Functional Analysis of PTH1R Variants Found in Primary Failure of Eruption

Although many variants of the parathyroid hormone 1 receptor (PTH1R) gene are known to be associated with primary failure of eruption (PFE), the mechanisms underlying the link remains poorly understood. We here performed functional analyses of PTH1R variants reported in PFE patients-namely, 356C>T (P119L), 395C>T (P132L), 439C>T (R147C), and 1148G>A (R383Q)-using HeLa cells with a lentiviral vector-mediated genetic modification. Two particular variants, P119L and P132L, had severe reduction in a level of N-linked glycosylation when compared with wild-type PTH1R, whereas the other 2 showed modest alteration. PTH1R having P119L or P132L showed marked decrease in the affinity to PTH_1-34, which likely led to severely impaired cAMP accumulation upon stimulation in cells expressing these mutants, highlighting the importance of these 2 amino acid residues for ligand-mediated proper functioning of PTH1R. To further gain insights into PTH1R functions, we established the induced pluripotent stem cell (iPSC) lines from a patient with PFE and the heterozygous P132L mutation. When differentiated into osteoblastic-lineage cells, PFE-iPSCs showed no abnormality in mineralization. The mRNA expression of RUNX2, SP7, and BGLAP, the osteoblastic differentiation-related genes, and that of PTH1R were augmented in both PFE-iPSC-derived cells and control iPSC-derived cells in the presence of bone morphogenetic protein 2. Also, active vitamin D₃ induced the expression of RANKL, a major key factor for osteoclastogenesis, equally in osteoblastic cells derived from control and PFE-iPSCs. In sharp contrast, exposure to PTH_1-34 resulted in no induction of RANKL mRNA expression in the cells expressing P132L variant PTH1R, consistent with the idea that a type of heterozygous PTH1R gene mutation would spoil PTH-dependent response in osteoblasts. Collectively, this study demonstrates a link between PFE-associated genetic alteration and causative functional impairment of PTH1R, as well as a utility of iPSC-based disease modeling for future elucidation of pathogenesis in genetic disorders, including PFE.

Simple standard equation for daily step count in Japanese patients with chronic obstructive pulmonary disease

Purpose

The improvement of physical activity in patients with COPD is an important issue. However, no standard for the recommended number of steps for patients with COPD has been determined. We conducted a retrospective observational study to create a simple standard equation for the daily step count, which makes it easier to determine whether each subject is attaining his/her predicted value or not.

Patients and methods

Stable outpatients diagnosed with COPD whose physical activities had been measured using a triaxial accelerometer for more than 2 weeks were recruited from 5 institutes in Japan. Factors associated with the step count were detected by multivariate regression analysis. After the data were transformed to a normalized distribution, a multivariate linear regression equation was created using stepwise regression.

Results

One hundred sixty-two patients aged 72.3 (7.2) years and of FEV1 %pred 59.2 (22.8) % were recruited. Among the parameters, age, mMRC dyspnea scale and inspiratory capacity (IC) were detected by the stepwise method. The created standard equation was “Step count = (−0.079×[age]−1.595×[mMRC]+2.078×[IC]+18.149)³”. The correlations between the calculated values and the measured values were observed, and fixed, and proportional biases between them were also observed. When patients with <6500 steps/day were selected, no systematic bias between them could be detected.

Conclusion

A simple standard equation for Japanese patients with COPD was created using age, mMRC and IC, and could provide an individual-predicted value, especially for patients with <6500 steps/day.

Abstract 414: Detection of AXL-expressing circulating tumor cells (CTCs) in non-small-cell lung cancer (NSCLC) patients using an automated microcavity array (MCA) system

Purpose: Noninvasive diagnostics has been developed over the last decade and we have previously reported that CTCs can be utilized for evaluating molecular features of NSCLC. AXL, a receptor tyrosine kinase is linked to epithelial-to-mesenchymal transition (EMT) leading to cancer progression and regarded as a potential therapeutic target. However, many of current technologies rely on epithelial markers to detect CTCs and that makes it difficult to detect AXL-expressing CTCs. Here, we established the detection of AXL expression on CTCs using MCA system.

