Executive Summary of the American Radium Society Appropriate Use Criteria for Brain Metastases in EGFR-mutated and ALK-fusion Non-Small Cell Lung Cancer

BACKGROUND

The American Radium Society (ARS) Central Nervous System (CNS) committee reviewed literature on epidermal growth factor receptor mutated (EGFRm) and ALK-fusion (ALK+) tyrosine kinase inhibitors (TKIs) for the treatment of brain metastases (BrMs) from non-small cell lung cancers (NSCLC) to generate appropriate use guidelines addressing use of TKIs in conjunction with or in lieu of radiotherapy (RT).

METHODS

The panel developed three key questions to guide systematic review: can radiotherapy be deferred in patients receiving EGFR or ALK TKIs at 1) diagnosis or 2) recurrence? Should TKI be administered concurrently with RT (3)? Two literature searches were performed (May 2019 and December 2023). The panel developed 8 model cases and voted on treatment options using a 9-point scale, with 1-3, 4-6 and 7-9 corresponding to usually not appropriate, may be appropriate, and usually appropriate (respectively), per the UCLA/RAND Appropriateness Method.

RESULTS

Consensus was achieved in only 4 treatment scenarios, all consistent with existing ARS-AUC guidelines for multiple BrM. The panel did not reach consensus that RT can be appropriately deferred in patients with BrM receiving CNS penetrant ALK or EGFR TKIs, though median scores indicated deferral may be appropriate under most circumstances. Whole brain RT with concurrent TKI generated broad disagreement except in cases with 2-4 BrM, where it was considered usually not appropriate.

CONCLUSIONS

We identified no definitive studies dictating optimal sequencing of TKIs and RT for EGFRm and ALK+ BrM. Until such studies are completed, the committee hopes these cases guide decision-making in this complex clinical space.

Global metabolomics revealed deviations from the metabolic aging clock in colorectal cancer patients

Background: Markers of aging hold promise in the context of colorectal cancer (CRC) care. Utilizing high-resolution metabolomic profiling, we can unveil distinctive age-related patterns that have the potential to predict early CRC development. Our study aims to unearth a panel of aging markers and delve into the metabolomic alterations associated with aging and CRC. Methods: We assembled a serum cohort comprising 5,649 individuals, consisting of 3,002 healthy volunteers, 715 patients diagnosed with colorectal advanced precancerous lesions (APL), and 1,932 CRC patients, to perform a comprehensive metabolomic analysis. Results: We successfully identified unique age-associated patterns across 42 metabolic pathways. Moreover, we established a metabolic aging clock, comprising 9 key metabolites, using an elastic net regularized regression model that accurately estimates chronological age. Notably, we observed significant chronological disparities among the healthy population, APL patients, and CRC patients. By combining the analysis of circulative carcinoembryonic antigen levels with the categorization of individuals into the "hypo" metabolic aging subgroup, our blood test demonstrates the ability to detect APL and CRC with positive predictive values of 68.4% (64.3%, 72.2%) and 21.4% (17.8%, 25.9%), respectively. Conclusions: This innovative approach utilizing our metabolic aging clock holds significant promise for accurately assessing biological age and enhancing our capacity to detect APL and CRC.

Tumor treating fields increases blood-brain barrier permeability and relative cerebral blood volume in patients with glioblastoma

BACKGROUND AND OBJECTIVE

200 kHz tumor treating fields (TTFields) is clinically approved for newly-diagnosed glioblastoma (nGBM). Because its effects on conventional surveillance MRI brain scans are equivocal, we investigated its effects on perfusion MRI (pMRI) brain scans.

METHODS

Each patient underwent institutional standard pMRI: dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) pMRI at three time points: baseline, 2-, and 6-months on-adjuvant therapy. At each timepoint, the difference between T1 pre- versus post-contrast tumor volume (ΔT1) and these pMRI metrics were evaluated: normalized and standardized relative cerebral blood volume (nRCBV, sRCBV); fractional plasma volume (Vp), volume of extravascular extracellular space (EES) per volume of tissue (Ve), blood-brain barrier (BBB) permeability (Ktrans), and time constant for gadolinium reflux from EES back into the vascular system (Kep). Between-group comparisons were performed using rank-sum analysis, and bootstrapping evaluated likely reproducibility of the results.

RESULTS

Among 13 pMRI datasets (11 nGBM, 2 recurrent GBM), therapies included temozolomide-only (n = 9) and temozolomide + TTFields (n = 4). No significant differences were found in patient or tumor characteristics. Compared to temozolomide-only, temozolomide + TTFields did not significantly affect the percent-change in pMRI metrics from baseline to 2 months. But during the 2- to 6-month period, temozolomide + TTFields significantly increased the percent-change in nRCBV (+26.9% [interquartile range 55.1%] vs -39.1% [37.0%], p = 0.049), sRCBV (+9.5% [39.7%] vs -30.5% [39.4%], p = 0.049), Ktrans (+54.6% [1768.4%] vs -26.9% [61.2%], p = 0.024), Ve (+111.0% [518.1%] vs -13.0% [22.5%], p = 0.048), and Vp (+98.8% [2172.4%] vs -24.6% [53.3%], p = 0.024) compared to temozolomide-only.

CONCLUSION

Using pMRI, we provide initial in-human validation of pre-clinical studies regarding the effects of TTFields on tumor blood volume and BBB permeability in GBM.

Multi-omics analysis identifies potential microbial and metabolite diagnostic biomarkers of bacterial vaginosis

BACKGROUND

Bacterial vaginosis (BV) is a common clinical manifestation of a perturbed vaginal ecology associated with adverse sexual and reproductive health outcomes if left untreated. The existing diagnostic modalities are either cumbersome or require skilled expertise, warranting alternate tests. Application of machine-learning tools to heterogeneous and high-dimensional multi-omics datasets finds promising potential in data integration and may aid biomarker discovery.

OBJECTIVES

The present study aimed to evaluate the potential of the microbiome and metabolome-derived biomarkers in BV diagnosis. Interpretable machine-learning algorithms were used to evaluate the utility of an integrated-omics-derived classification model.

METHODS

Vaginal samples obtained from reproductive-age group women with (n = 40) and without BV (n = 40) were subjected to 16S rRNA amplicon sequencing and LC-MS-based metabolomics. The vaginal microbiome and metabolome were characterized, and machine-learning analysis was performed to build a classification model using biomarkers with the highest diagnostic accuracy.

RESULTS

Microbiome-based diagnostic model exhibited a ROC-AUC (10-fold CV) of 0.84 ± 0.21 and accuracy of 0.79 ± 0.18, and important features were Aerococcus spp., Mycoplasma hominis, Sneathia spp., Lactobacillus spp., Prevotella spp., Gardnerella spp. and Fannyhessea vaginae. The metabolome-derived model displayed superior performance with a ROC-AUC of 0.97 ± 0.07 and an accuracy of 0.92 ± 0.08. Beta-leucine, methylimidazole acetaldehyde, dimethylethanolamine, L-arginine and beta cortol were among key predictive metabolites for BV. A predictive model combining both microbial and metabolite features exhibited a high ROC-AUC of 0.97 ± 0.07 and accuracy of 0.94 ± 0.08 with diagnostic performance only slightly superior to the metabolite-based model.

CONCLUSION

Application of machine-learning tools to multi-omics datasets aid biomarker discovery with high predictive performance. Metabolome-derived classification models were observed to have superior diagnostic performance in predicting BV than microbiome-based biomarkers.

A rare non-gadolinium enhancing sarcoma brain metastasis with microenvironment dominated by tumor-associated macrophages

Brain metastases occur in 1% of sarcoma cases and are associated with a median overall survival of 6 months. We report a rare case of a brain metastasis with unique radiologic and histopathologic features in a patient with low grade fibromyxoid sarcoma (LGFMS) previously treated with immune checkpoint inhibitor (ICI) therapy. The lone metastasis progressed in the midbrain tegmentum over 15 months as a non-enhancing, T2-hyperintense lesion with peripheral diffusion restriction, mimicking a demyelinating lesion. Histopathology of the lesion at autopsy revealed a rich infiltrate of tumor-associated macrophages (TAMs) with highest density at the leading edge of the metastasis, whereas there was a paucity of lymphocytes, suggestive of an immunologically cold environment. Given the important immunosuppressive and tumor-promoting functions of TAMs in gliomas and carcinoma/melanoma brain metastases, this unusual case provides an interesting example of a dense TAM infiltrate in a much rarer sarcoma brain metastasis.

Effect of Language Barriers and Use of Interpreters on Hope Among Patients With Central Nervous System Malignancies and Bone Metastases

PURPOSE

Hope is important in serious illnesses, as it has been linked to patient quality of life. We aimed to determine factors associated with lower hope scores among patients with central nervous system disease or bone metastases.

METHODS AND MATERIALS

The Adult Dispositional Hope Scale (AHS) is a 12-item questionnaire that measures hope through 2 qualities: agency (goal-directed energy) and pathways (plan to meet goals). Total scores range from 8 to 64, with higher scores reflecting higher agency and pathways thinking. We prospectively collected scores from patients seen in 2 radiation oncology clinics at our institution from October 2022 to April 2023. The method of least squares to fit general linear models and Pearson's correlation coefficients was used to determine relationships between AHS score and socioeconomic and disease factors.

RESULTS

Of the 197 patients who responded, the median age was 60.5 years (range, 16.9-92.5 years) and most patients were male (60.9%), were White (59.4%), and had malignant disease (59.4%). The median overall AHS score was 54 (range, 8-64), and median pathway and agency thinking scores were 27 (range, 4-32) and 27 (range, 4-32), respectively. Patients who needed an interpreter compared with those who did not had significantly lower overall AHS scores (mean score, 45.4 vs 51.2, respectively; P = .0493) and pathway thinking scores (mean score, 21.5 vs 25.7, respectively; P = .0085), and patients with poorer performance status had significantly worse overall AHS scores (Pearson's correlation coefficient = -0.2703, P = .0003).

CONCLUSIONS

Patients with central nervous system disease or bone metastases requiring the use of an interpreter had lower AHS scores, highlighting the possible association of language barriers to hope. Addressing patient language barriers and further studies on the possible association of language barriers to hope may improve hope, quality of life, and outcomes among these patients.

High-throughput quantitation of amino acids and acylcarnitine in cerebrospinal fluid: identification of PCNSL biomarkers and potential metabolic messengers

Background: Due to the poor prognosis and rising occurrence, there is a crucial need to improve the diagnosis of Primary Central Nervous System Lymphoma (PCNSL), which is a rare type of non-Hodgkin's lymphoma. This study utilized targeted metabolomics of cerebrospinal fluid (CSF) to identify biomarker panels for the improved diagnosis or differential diagnosis of primary central nervous system lymphoma (PCNSL). Methods: In this study, a cohort of 68 individuals, including patients with primary central nervous system lymphoma (PCNSL), non-malignant disease controls, and patients with other brain tumors, was recruited. Their cerebrospinal fluid samples were analyzed using the Ultra-high performance liquid chromatography - tandem mass spectrometer (UHPLC-MS/MS) technique for targeted metabolomics analysis. Multivariate statistical analysis and logistic regression modeling were employed to identify biomarkers for both diagnosis (Dx) and differential diagnosis (Diff) purposes. The Dx and Diff models were further validated using a separate cohort of 34 subjects through logistic regression modeling. Results: A targeted analysis of 45 metabolites was conducted using UHPLC-MS/MS on cerebrospinal fluid (CSF) samples from a cohort of 68 individuals, including PCNSL patients, non-malignant disease controls, and patients with other brain tumors. Five metabolic features were identified as biomarkers for PCNSL diagnosis, while nine metabolic features were found to be biomarkers for differential diagnosis. Logistic regression modeling was employed to validate the Dx and Diff models using an independent cohort of 34 subjects. The logistic model demonstrated excellent performance, with an AUC of 0.83 for PCNSL vs. non-malignant disease controls and 0.86 for PCNSL vs. other brain tumor patients. Conclusion: Our study has successfully developed two logistic regression models utilizing metabolic markers in cerebrospinal fluid (CSF) for the diagnosis and differential diagnosis of PCNSL. These models provide valuable insights and hold promise for the future development of a non-invasive and reliable diagnostic tool for PCNSL.

