to E, respectively, and the mOS time was not reached in period F. This time was significantly longer in period E than in period D (25.2 versus 17.9 mo, p < 0.005). Moreover, the mOS times of patients with EGFR mutation, those with ALK fusion, and those without both alterations were significantly longer in period E than in period D (46.0 versus 32.0 mo, p < 0.005; not reached versus 36.2 mo, p = 0.018; 14.6 versus 11.7 mo, p < 0.005). The history of treatment with next-generation TKIs and ICIs was found to be associated with overall survival. Conclusions: The survival of patients with NSCLC was improved from period D to period E, regardless of the presence of driver gene alteration. We found that next-generation TKIs and ICIs may be associated with improvements in overall survival.

Advances in the treatment of postoperative recurrence of non-small cell lung cancer and their impact on survival in Asian patients.

OBJECTIVES: We investigated the effect of tyrosine kinase inhibitors (TKIs) and immunotherapy on survival after postoperative recurrence of non-small cell lung cancer (NSCLC). METHODS: This single-center retrospective study included patients with NSCLC who underwent lobectomy or more with complete pathological resection between 2008 and 2018 (N = 2254). Median follow-up was 5.1 years. Survival trends and the effect of TKIs/immunotherapy were analyzed using Joinpoint (National Cancer Institute) and Cox regression. RESULTS: In 443 (19.7%) postoperative recurrences, median time to recurrence was 1.1 years; epidermal growth factor receptor mutation (EGFR+), 191 (43.1%); anaplastic lymphoma kinase rearrangement (ALK+), 13 (2.9%); not detected or unknown (ND), 239 (54.0%). In multivariable analysis, age, time to recurrence, adenocarcinoma, symptomatic recurrence, any treatment for recurrence, use of the epidermal growth factor receptor TKI, use of the anaplastic lymphoma kinase TKI, and use of immunotherapy were significant prognostic factors. Survival was significantly better in the EGFR+/ALK+ group than in the ND group (median, 4.7 vs 2.1 years; P < .01). Between 2010 and 2018, 2-year postrecurrence survival improved significantly (annual percentage change [APC], 4.2; 95% CI, 1.5-7.0). In subset analyses, neither change in 2-year survival nor TKI use was significant over time in the EGFR+/ALK+ group, but the ND group experienced significant improvement in 2-year survival (APC, 13.5; 95% CI, 5.4-22.2) and increasing trend in immunotherapy use (APC, 23.0; 95% CI, -5.9 to 60) after 2013. CONCLUSIONS: Survival after postoperative recurrence of NSCLC has improved significantly since 2010. Use of immunotherapy in patients without driver mutations may have contributed to that improvement. Prognosis in patients with driver mutations remains favorable with the TKIs introduced before the study period.

MIG6 loss confers resistance to ALK/ROS1 inhibitors in NSCLC through EGFR activation by low-dose EGF.

Although tyrosine kinase inhibitor (TKI) therapy shows marked clinical efficacy in patients with anaplastic lymphoma kinase-positive (ALK+) and ROS proto-oncogene 1-positive (ROS1+) non-small cell lung cancer (NSCLC), most of these patients eventually relapse with acquired resistance. Therefore, genome-wide CRISPR/Cas9 knockout screening was performed using an ALK+ NSCLC cell line established from pleural effusion without ALK-TKI treatment. After 9 days of ALK-TKI therapy, sequencing analysis was performed, which identified several tumor suppressor genes, such as NF2 or MED12, and multiple candidate genes. Among them, this study focused on ERRFI1, which is known as MIG6 and negatively regulates EGFR signaling. Interestingly, MIG6 loss induced resistance to ALK-TKIs by treatment with quite a low dose of EGF, which is equivalent to plasma concentration, through the upregulation of MAPK and PI3K/AKT/mTOR pathways. Combination therapy with ALK-TKIs and anti-EGFR antibodies could overcome the acquired resistance in both in vivo and in vitro models. In addition, this verified that MIG6 loss induces resistance to ROS1-TKIs in ROS1+ cell lines. This study found a potentially novel factor that plays a role in ALK and ROS1-TKI resistance by activating the EGFR pathway with low-dose ligands.