Methods: Preclinical experiments were performed using NSCLC cell lines H1299, PC9, and HCC827 and a breast cancer cell line MDA-MB231 with varying cytokeratin (CK) and AXL expression levels. The cells were spiked into 3 ml of peripheral blood from healthy donors, then enriched using MCA system, and detected by staining for CD45, DAPI, CK or vimentin (VM) with the addition staining for AXL. For clinical evaluation, 3ml of peripheral blood was collected from advanced NSCLC patients.

Results: DAPI-positive, CK or VM-positive, and CD45-negative cells were defined as CTCs. In spike-in experiments, when CK was used as a marker, AXL expression was detected in 5 and 17% of high CK-expressing HCC827 and PC9 cells, respectively and detected in 52 and 75% of low CK-expressing H1299 and MDA-MB231 cells, respectively. On the other hand, when VM was used as a marker, AXL expression was detected in 72 and 88% of high VM-expressing MDA-MB231 and H1299 cells, respectively whereas detected in 1 and 7% of PC9 and HCC827 cells with low VM expression, respectively. Twenty-four patients were enrolled in the clinical study. The patient characteristics were as follows: median age 69.5 years (range, 49-84); male 88%; stage III/IV, 25/75%; adenocarcinoma/ squamous cell carcinoma/ other, 63/33/4%. Both CK and VM staining in 17 patients, only CK in 6 patients, and only VM in 1 patient were performed. CK-positive single CTCs were detected in all patients (median, 4; range, 1-50) and AXL-expressing CK-positive single CTCs were detected in 26% of patients (median, 0; range, 0-1). On the other hand, VM-positive single CTCs were detected in 94% of patients (median, 6.5; range, 0-128) and AXL-expressing VM-positive single CTCs were detected in 89% of patients (median, 1; range, 0-106). Significantly more AXL-expressing single CTCs were detected in VM-positive than CK-positive (p &lt; 0.001). Notably, all of identified CTC clusters were positive for only VM, not CK and AXL-expressing CTC clusters were detected in 33% of patients (median, 0; range, 0-22).

Conclusion: Our data indicate that incorporating VM staining is necessary to detect AXL-positive CTCs due to EMT. Further clinical evaluation is warranted for validating the method and the clinical significance of AXL-positive CTCs.

Citation Format: Mio Ikeda, Yasuhiro Koh, Shunsuke Teraoka, Jun Oyanagi, Kuninobu Kanai, Atsushi Hayata, Nahomi Tokudome, Hiroaki Akamatsu, Yuichi Ozawa, Keiichiro Akamatsu, Masayuki Higuchi, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Detection of AXL-expressing circulating tumor cells (CTCs) in non-small-cell lung cancer (NSCLC) patients using an automated microcavity array (MCA) system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 414.

Abstract 416: Predictive significance of serum protein levels in advanced non-small-cell lung cancer patients treated with pembrolizumab

Background: We have previously reported that serum IL-8 and G-CSF were correlated with clinical benefit and immune-related adverse events (irAE), respectively in non-small-cell lung cancer (NSCLC) patients treated with nivolumab. Here, we measured multiple serum proteins serially in NSCLC patients treated with pembrolizumab and explored the potential of predicting clinical response or irAE onset. This study was registered at UMIN (ID: 000024414).

Patients and Methods: Advanced NSCLC patients received pembrolizumab monotherapy (200 mg/body, q3W) until progressive disease (PD) or unacceptable toxicity. Serum samples were collected at baseline and at week 6. Best response was classified into partial response (PR), stable disease (SD), or progressive disease (PD) according to RECIST v1.1. Using LuminexTM xMapTM technology, serum levels of 41 proteins consisting of cytokines, chemokines, growth factors, and angiogenesis factors were measured. All statistical analyses were carried out using JMP Pro software (ver. 13.0) and Mann-Whitney U test were performed accordingly. A p value &lt;0.05 was considered as significant.

