Efficacy of anti-programmed cell death-1/ligand 1 monotherapy for non-small cell lung cancer patients with active brain metastases

e14511

Background: The efficacy of anti-programmed cell death-1/ligand 1 (anti-PD-(L)1) for active brain metastases (BMs) is not established, because most clinical trials excluded patients (pts) with active BMs such as untreated, symptomatic, or unstable BMs. The aim of this study was to evaluate the efficacy of anti-PD-(L)1 monotherapy in non-small cell lung cancer (NSCLC) pts with active BMs. Methods: This retrospective study included NSCLC pts who had received anti-PD-(L)1 monotherapy in 2nd or later line between December 2015 and August 2019. Pts who had not evaluated BMs by CT/MRI before anti-PD-(L)1 were excluded. Pts were classified into those with or without active BMs which were defined as untreated or symptomatic BMs or BMs requiring systemic steroids. Progression free survival (PFS) and overall survival (OS) of pts with or without active BMs were compared. Intra-cranial and extra-cranial tumor responses were evaluated in pts with active BMs. Results: In this study, 242 pts who had received anti-PD-(L)1 monotherapy were identified and 197 pts were analyzed. Twenty-four pts were classified to pts with active BMs. Among pts without active BMs, 145 pts had no BMs and 28 pts had treated asymptomatic BMs. PFS of pts with active BMs was significantly shorter than that of pts without active BMs (1.3 versus 2.7 months; p < 0.001). OS of pts with active BMs was significantly shorter than that of pts without active BMs (4.5 vs 16.3 months; p = 0.001). Intracranial response rate (RR) was 13.3% (2/15) and extracranial RR was 26.7% (4/15) in pts with active BMs. In multivariate Cox regression analysis, active BM, poor PS and EGFR/ALK(+) were selected as significant factors associated with poor PFS. Active BM and poor PS were selected as significant factors associated with poor OS. Conclusions: Anti-PD-(L)1 monotherapy is not recommend for pts with active BMs.

Evaluation of Genexus system that automates specimen-to-report for cancer genomic profiling within a day using liquid biopsy

3538

Background: Genomic profiling of patients’ tumors using NGS system help in facilitating molecular-guided therapy. The turnaround time from specimen to report by the NGS system is important to deliver result timely for clinical decisions. The Genexus Integrated Sequencer automates all steps of the targeted NGS workflow starting from nucleic acid of formalin-fixed paraffin-embedded tissues or plasma that significantly reduce laborious procedures. Importantly, the whole specimen-to-report workflow delivers results in a single day. In this study, we evaluated detection rate of alteration using Oncomine Precision Assay (OPA) on Genexus system with cell-free DNA (cfDNA) from non-small cell lung cancer (NSCLC). Methods: Among the cfDNA from 48 plasma samples of NSCLC were evaluated, 19 were newly-diagnosed cases with EGFR mutations in cancer tissues and 29 cases were patients who experienced progression of disease after first line of EGFR, ALK or ROS1-targeted therapy. 13-20ng of input cfDNA were subjected to automated Genexus Integrated Sequencer for library construction using OPA panel, templating and sequencing. OPA panel covers actionable hotspot mutations, copy number gains or loss, fusion drivers. The concordance of mutation profiles between the tumor tissue and cfDNA and detection of a resistance mutation(s) during molecular-targeted therapy were evaluated. Results: The sequencing resulted in median overall reads of 8,698,358, median overall depth of 30,648 (range 15,069-48,707) and median molecular coverage of 1,595 (range 859-2,550). Among 48 samples examined, 44 were detected to carry at least one somatic mutation, giving the detection rate of 92%. A total of 17 of 19 newly diagnosed EGFR-positive patients were also detected to carry EGFR mutations. Importantly, these 17 patients carry the same mutation that was found in tissue samples implying complete concordance. In addition, we found novel resistance mutations in plasma of the patients who were under EGFR, ALK or ROS1 targeted therapies. Conclusions: Genexus Integrated Sequencer is a fully automated and highly accurate NGS system with a 1-day turnaround time that could assist clinicians to make more timely decision. Novel actionable, resistance mutations were detected using OPA panel that provide potential options for molecular-guided therapy and may help the better understanding of resistance mechanism of targeted therapy.

