Plasma Epidermal Growth Factor Research Articles

Plasma EGFR mutation ctDNA dynamics in patients with advanced EGFR-mutated NSCLC treated with Icotinib: phase 2 multicenter trial result

Plasma epidermal growth factor receptor mutation (EGFRm) circulating tumor DNA (ctDNA) dynamics exhibit promise in predicting outcomes in patients with EGFRm-advanced non-small cell lung cancer (NSCLC). However, there remains limited trial-level data on integrating ctDNA monitoring into clinical practice. We performed a prospective, multicenter trial to investigate the relationship between EGFRm ctDNA dynamic changes and clinical outcomes in NSCLC patients with EGFRm. Ninety-eight treatment-naive EGFRm-advanced NSCLC patients were recruited and administered icotinib until disease progression. Plasma samples were collected at baseline and four weeks after icotinib administration. ctDNA was analyzed using a droplet-digital polymerase chain reaction. At baseline, 71.4% of patients had detectable EGFRm ctDNA. Among them, 45.9% of patients’ ctDNA became undetectable within four weeks of treatment. These patients demonstrated significantly longer progression-free survival (PFS) and overall survival (OS) than those with detectable ctDNA after treatment (P = 0.004 and < 0.001, respectively) and were comparable to those with undetectable ctDNA at both baseline and four weeks. ctDNA detectable at four weeks emerged as a poor independent risk factor for PFS and OS. Patients whose ctDNA became undetectable after treatment had outcomes similar to those with initially undetectable ctDNA, underscoring the predictive value of ctDNA dynamics in treatment efficacy.Registry and the Registration No. of the study/trial: ChiCTR-DDD-17013131. Date of registration: 2017-10-27.

Early Clearance of Plasma Epidermal Growth Factor Receptor Mutations as a Predictor of Outcome on Osimertinib in Advanced Non-Small Cell Lung Cancer; Exploratory Analysis from AURA3 and FLAURA.

Plasma circulating tumor DNA (ctDNA) analysis is used for genotyping advanced non-small cell lung cancer (NSCLC); monitoring dynamic ctDNA changes may be used to predict outcomes. This was a retrospective, exploratory analysis of two phase III trials [AURA3 (NCT02151981), FLAURA (NCT02296125)]. All patients had EGFR mutation-positive (EGFRm; ex19del or L858R) advanced NSCLC; AURA3 also included T790M-positive NSCLC. Osimertinib (FLAURA, AURA3), or comparator EGFR-tyrosine kinase inhibitor (EGFR-TKI; gefitinib/erlotinib; FLAURA), or platinum-based doublet chemotherapy (AURA3) was given. Plasma EGFRm was analyzed at baseline and Weeks 3/6 by droplet digital PCR. Outcomes were assessed by detectable/non-detectable baseline plasma EGFRm and plasma EGFRm clearance (non-detection) at Weeks 3/6. In AURA3 (n = 291), non-detectable versus detectable baseline plasma EGFRm had longer median progression-free survival [mPFS; HR, 0.48; 95% confidence interval (CI), 0.33-0.68; P < 0.0001]. In patients with Week 3 clearance versus non-clearance (n = 184), respectively, mPFS (months; 95% CI) was 10.9 (8.3-12.6) versus 5.7 (4.1-9.7) with osimertinib and 6.2 (4.0-9.7) versus 4.2 (4.0-5.1) with platinum-pemetrexed. In FLAURA (n = 499), mPFS was longer with non-detectable versus detectable baseline plasma EGFRm (HR, 0.54; 95% CI, 0.41-0.70; P < 0.0001). For Week 3 clearance versus non-clearance (n = 334), respectively, mPFS was 19.8 (15.1 to not calculable) versus 11.3 (9.5-16.5) with osimertinib and 10.8 (9.7-11.1) versus 7.0 (5.6-8.3) with comparator EGFR-TKI. Similar outcomes were observed by Week 6 clearance/non-clearance. Plasma EGFRm analysis as early as 3 weeks on-treatment has the potential to predict outcomes in EGFRm advanced NSCLC.

Osimertinib treatment based on plasma T790M monitoring in patients with EGFR-mutant non-small-cell lung cancer (NSCLC): EORTC Lung Cancer Group 1613 APPLE phase II randomized clinical trial

