Overall survival and central nervous system activity of crizotinib in ROS1-rearranged lung cancer-final results of the EUCROSS trial

BACKGROUND

In 2019, we reported the first efficacy and safety analysis of EUCROSS, a phase II trial investigating crizotinib in ROS1 fusion-positive lung cancer. At that time, overall survival (OS) was immature and the effect of crizotinib on intracranial disease control remained unclear. Here, we present the final analysis of OS, systemic and intracranial activity, and the impact of co-occurring aberrations.

MATERIALS AND METHODS

EUCROSS was a prospective, single-arm, phase II trial. The primary endpoint was best overall response rate (ORR) using RECIST 1.1. Secondary and exploratory endpoints were progression-free survival (PFS), OS, and efficacy in pre-defined subgroups.

RESULTS

Median OS of the intention-to-treat population (N = 34) was 54.8 months [95% confidence interval (CI) 20.3 months-not reached (NR); median follow-up 81.4 months] and median all-cause PFS of the response-evaluable population (N = 30) was 19.4 months (95% CI 10.1-32.2 months). Time on treatment was significantly correlated with OS (R = 0.82; P < 0.0001). Patients with co-occurring TP53 aberrations (28%) had a significantly shorter OS [hazard ratio (HR) 11; 95% CI 2.0-56.0; P = 0.006] and all-cause PFS (HR 4.2; 95% CI 1.2-15; P = 0.025). Patients with central nervous system (CNS) involvement at baseline (N = 6; 20%) had a numerically shorter median OS and all-cause PFS. Median intracranial PFS was 32.2 months (95% CI 23.7 months-NR) and the rate of isolated CNS progression was 24%.

CONCLUSIONS

Our final analysis proves the efficacy of crizotinib in ROS1-positive lung cancer, but also highlights the devastating impact of TP53 mutations on survival and treatment efficacy. Additionally, our data show that CNS disease control is durable and the risk of CNS progression while on crizotinib treatment is low.

MET Fusions in NSCLC: Clinicopathologic Features and Response to MET Inhibition

INTRODUCTION

MET fusions have been described only rarely in NSCLC. Thus, data on patient characteristics and treatment response are limited. We here report histopathologic data, patient demographics, and treatment outcome including response to MET tyrosine kinase inhibitor (TKI) therapy in MET fusion-positive NSCLC.

METHODS

Patients with NSCLC and MET fusions were identified mostly by RNA sequencing within the routine molecular screening program of the national Network Genomic Medicine, Germany.

RESULTS

We describe a cohort of nine patients harboring MET fusions. Among these nine patients, two patients had been reported earlier. The overall frequency was 0.29% (95% confidence interval: 0.15-0.55). The tumors were exclusively adenocarcinoma. The cohort was heterogeneous in terms of age, sex, or smoking status. We saw five different fusion partner genes (KIF5B, TRIM4, ST7, PRKAR2B, and CAPZA2) and several different breakpoints. Four patients were treated with a MET TKI leading to two partial responses, one stable disease, and one progressive disease. One patient had a BRAF V600E mutation as acquired resistance mechanism.

CONCLUSIONS

MET fusions are very rare oncogenic driver events in NSCLC and predominantly seem in adenocarcinomas. They are heterogeneous in terms of fusion partners and breakpoints. Patients with MET fusion can benefit from MET TKI therapy.

Efficiency of B-RAF-/MEK-inhibitors in B-RAF mutated Ameloblastoma: Case report and review of literature

Background

Ameloblastoma is a benign but locally invasive and aggressive odontogenic tumor harboring activating BRAF V600E mutations in about two thirds of the cases.

Case presentation

Neoadjuvant therapy with Dabrafenib and Trametinib was given to a 42-year-old male patient with recurrent ameloblastoma of the right mandible with a BRAF V600E mutation for 18 months. The patient manifested an excellent response to the therapy with remarkable reduction in tumor size from 72.6 mm to 55.9 mm. Histopathologically, the tumor underwent significant degenerative changes with only a few sparse vital residuals revealing 0 % Ki67 proliferative index.

Conclusions

Neoadjuvant therapy with BRAF-inhibitors or BRAF-MEK-inhibitors is an effective means to reduce the size of mandibulary ameloblastomas. We propose the consideration of neoadjuvant therapy in future treatment modalities to minimize post-surgical morbidity and facial deformations.