Genetic profiling and the response to RET inhibitors in RET fusion positive non-small cell lung cancer (NSCLC) identified by international genomic screening project (LC-SCRUM-Asia)

9557

Background: RET fusions are targetable oncogenic drivers in 1 – 2 % of NSCLC, yet no RET inhibitors are approved. Selective RET inhibitors, such as LOXO-292 and BLU-667, are currently in development. The impact of co-occurring mutation on outcome in RET-TKI therapy remains largely unknown. Methods: In an international genome screening project in Asia (LC-SCRUM-Asia), 161 cancer-related genes have been analyzed by a next-generation sequencing (NGS) system, Oncomine™ Comprehensive Assay. The therapeutic efficacy and survival of RET fusion+ NSCLC were evaluated using a large-scale clinicogenomic database in the LC-SCRUM-Japan. Results: From Feb 2013 to Dec 2019, a total of 7177 patients with non-squamous NSCLC were enrolled. RET fusion were detected in 167 patients (2.3 %). Median age was 61 years (range: 29 - 85), 60 % were female, 61 % were never-smokers, 99 % had adenocarcinoma, and 78 % had stage IIIB/IV disease. Based on our database, the median overall survival was 37 months. 62 patients received RET inhibitor therapy. RET fusions was identified by NGS assay (KIF5B-RET: 75, CCDC6-RET: 30, Others: 2) in 107 patients. Co-occurring genomic alterations were detected in 62 (58 %) patients, the median number of co-mutations was 1 (range 0 - 4). The most common co-occurring mutations in tumor involved TP53 (31; 29 %), STK11 (6; 6 %), CDKN2A (5; 5 %) and TSC2 (5; 5 %). In 23 patients treated with RET inhibitor (unapproved drugs), there was a strong association between co-occurring mutation and time to treatment discontinuation (TTD) in RET inhibitor therapy; HR 2.75 (95%CI 1.71 - 15.6, P = 0.0096). Conclusions: RET rearrangements continue to represent a rare but high unmet need disease. Co-occurring mutation was significantly associated with shorter TTD. Our data is the largest cohort of advanced-stage RET fusion+ NSCLC profiled by NGS to date. Co-occurring mutation should be evaluated in the development of novel targeted therapies for RET fusion+ NSCLC.

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.

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.

Overcoming resistance by ALK compound mutation (I1171S + G1269A) after sequential treatment of multiple ALK inhibitors in non-small cell lung cancer

Background

Anaplastic lymphoma kinase (ALK) fusion genes are found in 3%–5% of non‐small cell lung cancers (NSCLCs). ALK inhibitors show a very high response rate to ALK‐positive NSCLCs. However, the emergence of acquired resistance is inevitable. In this study, we investigated the drugs for overcoming resistance especially compound mutations after sequential treatment with crizotinib, alectinib, and lorlatinib.

Method

Next‐generation sequencing (NGS) and Sanger sequencing were performed on a liver biopsy tissue obtained from a clinical case. Ba/F3 cells in which mutant EML4‐ALK were overexpressed were prepared, and cell viability assay and immunoblotting were performed to check the sensitivity of five independent ALK inhibitors.

Results

I1171S + G1269A double mutation was identified by NGS and Sanger sequencing on a liver biopsy tissue from a patient who relapsed on lorlatinib treatment. Ceritinib and brigatinib—but not other ALK inhibitors—were active against the compound mutations in the cell line model.

Conclusions

With the sequential ALK inhibitors treatment, cancer cells accumulate new mutations in addition to mutations acquired previously. The identified compound mutation (I1171S + G1269A) was found to be sensitive to ceritinib and brigatinib, and indeed the patient's tumor partially responded to ceritinib.

Key points

ALK compound mutation was found in a clinical sample that was resistant to lorlatinib after sequential ALK‐tyrosine kinase inhibitor (TKI) treatment.

Ceritinib and brigatinib are potential overcoming drugs against ALK I1171S + G1269A double mutation.

