Clinical Utility of Circulating Tumor DNA in Patients With Advanced KRASG12C-Mutated NSCLC Treated With Sotorasib

INTRODUCTION

For patients with KRASG12C-mutated NSCLC who are treated with sotorasib, there is a lack of biomarkers to guide treatment decisions. We therefore investigated the clinical utility of pretreatment and on-treatment circulating tumor DNA (ctDNA) and treatment-emergent alterations on disease progression.

METHODS

Patients with KRASG12C-mutated NSCLC treated with sotorasib were prospectively enrolled in our biomarker study (NCT05221372). Plasma samples were collected before sotorasib treatment, at first-response evaluation and at disease progression. The TruSight Oncology 500 panel was used for ctDNA and variant allele frequency analysis. Tumor response and progression-free survival were assessed per Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

Pretreatment KRASG12C ctDNA was detected in 50 of 66 patients (76%). Patients with detectable KRASG12C had inferior progression-free survival (hazard ratio [HR] 2.13 [95% confidence interval [CI]: 1.06-4.30], p = 0.031) and overall survival (HR 2.61 [95% CI: 1.16-5.91], p = 0.017). At first-response evaluation (n = 40), 29 patients (73%) had a molecular response. Molecular nonresponders had inferior overall survival (HR 3.58 [95% CI: 1.65-7.74], p = 0.00059). The disease control rate was significantly higher in those with a molecular response (97% versus 64%, p = 0.015). KRAS amplifications were identified as recurrent treatment-emergent alterations.

CONCLUSIONS

Our data suggest detectable pretreatment KRASG12C ctDNA as a marker for poor prognosis and on-treatment ctDNA clearance as a marker for treatment response. We identified KRAS amplifications as a potential recurring resistance mechanism to sotorasib. Identifying patients with superior prognosis could aid in optimizing time of treatment initiation, and identifying patients at risk of early progression could allow for earlier treatment decisions.

Hepatotoxicity in patients with non-small cell lung cancer treated with sotorasib after prior immunotherapy: a comprehensive clinical and pharmacokinetic analysis

BACKGROUND

Sotorasib given after immunotherapy could put patients at increased risk of hepatotoxicity. Therefore, there is a need to gain insight into the potential correlation between anti-PD-(L)1 treatment, anti-PD-(L)1 concentrations, sotorasib concentrations, and the incidence of hepatotoxicity during sotorasib.

METHODS

Patients with KRASG12C-mutated NSCLC treated with sotorasib were prospectively enrolled in our biomarker cohort study (NCT05221372). Plasma samples were collected prior and during sotorasib treatment for anti-PD-1 and sotorasib concentrations. ALT/AST/ALP/GGT increases were collected prospectively and graded according to CTCAEv5.0. Severe hepatotoxicity was defined as grade ≥3 ALT/AST/ALP/GGT increase.

FINDINGS

Of the 91 included patients, 80 (88%) received prior anti-PD-(L)1. Prior anti-PD-(L)1 and prior immune-related hepatotoxicity were associated with a higher incidence of severe hepatotoxicity (35% versus 0%, p = 0.016 and 75% versus 31%, p = 0.019, respectively). Patients with an interval of ≤6 weeks between anti-PD-(L)1 and sotorasib (n = 18) had a significantly higher incidence of severe hepatotoxicity than those with a 6-12 week (n = 24) and ≥12 week (n = 38) interval (83% versus 33% versus 13%, respectively, p < 0.0001). Sotorasib trough concentrations did not differ significantly between those with or without severe hepatotoxicity (106 versus 126 ng/mL, p = 0.16). Pembrolizumab concentrations were higher in those with severe hepatotoxicity versus those without (25.6 versus 6.1 μg/mL, p < 0.0001).

INTERPRETATION

In this preliminary prospective study, sotorasib after PD-(L)1 blockade was associated with severe hepatotoxicity, especially in patients with a short interval between treatments, prior immune-related hepatitis and higher anti-PD-1 plasma concentrations. Our results suggest a minimum interval of 6 weeks between anti-PD-(L)1 and sotorasib to minimize the risk of hepatotoxicity.

FUNDING

None.

A phase 2 trial combining afatinib with cetuximab in patients with EGFR exon 20 insertion-positive non-small cell lung cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations are the third most common EGFR mutations in patients with non-small cell lung cancer (NSCLC) and are associated with primary resistance to EGFR tyrosine kinase inhibitors (TKIs). There is evidence of activity of combining EGFR TKIs with monoclonal antibodies. This study reports on the efficacy and safety of afatinib in combination with cetuximab.

METHODS

In this single-arm phase 2 trial, patients with advanced NSCLC harboring an EGFR ex20ins mutation were treated with afatinib 40 mg once daily in combination with cetuximab 500 mg/m2 every 2 weeks. The primary end point was disease control rate (DCR) at 18 weeks of treatment.

RESULTS

Thirty-seven patients started treatment, with a median age of 65 years (range, 40-80 years), 78% female, and 95% White. The study achieved its primary end point with a DCR of 54% at 18 weeks, an overall response rate (ORR) of 43%, and a 32% confirmed ORR. Best responses were partial (n = 16), stable (n = 16), progressive disease (n = 2), or not evaluable (n = 3). Median progression-free survival was 5.5 months (95% CI, 3.7-8.3 months) and median overall survival was 16.8 months (95% CI, 10.7-25.8 months). The most common treatment-related adverse events (TRAEs) were diarrhea (70%), rash (65%), dry skin (59%), paronychia (54%), and erythema (43%). Grade 3 TRAEs were reported in 54% of all patients.

CONCLUSIONS

Combination treatment with afatinib and cetuximab demonstrated antitumor activity with a DCR of 54% at 18 weeks and a 32% confirmed ORR. Toxicity was significant, although manageable, after dose reduction.

Exploring the impact of patient-specific clinical features on osimertinib effectiveness in a real-world cohort of patients with EGFR mutated non-small cell lung cancer

Osimertinib is prescribed to patients with metastatic non-small cell lung cancer (NSCLC) and a sensitizing EGFR mutation. Limited data exists on the impact of patient characteristics or osimertinib exposure on effectiveness outcomes. This was a Dutch, multicenter cohort study. Eligible patients were ≥18 years, with metastatic EGFRm+ NSCLC, receiving osimertinib. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and safety. Kaplan-Meier analyses and multivariate Cox proportional hazard models were performed. In total, 294 patients were included. Primary EGFR-mutations were mainly exon 19 deletions (54%) and p.L858R point mutations (30%). Osimertinib was given in first-line (40%), second-line (46%) or beyond (14%), with median PFS 14.4 (95% CI: 9.4-19.3), 13.9 (95% CI: 11.3-16.1) and 8.7 months (95% CI: 4.6-12.7), respectively. Patients with low BMI (<20.0 kg/m2 ) had significantly shorter PFS/OS compared to all other subgroups. Patients with a high plasma trough concentration in steady state (Cmin,SS ; >271 ng/mL) had shorter PFS compared to a low Cmin,SS (<163 ng/mL; aHR 2.29; 95% CI: 1.13-4.63). A significant longer PFS was seen in females (aHR = 0.61, 95% CI: 0.45-0.82) and patients with the exon 19 deletion (aHR = 0.58, 95% CI: 0.36-0.92). A trend towards longer PFS was seen for TP53 wild-type patients, while age did not impact PFS. Patients with a primary EGFR exon 19 deletion had longer PFS, while a low BMI, male sex and a high Cmin,SS were indicative for shorter PFS and/or OS. Age was not associated with effectiveness outcomes of osimertinib.

