Systemic Therapy for Small-Cell Lung Cancer: ASCO-Ontario Health (Cancer Care Ontario) Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on the management of patients with small-cell lung cancer.

METHODS

An Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened to conduct a literature search, which included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2022. Outcomes of interest included response rates, overall survival, disease-free survival or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 95 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed to address systemic therapy options, timing of therapy, treatment in patients who are older or with poor performance status, role of biomarkers, and use of myeloid-supporting agents in patients with small-cell lung cancer.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

Co-targeting BCL-XL and MCL-1 with DT2216 and AZD8055 synergistically inhibit small-cell lung cancer growth without causing on-target toxicities in mice

Small-cell lung cancer (SCLC) is an aggressive malignancy with limited therapeutic options. The dismal prognosis in SCLC is in part associated with an upregulation of BCL-2 family anti-apoptotic proteins, including BCL-X_L and MCL-1. Unfortunately, the currently available inhibitors of BCL-2 family anti-apoptotic proteins, except BCL-2 inhibitors, are not clinically relevant because of various on-target toxicities. We, therefore, aimed to develop an effective and safe strategy targeting these anti-apoptotic proteins with DT2216 (our platelet-sparing BCL-X_L degrader) and AZD8055 (an mTOR inhibitor) to avoid associated on-target toxicities while synergistically optimizing tumor response. Through BH3 mimetic screening, we identified a subset of SCLC cell lines that is co-dependent on BCL-X_L and MCL-1. After screening inhibitors of selected tumorigenic pathways, we found that AZD8055 selectively downregulates MCL-1 in SCLC cells and its combination with DT2216 synergistically killed BCL-X_L/MCL-1 co-dependent SCLC cells, but not normal cells. Mechanistically, the combination caused BCL-X_L degradation and suppression of MCL-1 expression, and thus disrupted MCL-1 interaction with BIM leading to an enhanced apoptotic induction. In vivo, the DT2216 + AZD8055 combination significantly inhibited the growth of cell line-derived and patient-derived xenografts and reduced tumor burden accompanied by increased survival in a genetically engineered mouse model of SCLC without causing appreciable thrombocytopenia or other normal tissue injuries. Thus, these preclinical findings lay a strong foundation for future clinical studies to test DT2216 + mTOR inhibitor combinations in a subset of SCLC patients whose tumors are co-driven by BCL-X_L and MCL-1.

Peripheral blood immune cell dynamics reflect antitumor immune responses and predict clinical response to immunotherapy

BACKGROUND

Despite treatment advancements with immunotherapy, our understanding of response relies on tissue-based, static tumor features such as tumor mutation burden (TMB) and programmed death-ligand 1 (PD-L1) expression. These approaches are limited in capturing the plasticity of tumor-immune system interactions under selective pressure of immune checkpoint blockade and predicting therapeutic response and long-term outcomes. Here, we investigate the relationship between serial assessment of peripheral blood cell counts and tumor burden dynamics in the context of an evolving tumor ecosystem during immune checkpoint blockade.

METHODS

Using machine learning, we integrated dynamics in peripheral blood immune cell subsets, including neutrophil-lymphocyte ratio (NLR), from 239 patients with metastatic non-small cell lung cancer (NSCLC) and predicted clinical outcome with immune checkpoint blockade. We then sought to interpret NLR dynamics in the context of transcriptomic and T cell repertoire trajectories for 26 patients with early stage NSCLC who received neoadjuvant immune checkpoint blockade. We further determined the relationship between NLR dynamics, pathologic response and circulating tumor DNA (ctDNA) clearance.

RESULTS

Integrated dynamics of peripheral blood cell counts, predominantly NLR dynamics and changes in eosinophil levels, predicted clinical outcome, outperforming both TMB and PD-L1 expression. As early changes in NLR were a key predictor of response, we linked NLR dynamics with serial RNA sequencing deconvolution and T cell receptor sequencing to investigate differential tumor microenvironment reshaping during therapy for patients with reduction in peripheral NLR. Reductions in NLR were associated with induction of interferon-γ responses driving the expression of antigen presentation and proinflammatory gene sets coupled with reshaping of the intratumoral T cell repertoire. In addition, NLR dynamics reflected tumor regression assessed by pathological responses and complemented ctDNA kinetics in predicting long-term outcome. Elevated peripheral eosinophil levels during immune checkpoint blockade were correlated with therapeutic response in both metastatic and early stage cohorts.

CONCLUSIONS

Our findings suggest that early dynamics in peripheral blood immune cell subsets reflect changes in the tumor microenvironment and capture antitumor immune responses, ultimately reflecting clinical outcomes with immune checkpoint blockade.

Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

296 A comprehensive clinical and genomic characterization of long-term responders receiving immune checkpoint blockade for metastatic non-small cell lung cancer

Background

Five-year survival analyses of patients receiving immune checkpoint inhibitors (ICIs) for metastatic non-small cell lung cancer (NSCLC) have demonstrated continued clinical benefit compared to chemotherapy.1 2 Our study aims at understanding and defining the unique clinical and genomic underpinnings of a durable response to ICI in advanced NSCLC.

Methods

We conducted a retrospective case-control study using information abstracted from a Johns Hopkins IRB-approved database of NSCLC patients treated with an ICI-containing regimen. We defined long-term responders (LR) as patients who have achieved an overall survival (OS) of at least 3 years. We identified a comparison arm (C) of patients whose OS was less than a year. Univariate and multivariate analyses of the clinical and molecular characteristics were conducted between the LR and C groups using IBM Statistical Package for Social Sciences version 25.

Results

A cohort of 89 patients were included; 41 patients as LR and 48 as C. Mean duration of ICI was 21.6 months and 3.5 months for LR and C, respectively. On univariate analysis, there was no statistically significant difference in age, sex, race, histology or treatment characteristics between arms. However, ECOG performance status (PS) of 2 (p=0.011) and evidence of liver metastases were independently associated with a shorter response to ICI (p=0.012). Increased PD-L1 expression was significantly associated with likelihood of LR status (OR= 1.018, p=0.027). 65.9% (n=27) of LR patients developed an immune-related adverse event (irAE), of which 20 patients required discontinuation of therapy. In the C arm, 16.7% (n=8) of patients developed an irAE of which 4 patients required discontinuation. On multivariate analysis, including age, sex, race, ethnicity, smoking status, BMI, PS, liver and brain metastases as well as the presence of common oncogenic molecular alterations, PS of < 2 was statistically significantly associated with an OS ≥3 years (OR=16.7, p= 0.017). Molecular profiling was completed in 53 patients (LR=29, C=24). Common molecular alterations were identified in 28 out of 53 patients (LR=16, C=12). KRAS mutation was assessed in 34 patients (LR=16, C=18) and was associated with LR status versus C (Fisher’s exact test value p=0.0386).

Conclusions

Our retrospective study assessing multiple clinical and molecular determinants of patients with long-term response to immune checkpoint blockade, identified PS at diagnosis and KRAS mutation status to be associated with long-term response. Current efforts are ongoing to interrogate more deeply molecular features of LR, as well as their relationship to clinical aspects of a sustained benefit from ICI in NSCLC.

References

Borghaei H, et al. Five-year outcomes from the randomized, phase III trials checkMate 017 and 057: nivolumab versus docetaxel in previously treated non–small-cell lung cancer. Journal of Clinical Oncology 0, JCO.20.01605, doi:10.1200/jco.20.01605 (2021)

Reck M, et al. Five-year outcomes with pembrolizumab versus chemotherapy for metastatic non-small-cell lung cancer with PD-L1 tumor proportion score ≥ 50. J Clin Oncol 39:2339–2349, doi:10.1200/jco.21.00174 (2021)

Ethics Approval

The retrospective case-control study has obtained ethics approval from the Institutional Review Board at the Johns Hopkins School of Medicine.

Abstract 1617: Sex-specific genomic determinants of response to immunotherapy

Introduction: The magnitude of benefit from immune checkpoint inhibitors (ICI) may be sex-dependent, however the mechanisms underlying this sex dimorphism in ICI response are unknown.

Methods: To explore sex-specific genomic features linked with ICI response, we analyzed whole-exome sequence data of 89 patients with non-small cell lung cancer (NSCLC) treated with ICI. Sequence alteration, mutation signatures and clonality analyses were combined with HLA class I and II genotyping, and computationally derived mutation-associated neoantigens were evaluated based on the peptide-HLA binding affinity (&lt;500nM) and the relative binding affinity between mutated and wild-type peptides [quotient differential aggretopic index (qDAI) &gt;2]. Missense sequence alterations were characterized as putatively immunogenic mutations (IMM), and HLA class I and II matched IMM loads were calculated. Durable clinical benefit ≥6 months was used to define response. Our findings were validated in an independent cohort of ICI treated NSCLC (n=34).

Results: There were no differences in the genomic features assessed or in clinical outcomes between male (n=46) and female (n=43) patients. Female responders had higher tumor mutational burden (TMB; p=0.004), in contrast to male patients (p=0.15). Similarly, a mutation spectra-derived smoking signature was associated with response in females (p=0.001) but not in males (p=0.2). Responding female patients had a more clonal TMB compared to non-responders (p=0.008). Importantly, female responders harbored a significantly higher class I and II IMM load (p=0.008 and p=0.004 respectively), which was not appreciated in males. These findings were supported by analyses of a second independent cohort, where HLA class I and II IMM load differentiated responders from non-responders only in the female patient group (p=0.008 and p=0.004 for class I and II IMM, respectively). In the primary cohort, germline HLA class I zygosity was not associated with outcome for either sex, however a trend towards HLA DQ-B1 homozygosity and worse outcome was evident only in females. Importantly, when HLA class II diversity was combined with class II IMM load, a survival benefit was noted for tumors harboring a high IMM load and maximal HLA II germline diversity in males (log rank p=0.015) but not in females. Similarly, HLA class I diversity was important in males when combined with class I IMM load, such that low IMM load combined with reduced antigen presentation capacity was predictive of non-durable clinical benefit (p=0.003 vs p=0.68 for males and females respectively) and was linked with shorter overall survival (log rank p= 0.062 vs p=0.58 for males and females respectively).