Somatic rearrangements causing oncogenic ectodomain deletions of FGFR1 in squamous cell lung cancer

The discovery of frequent 8p11-p12 amplifications in squamous cell lung cancer (SQLC) has fueled hopes that FGFR1, located inside this amplicon, might be a therapeutic target. In a clinical trial, only 11% of patients with 8p11 amplification (detected by FISH) responded to FGFR kinase inhibitor treatment. To understand the mechanism of FGFR1 dependency, we performed deep genomic characterization of 52 SQLCs with 8p11-p12 amplification, including 10 tumors obtained from patients who had been treated with FGFR inhibitors. We discovered somatically altered variants of FGFR1 with deletion of exons 1-8 that resulted from intragenic tail-to-tail rearrangements. These ectodomain-deficient FGFR1 variants (ΔEC-FGFR1) were expressed in the affected tumors and were tumorigenic in both in vitro and in vivo models of lung cancer. Mechanistically, breakage-fusion-bridges were the source of 8p11-p12 amplification, resulting from frequent head-to-head and tail-to-tail rearrangements. Generally, tail-to-tail rearrangements within or in close proximity upstream of FGFR1 were associated with FGFR1 dependency. Thus, the genomic events shaping the architecture of the 8p11-p12 amplicon provide a mechanistic explanation for the emergence of FGFR1-driven SQLC. Specifically, we believe that FGFR1 ectodomain-deficient and FGFR1-centered amplifications caused by tail-to-tail rearrangements are a novel somatic genomic event that might be predictive of therapeutically relevant FGFR1 dependency.

Clinicopathologic and molecular characteristics of small-scale ROS1-mutant non-small cell lung cancer (NSCLC) patients

BACKGROUND

ROS1 fusions are well treatable aberrations in NSCLC. Besides solvent-front mutations (SFM) in resistance to targeted therapy, small-scale ROS1 mutations are largely unknown. We exploratively analyzed the clinical and molecular characteristics of small-scale ROS1 mutations in NSCLC patients without activating ROS1 fusions or SFMs.

METHODS

Next-generation sequencing was performed on tissue samples from NSCLC patients within the Network Genomic Medicine. Patients with ROS1 fusions and SFMs were excluded. We analyzed clinical characteristics of patients harboring small-scale ROS1-mutations, ROS1- and co-occurring mutations, and their response to systemic therapy.

RESULTS

Of 10,396 patients analyzed, 101 (1.0%) patients harbored small-scale ROS1 mutations. Most patients were male (73.3%) and smokers (96.6%). Nearly half of the patients presented with squamous-cell carcinoma (SqCC, 40.4%). Most mutations were transversions (50.5%), and 66% were in the kinase domain. Besides TP53 mutations (65.3%), KRAS (22.8%), EGFR (5.9%), PIK3CA (9.9%) and FGFR1-4 mutations (8.9%) co-occurred. In 10 (9.9%) patients, ROS1 mutation was the only aberration detected. Median overall survival (mOS) differed significantly in patients with or without KRAS co-mutations (9.7 vs 21.5 months, p = 0.02) and in patients treated with or without immune-checkpoint blockade (ICB) during treatment (21.5 vs 4.4 months, p = 0.003).

CONCLUSION

The cohort's clinical characteristics contrasted ROS1-fused cohorts. Co-occurrence of KRAS mutations led to shortened survival and patients benefited from ICB. Our data does not support the idea of ROS1 small-scale mutations as strong oncogenic drivers in NSCLC, but rather as relevant bystanders altering the efficacy of treatment approaches.

Radiomics for the non-invasive prediction of PD-L1 expression in patients with brain metastases secondary to non-small cell lung cancer

BACKGROUND

The expression level of the programmed cell death ligand 1 (PD-L1) appears to be a predictor for response to immunotherapy using checkpoint inhibitors in patients with non-small cell lung cancer (NSCLC). As differences in terms of PD-L1 expression levels in the extracranial primary tumor and the brain metastases may occur, a reliable method for the non-invasive assessment of the intracranial PD-L1 expression is, therefore of clinical value. Here, we evaluated the potential of radiomics for a non-invasive prediction of PD-L1 expression in patients with brain metastases secondary to NSCLC.