Association of High Neutrophil-to-Lymphocyte Ratio With Poor Outcomes of Pembrolizumab Therapy in High-PD-L1-expressing Non-small Cell Lung Cancer

BACKGROUND

This study aimed to determine whether the neutrophil-to-lymphocyte ratio (NLR) reflected poor treatment benefits in patients with tumor proportion score (TPS) ≥50% and who under went first-line pembrolizumab monotherapy.

PATIENTS AND METHODS

This study retrospectively analyzed patients with untreated stage III/IV or recurrent non-small cell lung cancer (NSCLC) with TPS ≥50% and who received pembrolizumab monotherapy at two hospitals between February 2017 and April 2019. The NLR was calculated from pre-treatment complete blood counts.

RESULTS

A total of 51 previously untreated patients with NSCLC who had TPS ≥50% and who underwent pembrolizumab monotherapy were evaluated. Multivariate analysis revealed that high NLR, Eastern Cooperative Oncology Group performance status (PS) ≥2, stage IV or recurrent cancer, and TPS=50-74% were significantly and independently associated with poor progression-free survival. Moreover, high NLR and PS ≥2 were significantly associated with short overall survival.

CONCLUSION

A high pre-treatment NLR was associated with significantly short progression-free and overall survival in previously untreated patients with NSCLC with high expression of programmed cell-death ligand 1 treated with pembrolizumab monotherapy.

Abstract B043: Identification of secreted PD-L1 variants as a decoy of PD-L1 blockade antibody mediating the therapeutic resistance

Immune checkpoint blockade therapy targeting PD-L1/PD-1 have been widely used and shown remarkable clinical response in various cancers. However, therapeutic resistance after initial response is increasingly observed and the detailed mechanisms of resistance have yet to be fully understood. Recently, several mechanisms including loss-of-function alteration in genes related to antigen presentation and interferon-receptor signaling have been suggested to induce the resistance to PD-1 blockade treatment, yet few studies have focused on anti-PD-L1 (aPD-L1) blockade therapy. In current study, we performed whole exome sequencing and RNA-sequencing analysis in two non-small cell lung cancer (NSCLC) patients who were refractory during aPD-L1 therapy. We have identified the mutations in RNA splicing related gene, TARDBP/TDP-43, which were uncovered as hot spot mutations in Amyotrophic lateral sclerosis (ALS), and found two unique secreted PD-L1 variants, which lacked the transmembrane domain by aberrant RNA splicing. These secreted PD-L1 variants were shown to be stable by pulse chase assay, and worked as “decoys” of aPD-L1 antibody in the HLA-matched coculture system of iPSC-derived CD8 T cells and cancer cells. Moreover, expression of secreted mPD-L1 variant in mouse MC38 cancer cells conferred the resistance to PD-L1 blockade therapy, and soluble PD-L1 were time dependently accumulated in plasma using the MC38 syngeneic mice model. To further investigate the presence of secreted PD-L1 splicing variants in patients, we additionally analyzed 15 specimen who were resistant to anti-PD-L1 treatment by RNA-seq. We revealed that approximately 20% of therapeutic resistant patients harbored secreted PD-L1 variants and several new mutations in JAK1/2, the key mediator of interferon-receptor signaling, were found in a part of patients as well. Furthermore, we also identified the presence of secreted PD-L1 variants in the surgical specimens of squamous NSCLC patients without prior chemotherapy, targeted therapy, and /or immune-checkpoint inhibitor therapy. Consistent to the data, the plasma level of soluble PD-L1 in patients with secreted PD-L1 variants were high than those without the variants. Collectively, our results elucidated a novel resistant mechanism of PD-L1 blockade antibody mediated by secreted PD-L1 variants. The presence of sPD-L1 splicing variants or the level of soluble PD-L1 in plasma or pleural effusion may work as a biomarker to predict a patient’s response to PD-L1 blockade therapy.

Citation Format: Bo Gong, Kazuma Kiyotani, Seiji Sakata, Ken Takahashi, Seiji Nagano, Shun Kumehara, Satoko Baba, Benjamin Besse, Noriko Yanagitani, Luc Friboulet, Makoto Nishio, Kengo Takeuchi, Hiroshi Kawamoto, Naoya Fujita, Ryohei Katayama. Identification of secreted PD-L1 variants as a decoy of PD-L1 blockade antibody mediating the therapeutic resistance [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B043. doi:10.1158/1535-7163.TARG-19-B043

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.