Conclusions: Our findings support a sex dimorphism in the genomic determinants of response to immune checkpoint blockade, which may point to differences in immune surveillance between males and females in the context of therapy and may be used to tailor therapeutic delivery.

Citation Format: Susan C. Scott, Xiaoshan M. Shao, Noushin Niknafs, Archana Balan, Mara Lanis, James White, Patrick Forde, Kristen Marrone, Vincent Lam, Josephine Feliciano, Benjamin Levy, Julie Brahmer, David Ettinger, Victor Velculescu, Rachel Karchin, Christine Hann, Jarushka Naidoo, Valsalmo Anagnostou. Sex-specific genomic determinants of response to immunotherapy [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 1617.

Abstract 27: Early dynamics in peripheral blood immune cell subsets and ctDNA are predictive of outcome to immunotherapy

Background: Treatment-induced anti-tumor immune response may be reflected in peripheral blood leukocyte composition and shifts. The relative abundance of immune cell subsets captured by neutrophil-to-lymphocyte ratio (NLR) is a promising biomarker of response to immune checkpoint inhibition (ICI). However early dynamics and integration with circulating tumor DNA (ctDNA) kinetics during ICI have not been comprehensively studied.

Methods: We evaluated the predictive role of early dynamic changes of peripheral immune cell subsets in 239 ICI treated metastatic non-small cell lung cancers (mNSCLC) and combined those with ctDNA dynamics in 18 early stage NSCLCs (esNSCLC) treated with neoadjuvant ICI. Blood cell counts were analyzed at baseline, 4 weeks on treatment, and at first radiographic follow up (mNSCLC) or preoperatively (esNSCLC). mNSCLC patients without progression at 6 months were considered to have durable clinical benefit (DCB). We employed eXtreme Gradient Boosting, a decision-tree based machine learning algorithm, to integrate baseline values and early changes in immune cell subsets. To reduce modeling overfitting, we trained an ensemble of models, incorporating 10-fold cross-validation that included feature selection (training n=171) and tested the model in an unseen independent set (n=68). For esNSCLCs, major pathologic response (MPR; ≤10% residual tumor; RT) was determined. We performed Targeted Error Correction next generation sequencing on 60 serial plasma and matched leukocyte DNA samples to assess ctDNA clonal dynamics. Changes in immune cell subsets were correlated with RT, MPR, progression-free (PFS) and overall survival (OS).

Results: Our machine learning integrative model predicted DCB with an area under the ROC curve (AUC) of 0.96 for training, 0.72 for cross-validation testing and 0.74 for unseen testing datasets. Feature importance analysis revealed that NLR at 4 weeks, first radiographic follow up, and relative change in NLR from baseline were the strongest predictors of outcome together with relative eosinophil and lymphocyte count. Our model's performance was superior to TMB (AUC=0.52) or PD-L1 (AUC=0.54). For esNSCLCs, change in NLR at 4 weeks after ICI initiation was predictive of tumor regression (p=0.02), such that those with MPR showed significant decrease in NLR. This was also predictive of PFS (log rank p=0.004) and OS (log rank p=0.02). Furthermore, higher eosinophil count at 4 weeks was correlated with MPR (p=0.006) and decreased RT (p=0.006). Immune cell subset kinetics were concordant with ctDNA clearance in all but two patients and importantly NLR dynamics at 4 weeks were predictive of MPR even when ctDNA was undetectable.

Conclusions: Early changes in peripheral immune cell subsets together with ctDNA are reflective of anti-tumor immune response during ICI and may more accurately predict ICI response than currently used biomarkers.

Citation Format: Michael Hwang, Jenna Canzoniero, Samuel Rosner, Guangfan Zhang, Mara Lanis, Lamia Rhymee, Alexandria Curry, Gavin Pereira, Kristen Marrone, Joshua Reuss, Jarushka Naidoo, Christine Hann, Vincent Lam, Benjamin Levy, David Ettinger, Patrick Forde, Julie Brahmer, Victor Velculescu, Tanguy Seiwert, Valsamo Anagnostou. Early dynamics in peripheral blood immune cell subsets and ctDNA are predictive of outcome to immunotherapy [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 27.