PATIENTS AND METHODS

Fifty-three NSCLC patients with brain metastases from two academic neuro-oncological centers (group 1, n = 36 patients; group 2, n = 17 patients) underwent tumor resection with a subsequent immunohistochemical evaluation of the PD-L1 expression. Brain metastases were manually segmented on preoperative T1-weighted contrast-enhanced MRI. Group 1 was used for model training and validation, group 2 for model testing. After image pre-processing and radiomics feature extraction, a test-retest analysis was performed to identify robust features prior to feature selection. The radiomics model was trained and validated using random stratified cross-validation. Finally, the best-performing radiomics model was applied to the test data. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

An intracranial PD-L1 expression (i.e., staining of at least 1% or more of tumor cells) was present in 18 of 36 patients (50%) in group 1, and 7 of 17 patients (41%) in group 2. Univariate analysis identified the contrast-enhancing tumor volume as a significant predictor for PD-L1 expression (area under the ROC curve (AUC), 0.77). A random forest classifier using a four-parameter radiomics signature, including tumor volume, yielded an AUC of 0.83 ± 0.18 in the training data (group 1), and an AUC of 0.84 in the external test data (group 2).

CONCLUSION

The developed radiomics classifiers allows for a non-invasive assessment of the intracranial PD-L1 expression in patients with brain metastases secondary to NSCLC with high accuracy.

Resistance to MET inhibition in MET-dependent NSCLC and therapeutic activity after switching from type I to type II MET inhibitors

OBJECTIVES

Resistance to MET inhibition occurs inevitably in MET-dependent non-small cell lung cancer and the underlying mechanisms are insufficiently understood. We describe resistance mechanisms in patients with MET exon 14 skipping mutation (METΔ^ex14), MET amplification, and MET fusion and report treatment outcomes after switching therapy from type I to type II MET inhibitors.

MATERIALS AND METHODS

Pre- and post-treatment biopsies were analysed by NGS (next generation sequencing), digital droplet PCR (polymerase chain reaction), and FISH (fluorescense in situ hybridization). A patient-derived xenograft model was generated in one case.

RESULTS

Of 26 patients with MET tyrosine kinase inhibitor treatment, eight had paired pre- and post-treatment biopsies (Three with MET amplification, three with METΔ^ex14, two with MET fusions (KIF5B-MET and PRKAR2B-MET).) In six patients, mechanisms of resistance were detected, whereas in two cases, the cause of resistance remained unclear. We found off-target resistance mechanisms in four cases with KRAS mutations and HER2 amplifications appearing. Two patients exhibited second-site MET mutations (p.D1246N and p. Y1248H). Three patients received type I and type II MET tyrosine kinase inhibitors sequentially. In two cases, further progressive disease was seen hereafter. The patient with KIF5B-MET fusion received three different MET inhibitors and showed long-lasting stable disease and a repeated response after switching therapy, respectively.

CONCLUSION

Resistance to MET inhibition is heterogeneous with on- and off-target mechanisms occurring regardless of the initial MET aberration. Switching therapy between different types of kinase inhibitors can lead to repeated responses in cases with second-site mutations. Controlled clinical trials in this setting with larger patient numbers are needed, as evidence to date is limited to preclinical data and case series.

P13.03.A Radiomics for the non-invasive assessment of the PDL-1 expression in patients with non-small cell lung cancer brain metastases

BACKGROUND

The expression level of programmed cell death ligand 1 (PDL-1) might be an indicator for response to immunotherapy using checkpoint inhibitors in patients with non-small cell lung cancer (NSCLC). As intra-tumoral differences and discrepancies between the PDL-1 expression in the primary tumor and the brain metastases may occur, a method for a reliable non-invasive assessment of the intracranial PDL-1 expression would be of clinical value. We evaluated the potential of MRI radiomics for a non-invasive assessment of the PDL-1 expression in patients with NSCLC brain metastases.

PATIENTS AND METHODS

Fifty-three patients with brain metastases from NSCLC from two university brain tumor centers (group 1, 36 patients; group 2, 17 patients) underwent tumor resection with subsequent immunohistochemical assessment of the PDL-1 expression. Brain metastases were manually segmented on preoperative T1-weighted contrast-enhanced MRI. Group 1 was used for model training and validation, group 2 for model testing. After image pre-processing and radiomics feature extraction from T1-weighted contrast-enhanced MRI, a test-retest analysis was performed to identify robust features prior to feature selection. The radiomics model was trained and validated using five-fold cross validation. Finally, the best performing radiomics model was applied to the test data. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

An intracranial PDL-1 expression was found by immunohistochemistry in 18 of 36 patients (50%) in group 1, and 7 of 17 patients (41%) in group 2. Univariate analysis identified tumor volume as a significant clinical feature for PDL-1 expression (area under the ROC curve (AUC), 0.77). A random forest classifier using a four-parameter radiomics signature including tumor volume yielded an AUC of 0.83 ± 0.18 in the training data (group 1). Finally, the classifier achieved an AUC of 0.84 in the external test data (group 2).