CNS Control after First-Line Osimertinib in Patients with Metastatic EGFR-Mutant NSCLC

PURPOSE/OBJECTIVE(S)

Although osimertinib (osi) has excellent intracranial activity in EGFR-mutant metastatic non-small cell lung cancer (NSCLC), there is no consensus regarding whether to continue osi for central nervous system (CNS) control with second-line chemotherapy (chemo) at the time of systemic progression. We aimed to compare CNS outcomes after first-line osi in patients receiving second-line chemo with or without continuation of osi.

MATERIALS/METHODS

We retrospectively reviewed patients with EGFR-mutant NSCLC with brain metastases (BrM) at the time of initiating first-line osi who experienced progression and started second-line chemo. Cumulative incidence of local and distant CNS progression, and extracranial (EC) progression was calculated from time of second-line chemo initiation with death as a competing risk. Overall survival (OS) was analyzed using Kaplan-Meier.

RESULTS

We included 52 patients with a median follow up of 9.6 months (range 0.4-36.4). Median OS and CNS progression-free survival (PFS) from the time of starting second-line chemo was 12.5 months (95% CI 8.1-16.9), and 5.3 months (95% CI 3.35-7.26), respectively. The 1-year cumulative incidence of local, distant CNS progression, any CNS progression, and EC progression was 14.4% (95% CI 4.5-24.2), 42.8% (95% CI 22.8-56.8), 42.8% (95% CI 22.8-56.8) and 66.8% (95% CI 53.5-80.2), respectively. After progression on first-line osi, 25 (48.1%) and 27 patients (51.9%) continued and discontinued osi, respectively. Patients who continued osi had significantly higher BrM burden than those who did not, with 17 (68%), 3 (12%), and 5 (20%) versus 26 (96%), 0, and 1 (3.7%) patient having <10 or >11 parenchymal brain lesions, or leptomeningeal disease (LMD) at the time of second line therapy, respectively (p<0.01). In those who continued osi vs those who did not, median OS (10.8 vs 12.5 months; p = 0.37), median intracranial PFS (5.3 vs 4.8 months; p = 0.99), 1-year cumulative incidence of local (8.4% versus 20 % p = 0.26), and 1-year distant CNS progression (24.8% vs 60%; p = 0.08) was not significantly different. CNS complications such as symptomatic, hospitalizations, and steroid initiation for CNS disease, and progression of LMD were not significantly different between the two groups. Eventually, 10 patients underwent salvage RT post first-line osi and median time to salvage RT was 7.8 months (range 2-9.4). Of patients who underwent salvage RT, 2 patients (20%) had continued osi with second-line chemo. Twelve patients (44.4%) who did not continue osi eventually re-started osi for progressive disease.

CONCLUSION

Patients who continued osi had significantly higher BrM tumor burden. Despite these patients being at higher risk for CNS progression, time to CNS progression and incidence of CNS complications were not significantly different in the two cohorts. Patients who discontinued osi were more likely to undergo salvage RT. Continuation of osi may allow patients to defer salvage RT.

Diagnostic and Therapeutic Updates in Leptomeningeal Disease

PURPOSE OF REVIEW

Leptomeningeal disease (LMD) is a devastating complication of advanced metastatic cancer associated with a poor prognosis and limited treatment options. This study reviews the current understanding of the clinical presentation, pathogenesis, diagnosis, and treatment of LMD. We highlight opportunities for advances in this disease.

RECENT FINDINGS

In recent years, the use of soluble CSF biomarkers has expanded, suggesting improved sensitivity over traditional cytology, identification of targetable mutations, and potential utility for monitoring disease burden. Recent studies of targeted small molecules and intrathecal based therapies have demonstrated an increase in overall and progression-free survival. In addition, there are several ongoing trials evaluating immunotherapy in LMD. Though overall prognosis of LMD remains poor, studies suggest a potential role for soluble CSF biomarkers in diagnosis and management and demonstrate promising findings in patient outcomes with targeted therapies for specific solid tumors. Despite these advances, there continues to be a gap of knowledge in this disease, emphasizing the importance of inclusion of LMD patients in clinical trials.

Patterns of Progression in Patients With Newly Diagnosed Glioblastoma Treated With 5-mm Margins in a Phase 1/2 Trial of 5-Fraction Stereotactic Radiosurgery With Concurrent and Adjuvant Temozolomide

PURPOSE

In patients with newly diagnosed glioblastoma (GBM), tumor margins of at least 20 mm are the standard of care. We sought to determine the pattern of tumor progression in patients treated with 5-fraction stereotactic radiosurgery with 5-mm margins.

METHODS AND MATERIALS

Thirty adult patients with newly diagnosed GBM were treated with 5-fraction stereotactic radiosurgery in escalated doses from 25 to 40 Gy with a 5-mm total treatment margin. Progression was scored as "in-field" if the recurrent tumor was within or contiguous with the 5-mm margin, "marginal" if between 5 and 20 mm, and "distant" if entirely occurring greater than 20 mm. As geometric patterns of progression do not reflect the biologic dose received, we calculated the minimum equi-effective dose in 2 Gy (EQD2) per day at the site of tumor recurrence. Progression was "dosimetrically in-field" if covered by a minimum EQD2 per day of 48 Gy10.

RESULTS

From 2010 to 2016, 27 patients had progressed. Progression was in-field in 17 (63%), marginal in 3 (11%), and distant in 7 (26%) patients. In the 3 patients with marginal progression, the minimum EQD2 to recurrent tumor were 48 Gy10, 56 Gy10 (both considered dosimetrically in-field), and 7 Gy10 (ie, dosimetrically out-of-field). Median overall survival was 12.1 months for in-field (95% confidence interval [CI], 8.9-17.6), 15.1 months (95% CI, 10.1 to not achieved) for marginal, and 21.4 months (95% CI, 11.2-33.5) for distant progression. Patients with radiation necrosis were less likely to have in-field progression (1 of 7; 14%) compared with those without radiation necrosis (16 of 20; 80%; P = .003); those with necrosis had a median overall survival of 27.2 months (95% CI, 11.2-48.3) compared with 11.7 months (95% CI, 8.9-17.6) for patients with no necrosis (P = .077).

CONCLUSIONS

In patients with newly diagnosed GBM treated with a 5-mm clinical target volume margin, 3 patients (11%) had marginal progression within 5 to 20 mm; only 1 patient (4%) may have dosimetrically benefitted from conventional 20-mm margins. Radiation necrosis was associated with in-field tumor control.

Anaesthesia for vascular emergencies - a state of the art review

In this state-of-the-art review, we discuss the presenting symptoms and management strategies for vascular emergencies. Although vascular emergencies are best treated at a vascular surgical centre, patients may present to any emergency department and may require both immediate management and safe transport to a vascular centre. We describe the surgical and anaesthetic considerations for management of aortic dissection, aortic rupture, carotid endarterectomy, acute limb ischaemia and mesenteric ischaemia. Important issues to consider in aortic dissection are extent of the dissection and surgical need for bypasses in addition to endovascular repair. From an anaesthetist's perspective, aortic dissection requires infrastructure for massive transfusion, smooth management should an endovascular procedure require conversion to an open procedure, haemodynamic manipulation during stent deployment and prevention of spinal cord ischaemia. Principles in management of aortic rupture, whether open or endovascular treatment is chosen, include immediate transfer to a vascular care centre; minimising haemodynamic changes to reduce aortic shear stress; permissive hypotension in the pre-operative period; and initiation of massive transfusion protocol. Carotid endarterectomy for carotid stenosis is managed with general or regional techniques, and anaesthetists must be prepared to manage haemodynamic, neurological and airway issues peri-operatively. Acute limb ischaemia is a result of embolism, thrombosis, dissection or trauma, and may be treated with open repair or embolectomy, under either general or local anaesthesia. Due to hypercoagulability, there may be higher numbers of acutely ischaemic limbs among patients with COVID-19, which is important to consider in the current pandemic. Mesenteric ischaemia is a rare vascular emergency, but it is challenging to diagnose and associated with high morbidity and mortality. Several peri-operative issues are common to all vascular emergencies: acute renal injury; management of transfusion; need for heparinisation and reversal; and challenging postoperative care. Finally, the important development of endovascular techniques for repair in many vascular emergencies has improved care, and the availability of transoesophageal echocardiography has improved monitoring as well as aids in surgical placement of endovascular grafts and for post-procedural evaluation.

NCCN Guidelines® Insights: Central Nervous System Cancers, Version 2.2022

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of the following adult CNS cancers: glioma (WHO grade 1, WHO grade 2-3 oligodendroglioma [1p19q codeleted, IDH-mutant], WHO grade 2-4 IDH-mutant astrocytoma, WHO grade 4 glioblastoma), intracranial and spinal ependymomas, medulloblastoma, limited and extensive brain metastases, leptomeningeal metastases, non-AIDS-related primary CNS lymphomas, metastatic spine tumors, meningiomas, and primary spinal cord tumors. The information contained in the algorithms and principles of management sections in the NCCN Guidelines for CNS Cancers are designed to help clinicians navigate through the complex management of patients with CNS tumors. Several important principles guide surgical management and treatment with radiotherapy and systemic therapy for adults with brain tumors. The NCCN CNS Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding molecular profiling of gliomas.

A Single-Institution Retrospective Series of SARS-CoV-2 Infection in Adult Glioma Patients

A subset of cancer patients is particularly vulnerable to SARS-CoV-2 infection; however, real-world outcomes-based data on primary central nervous system tumor patients is sparse. This retrospective series describes a cohort of adult glioma patients seen at Stanford Cancer Center between January 1, 2020, and June 30, 2022 who contracted SARS-CoV-2, which, to our knowledge, currently represents the largest single-institution comprehensive analysis of this patient population. We performed a retrospective search of patients seen in the Stanford Neuro-Oncology clinic, identifying 29 cases of COVID-19 amongst glioma patients and extracted clinical data via individual chart review. At the time of COVID-19 diagnosis, 15 patients had been vaccinated against SARS-CoV-2, 8 patients were taking dexamethasone, and 8 were undergoing cancer-specific treatment. Obesity, prior tobacco use, and diabetes were the most common comorbidities. Cough, sore throat, and congestion were the most common symptoms. Five patients were admitted to the hospital and two received COVID-19-specific treatment. None died from COVID-related causes or complications. Our data suggest that glioma patients seen at Stanford Cancer Center do not experience an exceptionally high COVID-19 infectivity, hospitalization, or mortality rate, especially when compared to other vulnerable populations such as lung cancer patients. High vaccination rates, adherence to COVID-19 guidelines, and low prevalence of comorbidities may have contributed to these results.

Real-world risk of brain metastases in stage III non-small cell lung cancer in the era of PET and MRI staging

Objective

The 2-year incidence of brain metastases (BrMs) in stage III non-small lung cell cancer (NSCLC) has been estimated to be around 30%. However, recent clinical trials have demonstrated considerably lower BrMs rates in this patient population. In this study, we aimed to review the real-world incidence, surveillance, and treatment patterns of BrMs in stage III NSCLC.

Materials and methods

Using a retrospective single-center study design, we identified patients with stage III NSCLC who received radiation with curative intent over a 10-year period. Outcome variables included BrMs incidence, overall survival (OS), and survival from date of BrMs. Additionally, we assessed patterns of BrMs surveillance in stage III NSCLC and treatment.