Abstract 1668: Longitudinal dynamics of circulating tumor DNA and plasma proteomics predict clinical outcomes to immunotherapy in non-small cell lung cancer

Given the success of immunotherapy (IO), multiple IO-based options exist for advanced non-small cell lung cancer (NSCLC). Currently used biomarkers do not fully predict clinical outcomes and response assessment remains limited to radiological evaluation. Dynamic biomarkers that evaluate both tumor and host immune responses to IO are needed. We studied patients with NSCLC that received IO and chemo-IO to identify predictive and longitudinal biomarkers of clinical response using circulating tumor DNA (ctDNA) and plasma proteomic dynamics. We conducted deep targeted error-correction sequencing (TEC-Seq) of plasma cell-free DNA (cfDNA) and matched white blood cell (WBC) genomic DNA (gDNA) to identify ctDNA variants. We performed multiplexed antibody-based proximity extension assays of serial plasma samples to detect immune-related proteins. From separate training (n=31) and validation (n=29) cohorts, a total of 288 plasma cfDNA and 52 WBC gDNA specimens underwent TEC-Seq. A total of 260 variants were detected in plasma cfDNA and 78 variants in WBC gDNA. Almost a third of the plasma cfDNA variants (32%, n=61 of 188) were also found in WBC gDNA and filtered out. ctDNA variants were identified in 82% of patients (n=50). In the training cohort, longitudinal decreases in ctDNA variant levels were observed in patients with durable clinical benefit (DCB). Molecular response, defined as the loss of detectable ctDNA, was associated with longer progression-free (PFS; p=0.0004, log-rank) and overall survival (OS; p=0.017, log-rank). We incorporated on-treatment ctDNA dynamics including molecular response, recrudescence, and emergence of new variants into a logistic regression model to predict clinical benefit. This integrative model predicted DCB at a sensitivity of 84%, specificity of 76%, and with an area under the curve (AUC) of 0.90, better than baseline tumor PD-L1 expression alone (AUC 0.70, p=0.044, bootstrap method). In the validation cohort, molecular response was associated with longer PFS (p=0.00098, log-rank) and OS (p=0.0037, log-rank) and the integrative model predicted DCB at a sensitivity of 100%, specificity of 78%, and AUC of 0.89. In a subset (n=28 of 31) of the training cohort, plasma proteomics analysis revealed that increased baseline levels of IL15 and DCN were independently associated with DCB (p&lt;0.05, Mann-Whitney), suggesting that pre-existing IL-15-mediated T-cell activation and DCN-mediated TGF-beta signaling may enable IO response. Sustained longitudinal increases in CCL17 were associated with DCB (p=0.037, Mann Whitney), which may reflect T-cell chemotaxis to promote on-treatment IO response. In summary, we validated longitudinal ctDNA alongside exploratory plasma proteomics dynamics to characterize on-treatment anti-tumor responses to IO, and enable prediction of clinical responses in NSCLC.

Citation Format: Joseph C. Murray, Karlijn Hummelink, Lamia Rhymee, Alessandro Leal, Leonardo Ferreira, Mara Lanis, James R. White, Noushin Niknafs, Kristen Marrone, Jarushka Naidoo, Benjamin Levy, Samuel Rosner, Christine Hann, Josephine Feliciano, Vincent Lam, David Ettinger, Qing K. Li, Peter Illei, Kim Monkhorst, Hatim Husain, Julie R. Brahmer, Victor Velculescu, Patrick Forde, Robert B. Scharpf, Valsamo Anagnostou. Longitudinal dynamics of circulating tumor DNA and plasma proteomics predict clinical outcomes to immunotherapy in non-small cell lung cancer [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 1668.

Abstract PR-008: Identification and characterization of the molecular mechanisms of SCLC chemo-radiation resistance

Small cell lung cancer (SCLC) is among the most aggressive form of lung malignancies and accounts for 15-20% of all lung cancers. It has the tendency to metastasize early, thus limited-stage SCLC patients still receive systemic treatment with chemo-radiotherapy (chemoXRT) for their localized disease. SCLC is exceptionally sensitive to chemoXRT and exhibits high response rates; however, the recurrence rate is almost 100% and patients relapse with tumors that resist further treatments. Elucidating mechanisms of chemoXRT resistance in SCLC is needed to develop improved therapies and positively impact patient outcomes. To better interrogate mechanisms of chemoXRT resistance, we developed a SCLC patient-derived xenograft (PDX) in vivo system for the major molecular subtypes of SCLC (classic and variant). Briefly, PDX tumor bearing mice were treated with: 1) vehicle control; 2) cisplatin plus etoposide (EP); 3) radiotherapy (XRT); and 4) both EP/XRT. A major response was observed within the EP/XRT arm compared to vehicle or single therapy arms. Whole transcriptome profiling among all treatment arms revealed molecular pathways and biological processes associated with chemoXRT resistance. Also, by comparing our data with two previous SCLC patient cohort studies, we identified gene candidates for functional validation of chemoXRT resistance (i.e. ST6GAL1, TNIK and SOHLH2). To enable real-time cellular and molecular analysis of PDX behavior ex vivo and to validate SCLC chemoXRT resistance candidate genes, we established a novel PDX organoid (PDO) model to study the molecular underpinnings of XRT resistance in SCLC. Classic and variant SCLC PDOs still retained the cellular, DNA and RNA markers consistent with their parental PDX molecular subtype classification using array comparative genomic hybridization and RNA-sequencing. We aim to utilize our novel SCLC PDX/PDO models as a tool to identify and validate candidates for chemoXRT resistance to be used as biomarkers and targets to combat chemoXRT resistance in SCLC.