Results: Thirty-seven patients were registered in the study between March 2017 and October 2018 at Wakayama Medical University Hospital and 32 were included in the final analysis. Demographics of the patients were as follows: median age 70 (range, 50 to 91); male 75%; smoker 88%; stage III/IV, 22/78%; squamous/non-squamous, 31/69%, previous treatment; 0/1≤, 47/53%. Objective response rate was 28% and disease control rate was 56% in the entire cohort and 40% and 67%, respectively in the first-line subset. Among 41 serum proteins measured, no serum protein at baseline was associated with efficacy or irAE onset in the entire cohort. Levels of serum VEGF-C and sCD40L at baseline, however, in the first-line subset were found significantly lower in the patient who had PR and SD than those who did not. RANTES was also found significantly lower in patients who had PR in the 2nd or later line subset. With regard to irAE prediction, changes of HB-EGF levels between baseline and week 6 were significantly smaller in irAE patients in the entire cohort and changes of MCP-1 levels were significantly smaller in irAE patients in second or later line subset. The serum proteins identified in the current study were not overlapped with those identified in advanced NSCLC patients treated with nivolumab in the previous study.

Conclusions: We identified potential serum protein markers associated with clinical benefit and irAE from pembrolizumab treatment in advanced NSCLC by multi-analyte protein-based assay. Our results suggest that serum proteins associated with efficacy and irAE may vary among different anti-PD-1 antibodies and also between in the first-line setting and later one.

Citation Format: Jun Oyanagi, Yasuhiro Koh, Shunsuke Teraoka, Kuninobu Kanai, Atsuhsi Hayata, Nahomi Tokudome, Hiroaki Akamatsu, Yuichi Ozawa, Keiichiro Akamatsu, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Predictive significance of serum protein levels in advanced non-small-cell lung cancer patients treated with pembrolizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 416.

Outbreak of aseptic meningitis caused by echovirus 30 in Kushiro, Japan in 2017

BACKGROUND

Echovirus 30 (E30) is one of the most common causative agents for aseptic meningitis.

OBJECTIVES

In the autumn of 2017, there was an outbreak caused by E30 in Kushiro, Hokkaido, Japan. The aim of this study was to characterize this outbreak.

STUDY DESIGN

Fifty-nine patients were admitted to the Department of Pediatrics, Kushiro Red Cross Hospital (KRCH) with clinical diagnosis of aseptic meningitis. Among those, 36 patients were finally diagnosed as E30-associated aseptic meningitis by the detection of viral RNA using reverse transcription-polymerase chain reaction (RT-PCR) and/or the evidence of more than four-fold rise in neutralizing antibody (NA) titers in the convalescent phase relative to those in the acute phase. We investigated these 36 confirmed cases.

RESULTS

The median age was 6 years (range: 6 months-14 years). The positive signs and symptoms were as follows: fever (100%), headache (94%), vomiting (92%), jolt accentuation (77%), neck stiffness (74%), Kernig sign (29%), and abdominal pain (28%). The median cerebrospinal fluid (CSF) white cell count, neutrophil count, and lymphocyte count were 222/μL (range: 3-1434/μL), 144/μL (range: 1-1269/μL), and 85/μL (range: 2-354/μL), respectively. Although the detected viral genes demonstrated same cluster, they were different from E30 strains observed in Japan between 2010 and 2014.

CONCLUSION

We mainly showed clinical and virological features of the E30-associated aseptic meningitis outbreak that occurred in Kushiro. To prevent further spread of E30 infection, continuous surveillance of enterovirus (EV) circulation and standard precautions are considered essential.

Heterogeneous Expression of Programmed Death Receptor-ligand 1 on Circulating Tumor Cells in Patients With Lung Cancer

BACKGROUND

Blockade of the programmed death receptor-1 (PD-1) pathway is effective against solid tumors including lung cancer. PD-ligand 1 (PD-L1) expression on tumor tissue serves as a predictive biomarker for the efficacy of PD-1 pathway blockade. Here, we evaluated the expression of PD-L1 on circulating tumor cells (CTCs) in patients with lung cancer.