Results

We identified a total of 279 stage III NSCLC patients, of which 160 with adequate records were included in the final analyses [adenocarcinoma (n = 96), squamous cell carcinoma (n = 53), other histology subtype (n = 11)]. The median OS for the entire cohort was 41 months (95% CI, 28-53), while the median time from BrMs to death was 19 months (95% CI, 9-21). Twenty-three patients (14.4%) received planned surveillance brain MRIs at 6, 12, and 24 months after completion of treatment. The remaining 137 patients (85.6%) received brain MRIs at systemic recurrence (restaging) or when neurologically symptomatic. A total of 37 patients (23%) developed BrMs, with a 2-year cumulative BrMs incidence of 17% (95% CI, 11-23). A higher incidence of BrMs was identified in patients with adenocarcinoma relative to those with squamous cell carcinoma (p < 0.01). Similarly, a higher 2-year BrMs incidence was observed in patients who received planned surveillance brain MRI relative to those who did not, although statistical significance was not reached. Stereotactic radiosurgery (SRS) treated 29 of BrMs patients (78.4%) and was preferred over WBRT, which treated only 3 patients (8.1%).

Conclusions

At our center, BrMs incidence in stage III NSCLC patients was lower than historically reported but notably higher than the incidence described in recent clinical trials. Routine BrMs surveillance potentially allows earlier detection of asymptomatic BrMs. However, asymptomatic BrMs were mostly detected on restaging MRI at the time of recurrence.

Interplay of Immunosuppression and Immunotherapy Among Patients With Cancer and COVID-19

Importance

Cytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.

Objective

To determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.

Design, Setting, and Participants

This registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.

Exposures

Immunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).

Main Outcomes and Measures

The primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.

Results

The median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).

Conclusions and Relevance

This cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.

Trial Registration

ClinicalTrials.gov Identifier: NCT04354701.

DDEL-01. ANIMAL STUDIES WITH A NEW CNS DRUG DELIVERY DEVICE TO EFFECTIVELY TREAT LEPTOMENINGEAL CARCINOMATOSIS PATIENTS

Background

Appropriate drug distribution is needed for effective treatment of brain metastases and leptomeningeal carcinomatosis. Lack of proper drug bioavailability in the CNS contributes to the poor outcome in these patients. EnClear Therapies has developed a device delivering intrathecal therapeutics utilizing the active control of CSF flow through an external pump. Herein, we look at intrathecal drug delivery of methotrexate with EnClear’s system and its impact of drug concentration in sheep and non-human primates.

METHODS

The EnClear device utilizes two implantable catheters (intracranial in the ventricular system and lumbar thecal sac) and an extracorporeal pump that controls the speed and direction of CSF flow. Software monitors the output from sensor arrays for pressure, respiration, and heart rate. Gadolinium and MRI were used to determine the CSF flow characteristics. Administration of Methotrexate via the EnClear system was compared to current two standards of delivery, intracerebroventricular or lumbar intrathecal administration. Methotrexate levels were measured with Liquid Chromatography/Mass Spectrometry in CSF, blood, and multiple CNS and peripheral tissues.

RESULTS

There was a two-fold increase in methotrexate levels in multiple regions of the brain including deeper brain structures including the striatum using the EnClear's system, compared to traditional lumbar intrathecal and intracerebroventricular delivery. Higher peak levels of methotrexate were reached in the CSF with the use of EnClear’s system, with simultaneous reduction in the peripheral nerves and systemic tissues – a potential source of toxicity.

Conclusions

In large animal studies, the EnClear device has for the first time, demonstrated increased brain parenchymal drug levels via intrathecal delivery. In addition to the drug parenchyma, drug delivery with this novel device has shown improved distribution throughout CNS and leptomeninges as compared to traditional intrathecal drug delivery and decreased peripheral distribution.

CTNI-56. A MULTI-INSTITUTIONAL RETROSPECTIVE SERIES OF ADULT-ONSET MEDULLOBLASTOMA

Adult-onset medulloblastoma is a rare tumor for which limited data exists. Current treatment is based on data from childhood medulloblastoma. We present a retrospective cohort of 130 consecutive patients age ≥ 18 years and treated at the University of Washington (N = 61), University of Florida (N = 50), and Stanford University (N = 19), from 2000-2021. Median duration of follow-up was 57.3 months. Patients were 57.7% male (75/130), with median age at diagnosis of 29 years. 5 and 10-year overall survival were 78.9% and 67.6% and no recurrence was seen beyond 10 years. 31/130 (23.8%) patients had Chang M1 or greater disease and molecular typing was available for 41/130 patients. There was no improvement in progression-free survival (PFS) or overall survival (OS) either in patients who received proton therapy or those who received concurrent vincristine. There was a trend favoring longer OS in patients receiving radiotherapy within 6 weeks of surgery. A trend towards shorter OS in patients receiving a higher craniospinal radiation dose ( &gt; 30Gy) likely reflected accurate clinical risk stratification. There was no improvement in OS or PFS for adjuvant chemotherapy overall, but patients receiving ≥ 5 cycles had improved PFS (HR 2.10, 95% CI = 1.19 - 3.90, p = 0.038) and a trend to improved OS (HR 2.07, 95%CI = 0.81-5.25, p = 0.125). After first progression, median OS was 20.7 months and both 5 and 10-year survival were 24.8%. We conclude that surveillance past 10 years may be unnecessary and that 1 in 4 patients achieve long-term survival after first relapse. Within the confines of a retrospective study, these data suggest equivalence between proton and photon radiotherapy, no benefit to concurrent vincristine, and that at least 5 cycles of adjuvant chemotherapy are required to delay progression.

NCOG-27. A SINGLE-INSTITUTION RETROSPECTIVE SERIES OF SARS-COV-2 INFECTION IN ADULT GLIOMA PATIENTS

A subset of cancer patients is particularly vulnerable to SARS-Cov-2 infection; however, real-world outcomes-based data on primary central nervous system tumor patients is sparse. This retrospective case series describes a cohort of adult glioma patients seen at Stanford Cancer Center between 1/20/2020 through 5/24/2022 who contracted SARS-Cov-2. We identified 18 patients with a diagnosis of glioma, with a median age of 54 years, who were infected with Covid-19. One patient contracted Covid-19 twice during this two-year period. Of these patients, four had pathology confirmed low-grade glioma, defined as oligodendroglioma or astrocytoma WHO grade 2, and 14 patients had high-grade glioma, defined as astrocytoma or glioblastoma WHO grade 4. Median KPS at time of infection was 70. Six individuals had notable cardiovascular comorbidities including coronary artery disease, obesity, and/or diabetes. All but one patient was vaccinated against Covid-19, and 6 were taking dexamethasone at the time of infection. Three patients required hospital admission for management of Covid-19 symptoms, although none required ICU-level of care. None died from Covid-related complications; however, two died from complications of their underlying cancer at the end of study. Our data suggest that glioma patients seen at Stanford Cancer Center do not experience an exceptionally high Covid-19 infectivity, hospitalization, or mortality rate, especially when compared to other vulnerable populations such as lung cancer patients. High vaccination rates, fairly low prevalence of cardiovascular comorbidities, and adherence to pandemic precautions among this cohort may have contributed to these results.

Local control of brain metastases with osimertinib alone in patients with EGFR-mutant non-small cell lung cancer

PURPOSE

Although osimertinib has excellent intracranial activity in metastatic non-small cell lung cancer (NSCLC) with exon 19 deletion or L858R EGFR alterations, measures of local control of brain metastases are less well-reported. We describe lesion-level outcomes of brain metastases treated with osimertinib alone.

METHODS

We retrospectively reviewed patients with EGFR-mutant NSCLC with untreated brain metastasis measuring ≥ 5 mm at the time of initiating osimertinib. Cumulative incidence of local recurrence in brain (LRiB) was calculated with death as a competing risk, and univariable and multivariable analyses were conducted to identify factors associated with LRiB.

RESULTS

We included 284 brain metastases from 37 patients. Median follow-up was 20.1 months. On initial MRI after starting osimertinib, patient-level response was complete response (CR) in 11 (15%), partial response (PR) in 33 (45%), stable disease (SD) in 18 (25%) and progressive disease (PD) in 11 (15%). The 1-year cumulative incidence of LRiB was 14% (95% CI 9.9-17.9) and was significantly different in patients with a CR (0%), PR (4%), and SD (11%; p = 0.02). Uncontrolled primary tumor (adjusted hazard ratio [aHR] 3.78, 95% CI 1.87-7.66; p < 0.001), increasing number of prior systemic therapies (aHR 2.12, 95% CI 1.49-3.04; p < 0.001), and higher ECOG score (aHR 7.8, 95% CI 1.99-31.81; p = 0.003) were associated with LRiB.

CONCLUSIONS

Although 1-year cumulative incidence of LRiB is < 4% with a CR or PR, 1-year cumulative incidence of LRiB is over 10% for patients with less than a PR to osimertinib on initial MRI. These patients should be followed closely for need for additional treatment such as stereotactic radiosurgery.

Predictive Model to Guide Brain Magnetic Resonance Imaging Surveillance in Patients With Metastatic Lung Cancer: Impact on Real-World Outcomes

PURPOSE

Brain metastasis is common in lung cancer, and treatment of brain metastasis can lead to significant morbidity. Although early detection of brain metastasis may improve outcomes, there are no prediction models to identify high-risk patients for brain magnetic resonance imaging (MRI) surveillance. Our goal is to develop a machine learning-based clinicogenomic prediction model to estimate patient-level brain metastasis risk.

METHODS

A penalized regression competing risk model was developed using 330 patients diagnosed with lung cancer between January 2014 and June 2019 and followed through June 2021 at Stanford HealthCare. The main outcome was time from the diagnosis of distant metastatic disease to the development of brain metastasis, death, or censoring.

RESULTS

Among the 330 patients, 84 (25%) developed brain metastasis over 627 person-years, with a 1-year cumulative brain metastasis incidence of 10.2% (95% CI, 6.8 to 13.6). Features selected for model inclusion were histology, cancer stage, age at diagnosis, primary site, and RB1 and ALK alterations. The prediction model yielded high discrimination (area under the curve 0.75). When the cohort was stratified by risk using a 1-year risk threshold of > 14.2% (85th percentile), the high-risk group had increased 1-year cumulative incidence of brain metastasis versus the low-risk group (30.8% v 6.1%, P < .01). Of 48 high-risk patients, 24 developed brain metastasis, and of these, 12 patients had brain metastasis detected more than 7 months after last brain MRI. Patients who missed this 7-month window had larger brain metastases (58% v 33% largest diameter > 10 mm; odds ratio, 2.80, CI, 0.51 to 13) versus those who had MRIs more frequently.

CONCLUSION

The proposed model can identify high-risk patients, who may benefit from more intensive brain MRI surveillance to reduce morbidity of subsequent treatment through early detection.

P11.33.B Tumour Treating Fields (TTFields; 200 kHz) with chemo-radiation and maintenance TTFields/temozolomide as first-line treatment for newly-diagnosed glioblastoma: The phase 3 TRIDENT Trial (EF-32)

Background

Tumour Treating Fields therapy (TTFields; 200 kHz) is a noninvasive, loco-regional, antimitotic treatment approved for newly diagnosed glioblastoma (ndGBM) and mesothelioma. In the phase 3 EF-14 trial, TTFields/temozolomide (TMZ) significantly increased overall survival (OS) and progression-free survival (PFS) vs TMZ alone in patients with ndGBM. TTFields-related adverse events (AEs) were mainly dermatological with no increases in systemic toxicity. In preclinical models, the addition of TTFields to radiotherapy (RT) increased the therapeutic effect. In 2 clinical pilot phase 2 studies, TTFields added to RT/TMZ was reported as feasible and well-tolerated.