CONCLUSION

The developed radiomics classifiers allows a non-invasive assessment of the intracranial PD-L1 expression in patients with NSCLC brain metastases with a high diagnostic performance.

KS02.7.A Impact of FET PET on multidisciplinary neurooncological tumor board decisions in patients with brain tumors

Background

Following neurooncological treatment of brain tumors, neurooncologists are often confronted with equivocal MRI findings (e.g., treatment-related changes such as pseudoprogression, non-measurable contrast-enhancing lesions, T2/FLAIR signal alterations, pseudoresponse). Especially in Europe, amino-acid PET is increasingly integrated into multidisciplinary neurooncological tumor boards (MNTB) to overcome these diagnostic uncertainties. We evaluated the correctness of MNTB decisions, in which amino acid PET findings were taken into account.

Material and Methods

In a single-university center study, we retrospectively evaluated 182 MNTB decisions of 154 patients with histomolecularly defined WHO grade 3 or 4 gliomas (n=123), including glioblastoma (n=80), anaplastic glioma (n=42), and gliosarcoma (n=1), or brain metastases (n=31) secondary to lung cancer, melanoma, breast cancer, or colorectal cancer presenting equivocal MRI findings following anticancer treatment. All patients underwent O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET imaging as an adjunct for decision-making. Additionally, the patients’ clinical status, pretreatment, and conventional MRI findings were considered for decision-making. The presence of neoplastic tissue was considered if the mean FET uptake as assessed by tumor-to-brain ratios was &gt; 2.0. MNTB decisions were validated using the neuropathological result in 42% (n=77) or clinicoradiologically in 58% (n=105). The diagnostic performance of MTNB decisions was evaluated using 2x2 contingency tables.

Results

The validation of all 182 MNTB recommendations, which integrated FET PET in the decision-making process, were correct in 95% (sensitivity, 97%; specificity, 75%; positive predictive value, 96%). Due to tumor progression, MNTB recommendations prompted a treatment change in 88% (n=160 of 182 decisions). When FET PET findings suggested progressive disease (n=157), MNTB decisions were correct in 96% (positive predictive value, 97%). In 22 MNTB decisions with the recommendation to continue the current treatment regimen, 82% were correctly identified as treatment-related changes.

Conclusion

FET PET seems to have a significant impact on MNTB decisions. A prospective evaluation of MNTB decisions with and without the integration of FET PET is warranted to define the added value of FET PET.

[Targeted treatment of non-small cell lung cancer]

Non-small cell lung cancer (NSCLC) has made a remarkable development in recent decades with respect to its perception. In the late 1990s it was the "problem child" as the main cause of cancer with increasing tendencies, especially in women and with a pronounced stigmatization. It is now the role model as a biologically rational targeted treatment based on molecular dependencies of the tumor with a vast improvement of the traditionally poor survival times. Molecular tumor boards have long followed the NSCLC example in the assessment of targeted treatment approaches for other tumor entities. This review article gives an overview of the current possibilities for targeted treatment of NSCLC, which nowadays are applicable for nearly one third of all patients with NSCLC.

Metastatic patterns plus clinical and molecular characteristics of ROS1 aberrations in non-small cell lung cancer patients without rearrangements