Correlation between serum adenosine deaminase activity and efficacy of anti-programmed cell death-1 antibody

OBJECTIVE

Serum adenosine deaminase (ADA) activity is a marker of immune reaction to several diseases. We evaluated changes in serum ADA in patients with lung cancer undergoing chemotherapy or anti-programmed cell death-1 (PD-1) therapy to examine the correlation between serum ADA and the therapy efficacy.

MATERIALS AND METHODS

We assessed 50 patients with advanced lung cancer receiving chemotherapy or anti-PD-1 therapy. Serum ADA was measured before and on day 7 of the first treatment cycle and day 0 of subsequent cycles. Correlations between ADA change and efficacy of treatment were evaluated.

RESULTS

Of the 50 patients, 20 were treated with chemotherapy and 30 were treated with anti-PD-1 therapy. Serum ADA decreased significantly between baseline and day 7 of the first cycle in patients undergoing chemotherapy, regardless of response (partial response [PR] or stable disease [SD]: -23% [-38 to +32; p =  0.002]; progressive disease [PD]: -12% [-42 to +6; p =  0.500]). Conversely, in patients undergoing anti-PD-1 therapy, serum ADA increased significantly between baseline and 7 days after the first dose and before subsequent doses in patients who had PR or SD. (day 7 of first cycle: +6% [-10 to +34; p =  0.034], day 0 of second cycle: 8% [-5 to +37; p =  0.002], day 0 of third cycle: 9% [-3 to +55; p =  0.002]). However, serum ADA did not significant change in PD patients undergoing anti-PD-1 therapy. Furthermore, early increases in serum ADA were associated with longer progression-free survival in patients receiving anti-PD-1 therapy (p =  0.006).

CONCLUSION

Changes in serum ADA could be used to predict clinical benefit from anti-PD-1 therapy in patients with lung cancer. The association between changes in serum ADA and the efficacy of ant-PD-1 therapy thus remains inconclusive and requires further study.

Correlation between thyroid transcription factor-1 expression, immune-related thyroid dysfunction, and efficacy of anti-programmed cell death protein-1 treatment in non-small cell lung cancer

Background

Recent studies have suggested a correlation between immune-related thyroid dysfunction (irTD) and the superior efficacy of anti-programmed cell death protein-1 (anti-PD-1) treatment in non-small cell lung cancer (NSCLC). Embryologically, the lung and thyroid are similar in origin, and thyroid transcription factor-1 (TTF-1) expresses in both organs, including NSCLC. We explored our hypothesis that TTF-1 expression in NSCLC might correlate with irTD incidence and anti-PD-1 treatment efficacy.

Methods

We identified 132 patients with NSCLC treated with anti-PD-1 antibody at our hospital between December 2015 and June 2017. We evaluated TTF-1 expression in tumor by immunohistochemistry using a mouse monoclonal antibody (clone 8G7G3/1, 1:100, Dako). IrTD was defined as two or more successive abnormal levels of thyroid-stimulating hormone (TSH) during anti-PD-1 treatment. We retrospectively assessed correlations between TTF-1 expression in tumor, irTD incidence, and anti-PD-1 treatment efficacy.

Results

Of 132 patients, 67 (51%) and 65 (49%) were positive and negative for TTF-1, respectively. We observed irTD in 19 patients (6 positives and 13 negatives for TTF-1). The incidence of irTD was 9% and 20% in TTF-1-positive and TTF-1-negative NSCLCs, respectively (P=0.086). Particularly, in non-squamous (NSQ) cell carcinomas, the irTD incidence was significantly higher in patients negative for TTF-1 (30%) than in those positive for TTF-1 (9%; P=0.010), and TTF-1 expression was identified as a significant risk factor for irTD on multivariate logistic regression analysis [odds ratio (OR), 0.18; 95% confidence interval (CI), 0.05-0.59; P=0.005]. Furthermore, longer median progression-free survival (10.3 months) was observed in patients with TTF-1-negative NSCLC with irTD compared to those with TTF-1-positive NSCLC with irTD, TTF-1-positive NSCLC without irTD, and TTF-1-negative NSCLC without irTD (4.2, 1.4, and 2.4 months, respectively).