Material and Methods

TRIDENT (EF-32; NCT04471844) is an international, phase 3 randomised trial comparing TTFields (200 KHz, ≥ 18 h/day)/RT/TMZ vs RT/TMZ alone. Eligibility criteria include histologically confirmed ndGBM, ≥ 18 years of age (≥ 22 years of age; US), Karnofsky Performance Status ≥ 70, life expectancy ≥ 3 months, adequate organ function and eligible for RT/TMZ - participants will be stratified by extent-of-resection and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. During the initial 6-week investigational period, patients in the experimental arm will receive continuous TTFields and concomitant RT/TMZ whilst patients in the control arm will receive only RT/TMZ. Subsequently, all patients will receive TTFields and 6 cycles of maintenance TTFields/TMZ. TTFields will continue for 24 months or until second disease progression per Response Assessment in Neuro-Oncology (RANO), whichever occurs first. The primary endpoint is median OS. Secondary endpoints include median PFS (RANO), 1- and 2-year survival rates, overall radiological response (RANO), PFS6, PFS12, severity and frequency of AEs (Common Terminology Criteria for Adverse Events v5.0), post-treatment pathological changes in resected GBM tumours, quality-of-life per EORTC QLQ-C30, OS correlation to TTFields duration-of-usage, and neurological assessment per NANO (Neurological Assessment in Neuro-Oncology) and RANO criteria. Survival will be measured from time-of-randomisation. Sample size (N = 950; randomised 1:1) was powered for a hazard ratio &lt; 0.8 with a 5% type I error. The hypothesis, that first-line TTFields/RT/TMZ can significantly improve OS vs RT/TMZ, will be tested using a stratified log-rank test.

The study is currently open to enrollment in locations in Austria, Belgium, Czech Republic, France, Germany, Israel, Switzerland, and across the US.

CLRM-09 FIRST-LINE Tumor TREATING FIELDS (200 KHZ) THERAPY FOR NEWLY-DIAGNOSED GLIOBLASTOMA: THE PHASE 3 TRIDENT TRIAL (EF-32)

BACKGROUND

Tumor Treating Fields therapy (TTFields; 200 kHz) comprise alternating electric fields that disrupt cancer cell division, and is approved for newly diagnosed glioblastoma (ndGBM), recurrent GBM and mesothelioma. In the phase 3 EF-14 trial, TTFields/temozolomide (TMZ) significantly increased overall survival (OS) and progression-free survival (PFS) vs TMZ alone in patients with ndGBM. TTFields-related adverse events (AEs) were mainly dermatological with no increases in systemic toxicity. In preclinical models, the addition of TTFields to radiotherapy (RT) increased the therapeutic effect. Additionally, TTFields added to RT/TMZ was reported as feasible and well-tolerated in 2 clinical pilot phase 2 studies.

MATERIALS AND METHODS

TRIDENT (EF-32; NCT04471844) is an international, phase 3 randomized trial comparing TTFields (200 KHz, ≥18 h/day)/RT/TMZ vs RT/TMZ alone. Adult patients (N=950; ≥18 years of age [≥22 years of age; US]) with histologically confirmed ndGBM, Karnofsky Performance Status ≥70, life expectancy ≥3 months, adequate organ function and eligible for RT/TMZ will be enrolled. Patients will be stratified by extent-of-resection and MGMT promoter methylation status and randomized 1:1 to receive continuous TTFields/RT/TMZ or RT/TMZ during the investigational period. Subsequently, all patients will receive TTFields/6 cycles of maintenance TTFields/TMZ; TTFields will continue for 24 months or until second disease progression per Response Assessment in Neuro-Oncology (RANO). The primary endpoint is median OS. Secondary endpoints include median PFS (RANO), 1- and 2-year survival rates, overall radiological response (RANO), PFS6, PFS12, severity and frequency of AEs and quality-of-life, OS per TTFields duration-of-usage. The study is powered at 80% to detect a hazard ratio of &lt;0.8 (5% type I error). The study is currently open to enrolment in Austria, Belgium, Czech Republic, France, Germany, Israel, Switzerland, and across the US.

Radiation Therapy for Brain Metastases: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides updated evidence-based recommendations addressing recent developments in the management of patients with brain metastases, including advanced radiation therapy techniques such as stereotactic radiosurgery (SRS) and hippocampal avoidance whole brain radiation therapy and the emergence of systemic therapies with central nervous system activity.

METHODS

The American Society for Radiation Oncology convened a task force to address 4 key questions focused on the radiotherapeutic management of intact and resected brain metastases from nonhematologic solid tumors. The guideline is based on a systematic review provided by the Agency for Healthcare Research and Quality. Recommendations were created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Strong recommendations are made for SRS for patients with limited brain metastases and Eastern Cooperative Oncology Group performance status 0 to 2. Multidisciplinary discussion with neurosurgery is conditionally recommended to consider surgical resection for all tumors causing mass effect and/or that are greater than 4 cm. For patients with symptomatic brain metastases, upfront local therapy is strongly recommended. For patients with asymptomatic brain metastases eligible for central nervous system-active systemic therapy, multidisciplinary and patient-centered decision-making to determine whether local therapy may be safely deferred is conditionally recommended. For patients with resected brain metastases, SRS is strongly recommended to improve local control. For patients with favorable prognosis and brain metastases receiving whole brain radiation therapy, hippocampal avoidance and memantine are strongly recommended. For patients with poor prognosis, early introduction of palliative care for symptom management and caregiver support are strongly recommended.

CONCLUSIONS

The task force has proposed recommendations to inform best clinical practices on the use of radiation therapy for brain metastases with strong emphasis on multidisciplinary care.

OP0068 DISTINCT STROMAL AND IMMUNE CELL INTERACTIONS SHAPE THE PATHOGENESIS OF RHEUMATOID AND PSORIATIC ARTHRITIS

Background

Rheumatoid (RA) and psoriatic arthritis (PsA) are common autoimmune and autoinflammatory diseases of unknown aetiology characterised by complex synovial pathology with a detrimental effect on the patient’s quality of life. Significant differences in pathophysiology may explain distinct clinical manifestations and account for differential responses to specific therapeutics. Recent implementation of single cell transcriptomic analysis of sorted synovial cells has revealed the diverse cellular landscape of the RA synovial stromal and immune cell compartments, however, a complete analysis of immune and stromal cells in tandem, for RA and PsA patient synovial tissue has not been performed.

Objectives

To combine novel scRNA transcriptomic approaches and ex vivo assays in order to: identify differences in the cellular landscape of RA and PsA synovial tissue inflammation and immune – stromal cell interactions that drive pathology in RA and PsA.

Methods

Single cell transcriptomic profiling of 178,000 synovial tissue cells from 5 PsA and 4 RA patients, importantly, without prior sorting of immune and stromal cells. This approach enabled the generation of a unique cell atlas of intact synovial tissue identifying immune and stromal cell interactions. State of the art data integration and annotation techniques identified and characterised 18 stromal and 14 immune cell clusters. Bioinformatic examination of cell-cell communication via construction of receptor-ligand interaction networks with further in vitro validation of stromal and immune cell crosstalk through flow cytometric analysis, multiplex ELISA and mitochondrial and single cell metabolic profiling by multiphoton and florescent lifetime imaging microscopy, seahorse.

Results

Following quality control and data integration the PsA and RA cellular landscape was generated and nine mega clusters indicative of fibroblasts, endothelial cells, pericytes, macrophages, dendritic cells (DC), B cells, plasma cells, T cells and NKT consisting of several sub clusters were identified. Distinct points of transcriptomic deviation and convergence between RA and PsA were identified for each of the major cell types of the joint. Specifically, cell cycle and trajectory analysis revealed that only a fraction of synovial T cells are actively proliferating. Additionally, the differential usage of immunoglobulin light chains by memory and plasma cells indicates that plasma cells are potentially not derived from the local memory B cell pool of the synovial tissue. Importantly, we report distinct fibroblast and endothelial cell transcriptomes indicating differentially abundant subpopulations in RA and PsA characterised by distinct transcription factor usage and signalling pathway enrichment. Specifically transcriptomic imputation analysis revealed abundance of invasive FAPα+THY1+ regulated by transcription factor TEAD1 in RA compared to PsA synovial tissue. In order to identify potential cell-cell communication driving inflammation in RA and PsA, novel receptor–ligand interaction networks were generated and downstream of the receptor, target characterisation was performed. Herein we identify RA-specific synovial T cell-derived TGF-β and macrophage IL-1β synergy in driving the transcriptional profile of FAPα+THY1+ invasive synovial-fibroblasts, expanded in RA compared to PsA synovial tissue biopsies (Figure 1). Ex vivo treatment of RA patient synovial fibroblasts identified TGF-b and IL-1b synergy are a major driver of IL-6 production, fibroblast activation and adhesion molecule expression. Interestingly, the aforementioned proinflammatory changes of RA patient synovial fibroblasts were coupled with significant alterations in mitochondrial eccentricity and size and a marked metabolic adaptation towards a strongly glycolytic profile (Figure 1).

Figure 1.

Conclusion

Disrupting specific immune and stromal cell interactions offers novel opportunities for targeted therapeutic intervention in RA and PsA.

Disclosure of Interests

Achilleas Floudas: None declared, Conor Smith: None declared, Orla Tynan: None declared, Nuno Neto: None declared, Vinod Krishna Employee of: Janssen Pharmaceuticals, Sarah Wade: None declared, Megan Hanlon: None declared, Clare Cunningham: None declared, Viviana Marzaioli: None declared, Mary Canavan: None declared, Jean Fletcher: None declared, Suzanne Cole Employee of: Janssen Pharmaceuticals, Ling-Yang Hao Employee of: Janssen Pharmaceuticals, Sunil Nagpal Employee of: Janssen Pharmaceuticals, GSK, Michael Monaghan: None declared, Douglas Veale Consultant of: Janssen, Eli Lilly, Pfizer, Ursula Fearon Consultant of: Janssen, Eli Lilly, Pfizer.

Intramuscular (IM) INO-5401 + INO-9012 with electroporation (EP) in combination with cemiplimab (REGN2810) in newly diagnosed glioblastoma

2004

Background: Novel T cell-enabling therapies plus checkpoint inhibition may improve OS in GBM. INO-5401 (synthetic DNA plasmid encoding hTERT, WT-1, PSMA) plus INO-9012 (synthetic DNA plasmid encoding IL-12), with cemiplimab (PD-1 inhibitor), was given to patients with newly diagnosed GBM with MRD to evaluate tolerability, efficacy, and immunogenicity. Median OS and immunogenicity at 18 months (OS18) are reported. Methods: This is a phase I/II, single arm, two cohort (A: unmethylated MGMT and B: methylated MGMT) study. Primary endpoint is safety; efficacy and immunogenicity are secondary. Nine mg INO-5401 plus 1 mg INO-9012 (4 doses Q3W, then Q9W) was given IM with EP in combination with cemiplimab (350 mg IV Q3W). Hypofractionated RT (40 Gy over 3 weeks) with TMZ was given to all patients, followed by maintenance (Cohort B only), which was a novel therapeutic approach. Immunogenicity was assessed by quantifying INO-5401-specific peripheral cellular immune responses via IFN-g ELISpot and flow cytometry. Intra-tumoral gene expression was analyzed by RNA-Seq of FFPE GBM tissue. Differences in gene expression were analyzed using the Wilcoxon rank sum test. Results: Fifty-two subjects were enrolled: 32 in Cohort A; 20 in Cohort B (35% women; median age 60 years [range 19-78 years]). The adverse event profile was consistent with known single-agent (INO-5401, INO-9012, EP or cemiplimab) events; most events were ≤Grade 2 and no related events were Grade ≥4. Median OS durations in Cohorts A and B were 17.9 months (95% CI 14.5-19.8) and 32.5 months (95% CI 18.4-not reached), respectively. Flow cytometry revealed activated, antigen specific CD4+CD69+PD1+ and CD8+CD69+PD1+ T cells, the latter with lytic potential as defined by presence of perforin and granzyme A. Both subsets exhibited HR < 1.0 and p < 0.05 when accounting for a 0.1% T cell frequency change, translating to a 23% and 28% reduced risk of death, respectively. Gene expression levels in pre-treatment tissues were similar between alive and deceased groups for INO-5401 antigens and immune cell markers; however, the alive group displayed significantly reduced expression of genes associated with anti-apoptosis, pro-proliferation, and immune response suppression. Post-treatment tumor tissue displayed altered gene expression for immune-related markers versus pre-treatment tissue, including markers of T cell infiltration, activation, and lytic potential. Conclusions: INO-5401 + INO-9012 has an acceptable risk/benefit profile and elicits robust immune responses that correlate with enhanced survival when administered with cemiplimab and RT/TMZ to newly diagnosed GBM patients. Pre-treatment gene expression signatures in MGMT-unmethylated patients were statistically associated with OS18. Overall, INO-5401 elicits antigen-specific T cells that can infiltrate GBM tumors. Clinical trial information: NCT03491683.