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Background: Fusions in the ROS1 proto-oncogene are among the best treatable genetic aberrations in Non-small cell lung cancer (NSCLC). Besides the occurrence of solvent-front mutations (SFM) in acquired resistance to targeted therapy, little is known about ROS1 aberrations other than fusions. We analyzed molecular and clinical characteristics and metastatic patterns of ROS1 mutations in NSCLC patients without activating ROS1 fusions or SFMs. Methods: Next-generation sequencing (NGS) was performed on tissue samples from NSCLC patients within the National Network Genomic Medicine (nNGM). Patients with activating ROS1 fusions detected by fluorescence in-situ hybridization (FISH) were excluded. Staging and restaging procedures were performed following local standards from each partner. We analyzed the mutations’ characteristics, co-occurring mutations and metastatic patterns. Results: Of 8072 patients analyzed by NGS between 2018 and 2021, 118 (1.5%) patients harbored ROS1 mutations. Most patients were male (76.3%) and had adenocarcinoma histology (57.6%). The median age at diagnosis amounted to 68 years. Nearly all of the patients (96.5%) had a smoking history, amassing 40 pack-years on average. Besides TP53 mutations (61.0%), KRAS (25.4%), EGFR (7.6%), PIK3CA and FGFR1-4 mutations (5.9% each) co-occurred most frequently. In 12 (10.2%) patients, ROS1 mutation was the only detected aberration. The majority (59.3%) of patients had UICC stage IV whereby 27.2% of patients featured Stage III; about 7% fall upon stage I and II. The metastatic pattern of all stage IV patients shows that 22.9% of metastasis is allotted to cerebral, 12.5% to lung, 16.7% to subdiaphragmatic, 14.9% to bone and 6.3% to skin metastasis. Thereby, the patients’ subgroup with mutually exclusive ROS1 mutations (10.2%) resembles this trend: about a half of these patients had UICC stage IV, too, and the metastasis distribution featured similar characteristics. Conclusions: The cohort contrasts the clinical characteristics of patients with ROS1 fusion regarding sex, age, and histology. This evidence implies a basic clinical impact exerted by this molecular subtype. We warrant further research on the detected mutations to characterize the biological impact and the potential to act as a drug target.

Screening of FGFR patients for FGFR directed clinical trials in Network Genomic Medicine (NGM): Real-world data

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Background: The fibroblast growth factor receptor (FGFR) 1-4 genes show a heterogenic landscape of alterations in non-small cell lung cancer (NSCLC) whereas only a small amount is yet considered to have oncogenic potential. The frequency of activating FGFR alterations is low, counting for approximately 2% of NSCLC. We have screened NSCLC patients (pts) for FGFR translocations/mutations within NGM and analysed them on FGFR alteration frequency, patient characteristics and outcome. Methods: From 04/2019 to 01/2020 we screened 472 squamous NSCLC for FGFR gene alterations and from 02/2020 to 12/2021 an additional 5286 patients including all NSCLC cases. Of these 5286 pts, 1097 pts were analysed for FGFR fusions. We used DNA-NGS for FGFR-mutations and RNA-NGS for FGFR–translocations. Activating mutations were defined according to the publicly available molecular data bases and published data. Results: Within the cohort of 5758 NSCLC patients, we found 316 (5.5%) patients with FGFR alterations. Sixty-six (20.9% of FGFR, 1.1% of NSCLC) patients had alterations classified as activating, of whom 39 had FGFR point mutations and 27 FGFR translocations. Concerning the patients with activating alterations, they had UICC stage III or IV at time of diagnosis; 22 were females; 58 patients had squamous cell carcinoma, 6 patients had adenocarcinoma and 2 had large cell neuroendocrine carcinoma. Fifty-three patients (80.3%) with activating FGFR alteration had a co-mutation: TP53 (inactivating) co-mutation was seen in 41 cases (62.1%) and 19 cases had either PTEN (7 pts), KRAS (4), EGFR (3), PIK3CA (2), ROS1 (1), ALK (1) or BRAF (1) mutations. Ten patients were included in a FGFR-targeted trial. Sixty patients were available for follow-up. The median overall survival (mOS) was 21.4 month (95%CI: 16.8–25.9) for all patients with activating FGFR alteration, whereas mOS was 18.5 month (95%CI: 13.2-23.9) for FGFR mutation and 25.3 months (95%CI: 17.8-32.9) for FGFR fusions. Conclusions: FGFR 1-4 gene alterations are rare. Large molecular and clinical networks are necessary to identify these pts. Prognostic factors of FGFR patients are currently not defined. Further assessments on molecular and clinical features in FGFR altered NSCLC are needed to identify sensitivity to FGFR inhibition. Clinical trials with specific FGFR inhibitors are ongoing.