The APPLE trial aimed to evaluate the feasibility of longitudinal plasma epidermal growth factor receptor (EGFR) T790M monitoring for the best sequencing strategy of gefitinib and osimertinib. APPLE is a randomized, non-comparative, phase II study in patients with common EGFR-mutant, treatment-naive non-small-cell lung cancer including three arms: arm A (osimertinib upfront until RECIST progression, PD), arm B [gefitinib until emergence of circulating tumor DNA (ctDNA) EGFR T790M mutation by cobas EGFR test v2 or RECIST PD], and arm C (gefitinib until RECIST PD), and then switch to osimertinib in both arms. The primary endpoint is the progression-free survival (PFS) rate 'on osimertinib' at 18 months (PFSR-OSI-18) after randomization in arm B (H0: PFSR-OSI-18 of ≤40%). Secondary endpoints include response rate, overall survival (OS), and brain PFS. We report the results of arms B and C. From November 2017 to February 2020, 52 and 51 patients were randomized into arms B and C, respectively. Most patients were females (70%) and had EGFR Del19 (65%); one-third had baseline brain metastases. In arm B, 17% of patients (8/47) switched to osimertinib based on the emergence of ctDNA T790M mutation before RECIST PD, with a median time to molecular PD of 266 days. The study met its primary endpoint of PFSR-OSI-18 of 67.2% (84% confidence interval 56.4% to 75.9%) in arm B versus 53.5% (84% confidence interval 42.3% to 63.5%) in arm C, with a median PFS of 22.0 months versus 20.2 months, respectively. The median OS was not reached in arm B versus 42.8 months in arm C. Median brain PFS in arms B and C was 24.4 and 21.4 months, respectively. The serial monitoring of ctDNA T790M status in advanced EGFR-mutant non-small-cell lung cancer during treatment with first-generation EGFR inhibitors was feasible, and a molecular progression before RECIST PD led to an earlier switch to osimertinib in 17% of patients with satisfactory PFS and OS outcomes.

Comparative analysis of QS3D versus droplet digital PCR for quantitative measures of EGFR T790M mutation from identical plasma

ObjectivesThe capacity of QuantStudio™ 3D (QS3D) and droplet digital PCR (dPCR) for the detection of plasma Epidermal Growth Factor Receptor (EGFR) mutations have been widely reported. Few comparative studies on the quantitative test of the identical DNA material, however, are carried out. Here we compared the performance of the two methods in detecting EGFR T790M mutation in cell-free DNA (cfDNA) from the same lung cancer patients. MethodsWe recruited 72 non-small cell lung cancer (NSCLC) patients who initially respond to tyrosine kinase inhibitor treatment but subsequently developed resistance. Two tubes of 10mL anticoagulant blood were collected and cfDNA was isolated from plasma. Identical cfDNA samples were analyzed for T790M mutation using QS3D and droplet dPCR in parallel. ResultsT790M mutation was detected in 15 and 21 cfDNA samples by QS3D and droplet digital PCR, respectively. The 6 discordant samples showed low mutation abundance (∼0.1%) and the discrepancy is caused by the stricter threshold settings for QS3D dPCR. The overall agreement between the two methods was 91.7% (66/72). The median allele frequencies for QS3D dPCR and droplet dPCR to detect T790M mutation was 2.01% and 2.62%, respectively. There was no significance in mutation abundance detected by both methods. Both methods are highly correlated with allele frequencies and copy numbers in T790M wild type and mutant, with R2 of 0.98, 0.92 and 0.95, respectively. ConclusionOur study demonstrated that QS3D dPCR are highly consistent with droplet PCR for quantitative determination of EGFR T790M mutation in plasma cfDNA.

Clinical Practice Guidelines for Pre-Analytical Procedures of Plasma Epidermal Growth Factor Receptor Variant Testing.

Standardization of cell-free DNA (cfDNA) testing processes is necessary to obtain clinically reliable results. The pre-analytical phase of cfDNA testing greatly influences the results because of the low proportion and stability of circulating tumor DNA (ctDNA). In this review, we provide evidence-based clinical practice guidelines for pre-analytical phase procedures of plasma epidermal growth factor receptor gene (EGFR) variant testing. Specific recommendations for pre-analytical procedures were proposed based on evidence from the literature and our experimental data. Standardization of pre-analytical procedures can improve the analytical performance of cfDNA testing.

MO021ENHANCED MCP-1 RELEASE IN EARLY AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Abstract Background and Aims Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in either the PKD1 or PKD2 gene. While kidney failure typically occurs in adulthood, the disease starts in utero. The best change of preserving renal function long term might be the use of agents with few side effects as early as possible. For this approach, both better early prognostic stratification and novel treatment options are needed. The pediatric phase of ADPKD, while kidney function is still normal and before significant tissue destruction has occurred could be the best stage both to identify and study prognostic biomarkers as well as to identify novel targets for early treatment. Copeptin (a surrogate for vasopressin), epidermal growth factor (EGF) ( a measure for functional tubular mass) and monocyte chemoattractant protein-1 (MCP-1) ( a chemoattractant for macrophages) are associated with severity and hold prognostic value in adults but remain unstudied in the early disease stage. Kidneys from adults with ADPKD exhibit macrophage infiltration, and a prominent role of MCP-1 secretion by tubular epithelial cells is suggested from rodent models. Method A monocentric cross-sectional study in a tertiary referral center was performed. All consenting genotyped ADPKD patients attending the outpatient pediatric ADPKD clinic of the university hospital of Leuven and age, sex and BMI matched healthy controls were included between June and October 2017. Plasma copeptin, urinary EGF and urinary MCP-1 were evaluated. MCP-1 was studied in mouse collecting duct cells, human proximal tubular cells and fetal kidney tissue. Results 53 genotyped ADPKD patients and 53 controls were included. Mean (SD) age was 10.4 (5.9) vs 10.5 (6.1) years (P=0.543), and eGFR 122.7 (39.8) vs 114.5 (23.1) ml/min/1.73 m2 (P= 0.177) in patients vs controls respectively. Outcome parameters in table. Plasma copeptin and EGF secretion were comparable between both groups. Median (IQR) urinary MCP-1 (pg/mg creatinine) was significantly higher in ADPKD patients (185.4 (213.8)) compared to controls (154.7 (98.0)) (P= 0.010). Human proximal tubular cells with a heterozygous PKD1 mutation and mouse collecting duct cells with a PKD1 knockout exhibited increased MCP-1 secretion triggered by fetal bovine serum. Human fetal ADPKD kidneys displayed prominent MCP-1 immunoreactivity and M2 macrophage infiltration. Conclusion An increase in tubular MCP-1 secretion is an early event in ADPKD, long before kidney function decline and in children with few kidney cysts. MCP-1 is a promising early disease severity marker and a potential treatment target.