OP0013 LOSS OF SYNOVIAL TISSUE MACROPHAGE HOMEOSTASIS PRECEDES RHEUMATOID ARTHRITIS CLINICAL ONSET

Background

Synovial tissue macrophages significantly contribute to Rheumatoid Arthritis, yet the precise nature/function of macrophage subsets within the inflamed joint remains unexplored.

Objectives

To fully explore the spectrum of distinct macrophage activation states residing within the synovium of RA, at risk and healthy individuals.

Methods

Single-cell synovial tissue suspensions from RA (n=44), IAR (n=5), HC (n=11), PsA (n=11) and OA (n=4) were obtained, and synovial macrophage subsets examined by advanced multiparameter flow cytometric analysis, bulk RNA-sequencing, metabolic and functional assays.

Results

Multidimensional analysis identifies enrichment of CD206+CD163+ synovial-tissue macrophages co-expressing CD40 in the RA joint compared to healthy synovial-tissue, with frequency of CD206+CD163+CD40+ macrophages associated with increased disease activity and treatment response. In contrast, CX3CR1-expressing macrophages which form a protective barrier in healthy synovium are significantly depleted in RA. Importantly this signature of enriched CD40 expression coupled with depleted CX3CR1 expression is an early phenomenon, occurring prior to clinical manifestation of disease in individuals ‘at-risk’ of RA (IAR). RNAseq and metabolic profiling of sorted RA synovial-macrophages identified that this population is transcriptionally distinct, displaying unique inflammatory, phagocytic and tissue-resident gene signatures, paralleled by a bioenergetically stable profile as indicated by NAD(P)H emission. Functionally CD206+CD163+ RA macrophages are potent producers of pro-inflammatory mediators (reversed by CD40-signalling inhibition) and induce an invasive phenotype in healthy synovial-fibroblasts. These findings identify a distinct pathogenic population of synovial-tissue macrophage involved in shaping the immune response in RA. Crucially, this signature is present pre-disease representing a unique opportunity for early diagnosis and therapeutic intervention.

Conclusion

We have identified a novel population of tissue-resident macrophages in the RA synovium which are transcriptionally/metabolically distinct and capable of contributing to disease pathology. Uncovering the molecular patterns and cues that transform this immunoregulatory macrophage population into a dysfunctional inflammatory activation state may provide opportunities to reinstate joint homeostasis in RA patients.

Disclosure of Interests

Megan Hanlon: None declared, Mary Canavan: None declared, Nuno Neto: None declared, Qingxuan Song Employee of: Employee of Janssen Pharmaceuticals, Phil Gallagher: None declared, Ronan Mullan: None declared, Conor Hurson: None declared, Barry Moran: None declared, Michael Monaghan: None declared, Sunil Nagpal Employee of: Employee of Janssen Pharmaceuticals, Douglas Veale Consultant of: Janssen, Eli Lilly, Pfizer, Ursula Fearon Consultant of: Janssen, Eli Lilly, Pfizer

DSC Perfusion MRI-Derived Fractional Tumor Burden and Relative CBV Differentiate Tumor Progression and Radiation Necrosis in Brain Metastases Treated with Stereotactic Radiosurgery

BACKGROUND AND PURPOSE

Differentiation between tumor and radiation necrosis in patients with brain metastases treated with stereotactic radiosurgery is challenging. We hypothesized that MR perfusion and metabolic metrics can differentiate radiation necrosis from progressive tumor in this setting.

MATERIALS AND METHODS

We retrospectively evaluated MRIs comprising DSC, dynamic contrast-enhanced, and arterial spin-labeling perfusion imaging in subjects with brain metastases previously treated with stereotactic radiosurgery. For each lesion, we obtained the mean normalized and standardized relative CBV and fractional tumor burden, volume transfer constant, and normalized maximum CBF, as well as the maximum standardized uptake value in a subset of subjects who underwent FDG-PET. Relative CBV thresholds of 1 and 1.75 were used to define low and high fractional tumor burden.

RESULTS

Thirty subjects with 37 lesions (20 radiation necrosis, 17 tumor) were included. Compared with radiation necrosis, tumor had increased mean normalized and standardized relative CBV (P = .002) and high fractional tumor burden (normalized, P = .005; standardized, P = .003) and decreased low fractional tumor burden (normalized, P = .03; standardized, P = .01). The area under the curve showed that relative CBV (normalized = 0.80; standardized = 0.79) and high fractional tumor burden (normalized = 0.77; standardized = 0.78) performed the best to discriminate tumor and radiation necrosis. For tumor prediction, the normalized relative CBV cutoff of ≥1.75 yielded a sensitivity of 76.5% and specificity of 70.0%, while the standardized cutoff of ≥1.75 yielded a sensitivity of 41.2% and specificity of 95.0%. No significance was found with the volume transfer constant, normalized CBF, and standardized uptake value.

CONCLUSIONS

Increased relative CBV and high fractional tumor burden (defined by a threshold relative CBV of ≥1.75) best differentiated tumor from radiation necrosis in subjects with brain metastases treated with stereotactic radiosurgery. Performance of normalized and standardized approaches was similar.

18F-FSPG PET/CT Imaging of System xC- Transporter Activity in Patients with Primary and Metastatic Brain Tumors

Background The PET tracer (4S)-4-(3-[¹⁸F]fluoropropyl)-l-glutamate (¹⁸F-FSPG) targets the system x_C^- cotransporter, which is overexpressed in various tumors. Purpose To assess the role of ¹⁸F-FSPG PET/CT in intracranial malignancies. Materials and Methods Twenty-six patients (mean age, 54 years ± 12; 17 men; 48 total lesions) with primary brain tumors (n = 17) or brain metastases (n = 9) were enrolled in this prospective, single-center study (ClinicalTrials.gov identifier: NCT02370563) between November 2014 and March 2016. A 30-minute dynamic brain ¹⁸F-FSPG PET/CT scan and a static whole-body (WB) ¹⁸F-FSPG PET/CT scan at 60-75 minutes were acquired. Moreover, all participants underwent MRI, and four participants underwent fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) PET imaging. PET parameters and their relative changes were obtained for all lesions. Kinetic modeling was used to estimate the ¹⁸F-FSPG tumor rate constants using the dynamic and dynamic plus WB PET data. Imaging parameters were correlated to lesion outcomes, as determined with follow-up MRI and/or pathologic examination. The Mann-Whitney U test or Student t test was used for group mean comparisons. Receiver operating characteristic curve analysis was used for performance comparison of different decision measures. Results ¹⁸F-FSPG PET/CT helped identify all 48 brain lesions. The mean tumor-to-background ratio (TBR) on the whole-brain PET images at the WB time point was 26.6 ± 24.9 (range: 2.6-150.3). When ¹⁸F-FDG PET was performed, ¹⁸F-FSPG permitted visualization of non-¹⁸F-FDG-avid lesions or allowed better lesion differentiation from surrounding tissues. In participants with primary brain tumors, the predictive accuracy of the relative changes in influx rate constant K_i and maximum standardized uptake value to discriminate between poor and good lesion outcomes were 89% and 81%, respectively. There were significant differences in the ¹⁸F-FSPG uptake curves of lesions with good versus poor outcomes in the primary brain tumor group (P < .05) but not in the brain metastases group. Conclusion PET/CT imaging with (4S)-4-(3-[¹⁸F]fluoropropyl)-l-glutamate (¹⁸F-FSPG) helped detect primary brain tumors and brain metastases with a high tumor-to-background ratio. Relative changes in ¹⁸F-FSPG uptake with multi-time-point PET appear to be helpful in predicting lesion outcomes. Clinical trial registration no. NCT02370563 © RSNA, 2022 Online supplemental material is available for this article.

A Clinical PET Imaging Tracer ([18F]DASA-23) to Monitor Pyruvate Kinase M2-Induced Glycolytic Reprogramming in Glioblastoma

PURPOSE

Pyruvate kinase M2 (PKM2) catalyzes the final step in glycolysis, a key process of cancer metabolism. PKM2 is preferentially expressed by glioblastoma (GBM) cells with minimal expression in healthy brain. We describe the development, validation, and translation of a novel PET tracer to study PKM2 in GBM. We evaluated 1-((2-fluoro-6-[18F]fluorophenyl)sulfonyl)-4-((4-methoxyphenyl)sulfonyl)piperazine ([18F]DASA-23) in cell culture, mouse models of GBM, healthy human volunteers, and patients with GBM.

EXPERIMENTAL DESIGN

[18F]DASA-23 was synthesized with a molar activity of 100.47 ± 29.58 GBq/μmol and radiochemical purity >95%. We performed initial testing of [18F]DASA-23 in GBM cell culture and human GBM xenografts implanted orthotopically into mice. Next, we produced [18F]DASA-23 under FDA oversight, and evaluated it in healthy volunteers and a pilot cohort of patients with glioma.

RESULTS

In mouse imaging studies, [18F]DASA-23 clearly delineated the U87 GBM from surrounding healthy brain tissue and had a tumor-to-brain ratio of 3.6 ± 0.5. In human volunteers, [18F]DASA-23 crossed the intact blood-brain barrier and was rapidly cleared. In patients with GBM, [18F]DASA-23 successfully outlined tumors visible on contrast-enhanced MRI. The uptake of [18F]DASA-23 was markedly elevated in GBMs compared with normal brain, and it identified a metabolic nonresponder within 1 week of treatment initiation.

CONCLUSIONS

We developed and translated [18F]DASA-23 as a new tracer that demonstrated the visualization of aberrantly expressed PKM2 for the first time in human subjects. These results warrant further clinical evaluation of [18F]DASA-23 to assess its utility for imaging therapy-induced normalization of aberrant cancer metabolism.

CTNI-09. TRIDENT PHASE 3 TRIAL (EF-32): FIRST-LINE TUMOR TREATING FIELDS (TTFields; 200 KHZ) CONCOMITANT WITH CHEMO-RADIATION, FOLLOWED BY MAINTENANCE TTFIELDS/TEMOZOLOMIDE IN NEWLY-DIAGNOSED GLIOBLASTOMA

INTRODUCTION

Tumor Treating Fields (TTFields; 200 kHz; non-invasive, loco-regional antimitotic treatment) is approved for newly-diagnosed glioblastoma (ndGBM). In the Phase 3 EF-14 trial, post-surgical radiotherapy/temozolomide, followed by maintenance TTFields/temozolomide significantly increased overall survival (OS) and progression-free survival (PFS) in patients with ndGBM versus TMZ alone. Addition of maintenance TTFields did not increase systemic toxicity; and related adverse events (AEs) were mainly dermatological. In preclinical models, addition of TTFields increased the benefit of radiotherapy. Two pilot studies showed that TTFields concomitant with radiotherapy/temozolomide is feasible and well-tolerated. The benefit of TTFields concomitant with radiotherapy/temozolomide will be investigated in the TRIDENT trial.