Efficacy and Tolerability of Osimertinib and Sotorasib Combination Treatment for Osimertinib Resistance Caused by KRAS G12C Mutation: A Report of Two Cases

Two cases show osimertinib/sotorasib combination could be effective in KRAS G12C-driven osimertinib resistance.

Molecular alterations and potential actionable mutations in peritoneal mesothelioma: a scoping review of high-throughput sequencing studies

BACKGROUND

Peritoneal mesothelioma (PeM) is a rare malignancy with a poor prognosis. Currently there is a lack of effective systemic therapies. Due to the rarity of PeM, it is challenging to study new treatment options. Off-label use of targeted drugs could be an effective approach. This scoping review aims to explore the genomic landscape of PeM to identify potential therapeutic targets.

MATERIALS AND METHODS

A systematic literature search of Embase, Medline, Web of Science, the Cochrane Library, and Google Scholar was carried out up to 1 November 2022. Studies that reported on molecular alterations in PeM detected by high-throughput sequencing techniques were included. Genes that were altered in ≥1% of PeMs were selected for the identification of potential targeted therapies.

RESULTS

Thirteen articles were included, comprising 824 PeM patients. In total, 142 genes were altered in ≥1% of patients, of which 7 genes were altered in ≥10%. BAP1 was the most commonly altered gene (50%). Other commonly altered genes were NF2 (25%), CDKN2A (23%), CDKN2B (17%), PBRM1 (15%), TP53 (14%), and SETD2 (13%). In total, 17% of PeM patients were carriers of a germline mutation, mainly in BAP1 (7%).

CONCLUSIONS

This scoping review provides an overview of the mutational landscape of PeM. Germline mutations might be a larger contributor to the incidence of PeM than previously thought. Currently available targeted therapy options are limited, but several targeted agents [such as poly (ADP-ribose) polymerase (PARP), enhancer of zeste homolog 2 (EZH2), and cyclin-dependent kinase 4/6 (CDK4/6) inhibitors] were identified that might provide new targeted therapy options in the future.

Analysis of Serious Weight Gain in Patients Using Alectinib for ALK-Positive Lung Cancer

INTRODUCTION

Alectinib is a standard-of-care treatment for metastatic ALK+ NSCLC. Weight gain is an unexplored side effect reported in approximately 10%. To prevent or intervene alectinib-induced weight gain, more insight in its extent and etiology is needed.

METHODS

Change in body composition was analyzed in a prospective series of 46 patients with ALK+ NSCLC, treated with alectinib. Waist circumference, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle were quantified using sliceOmatic software on computed tomography images at baseline, 3 months (3M), and 1 year (1Y). To investigate an exposure-toxicity relationship, alectinib plasma concentrations were quantified. Four patients with more than 10 kg weight gain were referred to Erasmus MC Obesity Center CGG for in-depth analysis (e.g., assessments of appetite, dietary habits, other lifestyle, medical and psychosocial factors, and extensive metabolic and endocrine assessments, including resting energy expenditure).

RESULTS

Mean increase in waist circumference was 9 cm (9.7%, p < 0.001) in 1Y with a 40% increase in abdominal obesity (p = 0.014). VAT increased to 10.8 cm2 (15.0%, p = 0.003) in 3M and 35.7 cm2 (39.0%, p < 0.001) in 1Y. SAT increased to 18.8 cm2 (12.4%, p < 0.001) in 3M and 45.4 cm2 (33.3%, p < 0.001) in 1Y. The incidence of sarcopenic obesity increased from 23.7% to 47.4% during 1Y of treatment. Baseline waist circumference was a positive predictor of increase in VAT (p = 0.037). No exposure-toxicity relationship was found. In-depth analysis (n = 4) revealed increased appetite in two patients and metabolic syndrome in all four patients.

CONCLUSIONS

Alectinib may cause relevant increased sarcopenic abdominal obesity, with increases of both VAT and SAT, quickly after initiation. This may lead to many serious metabolic, physical, and mental disturbances in long-surviving patients.

Influence of Food With Different Fat Concentrations on Alectinib Exposure: A Randomized Crossover Pharmacokinetic Trial

BACKGROUND

Alectinib is the keystone treatment in advanced anaplastic lymphoma kinase-positive (ALK+) non-small cell lung cancer (NSCLC). An exposure-response threshold of 435 ng/mL has recently been established, albeit 37% of patients do not reach this threshold. Alectinib is orally administered, and absorption is largely influenced by food. Hence, further investigation into this relationship is needed to optimize its bioavailability.

PATIENTS AND METHODS

In this randomized 3-period crossover clinical study in ALK+ NSCLC, alectinib exposure was compared among patients with different diets. Every 7 days, the first alectinib dose was taken with either a continental breakfast, 250-g of low-fat yogurt, or a self-chosen lunch, and the second dose was taken with a self-chosen dinner. Sampling for alectinib exposure (Ctrough) was performed at day 8, just prior to alectinib intake, and the relative difference in Ctrough was compared.

RESULTS

In 20 evaluable patients, the mean Ctrough was 14% (95% CI, -23% to -5%; P=.009) and 20% (95% CI, -25% to -14%; P<.001) lower when taken with low-fat yogurt compared with a continental breakfast and a self-chosen lunch, respectively. Administration with a self-chosen lunch did not change exposure compared with a continental breakfast (+7%; 95% CI, -2% to +17%; P=.243). In the low-fat yogurt period, 35% of patients did not reach the threshold versus 5% with the other meals (P<.01).

CONCLUSIONS

Patients and physicians should be warned for a detrimental food-drug interaction when alectinib is taken with low-fat yogurt, because it results in a clinically relevant lower alectinib exposure. Intake with a self-chosen lunch did not change drug exposure and could be a safe and patient-friendly alternative.

Chemotherapy for patients with EGFR-mutated NSCLC after progression on EGFR-TKI's: Exploration of efficacy of unselected treatment in a multicenter cohort study

OBJECTIVES

In patients with Epidermal Growth Factor Receptor (EGFR)-mutated non-small cell lung (NSCLC) chemotherapy remains standard of care after progression on EGFR-tyrosine kinase inhibitors (TKIs). With the development of anti-angiogenic agents and immune checkpoint inhibitors the landscape of systemic regimens has changed significantly. This cohort study aims to evaluate the efficacy of chemotherapy regimens after progression on EGFR-TKI in a European population.

MATERIAL AND METHODS

All consecutive patients treated with chemotherapy after progression on EGFR-TKI for EGFR-mutated NSCLC, were identified in two tertiary centers in the Netherlands. Data on best response, progression free survival (PFS) and overall survival (OS) were extracted from medical records.