Enhanced MCP-1 Release in Early Autosomal Dominant Polycystic Kidney Disease

IntroductionAutosomal dominant polycystic kidney disease (ADPKD) causes kidney failure typically in adulthood, but the disease starts in utero. Copeptin, epidermal growth factor (EGF), and monocyte chemoattractant protein-1 (MCP-1) are associated with severity and hold prognostic value in adults but remain unstudied in the early disease stage. Kidneys from adults with ADPKD exhibit macrophage infiltration, and a prominent role of MCP-1 secretion by tubular epithelial cells is suggested from rodent models.MethodsIn a cross-sectional study, plasma copeptin, urinary EGF, and urinary MCP-1 were evaluated in a pediatric ADPKD cohort and compared with age-, sex-, and body mass index (BMI)-matched healthy controls. MCP-1 was studied in mouse collecting duct cells, human proximal tubular cells, and fetal kidney tissue.ResultsFifty-three genotyped ADPKD patients and 53 controls were included. The mean (SD) age was 10.4 (5.9) versus 10.5 (6.1) years (P = 0.543), and the estimated glomerular filtration rate (eGFR) was 122.7 (39.8) versus 114.5 (23.1) ml/min per 1.73 m2 (P = 0.177) in patients versus controls, respectively. Plasma copeptin and EGF secretion were comparable between groups. The median (interquartile range) urinary MCP-1 (pg/mg creatinine) was significantly higher in ADPKD patients (185.4 [213.8]) compared with controls (154.7 [98.0], P = 0.010). Human proximal tubular cells with a heterozygous PKD1 mutation and mouse collecting duct cells with a PKD1 knockout exhibited increased MCP-1 secretion. Human fetal ADPKD kidneys displayed prominent MCP-1 immunoreactivity and M2 macrophage infiltration.ConclusionAn increase in tubular MCP-1 secretion is an early event in ADPKD. MCP-1 is an early disease severity marker and a potential treatment target.

Comprehensive evaluation of the clinical utility of plasma EGFR test in non-small cell lung cancer patients with acquired resistance to first-line EGFR inhibitors.

BackgroundPlasma epidermal growth factor receptor (EGFR) mutation tests are widely used when non-small cell lung cancer (NSCLC) patients acquire resistance to EGFR inhibitors. We comprehensively evaluated the clinical utility of plasma EGFR test.MethodsWe screened NSCLC patients who had a plasma EGFR test upon acquiring resistance to first- or second-generation EGFR inhibitors. Plasma EGFR tests were performed with the EGFR mutation test.ResultsA total of 355 patients were tested for plasma EGFR mutations, and T790M was detected in 83 patients (23%). Of 79 patients who were tested multiple times, T790M was newly detected in 13 subsequent plasma tests. When initial plasma tests did not detect any EGFR mutation types, the detection rate of T790M in subsequent tests was very low (9%, 5/56), while detection rates of T790M in subsequent tests increased (35%, 8/23) in those individuals in whom sensitizing mutations had been detected in the initial plasma test (P=0.005). Paired plasma and tissue EGFR test results were available for 235 patients. Sensitivity and specificity of the plasma tests for T790M were 14% and 87%, respectively. Among 235 patients, 140 patients had tissue EGFR tests performed after T790M-negative plasma results were reported. The subsequent tissue test detected T790M in 61% (44/72) of these patients when any EGFR mutations were not detected in prior plasma tests, while the detection rate of T790M in subsequent tissue tests was 37% (25/68) when sensitizing mutations were detected in prior plasma tests (P=0.004).ConclusionsBecause the sensitivity of plasma EGFR test for T790M is low, follow-up tissue or plasma tests are necessary. Presence or absence of a sensitizing mutation in the initial plasma tests can be used to determine which samples (tissue or plasma) should be submitted for further testing.