Crizotinib in ROS1-rearranged lung cancer (EUCROSS): Updated overall survival

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Background: ROS1 rearrangements are found in approximately 1% of non-small cell lung cancer (NSCLC) patients. Prospective clinical trials showed high efficacy of crizotinib in this molecular subset. Lately, we reported an overall response rate (ORR) of 70% and a median progression-free survival (PFS) of 19.4 months for patients treated within the EUCROSS trial (Michels et al. Clin Oncol, 37(15_suppl):9066-9066, 2019). Here we present an updated analysis of the overall survival. Methods: EUCROSS is a European multi-centre, single arm phase 2 trial (Clinicaltrial.gov identifier: NCT02183870). Key eligibility criteria were ≥18 years of age, advanced/metastatic lung cancer, centrally confirmed ROS1-rearranged (fluorescence-in situ hybridisation) and no or stable brain metastases at baseline. Crizotinib was given at a dose of 250 mg twice daily. Primary endpoint of the trial was investigator-assessed ORR in the response-evaluable population (Response Evaluation Criteria in Solid Tumors, version 1.1), with secondary endpoints of PFS and overall survival (OS). Results: Of the 34 patients who received at least one dose of crizotinib (intention-to-treat population, ITT), 30 were included the primary efficacy analysis set (PAS). After a median follow-up of 55.9 months, 13 (43%) patients in the PAS and 15 (44%) in the ITT had died. Median OS was not reached in either group (95% CI, 17.1-NR and 20.3-NR, respectively). OS was negatively correlated with the presence of brain metastases (Log-rank p = 0.1805) and TP53 mutations (Log-rank p = 0.015). Detailed listings of the survival rates are depicted in Table. No new safety signals were observed. Owing to the approval of crizotinib by the European Medicines Agency, all patients who were still on treatment by January 24th 2018 (n=8), were prescribed crizotinib outside the trial. Conclusions: Updated OS highlights the efficacy of crizotinib in patients with ROS1-rearranged lung cancer. Patients with co-occurring TP53 mutations or brain metastases had worse outcomes and represent challenging populations. Clinical trial information: NCT02183870. [Table: see text]

Reproducibility of dynamic contrast enhanced MRI derived transfer coefficient Ktrans in lung cancer

Dynamic contrast enhanced MRI (DCE-MRI) is a useful method to monitor therapy assessment in malignancies but must be reliable and comparable for successful clinical use. The aim of this study was to evaluate the inter- and intrarater reproducibility of DCE-MRI in lung cancer. At this IRB approved single centre study 40 patients with lung cancer underwent up to 5 sequential DCE-MRI examinations. DCE-MRI were performed using a 3.0T system. The volume transfer constant Ktrans was assessed by three readers using the two-compartment Tofts model. Inter- and intrarater reliability and agreement was calculated by wCV, ICC and their 95% confident intervals. DCE-MRI allowed a quantitative measurement of Ktrans in 107 tumors where 91 were primary carcinomas or intrapulmonary metastases and 16 were extrapulmonary metastases. Ktrans showed moderate to good interrater reliability in overall measurements (ICC 0.716-0.841; wCV 30.3-38.4%). Ktrans in pulmonary lesions ≥ 3 cm showed a good to excellent reliability (ICC 0.773-0.907; wCV 23.0-29.4%) compared to pulmonary lesions < 3 cm showing a moderate to good reliability (ICC 0.710-0.889; wCV 31.6-48.7%). Ktrans in intrapulmonary lesions showed a good reliability (ICC 0.761-0.873; wCV 28.9-37.5%) compared to extrapulmonary lesions with a poor to moderate reliability (ICC 0.018-0.680; wCV 28.1-51.8%). The overall intrarater agreement was moderate to good (ICC 0.607-0.795; wCV 24.6-30.4%). With Ktrans, DCE MRI offers a reliable quantitative biomarker for early non-invasive therapy assessment in lung cancer patients, but with a coefficient of variation of up to 48.7% in smaller lung lesions.