RESULTS

In total, 171 lines of chemotherapy were identified: platinum/pemetrexed (PP, n = 95), carboplatin/paclitaxel/bevacizumab/atezolizumab (CPBA, n = 32), paclitaxel/bevacizumab (PB, n = 36) and carboplatin/paclitaxel/bevacizumab (CPB, n = 8). Of the 171 lines, 106 were given as first-line after EGFR-TKI. Median PFS did not differ significantly between the first-line regimens (p = 0.50), with the highest PFS in PP (5.2 months [95% CI 4.5-5.9]) and CPBA (5.9 months [95% CI 3.8-80]). The majority of the PB group (n = 32) received this regimen in a second- or later line with a median PFS of 4.9 months (95% CI 3.3-6.6). First-line regimens had a median OS of 15.3 months (95% CI 11.6-18.9) with no significant difference between regimens (p = 0.85).

CONCLUSION

After progression on EGFR-TKI, patients with EGFR-mutated NSCLC show substantial benefit on different chemotherapy regimens. In particular, favorable outcomes were seen in patients treated with PP and CPBA as first-line chemotherapy, and PB in further lines of chemotherapy.

Abstract 2137: Clinical utility of circulating tumor DNA in patients with advanced KRAS G12C-mutated NSCLC treated with sotorasib

Introduction: The CodeBreaK 200 trial showed that in patients (pts) with advanced KRAS G12C mutated (KRAS+) NSCLC sotorasib, a KRAS G12C-specific inhibitor, is superior to docetaxel for progression free survival (PFS) (HR 0.66) with a one-year PFS of 25%. We hypothesized that the detection of circulating tumor DNA (ctDNA) in plasma could allow for treatment response prediction and longitudinal monitoring. We analyzed serial plasma samples at baseline and within 3 months of start of sotorasib to evaluate ctDNA changes and correlation with clinical response.

Methods: Pts with sotorasib treated KRAS+ NSCLC were prospectively enrolled in our biomarker START-TKI study (NCT05221372) after written informed consent. Plasma samples were collected prior to treatment (T0) and at first response evaluation (T1). The TruSight Oncology 500 ctDNA panel was used for mutation detection in cell-free DNA (cfDNA). cfDNA KRAS/TP53/STK11/KEAP1 status was determined and compared to tumor tissue pathology reports to filter out false positives. Radiological response and PFS was assessed per RECIST 1.1.

Results: Between May 2021 and August 2022, 35 pts were included (table 1). Of these, 29 (83%) had detectable ctDNA KRAS G12C at T0, and 24 had both T0 and T1 samples. A decrease in variant allele frequency (VAF) at T1 compared to T0 was observed in 88% (n=21); 42% (n=10) showed complete clearance of ctDNA KRAS G12C. Six-months PFS was 83% in T0 negative pts (n=6) versus 43% in T0 positive pts (n=29); and 65% in pts with complete clearance (n=10) versus 14% in pts with incomplete clearance (n=11). VAF increase was seen in 3 pts, of which 1 had progression at T1.

Conclusions: In pts with KRAS+ NSCLC treated with sotorasib, baseline ctDNA and ctDNA clearance within 3 months of treatment correlated with treatment response. Pts with undetectable KRAS ctDNA at baseline, or with complete clearance at first evaluation, had superior PFS. PFS will be updated as follow-up duration extends.

Table 1. Patient cohort Liver metastasis KRAS p.G12C ctDNA at T0, median VAF % (range) KRAS p.G12C ctDNA at T1, median VAF % (range) Median change in VAF % (range) TP53/STK11/KEAP1 ctDNA T0 T1 response Reason EOT ꝉ Time on treatment (months) * Negative at T0 (n=6) No = 6 0 NE NE NE 1x PR; 4x SD; 1x PD 2x PD; 4x ongoing &gt;8 months 6 (1 - 11) Positive at T0 (n=29) No = 20; Yes = 9 2.6 (0.1 - 46.7) 0.6 (0.1 - 38.9) -95% (-100 - +39) 4x TP53; 2x STK11; 1x STK11●; 2x KEAP1; 2x KEAP1●; 2x TP53 + KEAP1; 1x TP53 + STK11● 4x PR; 21x SD; 2x PD; 2x NE 19x PD; 3x toxicity; 6x ongoing &gt;4 months; 1x loss to follow up 3 (1 - 15) Complete clearance at T1 (n=10) No = 6; Yes = 4 1.4 (0.1 - 8.4) 0 100% 2x TP53; 1x TP53 + KEAP1; 1x KEAP1; 1x KEAP1● 1x PR; 9x SD 6x PD; 1x toxicity; 2x ongoing &gt;6 months; 1x loss to follow up 5 (1 - 11) Incomplete clearance at T1 (n=11) No = 7; Yes = 4 3.6 (1.3 - 46.7) 0.4 (0.1 - 29.4) -89% (-23 - -99) 2x TP53; 1x STK11; 1x STK11●; 2x TP53 + STK11●; 1x TP53 + STK11 + KEAP1; 1x STK11 + KEAP1 3x PR; 7x SD; 1x PD 8x PD; 2x toxicity; 1x ongoing &gt;4 months 3 (1 - 8) Increase in VAF at T1 (n=3) No = 2; Yes = 1 1.0 (0.5 - 35.2) 1.1 (0.6 - 38.9) +11% (+10 - +39) 1x TP53●; 1x TP53 + KEAP1; 1x STK11● + KEAP1● 1x PD; 2x SD 3x PD 3 (1 - 15) Positive T0, no T1 available (n=5) No = 5 6.2 (0.3 - 24.6) NE NE 1x TP53; 1x TP53●; 1x KEAP1; 1x STK11 + KEAP1 3x SD; 2x NE 2x PD; 3x ongoing &gt;3 months 2 (1 - 3) NE = Not evaluated; ● = Positive cell-free DNA (cfDNA), not tested in tumor tissue; PR = Partial response; SD = Stable disease; PD = Progressive disease; EOT = End of treatment; ꝉ for PFS analysis patients who discontinued treatment due to toxicity were censored at treatment discontinuation, and patients with ongoing sotorasib treatment were censored at data cut off (16-Nov-2022); * = excluding ongoing patients.

Citation Format: Sophie M. Ernst, Ronald van Marion, Peggy N. Atmodimedjo, Evert de Jonge, Ron H. Mathijssen, Marthe S. Paats, Peter de Bruijn, Ron H.N. van Schaik, Hendrikus J. Dubbink, Anne-Marie C. Dingemans. Clinical utility of circulating tumor DNA in patients with advanced KRAS G12C-mutated NSCLC treated with sotorasib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2137.

Therapeutic drug monitoring guided dosing versus standard dosing of alectinib in advanced ALK positive non-small cell lung cancer patients: Study protocol for an international, multicenter phase IV randomized controlled trial (ADAPT ALEC)

Background

Alectinib is first-line therapy in patients with stage IV non-small cell lung carcinoma (NSCLC) and an anaplastic lymphoma kinase (ALK) fusion. A shorter median progression-free survival (mPFS) was observed when alectinib minimum plasma concentrations during steady state (Cmin,SS) were below 435 ng/mL. This may suggest that patients should have an alectinib Cmin,SS ≥ 435 ng/mL for a more favorable outcome. This potential target could be attained by using therapeutic drug monitoring (TDM), i.e. adjusting the dose based on measured plasma trough concentrations. Hypothetically, this will increase mPFS, but this has not yet been evaluated in a randomized controlled trial (RCT). Therefore, the ADAPT ALEC trial is designed, with the primary objective to prolong mPFS in NSCLC patients treated with alectinib by using TDM.