Alteration of inflammatory factors between chronic stroke and post‐stroke dementia: A cross‐sectional study

AbstractBackgroundInflammation may play a role in the pathological processes of stroke and post‐stroke dementia. However, there has not been compared and discussed upon the alterations among the plasma inflammatory factors from stroke to post‐stroke dementia.MethodIn this study, an age‐ and gender‐matched normal controls and ischemic stroke patients with (PSD) or without (PSNoD) dementia had been recruited. The ischemic stroke patients had further examined the 30‐day Modified Rankin scale (MRS), stroke infarction subtypes, anti‐cholinergic treatment status and Clinical Dementia Rating (CDR). Levels of plasma inflammatory factors epidermal growth factor (EGF), growth‐regulated oncogene (GRO), soluble CD40 ligand (sCD40L), Interleukin 7 (IL‐7) and Interleukin 4 (IL‐4) were measured by Milliplex map human cytokine/chemokine magnetic bead panel assay. The butylcholinesterase (BChE) activity and plasma D‐amino acid oxidase (DAO) were also included in these analyses due to our previous published report [1, 2].ResultThe ischemic stroke patients showed significantly higher percentage of hypertension (HTN), Diabetes mellitus (DM) and self‐report smoking than normal controls (p&lt;0.01). Normal controls had significant higher plasma EGF, GRO, sCD40L, IL‐7, but lower plasma DAO levels than the ischemic stroke patients (p&lt;0.003). In comparisons between the PSD and PSNoD patients, the PSD showed significantly higher 30‐day MRS, CDR, percentage of anti‐cholinergic treatment than the PSNoD (p&lt;0.014) after adjust with age. The plasma BChE activity showed lower levels in PSD than PSNoD (p=0.0002) after adjust with age.ConclusionThe inflammatory factors of EGF, GRO, sCD40L, IL‐7 and plasma DAO levels were mainly associated with ischemic stroke. The BChE activity may be a better indicator for the post‐stroke dementia.

Longitudinal multi-gene panel assessment of circulating tumor DNA revealed tumor burden and molecular characteristics along treatment course of non-small cell lung cancer.

BackgroundMost studies associating circulating tumor DNA (ctDNA) with outcome in lung cancer treatment were either cross-sectional or, if longitudinal, only analyzed a limited number of genes. This study evaluated the potential of utilizing ctDNA profiled by a panel of common cancer genes to monitor tumor burden and to reveal molecular characteristics of tumor along treatment course.MethodsTwenty Chinese non-small cell lung cancer (NSCLC) patients with serial plasma samples collected (I) before starting on either first- or second-line treatment, (II) at stable disease on treatment, and (III) upon disease progression, were analyzed for mutations in ctDNA using the PGDx 64-gene panel. Paired statistics compared mutation profiles between any two of the three time points.ResultsProportions with detectable ctDNA decreased from 65% at baseline to 35% at stable disease and rose to 80% at progression (P=0.012, between stable disease and progression); median ctDNA levels (mutated fragments per mL) were 7.8, 0, and 24.7 at the three time points, respectively (P=0.013 between baseline and progression; P=0.007 between stable disease and progression). Although plasma epidermal growth factor receptor (EGFR) mutations were commonly detected, 15% of patients had mutations other than EGFR detected during progression, such as various types of TP53 mutations.ConclusionsctDNA profiling in serial blood samples reflected tumor burden over time, and a multi-gene panel was more sensitive in indicating lung cancer progression on treatment than a single gene approach. The detection of additional oncogenic mutations or their disappearance suggested evolution of tumor heterogeneity along treatment course.

An investigation of the equine epidermal growth factor system during hyperinsulinemic laminitis.

Equine laminitis is a disease of the digital epidermal lamellae typified by epidermal cell proliferation and structural collapse. Most commonly the disease is caused by hyperinsulinemia, although the pathogenesis is incompletely understood. Insulin can activate the epidermal growth factor (EGF) system in other species and the present study tested the hypothesis that upregulation of EGF receptor (EGFR) signalling is a key factor in laminitis pathophysiology. First, we examined lamellar tissue from healthy Standardbred horses and those with induced hyperinsulinemia and laminitis for EGFR distribution and quantity using immunostaining and gene expression, respectively. Phosphorylation of EGFR was also quantified. Next, plasma EGF concentrations were compared in healthy and insulin-infused horses, and in healthy and insulin-dysregulated ponies before and after feeding. The EGFR were localised to the secondary epidermal lamellae, with stronger staining in parabasal, rather than basal, cells. No change in EGFR gene expression occurred with laminitis, although the receptor showed some phosphorylation. No difference was seen in EGF concentrations in horses, but in insulin-dysregulated ponies mean, post-prandial EGF concentrations were almost three times higher than in healthy ponies (274 ± 90 vs. 97.4 ± 20.9 pg/mL, P = 0.05). Although the EGFR does not appear to play a major pathogenic role in hyperinsulinemic laminitis, the significance of increased EGF in insulin-dysregulated ponies deserves further investigation.