MATERIALS AND METHODS

Peripheral whole blood (3 mL) was collected from patients, and CTCs and PD-L1 expression were detected using a microcavity array (MCA) system. Immunohistochemistry for PD-L1 detection was also performed using matched tumor tissues.

RESULTS

Sixty-seven patients with lung cancer were enrolled in the study between July 2015 and April 2016 at Wakayama Medical University Hospital. The characteristics of the patients were as follows: median age, 71 years (range, 39-86 years); male, 72%; stage II to III/IV, 14%/85%; non-small-cell lung cancer/small-cell lung cancer/other, 73%/21%/6%. CTCs were detected in 66 of 67 patients (median, 19; range, 0-115), and more than 5 CTCs were detected in 78% of patients. PD-L1-expressing CTCs were detected in 73% of patients, and the proportion score of PD-L1-expressing CTCs ranged from 3% to 100%, suggesting intra-patient heterogeneity of PD-L1 expression on CTCs. Tumor tissues were available from 27 patients and were immunostained for PD-L1, and no correlation was observed between tumor tissues and CTCs based on the proportion score (R² = 0.0103).

CONCLUSION

PD-L1 expression was detectable on CTCs in patients with lung cancer, and intra-patient heterogeneity was observed. No correlation was observed between PD-L1 expression in tumor tissues and CTCs.

Predictive value of serum protein levels in patients with advanced non-small cell lung cancer treated with nivolumab

BACKGROUND

Although programmed cell death-ligand-1 (PD-L1) expression in tumor tissue has been established as predictive biomarker for the anti-programmed cell death-1 (PD-1) antibody treatment of non-small-cell lung cancer (NSCLC), additional biomarkers are critically needed. We evaluated serum proteins relevant to immune checkpoint blockade in patients with NSCLC treated with nivolumab to identify novel non-invasive predictive biomarkers.

PATIENTS AND METHODS

Patients with advanced NSCLC, who had failed at least one prior chemotherapy regimen, received nivolumab monotherapy (3 mg/kg, Q2W) until progressive disease (PD) or unacceptable toxicity was observed. Blood samples were collected at baseline and week 4. Fifty-seven serum protein levels were quantified with a Milliplex MAP assay. The associations of both clinical benefit (CB) and the onset of immune related adverse events (irAEs) with serum proteins levels were evaluated.

RESULTS

Thirty-eight patients with advanced NSCLC were enrolled in the study, with 38 and 32 paired serum samples at baseline and week 4 being available for efficacy analysis and irAE analysis, respectively. In durable CB (DCB) patients compared with non-DCB patients, the baseline serum levels of BMP-9 were significantly higher, whereas the follistatin, IL-8, IP-10, and TNF-α levels were significantly lower. In irAE patients compared with non-irAE patients the serum levels of G-CSF and RANTES at week 4 were significantly higher, whereas the levels of leptin were significantly lower. A multivariate analysis revealed that follistatin and IP-10 were statistically associated with DCB (p < 0.05) and RANTES was associated with irAE onset (p < 0.05). In a subset of irAE-developed patients, RANTES levels decreased after steroid administration, supporting its involvement in irAE.

CONCLUSION

Serum proteins have the potential to be predictive markers for DCB and irAEs onset in patients with NSCLC treated with nivolumab. In addition, antitumor activity and irAEs may not be regulated by the same mechanisms.

Periodically repeated rituximab administrations in children with refractory nephrotic syndrome: 2-year multicenter observational study

BACKGROUND

Rituximab (RTX) is effective in maintaining remission in patients with nephrotic syndrome (NS), but a standard protocol of RTX administration has not been established.

METHODS

This study was a 2-year multicenter observational study, in which consistent treatments and evaluations were performed. We enrolled pediatric patients with refractory NS between January 2015 and December 2015. RTX infusion was performed four times at 6-month intervals, followed by mizoribine pulse therapy with early discontinuation of calcineurin inhibitor (CNI). Primary endpoints were the relapse-free survival rate and the number of relapses after RTX administration. Secondary endpoints were changes in side effects associated with long-term steroid administration.