METHODS

TRIDENT (EF-32; NCT04471844) is an international, pivotal, phase 3 randomized trial comparing triple-combination of TTFields/radiotherapy/temozolomide versus standard radiotherapy/temozolomide. Patients in both arms will receive maintenance TTFields/TMZ. Arrays of the Optune® System will be used to deliver TTFields (200 KHz) for ≥18 hours/day concomitant with radiotherapy. TTFields treatment will be continued until second disease progression (RANO) or 24 months, whichever occurs first. Patients with pathologically-confirmed ndGBM, ≥ 18 years of age (≥ 22 years of age; US), KPS ≥ 70, post-surgery/biopsy, and amenable for radiotherapy/temozolomide will be stratified by extent-of-resection and MGMT promoter methylation status. The primary endpoint is median OS. Secondary endpoints include median PFS (RANO), 1-year and 2-year survival rates, overall radiological response (ORR; RANO), PFS (PFS-6M, PFS-12M, PFS-2Y), severity and frequency of AEs (CTCAE V5.0), pathological post-treatment changes in resected GBM tumors, quality-of-life (EORTC QLQ-C30), and OS correlation to TTFields duration-of-usage. The hypothesis is that first-line TTFields/RT/TMZ triple-combination will significantly improve OS compared to radiotherapy/temozolomide; each followed by maintenance TTFields/temozolomide. Sample size (N=950; 475/arm) was powered for a HR &lt; 0.8 with 5% type I error. Survival will be measured from time-of-randomization. The TRIDENT trial is currently enrolling patients.

RESULTS/CONCLUSIONS

N/A TiP.

Management of complications from brain metastasis treatment: a narrative review

OBJECTIVE

To describe the range of potential side effects associated with modern brain metastasis treatment and provide evidenced-based guidance on the effective management of these side effects.

BACKGROUND

Brain metastases are the most commonly diagnosed malignant intracranial tumor and have historically been associated with very poor prognosis. The standard treatment for brain metastases until the 1990s was whole-brain radiation therapy (WBRT) alone. Since then, however, numerous advances have established the role of neurosurgical resection, stereotactic radiosurgery (SRS), targeted systemic therapy, and immunotherapy in the multidisciplinary management of brain metastases and led to improvements in intracranial control, survival, and neurocognitive preservation among patients with brain metastases. As a result, however, brain metastasis treatment is associated with a wider range of potential side effects than ever before, and clinicians are tasked with the challenge of effectively managing these side effects without compromising cancer outcomes.

METHODS

We performed a narrative review of peer-reviewed articles related to the management of side effects from multidisciplinary brain metastasis treatment and synthesized the data in the context of our clinical experience and practice.

CONCLUSIONS

In this review, we summarize the major complications from intracranial radiotherapy, neurosurgical resection, and brain metastasis directed systemic therapy with corresponding evidenced-based, modern management principles to guide the practicing oncologist.

Comprehensive RNA analysis of CSF reveals a role for CEACAM6 in lung cancer leptomeningeal metastases

Non-small cell lung cancer (NSCLC) metastatic to the brain leptomeninges is rapidly fatal, cannot be biopsied, and cancer cells in the cerebrospinal fluid (CSF) are few; therefore, available tissue samples to develop effective treatments are severely limited. This study aimed to converge single-cell RNA-seq and cell-free RNA (cfRNA) analyses to both diagnose NSCLC leptomeningeal metastases (LM), and to use gene expression profiles to understand progression mechanisms of NSCLC in the brain leptomeninges. NSCLC patients with suspected LM underwent withdrawal of CSF via lumbar puncture. Four cytology-positive CSF samples underwent single-cell capture (n = 197 cells) by microfluidic chip. Using robust principal component analyses, NSCLC LM cell gene expression was compared to immune cells. Massively parallel qPCR (9216 simultaneous reactions) on human CSF cfRNA samples compared the relative gene expression of patients with NSCLC LM (n = 14) to non-tumor controls (n = 7). The NSCLC-associated gene, CEACAM6, underwent in vitro validation in NSCLC cell lines for involvement in pathologic behaviors characteristic of LM. NSCLC LM gene expression revealed by single-cell RNA-seq was also reflected in CSF cfRNA of cytology-positive patients. Tumor-associated cfRNA (e.g., CEACAM6, MUC1) was present in NSCLC LM patients' CSF, but not in controls (CEACAM6 detection sensitivity 88.24% and specificity 100%). Cell migration in NSCLC cell lines was directly proportional to CEACAM6 expression, suggesting a role in disease progression. NSCLC-associated cfRNA is detectable in the CSF of patients with LM, and corresponds to the gene expression profile of NSCLC LM cells. CEACAM6 contributes significantly to NSCLC migration, a hallmark of LM pathophysiology.

Isolated Leptomeningeal Progression in a Patient with NTRK Fusion+ Uterine Sarcoma: A Case Report

While neurotrophic tropomyosin receptor kinase (NTRK) fusions represent rare oncogenic drivers (<1% of solid cancers), the recent approval of NTRK inhibitors (larotrectinib and entrectinib) led to dramatic responses in patients with NTRK fusion+ tumors. Both drugs have phase I data, demonstrating efficacy in the central nervous system (CNS), including both primary brain tumors and brain metastases. We present a 29-year-old woman who was diagnosed with NTRK3-SPECC1L fusion+ undifferentiated uterine sarcoma and underwent resection, chemotherapy, and radiotherapy. Two years later, lung metastases were discovered. She was started on larotrectinib with complete response. She remained stable on larotrectinib until she presented with altered mental status and seizures. MRI demonstrated leptomeningeal enhancement, but because leptomeningeal progression from sarcoma is exceedingly rare and her symptoms improved dramatically with antiepileptics, these findings were initially attributed to seizures. After 2 unrevealing lumbar punctures and stable systemic imaging, a brain biopsy demonstrated metastatic sarcoma, still showing NTRK positivity. She underwent whole brain radiotherapy and was switched to entrectinib, but had clinical progression 1 month later and transitioned to hospice. This case demonstrates the efficacy of NTRK inhibitors in rare and aggressive cancer but highlights that these patients can develop isolated CNS progression even in the setting of CNS-penetrant drugs. CNS progression can occur if there is incomplete CNS drug penetration, discordance in molecular profiles between CNS and systemic disease, or acquired NTRK inhibitor resistance. In this case, CNS disease maintained the NTRK fusion status, but either inadequate CNS penetration or development of a resistance gene may explain the isolated CNS progression.

Brain Metastases in EGFR- and ALK-Positive NSCLC: Outcomes of Central Nervous System-Penetrant Tyrosine Kinase Inhibitors Alone Versus in Combination With Radiation

INTRODUCTION

Management of central nervous system (CNS) metastases in patients with driver-mutated NSCLC has traditionally incorporated both tyrosine kinase inhibitors (TKIs) and intracranial radiation. Whether next generation, CNS-penetrant TKIs can be used alone without upfront radiation, however, remains unknown. This multi-institutional retrospective analysis aimed to compare outcomes in patients with EGFR- or ALK-positive NSCLC who received CNS-penetrant TKI therapy alone versus in combination with radiation for new or progressing intracranial metastases.

METHODS

Data were retrospectively collected from three academic institutions. Two treatment groups (CNS-penetrant TKI alone versus TKI + CNS radiation therapy) were compared for both EGFR- and ALK-positive cohorts. Outcome variables included time to progression, time to intracranial progression, and time to treatment failure, measured from the date of initiation of CNS-penetrant TKI therapy.

RESULTS

A total of 147 patients were included (EGFR n = 94, ALK n = 52, both n = 1). In patients receiving radiation, larger metastases, neurologic symptoms, and receipt of steroids were more common. There were no significant differences between TKI and CNS radiation therapy plus TKI groups for any of the study outcomes, including time to progression (8.5 versus 6.9 mo, p = 0.13 [EFGR] and 11.4 versus 13.4 mo, p = 0.98 [ALK]), time to intracranial progression (14.8 versus 20.5 mo, p = 0.51 [EGFR] and 18.1 versus 21.8 mo, p = 0.65 [ALK]), or time to treatment failure (13.8 versus 8.6 mo, p = 0.26 [EGFR] and 13.5 versus 23.2 mo, p = 0.95 [ALK]).

CONCLUSIONS

These results provide preliminary evidence that intracranial activity of CNS-penetrant TKIs may enable local radiation to be deferred in appropriately selected patients without negatively affecting progression.

OMRT-13. Delivery of Ubidecarenone (BPM 31510) to mitochondria effectuates metabolic reprogramming and redox activated apoptosis in Glioblastoma

GBM is a highly metabolic cancer phenotype that confers sustained growth and evasion of cell death mechanism via mitochondrial dysregulation. Efforts to re-engage mitochondrial metabolism via anti-cancer therapeutics has not been successful. BPM 31510 is a CoQ10-lipid conjugate nanodispersion for delivery of CoQ10 preferentially to mitochondria of human cells. BPM has demonstrated anti-cancer effects across multiple cancers, without adversely affecting normal tissue. The anti-cancer mechanism of CoQ10 was elucidated by Interrogative Biology, a data-driven approach to understand disease biology, identify targets and biomarkers of disease. Specifically, oncogenic and corresponding non-disease normal cell-based models (e.g. breast, liver, prostate, kidney) were subjected to cancer specific perturbations (e.g. hypoxia, metabolic stress). Comprehensive multi-omic (genome, proteome, lipidome, metabolome) and functional endpoints data were profiled. A Bayesian artificial intelligence analytics was used to generate network models in a data driven manner to identify BPM 31510 mechanism (i.e. shift in oxygen and glucose utilization, increase in oxidative stress and apoptosis in cancer cells). BPM 31510 re-capitulated its anti-cancer effect in GBM models, including LN-229 xenograft and C6 glioma allograft, both as monotherapy and in combination with temozolomide (TMZ)/radiation. The platform generated network maps from longitudinal pharmacodynamic samples (20 samples/28 days) collected from GBM patient refractory to TMZ/radiation/bevacizumab (Phase 1, NCT03020602, Stanford) identified alterations in intermediary metabolism as drivers of Progression Free Survival (PFS) and Overall Survival (OS) in response to BPM 31510 treatment. The platform supports the ongoing Phase 2 trial of adjuvant BPM 31510 plus TMZ/radiation in newly diagnosed GBM patients and potential accelerated approval.

Abstract CT258: EF-32 (TRIDENT): A pivotal randomized trial of radiation therapy concomitant with temozolomide +/- Tumor Treating Fields (TTFields) in newly diagnosed glioblastoma

Purpose: Tumor treating fields (TTFields) is a non-invasive, loco-regional antimitotic treatment approved as a standard-of-care for newly diagnosed glioblastoma (ndGBM). In the Phase 3 EF-14 trial, TTFields (200 kHz) plus temozolomide (TMZ) post-surgery and chemoradiation significantly increased survival of ndGBM patients compared to TMZ alone. The addition of TTFields was not associated with any increases in systemic toxicity. TTFields-related adverse events (AEs) were mainly dermatological. In preclinical models, TTFields increase the therapeutic effects of radiation therapy (RT). A pilot study showed that TTFields concomitant with RT and TMZ is well tolerated. The benefit of TTFields concomitant with RT and TMZ will be investigated in the TRIDENT trial. Methodology: TRIDENT (NCT04471844) is an international, pivotal randomized trial comparing standard RT with concomitant TMZ vs the triple combination of RT with concomitant TMZ and TTFields. RT is delivered through the TTFields transducer arrays. Patients in both arms will receive maintenance TTFields and TMZ. TTFields (200 KHz) will be delivered &gt;18 hours/day using the Optune device. TTFields treatment will be continued until the second disease recurrence. Patients with pathologically confirmed ndGBM, ≥ 18 years (≥ 22 years in the US), KPS ≥ 70, either sex, post-surgery or biopsy, and candidates for RT/TMZ therapy will be stratified by extent of resection and MGMT promoter methylation status. The primary endpoint is overall survival (OS). Secondary end points include progression free survival (PFS; RANO), 1- and 2-year survival rates, overall radiological response (ORR; RANO), PFS (PFS6M, PF12M, PFS2Y); severity and frequency of AEs (CTCAE V5.0); pathological changes in resected GBM tumors post treatment; quality of life (EORTC QLQ-C30); and correlation of OS to TTFields compliance. The hypothesis is that concomitant TTFields/RT/TMZ will significantly improve OS versus RT/TMZ. Sample size (N=950; 475/arm) will detect a HR&lt; 0.8 with 5% type I error. Survival will be measured from the time of randomization until date of death. At the time of analysis, patients lost to follow-up or still on protocol follow-up will be censored at the last date known to be alive. The TRIDENT trial is currently enrolling patients.