Epidermal growth factor attenuates lingual papillae lesions in a rat model of sialoadenectomy

Salivary epidermal growth factor (EGF) plays an important role in the maintenance of the oral and gastro-esophageal mucosa. Sialoadenectomy delays healing of oral wounds and affects lingual papillae. In this work, we aimed to determine the effect of EGF deficiency induced by sialoadenectomy and evaluate the effect of exogenous EGF administration on the lingual papillae and taste buds in rats. Thirty male adult Wistar albino rats were equally divided into 3 groups; sham-operated control group, sialoadenectomy group and group of sialoadenectomy + EGF. EGF was given 8 weeks after sialoadenectomy in a dose of 1 μg /ml/day in drinking water for 2 weeks. The anterior two-thirds of the tongue was dissected and cut longitudinally into two halves; one half for light microscope and the other for electron microscope examinations. Saliva and blood were collected to determine salivary and plasma EGF. Our results revealed that sialoadenectomy significantly reduced plasma and saliva levels of EGF which resulted in severe disruption of the architecture of lingual papillae. These changes were effectively improved by the exogenous EGF administration. In conclusion, EGF supplementation reversed the effects of sialoadenectomy and restored almost normal architecture of lingual papillae and taste buds.

Decreased plasma epidermal growth factor (EGF) levels in patients with severe chronic obstructive pulmonary disease

Abstract Background Chronic mucus hypersecretion is a common feature in chronic obstructive pulmonary disease (COPD) and is associated with epidermal growth factor (EGF) activity. Aberrant EGF and its receptor signalling can cause airway hyperproliferation, increase in mucous cell differentiation and mucus hyperproduction. Furthermore, it can also promote subepithelial fibrosis and excessive collagen deposition in COPD. The objective of this research was to investigate the plasma levels of EGF in smokers with COPD in comparison with clinically healthy smokers. In addition, the relationship between the plasma levels of EGF and clinical features was investigated. Methods A cross-sectional study included 82 clinically stable male patients with mild-to-very severe COPD (mean age: 64.5±8.6 years), and the control group consisted of 86 healthy male smokers (mean age: 61.6±9.5 years). To define COPD, we performed spirometry and classified COPD using Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification. We analyzed the levels of EGF by enzyme-linked immunosorbent assay in plasma. Results The mean serum levels of EGF were significantly lower in smokers with COPD than those in controls (69.30 and 83.82 pg/mL, respectively, p = 0.046). The plasma levels of EGF were significantly different (p = 0.004) between mild COPD and moderate-to-very severe COPD. There were no significant differences between the levels of EGF in plasma of spontaneous sputum producers (COPD patients) vs. nonsputum producers (p = 0.101) and between nonexacerbated COPD and exacerbated COPD patients(p = 0.138). Conclusions There is a significant difference in the plasma levels of EGF in male smokers with COPD as compared with male healthy smokers. Our findings suggest that the plasma levels of EGF may contribute to the pathogenesis of COPD.

Facilitating Resolution of Life-Threatening Acute Graft-Versus-Host Disease By Supplementation of Human Chorionic Gonadotropin and Epidermal Growth Factor (Pregnyl): A Phase I Study