Clinical characteristics of patients with KRAS mutation detected by liquid biopsy.

BACKGROUND: KRAS mutation positive lung cancer is known to be clinically characterized by older age, males, and smokers. It is reported to be more common in mucinous adenocarcinoma, but all reports are based on analysis of tissue samples. Recently, blood samples have become available for analysis, suggesting a low detection rate of circulating tumor DNA in histological types, especially mucinous adenocarcinoma. In this study, we investigated the clinical characteristics of KRAS mutation-positive cases in the analysis of blood specimens, as these remain unclear. METHODS: The clinical background of patients with KRAS mutation among those who underwent next-generation sequencing (NGS) analysis using blood samples was evaluated. RESULTS: NGS analysis was performed on 214 blood samples. KRAS mutations were detected in blood samples in 33 cases (15.4%), of which 31 cases (14.5%) had a histological pathology diagnosis. Mucinous adenocarcinoma accounted for 28.6% of cases with positive blood and tissue specimens, 10.0% of cases with positive blood specimens only, and 57.1% of cases with positive tissue specimens only. Mucinous adenocarcinoma tended to be less common in cases with positive blood specimens. In KRAS-positive patients with lung metastasis only, only one nonmucinous adenocarcinoma had a positive blood sample, and the others all had mucinous adenocarcinomas with positive tissue samples only. CONCLUSION: The results showed that the detection rate of KRAS-positive lung cancers detected by blood and tissue samples differs, and that the detection rate of blood samples may be poor, especially in the case of mucinous adenocarcinoma with lung metastases only.

GSK3 inhibition circumvents and overcomes acquired lorlatinib resistance in ALK-rearranged non-small-cell lung cancer.

Anaplastic lymphoma kinase (ALK) fusion is found in ~3%-5% of patients with non-small-cell lung cancers (NSCLCs). Although the third-generation ALK tyrosine kinase inhibitor (TKI) lorlatinib shows high clinical efficacy in ALK-positive NSCLC, most of the patients eventually relapse with acquired resistance. Recently, drug-tolerant persister (DTP) cells have been considered an important seed of acquired resistance cells. In this study, we established lorlatinib intermediate resistant cells from a patient-derived cell model. Glycogen synthase kinase 3 (GSK3) inhibitions significantly suppressed lorlatinib intermediate resistant cell growth. GSK3 inhibition also sensitized acquired resistance cells derived from alectinib-treated patients with or without secondary mutations to lorlatinib. Therefore, GSK3 plays a crucial role in developing acquired resistance against lorlatinib in ALK-positive NSCLC mediated by lorlatinib intermediate resistant cells and could be a potential molecular target to prevent acquired lorlatinib resistance and overcome ALK-TKI resistance.

Rapid genomic profiling of circulating tumor DNA in non-small cell lung cancer using Oncomine Precision Assay with Genexus™ integrated sequencer.