Citation Format: Wenyin Shi, Lawrence Kleinberg, Suriya A. Jeyapalan, Samuel A. Goldlust, Seema Nagpal, Stephanie E. Combs, David Roberge, Ryo Nishigawa, Rachel Grossman, Martin Glas. EF-32 (TRIDENT): A pivotal randomized trial of radiation therapy concomitant with temozolomide +/- Tumor Treating Fields (TTFields) in newly diagnosed glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT258.

Impact of Low-Dose Computed Tomography Screening for Primary Lung Cancer on Subsequent Risk of Brain Metastasis

INTRODUCTION

Brain metastasis (BM) is one of the most common metastases from primary lung cancer (PLC). Recently, the National Lung Screening Trial revealed the efficacy of low-dose computed tomography (LDCT) screening on LC mortality reduction. Nevertheless, it remains unknown if early detection of PLC through LDCT may be potentially beneficial in reducing the risk of subsequent metastases. Our study aimed to investigate the impact of LDCT screening for PLC on the risk of developing BM after PLC diagnosis.

METHODS

We used the National Lung Screening Trial data to identify 1502 participants who were diagnosed with PLC in 2002 to 2009 and have follow-up data for BM. Cause-specific competing risk regression was applied to evaluate an association between BM risk and the mode of PLC detection-that is, LDCT screen-detected versus non-LDCT screen-detected. Subgroup analyses were conducted in patients with early stage PLC and those who underwent surgery for PLC.

RESULTS

Of 1502 participants, 41.4% had PLC detected through LDCT screening versus 58.6% detected through other methods, for example, chest radiograph or incidental detection. Patients whose PLC was detected with LDCT screening had a significantly lower 3-year incidence of BM (6.5%) versus those without (11.9%), with a cause-specific hazard ratio (HR) of 0.53 (p = 0.001), adjusting for age at PLC diagnosis, PLC stage, PLC histology, and smoking status. This significant reduction in BM risk among PLCs detected through LDCT screening persisted in subgroups of participants with early stage PLC (HR = 0.47, p = 0.002) and those who underwent surgery (HR = 0.37, p = 0.001).

CONCLUSIONS

Early detection of PLC using LDCT screening is associated with lower risk of BM after PLC diagnosis on the basis of a large population-based study.

AB0018 ACCUMULATION OF FUNCTIONALLY MATURE CD1C+ DENDRITIC CELLS CONTRIBUTES TO SYNOVIAL INFLAMMATION IN INFLAMMATORY ARTHRITIS

Background:

Myeloid Dendritic Cells (DC) are potent antigen presenting cells that can be subdivided into CD141 and CD1c+ DC. We have previously reported an unacknowledged role for CD141+DC in the IA synovium. However, the identification and function of CD1c+ DC in the IA synovium has yet to be fully elucidated.

Objectives:

To investigate if CD1c+DC reside in the IA synovium and ascertain if they represent a unique population, distinct from peripheral CD1c+DC and if they contribute to synovial inflammation.

Methods:

Synovial tissue (ST) biopsies and synovial fluid mononuclear cells (SFMC) were obtained via arthroscopy and healthy control (HC) ST was obtained during ACL surgery. Synovial tissue single cells suspensions were generated following enzymatic and mechanical digestion. Single cell analysis of synovial tissue cell suspensions, along with PBMC and SFMC was performed by multicolour flow cytometry. CD1c+DC were sorted from IA synovial fluid and peripheral blood and bulk RNA sequencing was performed. CD1c+DC functionality and maturation was assessed using OVA DQ phagocytosis assays, multiplex ELISA and DC: T cell cocultures.

Results:

Within the circulation the frequency of CD1c+DC are significantly decreased in IA peripheral blood compared to HC (p<0.01) in addition to expressing significantly higher levels of the maturation markers CD80 (p<0.01) and CD40 (p=0.08). IA peripheral blood DC also express significantly higher levels of CXCR3 (p<0.01) and CCR7 (p<0.05) compared to HC - suggestive of DC migration from the periphery to the synovium. Following RNA-seq analysis, IPA and differentially expressed gene (DEG) analysis revealed an enrichment in genes involved in DC maturation, TLR signalling and chemokine signalling in IA peripheral blood compared to HC. In support of the hypothesis that DC migrate and accumulate in the IA synovium, CD1c+ DC were identified in IA ST and were significantly enriched compared to IA peripheral blood (p<0.01). IA ST CD1c+DC express significantly higher levels of the activation marker CD80 compared to IA peripheral blood (p<0.05) or HC ST (p<0.05). Upon examination of IA synovial fluid, we report similar findings to ST, whereby CD1c+DC are enriched in synovial fluid compared to PB (p<0.001). Moreover, RNA sequencing and PCA analysis of synovial versus blood CD1c+DC revealed distinct transcriptional variation between both sites. Functionally, synovial CD1c+DC express higher levels of the maturation markers CD80, CD83, CD40, PD-L1 and BTLA (all p<0.05) and have distinct coexpression of these maturation markers which is unique to the synovium. Synovial CD1c+DC are less phagocytic compared to peripheral blood DC, have decreased production of MMP1 and MMP9 and importantly are still capable of additional activation in-vitro. Finally, synovial CD1c+DC induce the proinflammatory cytokines TNFα, GMCSF, IL-17a and IFNγ from CD4+ T-cells in allogeneic DC: T cells cocultures.

Conclusion:

Mature circulatory CD1c+DC migrate and accumulate in the IA synovium. Synovial DC are present in the IA synovium in a mature state, have distinct tissue specific characteristics and can induce proinflammatory CD4+T cell responses.

Acknowledgements:

We would like to thank all the patients who contributed to this study

Disclosure of Interests:

Mary Canavan: None declared, Viviana Marzaioli: None declared, Vipul Bhargava Employee of: Janssen Research and Development, Sunil Nagpal Employee of: Janssen Research and Development, Phil Gallagher: None declared, Conor Hurson: None declared, Ronan Mullan: None declared, Douglas Veale Speakers bureau: Abbvie, Janssen, Novartis, Pfizer, MSD, UCB, Consultant of: Abbvie, Janssen, Novartis, Pfizer, MSD, UCB, Grant/research support from: Pfizer, Janssen, AbbVie, UCB, Ursula Fearon Speakers bureau: Abbvie, Grant/research support from: Pfizer, Janssen, Abbvie, UCB

OP0028 CD206+CD163+ PATHOGENIC MACROPHAGES ENRICHED IN RHEUMATOID ARTHRITIS SYNOVIAL TISSUE WITH DISTINCT TRANSCRIPTIONAL SIGNATURES

Background:

Synovial tissue macrophages are an exquisitely plastic pool of innate cells that play a key role in RA disease progression. However, the precise nature, diversity, and function of macrophage subsets within the inflamed joint remains unexplored.

Objectives:

Therefore, the aims of this study are to phenotypically, transcriptionally and functionally characterise synovial tissue macrophages residing within the inflamed joint.

Methods:

Rheumatoid Arthritis, Psoriatic Arthritis, Osteoarthritis and healthy control synovial-tissue biopsies and synovial-fluid mononuclear cells were analysed using the following panel (CD40,-CD45,-CD64,-CD68,-CD163,-CD206,-CD253,-CCR4,-CCR7,-CXCR1,-CXCR3). CD206+CD163+ and CD206-CD163- macrophages were sorted from RA synovial-tissue by FACSAria sorter; RNAseq and FLIM analysis, autologous T-cell co-culture and heathy fibroblast experiments performed. Cytokine expression was measured by MSD immunoassay.

Results:

RA synovial tissue and fluid macrophages display markers typical of both M1 (CD40+CD253+) and M2 (CD206+CD163+) macrophages with a spectrum of macrophage activation states identified. Within this spectrum, significant enrichment of dominant CD206+CD163+ macrophage-subtype is present in synovial tissue versus fluid (p<0.05). CD206+CD163+ synovial tissue macrophages express significantly more CD40 than synovial fluid (p<0.0003), positively correlate with disease activity (r=0.6, p<0.01), with baseline levels predicting response to therapy (p<0.05). Moreover, CD206+CD163+CD40+ macrophages are enriched in RA synovial tissue compared to PsA and OA pathotypes (p<0.05). While the CD206+CD163+ subset is present in healthy synovial tissue, expression of CD40 is completely absent in healthy synovium (p<0.05) with dramatically decreased expression of CX3CR1 on RA macrophages. RNA-seq analysis indicates that CD206+CD163+ population is transcriptionally distinct from synovial tissue CD206-CD163-, synovial fluid CD206+CD163+, and RA monocyte-derived M1/M2 macrophages, with unique tissue-resident gene signatures. Moreover, differing metabolic demands between CD206+CD163+ and CD206-CD163- subsets was demonstrated by RNAseq and FLIM analysis. CD206+CD163+ macrophages enhance autologous T-cell responses, spontaneously secrete high levels of pro-inflammatory cytokines and activate healthy fibroblasts towards pro-inflammatory mechanisms thus further contributing to the local inflammatory response. Finally, inhibition of CD40 activity abrogates the expression of pro-inflammatory mediators (TNFa, IL-1B, IL-6, IFNy) and induces IL-10 expression in sorted CD206+CD163+ synovial tissue-macrophages suggesting a key role for CD40 in driving this pathogenic phenotype.

Conclusion:

This data identifies for the first-time enrichment of a previously undescribed dysfunctional dominant and transcriptionally distinct macrophage subtype in RA synovial tissue. Taken together, this data provides a greater understanding of the critical role tissue-resident macrophages play in perpetuating inflammation in RA. Further investigation of the molecular patterns and cues that shape specific synovial macrophage subsets may provide opportunities to reinstate RA joint homeostasis.

Disclosure of Interests:

Megan Hanlon: None declared, Mary Canavan: None declared, Qingxuan Song Employee of: Janssen Research & Development, Nuno Neto: None declared, Phil Gallagher: None declared, Ronan Mullan: None declared, Conor Hurson: None declared, Michael Monaghan: None declared, Sunil Nagpal Employee of: Janssen Research & Development, Douglas Veale Speakers bureau: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Consultant of: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Grant/research support from: Janssen, Abbvie, Pfizer, UCB, Ursula Fearon Speakers bureau: Abbvie, Grant/research support from: Janssen, Abbvie, Pfizer, UCB

POS0387 ACPA STATUS CORRELATES WITH DIFFERENTIAL IMMUNE PROFILE OF RHEUMATOID ARTHRITIS PATIENTS

Background:

Rheumatoid arthritis (RA) is a progressive erosive autoimmune disease that affects 1% of the world population. Anti-citrullinated protein autoantibodies (ACPA) are routinely used for the diagnosis of RA, however 20-30% of patients are ACPA negative. ACPA status is a delineator of RA disease endotypes with similar clinical manifestation but potentially different pathophysiology. Elucidating the underlying mechanisms of disease pathogenesis could inform a treat to target approach for both ACPA-positive and ACPA-negative RA patients.