INTRODUCTIONPatients with severe acute graft-versus-host disease (aGVHD) are at high risk of death due to damaged organs and tissues. We have previously shown that severe aGVHD is characterized by an imbalance of circulating tissue repair factors, with elevated amphiregulin (AREG) and very low (<10 pg/ml) plasma epidermal growth factor (EGF). We hypothesized that giving supplemental EGF, contained in an inexpensive, commercially available drug (urinary-derived human chorionic gonadotropin [hCG], Pregnyl®) in addition to standard aGVHD therapy would improve outcomes. HCG has well-known immunomodulatory properties, including shifting the balance of T cells toward a regulatory (Treg) phenotype that could also be beneficial in severe aGVHD. Therefore, we tested the use of hCG/EGF in patients with Minnesota High Risk and steroid dependent or refractory aGVHD to enhance both hCG-mediated immunologic tolerance and tissue repair via supplemental EGF in a phase I study. PATIENTS AND METHODSTwenty-six patients received hCG/EGF in addition to standard aGVHD therapy. We treated 13 patients with onset Minnesota High Risk aGVHD with high-dose steroids (methylprednisolone 48 mg/m2) plus subcutaneous (SQ) injections of hCG/EGF every other day for 7 days. In the 2nd line therapy cohort, we treated 13 patients with hCG/EGF SQ every other day for 14 days, recognizing the time to response may be longer in this cohort relative to those with onset aGVHD, along with increased steroids (steroid dependent, N=5) and intensified immune suppression (steroid refractory, N=8). We then assessed response after 7 days in High Risk aGVHD and after 14 days in steroid dependent/refractory aGVHD. In both cohorts, patients with a complete or partial response (CR/PR) at the end of the initial dosing period were eligible to receive maintenance hCG/EGF SQ twice weekly for up to 5 weeks, whereas patients with no response (NR) received no further study drug doses and received best available therapy from their treating physicians. Initial hCG dosing was at 500 units hCG/m2 SQ, escalating to 2,000 units hCG/m2 in cohorts of 2, with dose assignment by the continual reassessment method. We analyzed GVHD-associated plasma biomarkers and enumerated circulating CD4+FoxP3+CD127- Tregs and CD8+ T lymphocytes during therapy. RESULTSHCG/EGF was well tolerated, with no dose-limiting toxicities. The median EGF dose was 50,833 pg/ml. The most common treatment emergent side effect was edema (N=16, 62%). At day 28 of study, responses for initial therapy were 8/13 CR (62%), 0/13 PR (0%), and 5/13 NR (38%), higher than institutional historical (n=269) 26% CR, 16% PR, 57% NR (Figure 1A). Responses for 2nd line therapy were 7/13 CR (54%), 1/13 PR (8%), 5/13 NR (38%), 4 of which were deaths (31%), improved relative to historical outcomes (n=85) of 18% CR, 19% PR, 63% NR (including 16% deaths, Figure 1A). Cytopenias were not worse during hCG/EGF; responders had a slight leukocytosis (day 7 median white blood cells [WBC] 9.7 x 109/L), returning to baseline (WBC 5.8 x 109/L, p=0.015) by day 56. Patients had increases in serum hCG (median 1.5 vs 138 IU/L, p<0.001), estradiol (median 12 vs 36 pg/ml, p=0.003), and testosterone (median 106 vs 450 ng/dl, p=0.01) from baseline to day 7; all returned to baseline by day 56. In initial therapy patients, plasma EGF rose from baseline 3 pg/ml to 25.4 pg/ml at 6 hours post-hCG/EGF dose (p=0.02); while in 2nd line patients, plasma EGF never rose from baseline 5 pg/ml. Treg expansion peaked at 131% of baseline at day 7 in Arm 1, and 145% of baseline at day 14 in Arm 2. Patients with a day 28 CR/PR had a higher median Treg/CD8 ratio at day 28 (0.11 vs 0.01, p=0.03) and a 4.6-fold reduction in plasma AREG over time (baseline median 99.6 pg/ml to 21.8 pg/ml at day 56, p=0.006, Figure 1B). CONCLUSIONSHCG/EGF is a novel and well-tolerated adjunct therapy in high-risk and steroid-dependent/refractory aGVHD, associated with minimal toxicity and encouraging response rates. The mechanisms of benefit may include immunomodulation via Treg expansion despite high-dose steroids and facilitation of tissue repair with detectable increases in circulating EGF. The optimal dose and duration of hCG/EGF are under investigation, with ongoing dose escalation in patients with steroid-refractory aGVHD based upon these initial results. Decreasing plasma AREG over time may reflect successful treatment of life-threatening aGVHD. DisclosuresHoltan:Incyte: Consultancy. Bachanova:Gamida Cell: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; GT Biopharma: Research Funding. Brunstein:Gamidacell: Research Funding. Ustun:novartis: Speakers Bureau. Wagner:Novartis: Research Funding; Magenta Therapeutics: Consultancy, Research Funding. Blazar:Kadmon Corporation, LLC: Consultancy, Research Funding. MacMillan:Angiocrine: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Consultancy; Equillium: Consultancy. Weisdorf:SL Behring: Consultancy; FATE: Consultancy; Equillium: Consultancy; Seattle Genetics: Consultancy; Pharmacyclics: Consultancy.

Elevated AREG/EGF Ratio Prior to Transplantation Is Associated with Pre-Transplant Clostridium Difficile Infection, Unresolved Tissue Damage, and Poorer Overall Survival