Methods

ADAPT ALEC is a multicenter, phase IV RCT, in which patients aged ≥ 18 years with advanced ALK positive (+) NSCLC eligible for alectinib in daily care are enrolled. Participants will be randomized (1:1 ratio) into intervention arm A (TDM) or B (control), stratified by brain metastases and prior ALK treatments. Starting dose in both arms is the approved flat fixed dose of alectinib 600 mg taken twice daily with food. In case of alectinib Cmin,SS &lt; 435 ng/mL, arm A will receive increased doses of alectinib till Cmin,SS ≥ 435 ng/mL when considered tolerable. The primary outcome is mPFS, where progressive disease is defined according to RECIST v1.1 or all-cause death and assessed by CT-scans and MRI brain. Secondary endpoints are feasibility and tolerability of TDM, patient and physician adherence, overall response rate, median overall survival, intracranial PFS, quality of life, toxicity, alectinib-M4 concentrations and cost-effectiveness of TDM. Exploratory endpoints are circulating tumor DNA and body composition.

Discussion

The ADAPT ALEC will show whether treatment outcomes of patients with advanced ALK+ NSCLC improve when using TDM-guided dosing of alectinib instead of fixed dosing. The results will provide high quality evidence for deciding whether TDM should be implemented as standard of care and this will have important consequences for the prescribing of alectinib.

Clinical trial registration

ClinicalTrials.gov, identifier NCT05525338.

Cardiac Toxicity of Alectinib in Patients With ALK+ Lung Cancer: Outcomes of Cardio-Oncology Follow-Up

Background

Anaplastic lymphoma kinase (ALK) translocations in metastatic non-small cell lung cancer (3% to 7%) predict for response to ALK-inhibitors (eg, alectinib, first line), resulting in a 5-year survival rate of ∼60% and median progression-free survival of 34.8 months. Although the overall toxicity rate of alectinib is acceptable, unexplained adverse events, including edema and bradycardia, may indicate potential cardiac toxicity.

Objectives

This study's aim was to investigate the cardiotoxicity profile and exposure-toxicity relationship of alectinib.

Methods

Between April 2020 and September 2021, 53 patients with ALK-positive non-small cell lung cancer treated with alectinib were included. Patients starting with alectinib after April 2020 underwent a cardiac work-up at start, at 6 months and at 1 year at the cardio-oncology outpatients' clinic. Patients already receiving alectinib >6 months underwent 1 cardiac evaluation. Bradycardia, edema, and severe alectinib toxicity (grade ≥3 and grade ≥2 adverse events leading to dose modifications) data were collected. Alectinib steady-state trough concentrations were used for exposure-toxicity analyses.

Results

Left ventricular ejection fraction remained stable in all patients who underwent an on-treatment cardiac evaluation (n = 34; median 62%; IQR: 58%-64%). Twenty-two patients (42%) developed alectinib-related bradycardia (6 symptomatic bradycardia). One patient underwent a pacemaker implantation for severe symptomatic bradycardia. Severe toxicity was significantly associated with a 35% higher alectinib mean C_trough (728 vs 539 ng/mL, SD = 83 ng/mL; 1-sided P = 0.015).

Conclusions

No patients showed signs of a diminished left ventricular ejection fraction. Alectinib caused more bradycardia than previously reported (42%) with some instances of severe symptomatic bradycardia. Patients with severe toxicity generally had an elevated exposure above the therapeutic threshold.

Influence of esomeprazole on the bioavailability of afatinib: A pharmacokinetic cross-over study in patients with non-small cell lung cancer

Afatinib is an oral small-molecule kinase inhibitor (SMKI) approved for treatment of metastatic non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor (EGFR) driver mutation. Although oral administration is convenient, most SMKIs experience pH-dependent solubility. A drug-drug interaction between afatinib and proton-pump inhibitors (PPIs) has, however, never been studied in humans. Hence, we performed a randomized, three-period cross-over study. Afatinib (30 mg or 40 mg) was administered without PPI (period A), concomitantly with esomeprazole (period B) and three hours after esomeprazole intake (period C). Primary objective was the area under the curve (AUC_0-24 h) comparing period A to period B and period A to period C. Secondary objectives were other pharmacokinetic parameters and toxicity. Linear mixed effect modelling was performed for differences in AUC_0-24 h and C_max between periods A and B and periods A and C. In 18 evaluable NSCLC patients, concomitant use of 40 mg esomeprazole decreased the steady-state afatinib AUC_0-24 h with 10.2% (95% CI -29.2 to +14.0%; p = 0.564) compared to afatinib administration without PPI. Esomeprazole intake three hours prior to afatinib did not significantly influence afatinib AUC_0-24 h (-0.6%; 95% CI -14.9 to +16.1%; p = 1.0). No differences in toxicity were observed. To conclude, esomeprazole did not change the exposure to afatinib in patients with NSCLC. Since there is no clinically relevant drug-drug interaction, esomeprazole can safely be co-administered with afatinib. This is important for clinical practice, because other EGFR-SMKIs (e.g. erlotinib and gefitinib) do experience clinically relevant drug-drug interactions with acid-suppressive agents.

Real-World Approach for Molecular Analysis of Acquired EGFR Tyrosine Kinase Inhibitor Resistance Mechanisms in NSCLC

INTRODUCTION

With the approval of first-line osimertinib treatment in stage IV EGFR-mutated NSCLC, detection of resistance mechanisms will become increasingly important-and complex. Clear guidelines for analyses of these resistance mechanisms are currently lacking. Here, we provide our recommendations for optimal molecular diagnostics in the post-EGFR tyrosine kinase inhibitor (TKI) resistance setting.

METHODS

We compared molecular workup strategies from three hospitals of 161 first- or second-generation EGFR TKI-treated cases and 159 osimertinib-treated cases. Laboratories used combinations of DNA next-generation sequencing (NGS), RNA NGS, in situ hybridization (ISH), and immunohistochemistry (IHC).

RESULTS

Resistance mechanisms were identified in 72 first-generation TKI cases (51%) and 85 osimertinib cases (57%). RNA NGS, when performed, revealed fusions or exon-skipping events in 4% of early TKI cases and 10% of osimertinib cases. Of the 30 MET and HER2 amplifications, 10 were exclusively detected by ISH or IHC, and not detected by DNA NGS, mostly owing to low tumor cell percentage (<30%) and possibly tumor heterogeneity.

CONCLUSIONS

Our real-world data support a method for molecular diagnostics, consisting of a parallel combination of DNA NGS, RNA NGS, MET ISH, and either HER2 ISH or IHC. Combining RNA and DNA isolation into one step limits dropout rates. In case of financial or tissue limitations, a sequential approach is justifiable, in which RNA NGS is only performed in case no resistance mechanisms are identified. Yet, this is suboptimal as-although rare-multiple acquired resistance mechanisms may occur.

Early Cost Effectiveness of Whole-Genome Sequencing as a Clinical Diagnostic Test for Patients with Inoperable Stage IIIB,C/IV Non-squamous Non-small-Cell Lung Cancer

BACKGROUND

Advanced non-small-cell lung cancer (NSCLC) harbours many genetic aberrations that can be targeted with systemic treatments. Whole-genome sequencing (WGS) can simultaneously detect these (and possibly new) molecular targets. However, the exact added clinical value of WGS is unknown.