Conclusions

TTF-1 expression in NSCLC might correlate with irTD and anti-PD-1 treatment efficacy.

Secreted PD-L1 variants mediate resistance to PD-L1 blockade therapy in non-small cell lung cancer

Therapeutic resistance to PD-L1 blockade therapy following an initial positive response is increasingly observed. Gong et al. show that secreted PD-L1 splicing variants act as “decoys,” mediating resistance to the PD-L1 blockade therapy.

Immune checkpoint blockade against programmed cell death 1 (PD-1) and its ligand PD-L1 often induces durable tumor responses in various cancers, including non–small cell lung cancer (NSCLC). However, therapeutic resistance is increasingly observed, and the mechanisms underlying anti–PD-L1 (aPD-L1) antibody treatment have not been clarified yet. Here, we identified two unique secreted PD-L1 splicing variants, which lacked the transmembrane domain, from aPD-L1–resistant NSCLC patients. These secreted PD-L1 variants worked as “decoys” of aPD-L1 antibody in the HLA-matched coculture system of iPSC-derived CD8 T cells and cancer cells. Importantly, mixing only 1% MC38 cells with secreted PD-L1 variants and 99% of cells that expressed wild-type PD-L1 induced resistance to PD-L1 blockade in the MC38 syngeneic xenograft model. Moreover, anti–PD-1 (aPD-1) antibody treatment overcame the resistance mediated by the secreted PD-L1 variants. Collectively, our results elucidated a novel resistant mechanism of PD-L1 blockade antibody mediated by secreted PD-L1 variants.

First-in-Human Phase I Study of an Oral HSP90 Inhibitor, TAS-116, in Patients with Advanced Solid Tumors

HSP90 is involved in stability and function of cancer-related proteins. This study was conducted to define the MTD, safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor efficacy of TAS-116, a novel class, orally available, highly selective inhibitor of HSP90. Patients with advanced solid tumors received TAS-116 orally once daily (QD, step 1) or every other day (QOD, step 2) in 21-day cycles. Each step comprised a dose escalation phase to determine MTD and an expansion phase at the MTD. In the dose escalation phase, an accelerated dose-titration design and a "3+3" design were used. Sixty-one patients were enrolled in Japan and the United Kingdom. MTD was determined to be 107.5 mg/m2/day for QD, and 210.7 mg/m2/day for QOD. In the expansion phase of step 1, TAS-116 was administered 5 days on/2 days off per week (QD × 5). The most common treatment-related adverse events included gastrointestinal disorders, creatinine increases, AST increases, ALT increases, and eye disorders. Eye disorders have been reported with HSP90 inhibitors; however, those observed with TAS-116 in the expansion phases were limited to grade 1. The systemic exposure of TAS-116 increased dose-proportionally with QD and QOD regimens. Two patients with non-small cell lung cancer and one patient with gastrointestinal stromal tumor (GIST) achieved a confirmed partial response. TAS-116 had an acceptable safety profile with some antitumor activity, supporting further development of this HSP90 inhibitor.This is a result from a first-in-human study, in which the HSP90 inhibitor TAS-116 demonstrated preliminary antitumor efficacy in patients with advanced solid tumors, including those with heavily pretreated GIST.

Prediction of ALK mutations mediating ALK-TKIs resistance and drug re-purposing to overcome the resistance

BACKGROUND

Alectinib has shown a greater efficacy to ALK-rearranged non-small-cell lung cancers in first-line setting; however, most patients relapse due to acquired resistance, such as secondary mutations in ALK including I1171N and G1202R. Although ceritinib or lorlatinib was shown to be effective to these resistant mutants, further resistance often emerges due to ALK-compound mutations in relapse patients following the use of ceritinib or lorlatinib. However, the drug for overcoming resistance has not been established yet.