RESULTS

Twenty-two patients were analyzed. The relapse-free survival rate at 1 year and 2 years was 50 and 46%, respectively. Twenty-one patients accomplished our protocol and the frequency of relapse was reduced under the discontinuation of CNI. Although two patients were diagnosed with frequent relapse and/or steroid dependency during the observation period, the frequency of relapse decreased with each rituximab dose. Statistically significant improvements in all steroid complications were observed in the final examination, but no significant improvements were observed from 1 to 2 years after RTX administration. One patient had agranulocytosis, and three patients showed electrocardiographic abnormalities.

CONCLUSIONS

Our protocol was useful and safe for refractory NS. However, RTX administration four times might have been excessive in patients who had no relapse by 1 year after the initial RTX administration. Further investigation of the most appropriate method of RTX administration is required.

Cathepsin K inhibitor causes changes in crystallinity and crystal structure of newly-formed mandibular bone in rats

Cathepsin K inhibitors are new drugs with the potential for the treatment of osteoporosis because they sustain bony remodelling better than bone resorption inhibitors such as bisphosphonates. The treatment of osteoporosis with inhibitors of bony resorption is associated with osteonecrosis of the jaw, as the deterioration in bony quality that they induce is thought to be one of its causes. The quality of bone is delineated by structural and material characteristics (which include the degree and quality of mineralisation, and depends on the content of proteoglycan and the structural integrity of the bony collagen).^1,2 Animal and clinical studies have shown that cathepsin K inhibitors improve the mineral density and structural characteristics of bone, but their effect on the rest remains unknown. We therefore hypothesised that these inhibitors will affect the material characteristics of newly-formed mandibular bone. To verify our hypothesis, we used Raman microspectroscopy to examine such bone in rats that were given a cathepsin K inhibitor, and found unusual crystallinity and an increased substitution of carbonate (CO₃^2-) in its crystal structure.

Abstract 2608: Predictive values of serum protein levels in advanced non-small cell lung cancer patients treated with nivolumab

Background: Though PD-ligand 1 (PD-L1) expression on tumor tissue has been established as companion diagnostics in non-small-cell lung cancer (NSCLC) for anti-PD-L1 treatment, additional biomarkers to enrich the patients likely to benefit from the therapy are critically needed. Here, we conducted a serial evaluation of multiple serum proteins relevant to the modulation of immune system in NSCLC patients treated with nivolumab.

Patients and Methods: Advanced NSCLC patients after failure of at least one prior chemotherapy regimen received nivolumab monotherapy (3mg/kg, q2W) until progressive disease (PD) or unacceptable toxicity. Serum samples were collected at baseline and at week 4. Best response was classified into partial response (PR), stable disease (SD), or progressive disease (PD) according to RECIST v1.1. Using LuminexTM xMapTM technology, serum levels of 54 proteins consisting of cytokines, chemokines, growth factors, and angiogenesis factors were measured. All statistical analyses were carried out using JMP Pro software (ver. 13.0) and Mann-Whitney U test and Spearman's test were performed accordingly. A p value &lt;0.05 was considered as significant.

Results: Thirty-eight patients were registered in the study between January 2016 and March 2017 at Wakayama Medical University Hospital and 34 were included in the final analysis. Demographics of the patients were as follows: median age 68 (range, 49 to 86); male 73 %; stage IV, 100 %; squamous/non-squamous, 30/70 %. Overall response rate was 22% (7/34), and disease control rate was 53% (18/34). Among 54 serum proteins measured serially, the level of serum TNF-α was significantly lower at baseline in non-PD patients than PD patients (p &lt; 0.05). The level of TNF-α was also correlated with longer progression free survival (PFS) (r= -0.5693). Serum IL-8 level at week 4 in PR patients were significantly lower than those in non-PR patients (p &lt;0.01) though no difference was observed at baseline between the two, supporting the relevance of serum IL-8 level to the efficacy of nivolumab. Correlation between IL-8 levels at week 4 and longer PFS turned out to be more significant (r=-0.6864). In addition, serum levels of VEGF-A, TGF-β1 and PDGF-AB/BB were significantly lower in PR patients than those in non-PR patients at week 4 (p &lt;0.05). However, these protein levels were not correlated with PFS.