OBJECTIVE

The objective of this study was to determine the early cost effectiveness of using WGS in diagnostic strategies compared with currently used molecular diagnostics for patients with inoperable stage IIIB,C/IV non-squamous NSCLC from a Dutch healthcare perspective.

METHODS

A decision tree represented the diagnostic pathway, and a cohort state transition model represented disease progression. Three diagnostic strategies were modelled: standard of care (SoC) alone, WGS as a diagnostic test, and SoC followed by WGS. Treatment effectiveness was based on a systematic review. Probabilistic cost-effectiveness analyses were performed, and threshold analyses (using €80,000 per quality-adjusted life-year [QALY]) was used to explore the early cost effectiveness of WGS.

RESULTS

WGS as a diagnostic test resulted in more QALYs (0.002) and costs (€1534 [incremental net monetary benefit -€1349]), and SoC followed by WGS resulted in fewer QALYs (-0.002) and more costs (€1059 [-€1194]) compared with SoC alone. WGS as a diagnostic test was only cost effective if it was priced at €2000 per patient and identified 2.7% more actionable patients than SoC alone. Treating these additional identified patients with new treatments costing >€4069 per month decreased the probability of cost effectiveness.

CONCLUSIONS

Our analysis suggests that providing WGS as a diagnostic test is cost effective compared with SoC followed by WGS and SoC alone if costs for WGS decrease and additional patients with actionable targets are identified. This cost-effectiveness model can be used to incorporate new findings iteratively and to support ongoing decision making regarding the use of WGS in this rapidly evolving field.

Defining oligometastatic non-small cell lung cancer: concept versus biology, a literature review

Objective

In this review, the concept of (synchronous) oligometastatic disease in patients with non-oncogene-driven non-small cell lung cancer (NSCLC) will be placed in the context of tumor biology and metastatic growth patterns. We will also provide considerations for clinical practice and future perspectives, which will ultimately lead to better patient selection and oligometastatic disease outcome.

Background

The treatment landscape of metastasized NSCLC has moved from "one-size fits all" to a personalized approach. Prognosis has traditionally been poor but new treatment options, such as immunotherapy and targeted therapy, brighten future perspectives. Another emerging development is the recognition of patients with so-called "oligometastatic" state of disease. Oligometastatic disease has been recognized as a distinct clinical presentation in which the tumor is stated to be early in its evolution of metastatic potential. It is suggested that this stage of disease has an indolent course, comes with a better prognosis and therefore could be considered for radical multimodality treatment.

Methods

Narrative overview of the literature synthesizing the findings of literature retrieved from searches of computerized databases, hand searches, and authoritative texts.

Conclusions

Oligometastatic NSCLC is a broad spectrum disease, with a variable prognosis. Although the biology and behavior of "intermediate state" of metastatic disease are not fully understood, there is evidence that a subgroup of patients can benefit from local radical treatment when integrated into a multimodality regime. The consensus definition of oligometastatic NSCLC, including accurate staging, may help to uniform future trials. The preferable treatment strategy seems to sequential systemic treatment with subsequent local radical treatment in patients with a partial response or stable disease. Prognostic factors such as N-stage, number and site of distant metastases, tumor volume, performance status, age, and tumor type should be considered. The local radical treatment strategy has to be discussed in a multidisciplinary team meeting, taking into account patient characteristics and invasiveness of the procedure. However, many aspects remain to be explored and learned about the cancer biology and characteristics of intermediate state tumors.

Multicenter Comparison of Molecular Tumor Boards in The Netherlands: Definition, Composition, Methods, and Targeted Therapy Recommendations

BACKGROUND

Molecular tumor boards (MTBs) provide rational, genomics-driven, patient-tailored treatment recommendations. Worldwide, MTBs differ in terms of scope, composition, methods, and recommendations. This study aimed to assess differences in methods and agreement in treatment recommendations among MTBs from tertiary cancer referral centers in The Netherlands.

MATERIALS AND METHODS

MTBs from all tertiary cancer referral centers in The Netherlands were invited to participate. A survey assessing scope, value, logistics, composition, decision-making method, reporting, and registration of the MTBs was completed through on-site interviews with members from each MTB. Targeted therapy recommendations were compared using 10 anonymized cases. Participating MTBs were asked to provide a treatment recommendation in accordance with their own methods. Agreement was based on which molecular alteration(s) was considered actionable with the next line of targeted therapy.

RESULTS

Interviews with 24 members of eight MTBs revealed that all participating MTBs focused on rare or complex mutational cancer profiles, operated independently of cancer type-specific multidisciplinary teams, and consisted of at least (thoracic and/or medical) oncologists, pathologists, and clinical scientists in molecular pathology. Differences were the types of cancer discussed and the methods used to achieve a recommendation. Nevertheless, agreement among MTB recommendations, based on identified actionable molecular alteration(s), was high for the 10 evaluated cases (86%).

CONCLUSION

MTBs associated with tertiary cancer referral centers in The Netherlands are similar in setup and reach a high agreement in recommendations for rare or complex mutational cancer profiles. We propose a "Dutch MTB model" for an optimal, collaborative, and nationally aligned MTB workflow.

IMPLICATIONS FOR PRACTICE

Interpretation of genomic analyses for optimal choice of target therapy for patients with cancer is becoming increasingly complex. A molecular tumor board (MTB) supports oncologists in rationalizing therapy options. However, there is no consensus on the most optimal setup for an MTB, which can affect the quality of recommendations. This study reveals that the eight MTBs associated with tertiary cancer referral centers in The Netherlands are similar in setup and reach a high agreement in recommendations for rare or complex mutational profiles. The Dutch MTB model is based on a collaborative and nationally aligned workflow with interinstitutional collaboration and data sharing.

Do-not-intubate status and COVID-19 mortality in patients admitted to Dutch non-ICU wards

Mortality from COVID-19 has been particularly high in elderly patients on mechanical ventilation. Treatment outcomes for patients with do-not-intubate (DNI) status are unknown. One hundred patients admitted to the non-ICU ward during the “first wave” were retrospectively analyzed. Mortality rate was 49% in patients with a DNI order. This subgroup was characterized by significantly higher age, more comorbidity, and care dependency. Mortality among DNI patients was three times higher than other patients, but not higher than some of the published mortality rates for elderly mechanically ventilated patients. Advanced care planning is essential in COVID-19 to assist patient autonomy and prevent non-beneficial medical interventions.

Influence of Cow's Milk and Esomeprazole on the Absorption of Erlotinib: A Randomized, Crossover Pharmacokinetic Study in Lung Cancer Patients

INTRODUCTION

Erlotinib's gastrointestinal solubility and absorption are decreased by proton pump inhibitors (PPIs). Since erlotinib is a lipophilic drug, we hypothesized that concomitant intake with the fatty beverage milk may be a feasible way to increase erlotinib uptake. We performed a two-period, randomized, crossover study to investigate the influence of cow's milk with 3.9% fat on the exposure of erlotinib with and without the PPI esomeprazole in patients with non-small cell lung cancer (NSCLC). The effect of esomeprazole was studied in an additional intrapatient comparison.