Hematopoietic cell transplantation (HCT) is curative for many malignancies and genetic disorders but is hampered by significant early morbidity related to infection, regimen-related toxicities, acute graft versus host disease (GVHD), and risk of relapse. An excess risk of early death may be predicted by biomarkers associated with tissue healing, inflammation, and angiogenesis, as complementary to clinical variables. We have previously shown that pre-transplant low levels of one such biomarker, epidermal growth factor (EGF), is associated with poor survival after HCT. We have also shown that another EGF receptor ligand, amphiregulin (AREG), is elevated at the onset of aGVHD and is associated with a poor prognosis, especially if markedly elevated relative to EGF. AREG is active in type 2 immune responses and in dampening localized inflammation, but it found in the circulation in the states of unresolved tissue damage. We hypothesized that an elevated AREG relative to EGF prior to HCT would be associated with poor survival.To test this hypothesis, we measured pre-HCT plasma EGF and AREG in 142 pediatric and adult HCT recipients from 2015-2017, with patients undergoing HCT for both malignant and non-malignant disease using various stem cell sources, GVHD prophylaxis, and conditioning regimens. We measured baseline plasma concentration of factors associated with tissue damage and repair, AREG by ELISA and EGF, vascular endothelial growth factor-A (VEGF-A), and placental growth factor (PlGF) by multiplex. We determined the optimal cutpoint for dichotomized analyses of AREG/EGF based on overall survival (OS) through 12 months post-transplant by method of Contal and O'Quigley, choosing a point that maximizes the log-rank statistic.Patients (table) had a median 2.1 years of follow-up and a median baseline AREG/EGF ratio of 0.3 (IQR 0.1 - 1.7). A high baseline AREG/EGF ratio (cutoff of ≥2.5, in 30 patients, 21%) was associated with a >2-fold increased risk of all-cause mortality after HCT (HR 2.1, p = 0.037, Figure 1A). Clinical factors such as age, donor type, conditioning, disease, and overall comorbidity were not related to baseline AREG/EGF ratio. However, more patients with a baseline high AREG /EGF ratio had infections requiring systemic treatment at the time of transplant (26.7% vs 11.6%, p=0.039), higher rates of recent C. difficileinfections (23.3% vs 9.7%, p=0.046), suggesting a vulnerability to dysbiosis. Furthermore, a high AREG/EGF ratio at baseline was associated with other plasma biomarkers associated with tissue injury, with lower VEGF-A levels (61 vs 226 pg/ml, p<0.001, Figure 1B) and higher PlGF levels (34 vs 23 pg/ml, p=0.01, Figure 1C) prior to transplantation.In this large and broad cohort of allograft recipients, over 20% of pediatric and adult HCT recipients have an elevated plasma AREG/EGF ratio prior to transplantation. These patients have a biomarker profile of unresolved tissue injury (low VEGF-A and high PlGF) and more frequent infections at the time of transplantation, including C. difficile. Further research into the systemic effects of dysbiosis may clarify the pathophysiology of this elevated AREG/EGF ratio and unresolved tissue injury. If confirmed, baseline AREG/EGF could identify patients most likely to benefit from novel tissue and/or microbial restorative therapies prior to HCT. [Display omitted] DisclosuresMacMillan:Equillium: Consultancy; CSL Behring: Consultancy; Angiocrine: Membership on an entity's Board of Directors or advisory committees. Weisdorf:Equillium: Consultancy; FATE: Consultancy; Seattle Genetics: Consultancy; SL Behring: Consultancy; Pharmacyclics: Consultancy. Holtan:Incyte: Consultancy.

461P - The role of plasma epidermal growth factor receptor mutations test in non-small cell lung cancer

Background: Detecting epidermal growth factor receptor (EGFR) mutated in NSCLC patients by plasma samples (ctDNA) is a non-invasive method, which has demonstrated many substantial benefits in clinical practice. In this study, we evaluated the possibility of detecting EGFR mutations in plasma of stage IIIB-IV NSCLC patients, and monitoring the genetic changes of mutations in the course of treatment. Methods: Prospective study with longitudinal follow-up. Plasma and tissue samples of 73 stage IIIB-IV NSCLC cases, including 68 cases of newly diagnosed and 5 cases of EGFR mutation positive being underwent treatment were analyzed to define EGFR mutation status. Pyrosequencing was used for tumor tissue, and scorpions ARMS was used for plasma analysis. Response evaluation based on criteria RECIST v.1.1. Results: EGFR mutation frequency was 45.6% (31/68) in tissue samples, and 29.4% (20/68) in plasma samples. The difference was statistically significant (p = 0.026) with EGFR mutations frequency in tissue and plasma samples. Concordance rate of EGFR mutation test between ctDNA and tumor samples was 83.8% (95%CI: 72.9 - 91.6), with sensitivity was 65.4% (95%CI: 45.4 - 80.8), and specificity was 100.0% (95%CI: 90.5 - 100.0). Positive predict value and negative predict value of EGFR mutations testing with ctDNA was 100.0% (95%CI: 83.2 - 100.0) and 77.1% (95%CI: 62.7 - 88.0) respectively. Concordance rate, sensitivity and specificity of 19del mutations were 91.2%, 68.4% and 100.0% respectively; according to T790M mutation were 92.6%, 25.0% and 96.9% respectively; and according to L858R mutation were 95.6%, 70.0%, and 100.0% respectively. Secondary T790M mutation was 44.4% (4/9) cases of acquired resistance of EGFR TKIs, after a median time of about 11.9 months. Conclusions: With high concordance rate and specificity, EGFR mutation testing with ctDNA by scorpions ARMS technology will be a good choice if the tissue sample is insufficient, and demonstrates the feasibility in monitoring the acquired resistance T790M mutation. However, it is necessary to test with tissue sample to have confirmed result. Legal entity responsible for the study: Ethics Committees of Cho Ray hospital Funding: Qiagen Global for patient free testing. AstraZeneca Vietnam for publishing. Disclosure: All authors have declared no conflicts of interest.

Correlation of Plasma EGF with Striatal Dopamine Transporter Availability in Healthy Subjects

We aimed to evaluate the association between plasma epidermal growth factor (EGF) and the availability of dopamine transporter (DAT) measured from 123I-FP-CIT single-photon emission computed tomography in healthy controls in this study. Volume of interest template was applied to measure specific binding ratios (SBRs) of caudate nucleus, putamen, and striatum representing DAT availability as follows; SBR = (target– cerebellum)/cerebellum. Plasma EGF was negatively correlated with the availabilities of both caudate nucleus (r = −0.261, p = 0.019), and putamen (r = −0.341, p = 0.002). After dividing subjects according to Apo E genotyping, DAT availability of caudate nucleus of Apo e4 non-carriers (n = 60) showed the positive correlation with cerebrospinal fluid (CSF) α-synuclein (r = 0.264, p = 0.042). Plasma EGF was negatively correlated with DAT availabilities of Apo e4 non-carriers. Further studies are needed to clarify underlying mechanisms of this phenomenon.