KEAP1 mutations in squamous cell lung cancer

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Background: KEAP1 mutations have been shown to decrease the efficacy of both chemotherapy (CTX) and immune-checkpoint inhibition (ICI) in lung adenocarcinoma. However, few is known about their impact on systemic treatment of squamous cell lung cancer (SqCC). The aim of this study was to assess the impact of KEAP1 mutations on systemic treatment outcome in SqCC. Methods: Tumor biopsies of SqCC patients were analyzed within the German Network Genomic Medicine (NGM) using a next-generation DNA sequencing (NGS) panel comprising 17 genes. In subsets, PD-L1 expression was tested with immunohistochemistry (IHC). MET amplification and FGFR1 amplification was tested with fluorescence in situ hybridization (FISH). Overall survival was estimated using Kaplan Meier statistics. For comparisons, we used log rank. A cohort with KEAP1 wild-type patients from the same panel served as control group. Results: Out of 1399 SqCC patients analyzed, 151 had a KEAP1 mutation (11%). The most common co-occurring mutations besides TP53 were PTEN, KRAS and NFE2L2. The median overall survival (OS) of stage IV KEAP1 mutated patients (n = 82) compared to stage IV control group patients (n = 82) was 7.3 vs. 11.4 months (hazard ratio (HR) 0.87 [95% confidence interval (CI) 0.62-1.23], p = 0.43). The addition of a second treatment line with ICI led to marked OS improvements in both KEAP1 mutant patient group (18.7 vs. 6.6 months, HR 0.11, [95% CI 0.04-0.25], p < 0.0001) and control group (20.3 vs. 5.0 months, HR 0.12 [95% CI 0.06-0.24], p < 0.0001). PD-L1 expression did not differ significantly in both groups. Conclusions: KEAP1 mutations occur commonly in SqCC patients and do not impact the efficacy of ICI in terms of OS. To identify prognostic markers for response to ICI further research is needed.

Genetic Heterogeneity of MET-Aberrant NSCLC and Its Impact on the Outcome of Immunotherapy

INTRODUCTION

Robust data on the outcome of MET-aberrant NSCLC with nontargeted therapies are limited, especially in consideration of the heterogeneity of MET-amplified tumors (METamp).

METHODS

A total of 337 tumor specimens of patients with MET-altered Union for International Cancer Control stage IIIB/IV NSCLC were analyzed using next-generation sequencing, fluorescence in situ hybridization, and immunohistochemistry. The evaluation focused on the type of MET aberration, co-occurring mutations, programmed death-ligand 1 expression, and overall survival (OS).

RESULTS

METamp tumors (n = 278) had a high frequency of co-occurring mutations (>80% for all amplification levels), whereas 57.6% of the 59 patients with MET gene and exon 14 (METex14) tumors had no additional mutations. In the METamp tumors, with increasing gene copy number (GCN), the frequency of inactivating TP53 mutations increased (GCN < 4: 58.2%; GCN ≥ 10: 76.5%), whereas the frequency of KRAS mutations decreased (GCN < 4: 43.2%; GCN ≥ 10: 11.8%). A total of 10.1% of all the METamp tumors with a GCN ≥ 10 had a significant worse OS (4.0 mo; 95% CI: 1.9-6.0) compared with the tumors with GCN < 10 (12.0 mo; 95% confidence interval [CI]: 9.4-14.6). In the METamp NSCLC, OS with immune checkpoint inhibitor (ICI) therapy was significantly better compared with chemotherapy with 19.0 months (95% CI: 15.8-22.2) versus 8.0 months (95% CI: 5.8-10.2, p < 0.0001). No significant difference in median OS was found between ICI therapy and chemotherapy in the patients with METex14 (p = 0.147).

CONCLUSIONS

METex14, METamp GCN ≥ 10, and METamp GCN < 10 represent the subgroups of MET-dysregulated NSCLC with distinct molecular and clinical features. The patients with METex14 do not seem to benefit from immunotherapy in contrast to the patients with METamp, which is of particular relevance for the prognostically poor METamp GCN ≥ 10 subgroup.

Abstract CT255: EATON: A phase I dose-escalation trial of nazartinib (EGF816) and trametinib in EGFR-mutant NSCLC