Conclusions: We identified that the serum levels of IL-8, TNF-α, VEGF-A, TGF-β1 and PDGF-AB/BB as potential biomarkers to predict clinical benefit from nivolumab treatment in advanced NSCLC by multi-analyte protein-based assay. Incorporating additional serum protein levels may have potential to improve the patient enrichment besides previously reported potential biomarkers such as IL-8 and VEGF levels. Further evaluation is warranted in a larger cohort to validate the findings.

Citation Format: Jun Oyanagi, Yasuhiro Koh, Hiroaki Akamatsu, Kuninobu Kanai, Atsushi Hayata, Nahomi Tokudome, Keiichiro Akamatsu, Keiichiro Akamatsu, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Predictive values of serum protein levels in advanced non-small cell lung cancer patients treated with nivolumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2608.

Abstract 5595: Predictive impact of sequential evaluation of PD-L1-expressing circulating tumor cells in NSCLC patients treated with nivolumab

Background: Anti-PD-1 antibody nivolumab has become a new standard treatment for pretreated, advanced non-small cell lung cancer (NSCLC). Although PD-L1 expression on tumor tissue has a predictive value, significance of its expression on circulating tumor cells (CTCs) is unknown. Here, we conducted a sequential evaluation of PD-1-expressing CTCs in NSCLC patients treated with nivolumab.

Methods: Advanced NSCLC patients who received nivolumab at Wakayama Medical University Hospital were enrolled in the study (UMIN000024414). Nivolumab was administered 3 mg/kg bi-weekly until progressive disease (PD) or unacceptable toxicity. Peripheral whole blood (3 mL) was collected in an EDTA collection tube (BD vacutainer) and processed within 3 hours for CTC evaluation at baseline, week 4 and week 8. CTCs were detected using automated microcavity array system (Hitachi Chemical Co.). PD-L1 expression was immunohistochemically examined on both tumor tissues and CTCs using anti-PD-L1 antibody, clone 28-8 (Abcam).

Results: Thirty-eight patients were registered in the study between January 2016 and September 2016. Clinical characteristics of the patients were as follows: median age 68 (range, 49 to 86); male 73 %; stage IV 100 %; squamous/non-squamous, 30/65 %. Regarding nivolumab treatment, overall response rate (ORR) was 22% (95% confidence interval [CI]: 10-38%), and median progression-free survival (PFS) was 62 days (95%CI: 40-235 days). At baseline, CTCs were detected in all patients (median, 15; range, 1-90) and PD-L1-expressing CTCs were detected in 87% of patients. Tumor proportion score (TPS) of PD-L1 expression on CTCs varied from 6% to 100%. Matched tumor tissues were available from 14 patients and 7 showed the PD-L1 TPS ≥50%. PD-L1 status on CTCs was not correlated with that on tumor tissues both using proportional score and H score (Spearman's correlation: r = 0.0007 and 0.08, respectively). On CTCs, patients with PD-L1 ≥50 % have significantly higher disease control rate than those with below 50% (83.3% versus 36.4%, p&lt;0.01). Similarly, patients with PD-L1 ≥50 % on CTC had significantly longer PFS compared with those with below 50% (293 days versus 49 days, hazard ratio 2.41 (95% CI: 1.05-5.54), p = 0.03). During nivolumab treatment, number of CTCs was decreased (median number was 10 at 4 weeks, and 5 at 8 weeks). Among those with PD-L1 ≥50 % on CTC at baseline, changes in number and PD-L1 status on CTCs at 4 weeks did not correlate with PFS.