METHOD

Pharmacokinetic sampling was performed on days 7 and 14 during 24 consecutive hours. During the 7 days prior to pharmacokinetic sampling, erlotinib was taken daily with 250 mL of either water or milk. In the PPI arm, esomeprazole (40 mg once daily 3 h prior to erlotinib) was taken for 3 days.

RESULTS

Erlotinib area under the curve from time zero to 24 h (AUC24) did not significantly change when administered with milk, compared with water, in both non-PPI users (n = 14; - 3%; 95% confidence interval [CI] - 12 to 8%; p = 0.57) and patients who used esomeprazole (n = 15; 0%; 95% CI - 15 to 17%; p = 0.95). Esomeprazole decreased erlotinib AUC24 by 47% (n = 9; 95% CI - 57 to - 34%; p < 0.001) and Cmax by 56% (95% CI - 64 to - 46%; p < 0.001). No differences in toxicities were observed between milk and water.

CONCLUSION

Milk with 3.9% fat has no effect on the exposure to erlotinib in NSCLC patients, independent of PPI use. The combination with milk is safe and well tolerated. Concomitant esomeprazole treatment strongly decreased both erlotinib AUC24 and Cmax and should be avoided if possible.

Differentiation of COVID-19 Pneumonitis and ICI Induced Pneumonitis

Immune checkpoint inhibitors (ICI) have become the standard of care treatment for several tumor types. ICI-induced pneumonitis is a serious complication seen with treatment with these agents. Cancer has been reported to be one of the risk factors for severe coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that has engulfed the world in the last couple of months. In patients with cancer treated with ICI who present at the emergency department with respiratory symptoms during the COVID-19 pandemic, correct diagnosis can be challenging. Symptoms and radiological features of ICI pneumonitis can be overlapping with those of COVID-19 related pneumonia. For the latter, dexamethasone and remdesivir have shown encouraging results, while vaccines are currently being evaluated in phase III trials. The mainstay of treatment in ICI pneumonitis is immunosuppressive therapy, as this is a potentially fatal adverse event. It has been speculated that immunosuppression may be associated with increased risk of progression to severe COVID-19, especially during the early stage of infection with SARS-CoV-2. Therefore, distinction between these two entities is warranted. We summarize the clinical, radiological features as well as additional investigations of both entities, and suggest a diagnostic algorithm for distinction between the two. This algorithm may be a supportive tool for clinicians to diagnose the underlying cause of the pneumonitis in patients treated with ICI during this COVID-19 pandemic.

Plasma Predictive Features in Treating EGFR-Mutated Non-Small Cell Lung Cancer

Although epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are the preferred treatment for patients with EGFR-mutated non-small cell lung cancer (NSCLC), not all patients benefit. We therefore explored the impact of the presence of mutations found in cell-free DNA (cfDNA) and TKI plasma concentrations during treatment on progression-free survival (PFS). In the prospective START-TKI study blood samples from 41 patients with EGFR-mutated NSCLC treated with EGFR-TKIs were available. Next generation sequencing (NGS) on cfDNA was performed, and plasma TKI concentrations were measured. Patients without complete plasma conversion of EGFR mutation at week 6 had a significantly shorter PFS (5.5 vs. 17.0 months, p = 0.002) and OS (14.0 vs. 25.5 months, p = 0.003) compared to patients with plasma conversion. In thirteen (second line) osimertinib-treated patients with a (plasma or tissue) concomitant TP53 mutation at baseline, PFS was significantly shorter compared to six wild-type cases; 8.8 vs. 18.8 months, p = 0.017. Erlotinib Cmean decrease of ≥10% in the second tertile of treatment was also associated with a significantly shorter PFS; 8.9 vs. 23.6 months, p = 0.037. We obtained evidence that absence of plasma loss of the primary EGFR mutation, isolated plasma p.T790M loss after six weeks, baseline concomitant TP53 mutations, and erlotinib Cmean decrease during treatment are probably related to worse outcome.

Pleural metastasis of anaplastic meningioma

A 52-year-old woman presented to the emergency department with several days of progressive dyspnoea and thoracic pain. Her medical history included a (recurrent) anaplastic meningioma, for which she was treated with surgery and radiotherapy. A chest X-ray showed occurrence of total opacification of the left lower lobe and a chest computed tomography demonstrated a pleural mass of 12 × 9 × 15 cm in the left lower lobe. Biopsy of the pleural mass revealed a metastasis of the patient's anaplastic meningioma. Extracranial metastases from meningioma are extremely uncommon (≤ 0.1%-0.2% of cases), but important for a patient's prognosis.

Impact of panel design and cut-off on tumour mutational burden assessment in metastatic solid tumour samples

Tumour mutational burden (TMB) has emerged as a promising biomarker to predict immune checkpoint inhibitors (ICIs) response in advanced solid cancers. However, harmonisation of TMB reporting by targeted gene panels is lacking, especially in metastatic tumour samples. To address this issue, we used data of 2841 whole-genome sequenced metastatic cancer biopsies to perform an in silico analysis of TMB determined by seven gene panels (FD1CDx, MSK-IMPACT™, Caris Molecular Intelligence, Tempus xT, Oncomine Tumour Mutation Load, NeoTYPE Discovery Profile and CANCERPLEX) compared to exome-based TMB as a golden standard. Misclassification rates declined from up to 30% to <1% when the cut-point for high TMB was increased. Receiver operating characteristic analysis demonstrated that, for correct classification, the cut-point for each gene panel may vary more than 20%. In conclusion, we here demonstrate that a major limitation for the use of gene panels is inter-assay variation and the need for dynamic thresholds to compare TMB outcomes.

Osimertinib treatment for patients with EGFR exon 20 mutation positive non-small cell lung cancer

OBJECTIVES

Epidermal growth factor receptor (EGFR) exon 20 insertions comprise 4-10 % of EGFR mutations in non-small cell lung cancer (NSCLC) and are associated with primary resistance to first and second generation EGFR tyrosine kinase inhibitors (TKIs). In vitro and preclinical animal studies have shown that osimertinib exerts antitumor activity against EGFR exon 20 mutation positive NSCLC. We report on a cohort of advanced stage NSCLC patients who harbor an EGFR exon 20 mutation and received osimertinib treatment.

MATERIAL AND METHODS

Twenty-one patients were treated with osimertinib 80 or 160 mg once daily from April 2016 to June 2018, in four institutions in the Netherlands. Data were obtained retrospectively. Progression free survival (PFS), disease control rate (DCR), overall survival (OS) and objective response rate (ORR) were assessed using RECIST v1.1.

RESULTS

Thirteen patients received prior platinum-based chemotherapy, and three patients a first - or second generation EGFR TKI. We observed 1 partial response, 17 patients with stable disease and 3 with progressive disease as best response to osimertinib (ORR 5 %). Median PFS was 3.6 (95 % CI, 2.6-4.5) months. PFS did not differ for patients with co-occurring TP53 mutations (p = 0.937). The DCR at three months was 71 %. Median OS was 8.7 (95 % CI, 1.1-16.4) months.

CONCLUSION

Osimertinib has limited antitumor activity in patients with EGFR exon 20 mutated NSCLC, with an ORR of 5 %.