Background: Genomic profiling of tumors from cancer patients facilitates molecular-guided therapy. The turnaround time is one of important issues to deliver results timely for clinical decisions. The Ion Torrent™ Genexus™ Integrated Sequencer automates all next generation sequencing (NGS) workflows and delivers results within a day. Methods: In this study, we conducted a feasibility study to evaluate the detection rate of genomic alterations from cell-free total nucleic acid (cfTNA, containing cfDNA and cfRNA) of 119 non-small cell lung cancer using Oncomine Precision Assay on Genexus™ Integrated Sequencer. Oncomine Precision Assay (OPA) covers actionable mutations, copy number variations and fusion genes and that are applicable for the selection of targeted therapy. cfTNA isolated from plasma (derived from 14 ml of blood) were subjected to the Genexus system for library construction, templating, sequencing, and data analyses. Results: The sequencing resulted in median overall depth of 35,773× and median molecular coverage of 2,192× with cfTNA input ranged from 11 to 36 ng. Among the 119 samples evaluated, we detected at least one genomic alteration in plasma cfTNA of 79 cases (66%). When comparing to standard-of-care testing, the sensitivity and specificity of mutation detection in non-small cell lung cancer related genes using liquid biopsy with Genexus-OPA ranged between 49-67% and 93-100%, respectively. 59% of actionable mutations, which were present in tumor tissues, were detected by the Genexus- Oncomine Precision Assay using plasma cfTNA. Among the 5 mutations detected from liquid biopsy only, three mutations are of level 1 evidence according to OncoKB database, highlighting the clinical utilities of liquid biopsy in addressing tumor heterogeneity. Extrathoracic metastasis and levels of lactate dehydrogenase (LDH), C-reactive protein (CRP) and Carcinoembryonic Antigen (CEA) are found to be associated with increased circulating tumor DNA detection. Conclusions: The Genexus™ Integrated Sequencer system is an automated, accurate NGS system with short turnaround time (TAT) that could assist clinicians to make more timely decision.

A phase II feasibility study of carboplatin and nab-paclitaxel for advanced non-small cell lung cancer patients with interstitial lung disease (YLOG0114).

BACKGROUND: A standard treatment regimen for advanced non-small cell lung cancer (NSCLC) patients with interstitial lung disease (ILD) has not been established since most clinical trials exclude such patients because of the high risk of acute exacerbation of ILD. This study aimed to prospectively investigate the efficacy and safety of carboplatin and nab-paclitaxel as a first-line regimen for NSCLC patients with ILD. METHODS: The enrolled patients had treatment-naïve advanced NSCLC with ILD. The patients received 4-6 cycles of carboplatin (area under the curve = 5) on day 1 and nab-paclitaxel 100 mg/m2 on days 1, 8, and 15 every 4 weeks. The primary endpoint was the completion rate of four or more cycles. Secondary endpoints included toxicity, overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). RESULTS: Twenty-five patients were enrolled in this study. Nine patients had adenocarcinoma, 11 had squamous cell carcinoma, one had large cell carcinoma, and four had NSCLC, not otherwise specified. The completion rate of ≥4 cycles was 76% (95% confidence interval: 56.2%-88.8%), which met the primary endpoint. The ORR and DCR were 44% and 88%, respectively. The median PFS and OS were 5.8 months and 15.8 months, respectively. Three patients experienced grade ≥2 pneumonitis, and one patient met the acute exacerbation criteria. CONCLUSION: The 4-week modified regimen of carboplatin and nab-paclitaxel showed tolerable toxicity with favorable efficacy in NSCLC patients with ILD. This regimen may be an effective treatment option for patients in real clinical settings.

Soluble PD-L1 works as a decoy in lung cancer immunotherapy via alternative polyadenylation.

Immune checkpoint therapy targeting the PD-1/PD-L1 axis is a potentially novel development in anticancer therapy and has been applied to clinical medicine. However, there are still some problems, including a relatively low response rate, innate mechanisms of resistance against immune checkpoint blockades, and the absence of reliable biomarkers to predict responsiveness. In this study of in vitro and in vivo models, we demonstrate that PD-L1-vInt4, a splicing variant of PD-L1, plays a role as a decoy in anti-PD-L1 antibody treatment. First, we showed that PD-L1-vInt4 was detectable in clinical samples and that it was possible to visualize the secreting variants with IHC. By overexpressing the PD-L1-secreted splicing variant on MC38 cells, we observed that an immune-suppressing effect was not induced by their secretion alone. We then demonstrated that PD-L1-vInt4 secretion resisted anti-PD-L1 antibody treatment, compared with WT PD-L1, which was explicable by the PD-L1-vInt4's decoying of the anti-PD-L1 antibody. The decoying function of PD-L1 splicing variants may be one of the reasons for cancers being resistant to anti-PD-L1 therapy. Measuring serum PD-L1 levels might be helpful in deciding the therapeutic strategy.