Citation Format: Francesca Anna Carrieri, Nick Connis, Eloise Grasset, Eddie Luidy-Imada, Andrew Ewald, Luigi Marchionni, Christine Hann, Phuoc T. Tran. Identification and characterization of the molecular mechanisms of SCLC chemo-radiation resistance [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PR-008.

Phase IB Study of Osimertinib in Combination with Navitoclax in EGFR-mutant NSCLC Following Resistance to Initial EGFR Therapy (ETCTN 9903)

PURPOSE

Osimertinib is an effective therapy in EGFR-mutant non-small cell lung cancer (NSCLC), but resistance invariably develops. Navitoclax is an oral inhibitor of BCL-2/BCL-xL that has exhibited synergy with osimertinib in preclinical models of EGFR-mutant NSCLC. In hematologic malignancies, BCL-2 family inhibitors in combination therapy effectively increase cellular apoptosis and decrease drug resistance.

PATIENTS AND METHODS

This single-arm phase Ib study evaluated safety, tolerability, and feasibility of osimertinib and navitoclax, including dose expansion in T790M-positive patients at the recommended phase II dose (RP2D). Eligible patients had advanced EGFR-mutant NSCLC with prior tyrosine kinase inhibitor exposure. Five dose levels were planned with osimertinib from 40 to 80 mg orally daily and navitoclax from 150 to 325 mg orally daily.

RESULTS

A total of 27 patients were enrolled (18 in the dose-escalation cohort and nine in the dose-expansion cohort): median age 65, 67% female, 48% exon 19 del, and 37% L858R, median one prior line of therapy. The most common adverse events were lymphopenia (37%), fatigue (22%), nausea (22%), and thrombocytopenia (37%). No dose-limiting toxicities were seen in dose-escalation cohort; osimertinib 80 mg, navitoclax 150 mg was chosen as the RP2D. Most patients (78%) received >95% of planned doses through three cycles. In expansion cohort, objective response rate was 100% and median progression-free survival was 16.8 months. A proapoptotic effect from navitoclax was demonstrated by early-onset thrombocytopenia.

CONCLUSIONS

Oral combination therapy with navitoclax and osimertinib was safe and feasible at RP2D with clinical efficacy. Early thrombocytopenia was common, supporting an target engagement by navitoclax. Further study of BCL-2/BCL-xL inhibition to enhance osimertinib activity is warranted.

Steroid-refractory PD-(L)1 pneumonitis: incidence, clinical features, treatment, and outcomes

BACKGROUND

Immune-checkpoint inhibitor (ICI)-pneumonitis that does not improve or resolve with corticosteroids and requires additional immunosuppression is termed steroid-refractory ICI-pneumonitis. Herein, we report the clinical features, management and outcomes for patients treated with intravenous immunoglobulin (IVIG), infliximab, or the combination of IVIG and infliximab for steroid-refractory ICI-pneumonitis.

METHODS

Patients with steroid-refractory ICI-pneumonitis were identified between January 2011 and January 2020 at a tertiary academic center. ICI-pneumonitis was defined as clinical or radiographic lung inflammation without an alternative diagnosis, confirmed by a multidisciplinary team. Steroid-refractory ICI-pneumonitis was defined as lack of clinical improvement after high-dose corticosteroids for 48 hours, necessitating additional immunosuppression. Serial clinical, radiologic (CT imaging), and functional features (level-of-care, oxygen requirement) were collected preadditional and postadditional immunosuppression.

RESULTS

Of 65 patients with ICI-pneumonitis, 18.5% (12/65) had steroid-refractory ICI-pneumonitis. Mean age at diagnosis of ICI-pneumonitis was 66.8 years (range: 35-85), 50% patients were male, and the majority had lung carcinoma (75%). Steroid-refractory ICI-pneumonitis occurred after a mean of 5 ICI doses from PD-(L)1 start (range: 3-12 doses). The most common radiologic pattern was diffuse alveolar damage (DAD: 50%, 6/12). After corticosteroid failure, patients were treated with: IVIG (n=7), infliximab (n=2), or combination IVIG and infliximab (n=3); 11/12 (91.7%) required ICU-level care and 8/12 (75%) died of steroid-refractory ICI-pneumonitis or infectious complications (IVIG alone=3/7, 42.9%; infliximab alone=2/2, 100%; IVIG + infliximab=3/3, 100%). All five patients treated with infliximab (5/5; 100%) died from steroid-refractory ICI-pneumonitis or infectious complications. Mechanical ventilation was required in 53% of patients treated with infliximab alone, 80% of those treated with IVIG + infliximab, and 25.5% of those treated with IVIG alone.