Objectives:

To identify peripheral blood and synovial tissue immune population differences that associate with RA disease endotype.

To identify unique RA patient synovial tissue gene signatures and enriched pathways that correlate with ACPA status.

Methods:

Detailed high dimensionality flow cytometric analysis with supervised and unsupervised algorithm analysis of ACPApos and ACPAneg RA patient peripheral blood and synovial tissue single cell suspensions. Ex vivo peripheral blood and synovial tissue T cell stimulation and cytokine production characterisation. RNAseq analysis with specific pathway enrichment analysis of APCApos and ACPAneg RA patient synovial tissue biopsies.

Results:

Detailed profiling based on high dimensionality flow cytometric analysis of key peripheral blood and synovial tissue immune populations including B cells, T follicular helper (Tfh) cells, T peripheral helper cells (Tph) and CD4 T cell proinflammatory cytokine responses with supervised and unsupervised algorithm analysis revealed unique RA patient peripheral blood B cell and Tfh cell profiles. ACPApos RA patients were characterised by significantly (*P=0.03) increased frequency of Tfh (CXCR5+CD4+) cells and distinct clustering influenced by increased switched (IgD-CD27+) and DN (IgD-CD27-) memory B cells compared to APCAneg RA patients. Surprisingly synovial tissue B cell subpopulation distribution was similar between ACPAneg and ACPApos RA patients, with significant accumulation of switched and double negative memory B cells, highlighting a key role for specific B cell subsets in both disease endotypes. Interestingly, synovial tissue CD4 T cell proinflammatory cytokine (TNF-α, IFN-γ, IL-2, GM-CSF, IL-17A, IL-22, IL-4) production was markedly different between ACPAneg and APCApos RA patients with hierarchical clustering and PCA analysis revealing endotype specific cytokine profiles with ACPAneg RA patient synovial T cells showing increased TNF-α (P=0.01) expression. RNAseq analysis of RA patient synovial tissue revealed significant disease endotype specific gene signatures with specific enrichment for B cell receptor signalling and T cell specific pathways in ACPApos compared to ACPAneg RA patients. Additionally, significantly different chemokine receptor expression based on RA patient ACPA status was observed with increased CXCR3 (P<0.001), CCR7 (P=0.002), and CCR2 (P=0.004) but decreased CXCR7 (P=0.007) expression in APCApos compared to ACPAneg RA patient synovial biopsies.

Conclusion:

ACPA status associates with unique synovial tissue immune cell and gene profile signatures highlighting differences in the underlying immunological mechanisms involved, therefore reinforcing the need for a treat to target approach for both endotypes of RA.

Figure 1.

RNAseq analysis of synovial tissue biopsies revealed specific T cell related pathway enrichment in ACPA positive compared to ACPA negative RA patients (n=50, analysis performed with the DESq2 and pathfindeR pipelines in R).

Disclosure of Interests:

Achilleas Floudas: None declared, Mary Canavan: None declared, Trudy McGarry Employee of: Novartis, Vinod Krishna Employee of: Janssen, Sunil Nagpal Employee of: Janssen, GSK, Douglas Veale Speakers bureau: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Consultant of: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Grant/research support from: Janssen, Abbvie, Pfizer, UCB, Ursula Fearon Speakers bureau: Abbvie, Grant/research support from: Janssen, Abbvie, Pfizer, UCB

POS0007 LOSS OF BALANCE BETWEEN PROTECTIVE AND PRO-INFLAMMATORY SYNOVIAL TISSUE T CELL POLYFUNCTIONALITY PREDATES CLINICAL ONSET OF RHEUMATOID ARTHRITIS

Background:

Effective treatment of Rheumatoid arthritis (RA) patients is achievable within a short window of opportunity following diagnosis. T-cells are early drivers of synovial inflammation of RA, therefore, identification of pathogenic T-cell subsets at the synovial tissue of pre-RA, arthralgia subjects, would greatly improve our understanding of disease pathogenesis. Comparative analysis of healthy control, arthralgia subject and RA-patient derived synovial tissue T-cell responses will lead to the identification of pathogenic as well as protective cytokine milieu, thus enabling the identification of early therapeutic targets to help steer the immune response towards resolution.

Objectives:

Characterization of T-cell polyfunctionality in the periphery and synovial tissue of ’at-risk; subjects (Arthralgia) RA-patients and healthy controls (HC).

Identification of specific, pathogenic, synovial tissue T-cell subsets.

Methods:

Synovial biopsies from RA, AR and HC were obtained by arthroscopic surgery followed by RNAseq analysis (Guo et al., PLoS One, 2018). Single cell synovial tissue cell suspensions from RA, AR and HC and paired PBMC were stimulated in vitro and polyfunctional synovial T-cell subsets examined by flow cytometric analysis, SPICE visualization and FlowSom clustering. Flow-Imaging, was utilised to confirm specific T-cell cluster identification. Fluorescent Lifetime Imaging Microscopy (FLIM) was used to visualise metabolic status of specific T-cell populations.

Results:

T-cell associated pro-inflammatory gene pathways were increased in RNAseq analysis of RA-patient and arthralgia subject compared to HC synovial tissue biopsies. Flow cytometric analysis of pro-inflammatory cytokine (TNF-α, IFN-γ, IL-2, GM-CSF, IL-17A, IL-22) production and SPICE analysis of ex vivo stimulated T-cells revealed marked polyfunctionality of arthralgia subject synovial T-cells, thus providing evidence for a dysregulated synovial T-cell response that pre-dates clinical onset of disease. Importantly, HC synovial tissue harbours a small, albeit surprisingly polyfunctional, CD4 T-cell population characterised by significantly increased IL-4 and GM-CSF cytokine production compared to arthralgia subject (P<0.001 and P=0.01) and RA-patient (P<0.001 and P=0.004) synovial tissue. However, not all polyfunctional T-cells are equal in their pathogenic potential. Therefore, in order to identify highly pathogenic synovial T-cells, cluster analysis of flow cytometric data using the unsupervised algorithm FlowSom was performed and led to the identification of specific T-cell clusters with unique polyfunctionality characteristics. Specifically a cluster of CD4+CD8+ double positive (DP) T-cells with high polyfunctionality scores was identified. Hybrid flow cytometry and imaging technique confirmed the co-expression of CD4 and CD8 by a synovial T-cell population. DP T-cells are enriched in RA-patient synovial fluid and synovial tissue and arthralgia subject synovial tissue, but are absent from HC synovial tissue. Importantly, DP T-cell synovial accumulation strongly (P=0.002) correlates with DAS28(CRP) of RA-patients. Initial studies utilising the novel, non-invasive FLIM technique for visualisation of cellular NAD, revealed that DP T-cells have a metabolic profile indicative of activated memory T-cells.

Conclusion:

These data highlight a key early loss of balance between protective and pathogenic synovial T-cell polyfunctionality and the emergence of specific, highly polyfunctional and pathogenic T-cell clusters in RA.

Figure 1.

Identification of highly polyfunctional and pro-inflammatory synovial DP T-cells. A. Cluster analysis of RA-patient synovial tissue T-cells (asterisks indicate DP T-cell clusters). B. Flow imaging of CD4+, CD8+ and DP synovial T-cells. C. SPICE flow cytometric data visualization of DP arthralgia subject and RA-patient synovial T-cells. D. Correlation between the frequency of RA-patient synovial DP T-cells and disease severity.

Disclosure of Interests:

Achilleas Floudas: None declared, Nuno Neto: None declared, Mary Canavan: None declared, Trudy McGarry Employee of: Novartis, Vinod Krishna Employee of: Janssen, Sunil Nagpal Employee of: Janssen, GSK, Michael Monaghan: None declared, Douglas Veale Speakers bureau: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Consultant of: Abbvie, Janssen, Novartis, MSD, Pfizer, UCB, Grant/research support from: Janssen, Abbvie, Pfizer, UCB, Ursula Fearon Speakers bureau: Abbvie, Grant/research support from: Janssen, Abbvie, Pfizer, UCB.

EGFR-targeted intraoperative fluorescence imaging detects high-grade glioma with panitumumab-IRDye800 in a phase 1 clinical trial

Rationale: First-line therapy for high-grade gliomas (HGGs) includes maximal safe surgical resection. The extent of resection predicts overall survival, but current neuroimaging approaches lack tumor specificity. The epidermal growth factor receptor (EGFR) is a highly expressed HGG biomarker. We evaluated the safety and feasibility of an anti-EGFR antibody, panitumuab-IRDye800, at subtherapeutic doses as an imaging agent for HGG. Methods: Eleven patients with contrast-enhancing HGGs were systemically infused with panitumumab-IRDye800 at a low (50 mg) or high (100 mg) dose 1-5 days before surgery. Near-infrared fluorescence imaging was performed intraoperatively and ex vivo, to identify the optimal tumor-to-background ratio by comparing mean fluorescence intensities of tumor and histologically uninvolved tissue. Fluorescence was correlated with preoperative T1 contrast, tumor size, EGFR expression and other biomarkers. Results: No adverse events were attributed to panitumumab-IRDye800. Tumor fragments as small as 5 mg could be detected ex vivo and detection threshold was dose dependent. In tissue sections, panitumumab-IRDye800 was highly sensitive (95%) and specific (96%) for pathology confirmed tumor containing tissue. Cellular delivery of panitumumab-IRDye800 was correlated to EGFR overexpression and compromised blood-brain barrier in HGG, while normal brain tissue showed minimal fluorescence. Intraoperative fluorescence improved optical contrast in tumor tissue within and beyond the T1 contrast-enhancing margin, with contrast-to-noise ratios of 9.5 ± 2.1 and 3.6 ± 1.1, respectively. Conclusions: Panitumumab-IRDye800 provided excellent tumor contrast and was safe at both doses. Smaller fragments of tumor could be detected at the 100 mg dose and thus more suitable for intraoperative imaging.

Comprehensive molecular pharmacodynamic assessment identifies response markers of intermediary metabolism associated with BPM 31510-IV treatment in advanced glioblastoma multiforme patients

2059

Background: BPM 31510-IV is a drug-lipid conjugate nanodispersion containing oxidized Coenzyme Q10 (CoQ10) in clinical development for glioblastoma multiforme (GBM). In a recently concluded Phase 1 study of BPM 31510-IV (NCT03020602), in addition to safety and tolerability, longitudinal pharmacodynamic samples (20 samples/cycle of 28 days) were collected at various times in patient’s refractory to radiation, temozolomide, and bevacizumab. Methods: Comprehensive multi-omic (proteomic, lipidomic, metabolomic) profiles were generated from buffy coat (proteomics only), plasma, and urine matrices. These data were further analyzed using bAIcis, a Bayesian statistics based artificial intelligence (AI) software, creating causal networks linking clinical information and endpoints to molecular composition of diverse biomatrices of patients prior to, as well as during, treatment with BPM 31510-IV. Twelve subjects comprised the intent to treat population (ITT) which were stratified across days of treatment (DR1; ≤28 days; DLT period; n=6) and (DR2, OS; >28 days; n=6). Bayesian networks and regression analysis were performed on the outputs of the analysis. Molecular analyte panels (combination of proteins, lipids, and metabolites) descriptive of progression free survival (PFS), adverse events (possibly/probably related to BPM 31510-IV), and of overall survival (OS) were generated. Results: Significant alteration (p<0.05) of metabolically associated protein and critical metabolite drivers of intermediary metabolism were identified as causally related to PFS. Significant quantitative changes in levels of several proteins (buffy coat) and metabolites (urine) were identified with probable or possible associations to adverse events in BPM 31510-IV treated subjects. Conclusions: Overall, alterations in proteins and metabolites influencing mitochondrial function and intermediary metabolism that differentiated responders versus non-responders and identified potential markers of adverse events associated with BPM 31510-IV exposure were identified and will be further explored for complementary diagnostic utility.