Conclusions: Sequential monitoring of PD-L1 expression on CTCs during nivolumab treatment was successfully conducted. PD-L1 expression on CTCs at baseline was a strong predictor in efficacy. Predictive significance of PD-L1-positive CTCs should be evaluated in a larger validation cohort.

Citation Format: Yasuhiro Koh, Hiroaki Akamatsu, Keita Mori, Kuninobu Kanai, Atsushi Hayata, Nahomi Tokudome, Masayuki Higuchi, Keiichiro Akamatsu, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Predictive impact of sequential evaluation of PD-L1-expressing circulating tumor cells in NSCLC patients treated with nivolumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5595.

Molecular alterations of newly formed mandibular bone caused by zoledronate

Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n=12), ovariectomized rats (OVX, n=12), and ovariectomized rats treated with zoledronate (ZOL, n=12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43±1.88 vs. 7.86±2.05), while crystallinity (0.055±0.002 vs. 0.050±0.002), relative proteoglycan content (0.43±0.10 vs. 0.31±0.05), and collagen structural integrity (1.16±0.21 vs. 0.72±0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.

Subxiphoid approach for extracting a giant solitary fibrous tumour of the pleura

We describe a case of resection of a solitary fibrous tumour of the pleura using video-assisted thoracic surgery and removal of the giant tumour using a subxiphoid incision without the need for minithoracotomy. Use of the subxiphoid approach as a retrieval port is simple and feasible.

Abstract A056: Sequential tracking of PD-L1 expression on circulating tumor cells in NSCLC patients treated with nivolumab

Background: Nivolumab (anti-PD-1 antibody) has become a new standard treatment in pretreated, advanced non-small cell lung cancer (NSCLC). Although strong expression of PD-L1 on tumor tissue has predictive value, significance of its expression on circulating tumor cell (CTC) is unknown and its status can be changed during the treatment. Here, we conducted a serial evaluation of PD-1-expressing CTCs in NSCLC patients treated with nivolumab. Methods: Advanced NSCLC patients who receive nivolumab at Wakayama Medical University Hospital were enrolled in this prospective observational study (registered at UMIN (000024414)). Nivolumab was administered 3 mg/kg biweekly until progressive disease (PD) or unacceptable toxicity. Peripheral whole blood (3 mL) was collected in a EDTA collection tube (BD vacutainer) and processed within 3 hours for CTC evaluation at baseline, week 4, and week 8. CTCs were detected using microcavity array system (Hitachi Chemical Co.). PD-L1 expression was immunohistochemically examined on both tumor tissues and CTCs using anti-PD-L1 antibody, clone 28-8 (Abcam). Results: Thirty-eight patients were registered in this study between January 2016 and September 2016. Clinical characteristics of the patients were as follows: median age 68 (range, 49 to 86); male 73%; stage IV 100%; squamous/non-squamous, 30/65%. Regarding nivolumab treatment, overall response rate (ORR) was 22% (95% confidence interval (CI): 10-38%), and median progression-free survival (PFS) was 62 days (95%CI: 40-235 days). At baseline, CTCs were detected in all patients (median, 15; range, 1-90) and PD-L1-expressing CTCs were detected in 87% of patients. Tumor proportion score (TPS) of PD-L1 expression on CTCs varied from 6% to 100%. Matched tumor tissues were available from 14 patients and 7 showed the PD-L1 TPS ≥ 50%. PD-L1 status on CTCs was not correlated with that on tumor tissues both using proportional score and H score (Spearman’s correlation: r = 0.0007 and 0.08, respectively). On CTCs, patients with PD-L1 ≥ 50 have significantly higher disease control rate than those with below 50% (83.3% versus 36.4%, p&lt;0.01). Similarly, patients with PD-L1 ≥ 50% on CTC was significantly longer PFS compared with those with below 50% (293 days versus 49 days, hazard ratio 2.41 (95% CI: 1.05-5.54), p = 0.03). During nivolumab treatment, number of CTCs was decreased (median number was 10 at 4 weeks and 5 at 8 weeks). Among those with PD-L1 ≥ 50% on CTC at baseline, changes in number and PD-L1 status on CTCs at 4 weeks did not correlate with PFS. Conclusions: Serial monitoring of PD-L1 expression on CTCs during nivolumab treatment was successfully conducted. PD-L1 expression on CTCs at baseline was a strong predictor in efficacy. Predictive significance of PD-L1-positive CTCs should be also evaluated in validation cohort using pembrolizumab.