CONCLUSIONS

Steroid-refractory ICI-pneumonitis constituted 18.5% of referrals for multidisciplinary irAE care. Steroid-refractory ICI-pnuemonitis occurred early in patients' treatment courses, and most commonly exhibited a DAD radiographic pattern. Patients treated with IVIG alone demonstrated an improvement in both level-of-care and oxygenation requirements and had fewer fatalities (43%) from steroid-refractory ICI-pneumonitis when compared to treatment with infliximab (100% mortality).

359 AMG 757, a half-life extended bispecific T-cell engager (BiTE®) immune therapy against DLL3 in SCLC: phase 1 interim results

Background

Delta-like ligand 3 (DLL3) is an inhibitory Notch ligand that is highly expressed in small cell lung cancer (SCLC) and minimally expressed in normal tissues.1 AMG 757, a half-life extended BiTE® immune therapy, binds to DLL3 on tumor cells and CD3 on T cells, resulting in T cell-dependent killing of tumor cells. We report initial safety and efficacy from the ongoing phase 1 study of AMG 757 in patients with SCLC.

Methods

AMG 757 was administered intravenously every two weeks (with/without step dose) at doses of 0.003–3.0 mg. Eligible patients had SCLC that progressed or recurred following ≥1 platinum-based regimen. Antitumor activity was assessed using modified RECIST 1.1. The study was approved by the Ethics Board at participating institutions.

Results

As of 1 June 2020, safety and efficacy data are available for 31 patients enrolled at the first seven dose levels (DL) with median age, 63 (44–74) years; ECOG PS: 0–1, n=30 (96.8%); median prior lines, 2.0 (1–6); and previous PD-1/PD-L1 treatment: n=12 (38.7%). Median treatment duration was 6.1 (0.1–59.4) weeks. Treatment-emergent adverse events (AEs) were reported for 30 (96.8%) patients. AMG 757-related AEs occurred in 25 (80.6%) patients, including 5 (16.1%) that were grade ≥3 and one (3.2%) grade 5 (pneumonitis in DL5 [0.3 mg]). Three AEs (dyspnea, pneumonitis, fatigue) led to treatment discontinuation. The most common AE was cytokine release syndrome (CRS), which was reported in 11 (35.5%) patients. CRS AEs were grade 1–2, consisted mainly of fever with/without hypotension, and occurred mostly within 24 hours of the first or second dose of AMG 757. CRS events were reversible, did not lead to treatment interruption or discontinuation, and were managed with supportive care, corticosteroids, and/or anti-IL 6 therapy. The MTD for AMG 757 has not yet been reached. AMG 757 exhibited dose proportional increase in exposures. Response to AMG 757 is shown (figure 1). Confirmed partial response was reported in 5 (16.1%) patients (1/12 [8.3%] in DL5, 1/8 [12.5%] in DL6, 3/7 [42.9%] in DL7), and stable disease in 8 (25.8%) of all treated patients. Most responses occurred after 8 weeks on treatment. All responders remain on treatment with duration of response ranging from 2.0+ to 7.4 months+.

Abstract 359 Figure 1

Tumor shrinkage over time in response to AMG 757

Conclusions

AMG 757 administered at a dose of up to 3 mg every two weeks has an acceptable safety profile and shows anti-tumor activity in patients with relapsed/refractory SCLC. Further dose escalation is ongoing.

Trial Registration

NCT03319940

Ethics Approval

The study was approved by the Ethics Board at participating institutions.

Consent

N/A

Reference

Leonetti A, Facchinetti F, Minari R, Cortellini A, Rolfo CD, Giovannetti E, Tiseo M. Cell Oncol (Dordr). 2019;42:261–273.

New Approaches to SCLC Therapy: From the Laboratory to the Clinic

The outcomes of patients with SCLC have not yet been substantially impacted by the revolution in precision oncology, primarily owing to a paucity of genetic alterations in actionable driver oncogenes. Nevertheless, systemic therapies that include immunotherapy are beginning to show promise in the clinic. Although, these results are encouraging, many patients do not respond to, or rapidly recur after, current regimens, necessitating alternative or complementary therapeutic strategies. In this review, we discuss ongoing investigations into the pathobiology of this recalcitrant cancer and the therapeutic vulnerabilities that are exposed by the disease state. Included within this discussion, is a snapshot of the current biomarker and clinical trial landscapes for SCLC. Finally, we identify key knowledge gaps that should be addressed to advance the field in pursuit of reduced SCLC mortality. This review largely summarizes work presented at the Third Biennial International Association for the Study of Lung Cancer SCLC Meeting.