METHODS

We established lorlatinib-resistant cells harboring ALK-I1171N or -G1202R compound mutations by performing ENU mutagenesis screening or using an in vivo mouse model. We performed drug screening to overcome the lorlatinib-resistant ALK-compound mutations. To evaluate these resistances in silico, we developed a modified computational molecular dynamic simulation (MP-CAFEE).

FINDINGS

We identified 14 lorlatinib-resistant ALK-compound mutants, including several mutants that were recently discovered in lorlatinib-resistant patients. Some of these compound mutants were found to be sensitive to early generation ALK-TKIs and several BCR-ABL inhibitors. Using our original computational simulation, we succeeded in demonstrating a clear linear correlation between binding free energy and in vitro experimental IC50 value of several ALK-TKIs to single- or compound-mutated EML4-ALK expressing Ba/F3 cells and in recapitulating the tendency of the binding affinity reduction by double mutations found in this study. Computational simulation revealed that ALK-L1256F single mutant conferred resistance to lorlatinib but increased the sensitivity to alectinib.

INTERPRETATION

We discovered lorlatinib-resistant multiple ALK-compound mutations and an L1256F single mutation as well as the potential therapeutic strategies for these ALK mutations. Our original computational simulation to calculate the binding affinity may be applicable for predicting resistant mutations and for overcoming drug resistance in silico. FUND: This work was mainly supported by MEXT/JSPS KAKENHI Grants and AMED Grants.

Epithelial-to-Mesenchymal Transition Is a Mechanism of ALK Inhibitor Resistance in Lung Cancer Independent of ALK Mutation Status

Mutations in the ALK gene are detectable in approximately 40% of ALK-rearranged lung cancers resistant to ALK inhibitors. Although epithelial-to-mesenchymal transition (EMT) is a mechanism of resistance to various targeted drugs, its involvement in ALK inhibitor resistance is largely unknown. In this study, we report that both ALK-mutant L1196M and EMT were concomitantly detected in a single crizotinib-resistant lesion in a patient with ALK-rearranged lung cancer. Digital PCR analyses combined with microdissection after IHC staining for EMT markers revealed that ALK L1196M was predominantly detected in epithelial-type tumor cells, indicating that mesenchymal phenotype and ALK mutation can coexist as independent mechanisms underlying ALK inhibitor-resistant cancers. Preclinical experiments with crizotinib-resistant lung cancer cells showed that EMT associated with decreased expression of miR-200c and increased expression of ZEB1 caused cross-resistance to new-generation ALK inhibitors alectinib, ceritinib, and lorlatinib. Pretreatment with the histone deacetylase (HDAC) inhibitor quisinostat overcame this resistance by reverting EMT in vitro and in vivo. These findings indicate that HDAC inhibitor pretreatment followed by a new ALK inhibitor may be useful to circumvent resistance constituted by coexistence of resistance mutations and EMT in the heterogeneous tumor. SIGNIFICANCE: These findings show that dual inhibition of HDAC and ALK receptor tyrosine kinase activities provides a means to circumvent crizotinib resistance in lung cancer.

Lung Adenocarcinoma with Lynch Syndrome and the Response to Nivolumab

Lynch syndrome is caused by mutations in mismatch repair genes that lead to microsatellite instability (MSI). An increased number of mutation-associated neoantigens have been observed in patients with high-frequency MSI (MSI-H) cancer; in addition, membranous programmed death ligand-1 (PD-L1) tends to be expressed at higher levels in MSI-H cancers than in microsatellite-stable cancers. MSI-H cancer patients are therefore considered to be susceptible to immune checkpoint blockade. We herein report for the first time a case of lung adenocarcinoma with Lynch syndrome and the response to nivolumab.

Characterization of Computed Tomography Imaging of Rearranged During Transfection-rearranged Lung Cancer

BACKGROUND

Rearranged during transfection (RET)-rearranged non-small-cell lung cancer (NSCLC) is relatively rare and the clinical and computed tomography (CT) image characteristics of patients with an advanced disease stage have not been well documented.

PATIENTS AND METHODS

We identified patients with advanced-stage RET-rearranged NSCLC treated in the Cancer Institute Hospital, Japanese Foundation for Cancer Research, and analyzed the clinical and CT imaging characteristics.