Plasma Cell-Free DNA Testing of Patients With EGFR Mutant Non–Small-Cell Lung Cancer: Droplet Digital PCR Versus Next-Generation Sequencing Compared With Tissue-Based Results

PURPOSE

To compare the results of plasma cell-free DNA (cfDNA) droplet digital PCR (ddPCR) and next-generation sequencing (NGS) on detection of epidermal growth factor receptor ( EGFR) primary activating mutations and p.T790M with results of tissue analysis in patients with EGFR mutated non–small-cell lung cancer.

METHODS

All patients with EGFR mutated non–small cell lung cancer for which a pathology and a plasma specimen were available upon progression between November 2016 and July 2018 were selected. Concordance, Cohen’s κ, and intraclass correlation coefficients were calculated.

RESULTS

Plasma cfDNA and pathology specimens of 36 patients were analyzed. Agreement between ddPCR and NGS was 86% (κ = 0.63) for the primary activating mutation and 94% (κ = 0.89) for the p.T790M detection. Allele ratios were comparable, with an intraclass correlation coefficient of 0.992 and 0.997, respectively. Discrepancies of some degree were found in 15 patients (41.7%). In six patients (16.7%), no mutations were detected in cfDNA. In three patients (8.3%), p.T790M was detected in plasma but not in the pathology specimen, whereas in three other patients (8.3%), p.T790M was demonstrated in the pathology specimen but not in plasma. Concordance of cfDNA and pathology for the primary activating mutation was 69% for ddPCR and 83% for NGS. For the detection of p.T790M, this was 75% (κ = 0.49) for ddPCR as well as for NGS.

CONCLUSION

Mutual agreement is high between NGS and ddPCR in cfDNA on the level of a specific mutation, with comparable ratio results. Plasma testing of EGFR primary activating mutations and p.T790M shows high concordance with pathology results, for NGS as well as for ddPCR, depending on the extent of the panel used. In NGS, more genetic aberrations can be investigated at once.

Abstract B136: Highly accurate DNA-based detection of MET exon 14 skipping mutations in non-small cell lung cancer and clinical response upon targeted treatment

Background: Approximately 1.6%-5.7% of non-small cell lung cancers (NSCLC) are described to be driven by oncogenic MET exon 14 skipping mutations (METex14del). Although currently no therapy is registered specifically against METex14del, Phase I/II clinical trials and named patient based programs with cMET inhibitors show promising results. RNA-based analysis seems most optimal for METex14del detection, because theoretically, it would capture all MET exon 13-exon 15 fusions, regardless of the underlying DNA changes. However, acquiring sufficient RNA is often problematic. An alternative is DNA-based analysis, but commercially available DNA-based panels only detect up to 63% of known METex14del alterations. The goal of this study is to describe an optimized DNA-based diagnostic test for METex14del, and to report the histologic and clinical features of a real world METex14del non-squamous NSCLC patient cohort, including follow-up of patients treated with cMET-targeted therapy and consequent resistance mechanisms to cMET inhibition. Methods: Routine diagnostic pathology NSCLC FFPE specimens were investigated by a custom-made DNA-based targeted amplicon-based next generation sequencing (NGS) panel which includes 4 amplicons for METex14del detection. Retrospectively, histopathological characteristics and clinical follow up were investigated for advanced NSCLC with METex14del. We only present data of patients receiving crizotinib in a named patient based program (Pfizer Oncology). Results: In silico analysis showed that our custom-made NGS panel can detect 96% of reported METex14 alterations. From Jan 2016 - May 2018, METex14del was found in 2% of patients with NSCLC tested for therapeutic purposes (31/1496). Outside above mentioned timeframe and tested for other purposes, an additional 15 patients were detected, making a total of 46 NSCLC patients with METex14del, since introduction of our panel in May 2015. Adenocarcinoma was the most common histological type (31/46, 68.9%), followed by sarcomatoid carcinoma (8/46, 17.8%). Thirty-six patients had advanced NSCLC, they were predominantly male (69% vs 31%) and mostly (ex) smokers (64% vs 31%), with a median age of 76.5 years at disease onset [range 53-90]. Eleven patients were treated with targeted therapy, either with crizotinib in named patient based program or in clinical trials. With crizotinib, disease control was achieved for 4 out of 5 patients (3 PR [PFS 4 -12 mo], 1 SD [14 mo]). Biopsy at progression revealed a resistance mechanism (MET c.3682G&gt;A; p.D1228N) to crizotinib in two patients, respectively, 6 and 12 months after start of crizotinib treatment. Conclusions: In this study, we show that we can detect 96% of the known MET exon 14 skipping mutations using our custom-made DNA based NGS approach for DNA isolated from FFPE tissue. In this large consecutive series, METex14del was found in 2% of NSCLC, mostly elderly patients, in a good condition and with a smoking history. Although a small cohort, patients responded well to targeted treatment, underlining the need for routine testing of METex14del in advanced non-squamous NSCLC to guarantee optimal personalized treatment.

Citation Format: Melinda Pruis, WRR Geurts, JH von der Thüsen, IC Meijssen, WNM Dinjens, JGJV Aerts, MP Lolkema, HJ Dubbink, MS Paats. Highly accurate DNA-based detection of MET exon 14 skipping mutations in non-small cell lung cancer and clinical response upon targeted treatment [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 B136. doi:10.1158/1535-7163.TARG-19-B136

Highly accurate DNA-based detection and treatment results of MET exon 14 skipping mutations in lung cancer

OBJECTIVES

The oncogenic MET exon 14 skipping mutation (METex14del) is described to drive 1.3 %-5.7 % of non-small-cell lung cancer (NSCLC) and multiple studies with cMET inhibitors show promising clinical responses. RNA-based analysis seems most optimal for METex14del detection, however, acquiring sufficient RNA material is often problematic. An alternative is DNA-based analysis, but commercially available DNA-based panels only detect up to 63 % of known METex14del alterations. The goal of this study is to describe an optimized DNA-based diagnostic test for METex14del in NSCLC, including clinical features and follow-up of patients treated with cMET-targeted therapy and consequent resistance mechanisms.

MATERIAL AND METHODS

Routinely processed diagnostic pathology non-squamous NSCLC specimens were investigated by a custom-made DNA-based targeted amplicon-based next generation sequencing (NGS) panel, which includes 4 amplicons for METex14del detection. Retrospectively, histopathological characteristics and clinical follow up were investigated for advanced non-squamous NSCLC with METex14del.

RESULTS

In silico analysis showed that our NGS panel is able to detect 96 % of reported METex14 alterations. METex14del was found in 2 % of patients with non-squamous NSCLC tested for therapeutic purposes. In total, from May 2015 - Sep 2018, METex14del was found in 46 patients. Thirty-six of these patients had advanced non-squamous NSCLC, they were predominantly elderly (76.5 years [53-90]), male (25/36) and (ex)-smokers (23/36). Five patients received treatment with crizotinib (Pfizer Oncology), in a named patient based program, disease control was achieved for 4/5 patients (3 partial responses, 1 stable disease) and one patient had a mixed response. Two patients developed a MET D1228N mutation during crizotinib treatment, inducing a resistance mechanism to crizotinib.

CONCLUSIONS

This study shows that METex14del can be reliably detected by routine DNA NGS analysis. Although a small cohort, patients responded well to targeted treatment, underlining the need for routine testing of METex14del in advanced non-squamous NSCLC to guarantee optimal personalized treatment.