Background: EGFR tyrosine kinase inhibitor (TKI) treatment is highly effective in EGFR-mutant NSCLC. However, resistance to treatment inevitably develops. Multiple mechanisms of resistance to EGFR TKIs have been described. Besides secondary EGFR mutations, RAS/MEK pathway activation through different mechanisms has been found in cell models and in patients, resulting in TKI failure. Inhibition of MEK, resensitized cells to EGFR-targeted treatment in pre-clinical models. We thus hypothesize that combined MEK and EGFR inhibition may break resistance and delay treatment failure in EGFR-mutant NSCLC patients. Methods: EATON (NCT03516214) is an investigator-initiated, multicenter, phase I, dose-escalation trial investigating the recommended phase 2 dose (RP2D), pharmacokinetic parameters and safety/efficacy of the combination of EGF816 (nazartinib) and trametinib. Eligibility criteria: Advanced/metastatic EGFR-mutant (del19 or p.L858R) NSCLC, EGFR p.T790M-positive/-negative, absence of other secondary EGFR-mutations, MET amplification-negative (MET/CEN7 ratio ≥2.0 and/or average MET gene copy number per cell ≥6.0), first-line or after failure of any EGFR TKI, including osimertinib. Dose level escalation will be based on a 3+3 up-and-down design (total number: 24 patients) with a dose-limiting toxicity (DLT) period of 28 days. Minimum treatment exposure for DLT assessment is 21 days. Exploratory endpoints: Identification of mechanisms of resistance by analysis of baseline tissue, PD biopsies and ctDNA. Results: At the time of data cut-off, three patients received treatment at dose-level 1 (nazartinib (EGF816) 100 mg QD and trametinib 1 mg QD). All patients met the minimum exposure criterion for DLT assessment. In one patient a grade 3 creatinine phosphokinase elevation was observed and assessed as a DLT. No other DLTs were reported. Other related adverse events (AEs) grade ≥2 were rash (n=2), anemia (n=1), soft-tissue infection (n=1), diarrhea (n=1), and elevated liver enzymes (n=1). Two patients were evaluable for efficacy assessment. One stopped treatment prior to first assessment due to a grade 4 soft tissue infection at day 37. Best objective response according to RECIST 1.1 was stable disease in one patient (afatinib-resistant, T790M-negative), lasting for more than 4 months and progressive disease in the other patient (osimertinib-resistant, T790M-negative). Conclusions: Treatment with nazartinib 100 mg QD and trametinib 1 mg QD resulted in a DLT in one of three patients. Thus, three additional patients will be enrolled at the same dose level. Efficacy data is premature. But, a significant progression-free survival period was observed in one EGFR p.T790M-negative patient.

Citation Format: Sebastian Michels, Lucia Nogova, Matthias Scheffler, Barbara Deschler-Baier, Martin Sebastian, Martin Schuler, Martin Wermke, Enriqueta Felip, Rafael Rosell, Delvys Rodriguez Abreu, Diana S.Y. Abdulla, Rieke N. Fischer, Sophia Koleczko, Anna Kron, Richard Riedel, Jan-Philipp Weber, Jana Fassunke, Sabine Merkelbach-Bruse, Heinz Haverkammp, Martin Hellmich, Reinhard Büttner, Jürgen Wolf, Lung Cancer Group Cologne (LCGC) and Network Genomic Medicine (NGM). EATON: A phase I dose-escalation trial of nazartinib (EGF816) and trametinib in EGFR-mutant NSCLC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT255.

Sorafenib and everolimus in patients with advanced solid tumors and KRAS-mutated NSCLC: A phase I trial with early pharmacodynamic FDG-PET assessment

BACKGROUND

Treatment of patients with solid tumors and KRAS mutations remains disappointing. One option is the combined inhibition of pathways involved in RAF-MEK-ERK and PI3K-AKT-mTOR.

METHODS

Patients with relapsed solid tumors were treated with escalating doses of everolimus (E) 2.5-10.0 mg/d in a 14-day run-in phase followed by combination therapy with sorafenib (S) 800 mg/d from day 15. KRAS mutational status was assessed retrospectively in the escalation phase. Extension phase included KRAS-mutated non-small-cell lung cancer (NSCLC) only. Pharmacokinetic analyses were accompanied by pharmacodynamics assessment of E by FDG-PET. Efficacy was assessed by CT scans every 6 weeks of combination.

RESULTS

Of 31 evaluable patients, 15 had KRAS mutation, 4 patients were negative for KRAS mutation, and the KRAS status remained unknown in 12 patients. Dose-limiting toxicity (DLT) was not reached. The maximum tolerated dose (MTD) was defined as 7.5 mg/d E + 800 mg/d S due to toxicities at previous dose level (10 mg/d E + 800 mg/d S) including leucopenia/thrombopenia III° and pneumonia III° occurring after the DLT interval. The metabolic response rate in FDG-PET was 17% on day 5 and 20% on day 14. No patient reached partial response in CT scan. Median progression free survival (PFS) and overall survival (OS) were 3.25 and 5.85 months, respectively.

CONCLUSIONS

Treatment of patients with relapsed solid tumors with 7.5 mg/d E and 800 mg/d S is safe and feasible. Early metabolic response in FDG-PET was not confirmed in CT scan several weeks later. The combination of S and E is obviously not sufficient to induce durable responses in patients with KRAS-mutant solid tumors.