Effect of psoriasis activity and topical treatment on plasma epidermal growth factor (EGF) and its soluble receptor (sEGFR)

Background: Pathogenesis of psoriasis involves epidermal growth factor (EGF) that participates in keratinocyte proliferation, angiogenesis and cell differentiation through binding to soluble epidermal growth factor receptor (sEGFR). It is synthesised by, among others, keratinocytes, especially within psoriatic skin.Objective: To evaluate EGF and sEGFR plasma concentrations during topical psoriatic treatment.Methods: Blood samples were collected from 51 patients with plaque psoriasis. EGF and sEGFR plasma concentrations were examined with immunoenzymatic method prior and 14 days after topical treatment. The outcomes were analyzed with respect to PASI.Results: Mean EGF concentration was higher in the plasma of psoriatic patients compared to the control group (p = .401) while mean sEGFR concentration was over twofold lower compared to the control group (p < .001). After the therapy, an insignificant decrease in EGF plasma concentration (p = .835) and a significant increase in sEGFR concentration (p = .017) compared to initial values were observed. The coefficient of EGF/sEGFR concentration calculated for each individual had similar values before and after the treatment (p = .009), both of which were significantly higher compared to control group (respectively p < .001, p < .008).Conclusion: Epidermal growth factor and its soluble receptor may be a useful markers in monitoring clinical course of psoriasis and the effectiveness of therapy.

Association of mutant EGFR L858R and exon 19 concentration in circulating cell-free DNA using droplet digital PCR with response to EGFR-TKIs in NSCLC.

The present study aimed to determine the diagnostic concordance of plasma epidermal growth factor receptor (EGFR) mutation using droplet digital polymerase chain reaction (ddPCR) with tumor tissue samples and the predictive clinical significance of plasma EGFR mutation concentration. Plasma DNA samples from patients with non-small cell lung cancer (NSCLC) were analyzed for EGFR exon 21 codon 858 (L858R) mutation, deletion of exon 19 (ex19del) and exon 20 codon 790 (T790M) mutation using ddPCR. Firstly, the mutations in the plasma samples were compared with the matched tumor samples to determine the concordance. Secondly, image examination follow-ups were analyzed to assess the association between plasma EGFR mutation concentration and patients' response to EGFR-tyrosine kinase inhibitors (TKIs). A total of 51 patients with NSCLC were enrolled, including 48 newly diagnosed patients. Compared with tumor tissue samples, the sensitivity and specificity of ddPCR were 76.19% (16/21) and 96.55% (28/29) for mutant L858R, and 88.89% (8/9) and 100% (41/41) for ex19del, respectively. No patient exhibited the T790M mutation in the tumor tissue or plasma samples. Furthermore, 5 patients with the L858R mutation and 4 patients with ex19del in plasma and tumor tissue samples had been followed up with image examination for ≥3 months following EGFR-TKI treatment. The baseline mutant EGFR concentrations were positively correlated with a reduction in tumor burden (Spearman's r=0.7000, P=0.0358). When analyzed separately, ex19del concentrations (Spearman's r=1.0000, P<0.0001) were also positively correlated with the reduction, while mutant L858R concentrations were not (Spearman's r=0.7000, P=0.1881). In the present study, detection of plasma EGFR mutations using ddPCR exhibited sufficient concordance with tumor tissue sample results. Baseline plasma mutant EGFR and ex19del concentrations were significantly and positively correlated with response to EGFR-TKIs.

Low EGF in myeloablative allotransplantation: association with severe acute GvHD in BMT CTN 0402.

Epidermal growth factor (EGF) is a recently described biomarker of acute GvHD (aGvHD). Whether low plasma EGF prior to hematopoietic cell transplantation (HCT) predisposes to the development of aGvHD, or whether EGF levels fall because of severe aGvHD, is unknown. To evaluate this, we tested plasma samples collected at pre-HCT baseline, day +28 and day +100 during the course of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0402. We found that baseline EGF plasma concentrations were three-fold lower in HCT recipients compared to donors (24.3 vs 76.0 pg/mL, P<0.01). Ninety-one patients (43%) had a markedly low plasma EGF at pre-HCT baseline, defined as <2.7 pg/mL-an optimal cutpoint associated with development of grade III-IV aGvHD. Patients with these low EGF levels at pre-HCT baseline had a 2.9-fold increased risk of grade III-IV aGvHD by day +100. Patients with low EGF at day +28 after HCT had an increased risk of death (relative risk 2.3, P=0.02) by 1 year due to transplant-related toxicities, especially aGvHD. Our results suggest that very low plasma EGF early in the HCT process may predispose patients to an increased risk of death, potentially due to epithelial damage and limited repair capacity.