RARE-29. AZD8055 ENHANCES IN VIVO EFFICACY OF AFATINIB IN CHORDOMAS

INTRODUCTION

Chordomas are rare, locally aggressive bone tumors that arise in cranial base, mobile spine, and sacrum. Currently, there are no FDA-approved therapies for chordoma patients, thus there is a high unmet need to develop effective treatments. In this study, we aim to evaluate the anti-tumor efficacy of small molecule inhibitors that target crucial oncogenic pathways in chordoma, as single agents or in combination, to identify novel therapies with the greatest translation potential.

METHODS

A panel of small molecule compounds that had exhibited in vitro efficacy against human chordoma cell lines or target known chordoma drivers was screened in vivo against patient-derived xenograft (PDX) models of chordoma, and their efficacy was further evaluated using chordoma cell lines and xenograft models.

RESULTS

The in vivo activity of compounds identified in a NIH Chemical Genomics Center screen utilizing chordoma cell lines, together with inhibitors of c-MET and PDGFR, were evaluated in PDX models of chordoma that were previously described or recently established for this study. Inhibitors of EGFR (BIBX1382, erlotinib and afatinib), c-MET (crizotinib) or mTOR (AZD8055) significantly inhibited tumor growth in vivo but did not induce tumor regression. Co-inhibition of EGFR and c-MET using erlotinib and crizotinib synergistically reduced cell viability in chordoma cell lines but did not result in enhanced in vivo activity. Co-inhibition of EGFR and mTOR pathways using afatinib and AZD8055 synergistically reduced cell viability in chordoma cell lines. Importantly, co-inhibition of EGFR and mTOR also synergistically suppressed tumor growth in vivo, showing improved disease control.

CONCLUSION

Single inhibition of EGFR, c-MET or mTOR suppresses chordoma growth both in vitro and in vivo. Co-inhibition of EGFR and mTOR synergistically inhibits chordoma growth in a range of preclinical models. The insights gained from our study provide a novel combination therapeutic strategy for patients with chordoma.

Lung cancer and family-centered concerns

BACKGROUND

Genetic and environmental interactions predispose certain groups to lung cancer, including families. Families or caregiving units experience the disease interdependently. We have previously evaluated the concerns and preferences of patients in addressing the lung cancer experience and cancer risks in their families. This qualitative study evaluates the concerns and preferences of family members and caregivers of patients with lung cancer in the lung cancer experience and familial cancer risks.

METHODS

We held focus groups to discuss the format and timing of addressing these preferences and concerns. Qualitative data generated was analyzed using a grounded theory approach.

RESULTS

Five focus groups totaling 19 participants were conducted. Seven themes were identified: (1) journey to lung cancer diagnosis has core dimensions for patient and family, (2) importance of communication between patients, families, and providers, (3) challenges for caregivers and family, (4) mixed perceptions of lung cancer causation among relatives, (5) discussion of cancer risk with relatives has complex dynamics, (6) impact of diagnosis on family health behaviors and screening, (7) role of genetic counseling.

CONCLUSIONS

Family members of patients with lung cancer are interested in discussing risk factors, prevention, and diagnoses and also would like access to other supportive services do learn about and cope with some of the stresses and barriers they experience in the family lung cancer journey. The diagnosis represents a potential teachable moment with the opportunity to reduce the risk of LC development or improve early detection in LC patient's family members.

Radiotherapy in small-cell lung cancer

Radiotherapy is a critical component of multi-modality treatment of LS-SCLC and has an emerging role in ES-SCLC. Many of the recent advances in the management of SCLC have come by refining the role of radiotherapy in this disease. A significant amount of research is currently focused on the targeting of specific signaling cascades implicated in SCLC pathogenesis (eg Hedgehog, c-MET, insulin-like growth factor receptor 1 [IGFR-1R], mammalian target of rapamycin [mTOR], vascular endothelial growth factor [VEGF], and p53 and Bcl-2 pathways) and on other novel approaches to therapy including treatment with a novel oncolytic virus with tropism for neuroendocrine cells and CD56-targeted drug delivery. Clinical investigations of many of these therapies are ongoing, and the results may become available over the next several years.

Dynamic models of ARDS lung mechanics for optimal patient ventilation

Mechanical ventilation is often used to treat patients with acute respiratory distress syndrome (ARDS). However, the optimal setting is still controversial, and physicians often rely on experience and intuition. The purpose of this research is to develop a model of the essential lung mechanics to help determining the optimal ventilator setting in clinical situations. The model is a compilation of physiologically based mechanics parameters, which are adjustable to represent patient specific conditions. Further investigation improvements are required, however it shows good initial for eventual clinical use.