Citation Format: Hiroaki Akamatsu, Yasuhiro Koh, Keita Mori, Kuninobu Kanai, Atsushi Hayata, Nahomi Tokudome, Masayuki Higuchi, HIsashige Kanbara, Keiichiro Akamatsu, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Sequential tracking of PD-L1 expression on circulating tumor cells in NSCLC patients treated with nivolumab [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A056.

Abstract A057: Serial evaluation of multiple serum protein levels in non-small lung cancer patients treated with nivolumab

Background: Blockade of programmed death receptor-1 (PD-1) pathway is effective against various malignancies. Although PD-ligand 1 (PD-L1) expression on tumor tissue has been established as companion diagnostics in non-small cell lung cancer (NSCLC), additional biomarkers to enrich the patients likely to benefit from the therapy are critically needed. Here, we conducted a serial evaluation of multiple serum cytokines, growth factors, and angiogenesis factors relevant to immune checkpoint blockade in NSCLC patients treated with nivolumab. Patients and Methods: Advanced NSCLC patients after failure of at least one prior chemotherapy regimen received nivolumab monotherapy (3mg/kg, q2W) until progressive disease (PD) or unacceptable toxicity. Serum samples were collected in a serum separation tube (Venoject II autosep, TERUMO) at baseline and at week 4. Best response was classified into partial response (PR), stable disease (SD), or progressive disease (PD) according to RECIST v1.1. Using LuminexTM xMapTM technology, serum levels of 54 proteins consisting of cytokines, chemokines, growth factors, and angiogenesis factors were analyzed. All statistical analyses were carried out using JMP Pro software (ver. 13.0) and Mann-Whitney U test and Spearman's test were performed accordingly. A p value &lt;0.05 was considered as significant. Results: Thirty-eight patients were registered in the study between January 2016 and March 2017 at Wakayama Medical University Hospital and 34 were included in the analysis. Demographics of the patients were as follows: median age 68 (range, 49 to 86); male 73 %; stage IV, 100%; squamous/non-squamous, 30/70 %. Overall response rate was 22% (7/34), and disease control rate was 53% (18/34). Among 54 serum proteins measured serially, the levels of serum IL-8 and TNF-α were significantly lower at baseline in non-PD patients than in PD patients (p &lt; 0.01 in both cases). In addition, the levels of both serum IL-8 and TNF-α were correlated with longer progression-free survival (PFS) (r=-0.4695 and -0.5912, respectively). It is noteworthy that serum IL-8 levels at week 4 in PR patients were significantly lower than those in non-PR patients (p &lt;0.01). Correlation between IL-8 levels at week 4 and longer PFS was shown to be more significant (r=-0.6864). Serum VEGF-A levels were significantly lower in PR patients than those in non-PR patients at week 4 (p &lt;0.05). Conclusions: We identified the serum levels of IL-8, TNF-α, and VEGF-A as potential biomarkers to predict clinical benefit from nivolumab treatment in advanced NSCLC by multi-analyte protein-based assay. Incorporating serum TNF-α levels may have potential to improve the patient enrichment in addition to previously reported potential biomarkers such as IL-8 and VEGF levels. Further evaluation is warranted in a larger cohort to validate the findings.

Citation Format: Jun Oyanagi, Yasuhiro Koh, Hiroaki Akamatsu, Kuninobu Kanai, Atsushi Hayata, Nahomi Tokudome, keiichiro Akamatsu, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Serial evaluation of multiple serum protein levels in non-small lung cancer patients treated with nivolumab [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A057.