RESULTS

In 21 patients with advanced RET-rearranged NSCLC, RET rearrangements were identified using fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction. The fusion partner genes were identified as KIF5B (57%), CCDC6 (19%), and unknown (24%). CT imaging showed that 12 primary lesions (92%) were peripherally located and all were solid tumors without ground-glass, air bronchograms, or cavitation. The median size of the primary lesions was 30 mm (range, 12-63 mm). Of the 18 patients with CT images before initial chemotherapy, 12 (67%) showed an absence of lymphadenopathy. Distant metastasis included 13 with pleural dissemination (72%), 10 with lung metastasis (56%), 8 with bone metastasis (44%), and 2 with brain metastasis (11%).

CONCLUSION

Advanced RET-rearranged NSCLC manifested as a relatively small and peripherally located solid primary lesion with or without small solitary lymphadenopathy. Pleural dissemination was frequently observed.

Dramatic response to alectinib in inflammatory myofibroblastic tumor with anaplastic lymphoma kinase fusion gene

Inflammatory myofibroblastic tumor (IMT) is a neoplasm characterized by the proliferaton of myofibroblasts with the infiltration of inflammatory cells. There is no standard treatment for patients with recurrent or metastatic IMT. We describe here a patient with hyper-progressive IMT with an anaplastic lymphoma kinase (ALK) fusion gene that dramatically responded to alectinib without adverse events. His dramatic and enduring response supports the observation that alectinib may be considered a good treatment option for rare aggressive ALK-positive tumors.

EGFR T790M mutation after chemotherapy for small cell lung cancer transformation of EGFR-positive non-small cell lung cancer

In non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor (EGFR) mutation, 50%–65% of cases acquire resistance after treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) because of an EGFR T790M point mutation and 3%–14% of these cases transformed to small cell lung cancer (SCLC). Generally, the EGFR T790M secondary mutation develops with ongoing ATP competitive inhibition. We present a case of a 76-year-old woman with lung adenocarcinoma harboring an EGFR-L858R mutation who received first-line gefitinib and developed SCLC transformation. She was administered several chemotherapy agents, including a platinum doublet. The primary lesion that showed SCLC transformation had reconverted to adenocarcinoma with EGFR L858R and T790M mutations at the time of a second re-biopsy. Therefore, she was administered osimertinib, which resulted in clinical remission. This case suggested that serial biopsies are necessary even after SCLC transformation.

High ratio of T790M to EGFR activating mutations correlate with the osimertinib response in non-small-cell lung cancer

OBJECTIVES

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that can overcome resistance due to the Thr790Met (T790M) mutation. However, osimertinib occasionally shows limited efficacy in a small population of patients. We investigated the correlation between the ratio of T790M to EGFR activating mutation and the response to osimertinib.

MATERIALS AND METHODS

Between April 2016 and April 2017, 44 patients started osimertinib therapy at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research. We performed EGFR mutation analysis of cytological samples from 33 patients using droplet digital PCR. We calculated the ratio of T790M to EGFR activating mutations and correlated it with the systemic response to osimertinib.

RESULTS

In tumors from the 33 patients, the average ratio of T790M to EGFR activating mutations was 0.420. Twenty-one of the 33 patients had tumors with a T790M ratio of ≥0.4. The osimertinib response rate was significantly higher (92.3%) in patients with a T790M ratio of ≥0.4 than in those with a T790M ratio of <0.4 (52.6%; p = 0.0237). We examined the correlation between the T790M ratio and the tumor reduction rate and obtained a coefficient of r = 0.417 (p = 0.0175). In patients with a T790M ratio of ≥0.4, the median progression-free survival was 355 days, which was longer, but not significant, than that in patients with a T790M ratio of <0.4 (median: 264 days). In patients with a T790M ratio of ≥0.4, the median treatment duration from first-line therapy onward was 931 days, which was significantly longer than that in patients with a T790M ratio of <0.4 (median, 567.5 days) (p = 0.044).

CONCLUSION

The T790M ratio to EGFR activating mutation in tumor may correlate with the response to osimertinib, and patients with a higher T790M ratio have a longer treatment history.