Cytokines in nasal lavages and plasma and their correlation with clinical parameters in cystic fibrosis

BACKGROUND

Because persistent inflammation plays a dominant role in cystic fibrosis (CF), we assessed systemic and local upper airway responses during and after pulmonary exacerbation.

METHODS

We followed a cohort of Pseudomonas aeruginosa-infected adult CF patients (n=16) over time in pulmonary exacerbation and in stable disease. Interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-17A, IL-22, interferon-γ and TNFα levels were measured in sputum, nasal lavages and plasma.

RESULTS

In CF patients IL-6 and IL-10 levels in nasal lavages were significantly increased in exacerbation compared with stable disease. Systemic IL-6 significantly correlated with CRP levels and FEV1 (%predicted), independently of disease status. Systemic IL-10 also correlated significantly with CRP and FEV1 (%predicted), but only in exacerbation. Other cytokines tested did not discriminate between exacerbation and stable disease.

CONCLUSIONS

Determination of IL-6 and IL-10 in nasal lavages may provide a minimally invasive tool in the assessment of an exacerbation in CF.

Local and systemic cytokine profiles in nonsevere and severe community-acquired pneumonia

Local inflammatory responses in community-acquired pneumonia (CAP) remain insufficiently elucidated, especially in patients with nonsevere CAP. In this study we determined local and systemic cytokine responses in CAP patients and correlated these with disease severity and other clinical parameters. Levels of interleukin (IL)-6, IL-8, IL-10, IL-1β, tumour necrosis factor-α, interferon (IFN)-γ, IL-22, IL-17A and IL-4 were determined in bronchoalveolar lavage fluid and serum of 20 CAP patients upon admission and 10 healthy individuals. Systemic cytokine levels were also measured on days 7 and 30. In bronchoalveolar lavage fluid of CAP patients, levels of IL-6, IL-8 and IFN-γ were significantly increased compared with healthy individuals, but no correlations with disease severity were found. Systemic levels of IL-6, IL-10 and IFN-γ were significantly higher in severe CAP patients than in nonsevere CAP patients and healthy individuals. Moreover, these cytokines showed a significant correlation with the pneumonia severity index. In the total group of CAP patients, systemic IL-8 and IL-22 levels were also increased compared with healthy individuals. We therefore conclude that IL-6, IL-10 and IFN-γ are important cytokines in CAP, although differences in disease severity upon admission are only reflected by systemic levels of these cytokines.

T helper 17 cells are involved in the local and systemic inflammatory response in community-acquired pneumonia

BACKGROUND

Recent findings in mouse models suggest that T helper (Th)17 cells, characterised by production of interleukin (IL)-17A and IL-22, are involved in the immunopathogenesis of pneumonia.

OBJECTIVE

In this study, we aimed to identify the involvement of Th17 cells in human community-acquired pneumonia (CAP).

DESIGN

Within 24 h of admission, T cells from peripheral blood (n=39) and bronchoalveolar lavage (BAL, n=20) of CAP patients and of 10 healthy individuals were analysed by intracellular flow cytometry for the production of various cytokines, including IL-17A and IL-22. Peripheral blood T cells were also analysed 7 and 30 days after admission. Th17 cytokine profiles were correlated with pneumonia severity index and microbial aetiology.

RESULTS

In the BAL of CAP patients, proportions of IL-17A and IL-22 single positive, as well as IL-17A/IL-22 double positive CD4 T cells were significantly increased compared with healthy individuals. Significantly increased proportions of IL-17A/IL-22 double positive CD4 T cells in BAL were found in non-severe and severe CAP patients, as well as in pneumococcal and non-pneumococcal CAP. In the peripheral blood of CAP patients upon admission, we found significantly increased proportions of IL-17A/IL-22 double positive CD4 T cells. One week after admission, the proportions of these double positive cells were still significantly increased in CAP patients compared with healthy individuals.

CONCLUSIONS

These data indicate that Th17 cells are engaged in the local and systemic immune response in human pneumonia. Especially, IL-17A/IL-22 double positive Th17 cells may be involved in the immunopathogenesis of CAP.

Systemic CD4+ and CD8+ T-cell cytokine profiles correlate with GOLD stage in stable COPD

Chronic obstructive pulmonary disease (COPD) is associated with pulmonary and systemic inflammation. Both CD4+ and CD8+ T-lymphocytes play a key role in COPD pathogenesis, but cytokine profiles in circulating T-lymphocytes have not been well characterised. Here we report the analysis of peripheral blood T-cells from 30 stable COPD patients and 10 healthy never-smokers for interferon (IFN)-γ, interleukin (IL)-4, tumour necrosis factor (TNF)-α and the T-helper 17 cytokines IL-17A, IL-17F and IL-22 by intracellular flow cytometry. We found significantly increased proportions of IFN-γ+ and TNF-α+ CD8+ T-cells in COPD patients, when compared with healthy controls. This was most evident in patients with less severe disease. In contrast, expression profiles in circulating CD4+ T-cells were similar in COPD patients and healthy controls for all cytokines tested, except for IL-17F. COPD patients with more severely reduced diffusing capacity had lower proportions of IL-17A+ CD4+ T-cells. Proportions of IL-22+ cells in the CD4+ memory T-cell population were significantly increased in active smokers, when compared with past smokers. Collectively, this comprehensive cytokine analysis of circulating T-cells in COPD patients revealed a correlation for CD8+ T-cells between Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage and IFN-γ or TNF-α expression, but not for CD4+ T-cells.

Increased IL-17A expression in granulomas and in circulating memory T cells in sarcoidosis

OBJECTIVE

Sarcoidosis is a systemic inflammatory disorder characterized by granulomas. Although the aetiology is unknown, sarcoidosis is thought to be mediated by Th1 lymphocytes. Recently, IL-17A has been implicated in granuloma formation in various diseases, including tuberculosis. Therefore, we hypothesized that Th17 cells play a role in sarcoidosis, paralleling recent findings in autoimmune diseases such as RA. The aim of our study was to investigate the role of Th17 cells in sarcoidosis.

METHODS

T cells were investigated by intracellular flow cytometry and immunohistochemistry, in blood, bronchoalveolar lavages (BALs) and bronchial mucosal biopsies from a cohort of newly diagnosed sarcoidosis patients and healthy controls.

RESULTS

Circulating memory CD4(+) T-cell populations of sarcoidosis patients contained significantly increased proportions of IL-17A(+) cells when compared with healthy controls. Interestingly, proportions of IL-17A/IFN-γ and IL-17A/IL-4 double-producing cells were significantly increased in blood of sarcoidosis patients and were present in substantial numbers in BAL. In granuloma-containing, but not in non-granulomatous sarcoidosis biopsies, we found significantly increased numbers of IL-17A(+) T cells, located in and around granulomas throughout the lamina propria. IL-22(+) T cells were increased in the subepithelial layer.

CONCLUSIONS

Enhanced IL-17A expression in granulomas and the presence of IL-17A(+), IL-17A(+)IFN-γ(+) and IL-17A(+)IL-4(+)memory Th cells in the circulation and BAL indicate Th17 cell involvement in granuloma induction or maintenance in sarcoidosis. Therefore, neutralization of IL-17A activity may be a novel strategy to treat sarcoidosis.