Both food preferences and food frequency scores predict fat intakes of women with breast cancer

OBJECTIVE

To determine whether self-reported frequencies of food use were linked to self-reported preferences for the same foods. The hypothesis was that both food frequencies and food preferences can predict nutrient intakes.

RESPONDENTS

Participants were adult women patients (n = 339), recruited through the University of Michigan Breast Care Center. The sample included both persons with breast cancer and persons who were cancer-free.

DESIGN

All women completed a 98-item food frequency questionnaire and rated preferences for many of the same foods using a 9-point category scale. Percent energy from fat and saturated fat, and intakes of dietary fiber and vitamin C were estimated from analyses of 4-day food records.

STATISTICAL ANALYSES

Pearson correlations coefficients were used for data analysis.

RESULTS

Dislike was a strong predictor of nonuse. In contrast, the more preferred foods were also reported as more frequently consumed. Significant correlations between preference and frequency scores were obtained for virtually all item pairs. Median Pearson correlation coefficient was 0.30 (range 0.04 to 0.56). Correlations improved when foods were aggregated into the chief dietary sources of fat, saturated fat, and vitamin C. Food frequencies and food preferences showed the same strength of association with percent energy from fat and saturated fat (r = 0.20 to 0.25). Food frequencies showed a stronger association with vitamin C intakes than did preferences for vegetables and fruit.

APPLICATIONS

Food preferences may provide a potential alternative to the food frequency approach.

Taste and food preferences as predictors of dietary practices in young women

OBJECTIVE

To investigate links between taste responses, self-reported food preferences and selected dietary outcomes in young women.

METHODS

Subjects were 159 women, with a mean age of 27.0 years. Taste responses were measured using aqueous solutions of 6-n-propylthiouracil (PROP) and sucrose. All subjects completed a 171-item food preference checklist, using nine-point category scales. Food preference data were reduced using principal components factor analyses, with the internal consistency of factor-based subscales established using Cronbach's alpha. Dietary intakes, available for a subset of 87 women, were based on 3 days of food records. Estimated intakes of carbohydrate, fibre and beta-carotene were the key dietary outcome variables.

RESULTS

Genetically-mediated sensitivity to the bitter taste of PROP was associated with reduced preferences for Brussels sprouts, cabbage, spinach and coffee beverages. Higher preferences for sucrose in water were associated with increased preferences for sweet desserts. Food preferences, in turn, were associated with measures of current diet. Reduced acceptability of vegetables and fruits was associated with lower estimated intakes of carbohydrate, fibre and beta-carotene.

CONCLUSIONS

Taste responses to sucrose and PROP were predictive of some food preferences. Food preferences, in turn, were associated with food consumption patterns. Given that taste responsiveness to PROP is an inherited trait, there may be further links between genetic taste markers, eating habits and the selection of healthful diets.

Food preferences and reported frequencies of food consumption as predictors of current diet in young women

BACKGROUND

Self-reported food preferences and frequencies of food consumption have served as proxy measures of the current diet in consumer research and in nutritional epidemiology studies, respectively.

OBJECTIVE

The objective was to determine whether food preferences and food-frequency scores are associated variables that are predictive of nutrient intakes.

DESIGN

College-age women (n = 87) completed a 98-item food-frequency questionnaire and rated preferences for many of the same foods on a 9-point category scale. Estimated intakes of fat, fiber, and vitamin C were obtained by using 3-d food records.

RESULTS

For virtually all item pairs tested, food preferences and reported frequencies of consumption of the same foods were significantly correlated with each other. The median Pearson correlation coefficient was 0.40 (range: -0.04 to 0.62). Correlations improved when foods were aggregated into factor-based food groups. The slope of the relation between food preferences and frequency of consumption varied with food category. Both food preferences and food frequencies predicted dietary outcomes. Fat consumption was predicted equally well by either approach in a multiple regression model. Intakes of fiber and vitamin C were better predicted by food-frequency scores than by stated preferences for vegetables and fruit.

CONCLUSIONS

Reported frequencies of food consumption, the core of the food-frequency approach, were associated with food likes and dislikes. Food preferences were a predictor of dietary intakes and may provide an alternative to the food-frequency approach for dietary intake assessment.

Differential plasma endothelin levels in subgroups of patients with angina and angiographically normal coronary arteries. Coronary Artery Disease Research Group

BACKGROUND

Raised plasma endothelin concentrations have previously been reported in patients with cardiac syndrome X, but it is not known whether these levels vary between clinically distinct subgroups in this heterogeneous condition.

METHODS AND RESULTS

We compared plasma immunoreactive endothelin levels in 54 patients with angina pectoris and normal coronary angiograms and 21 healthy control subjects. The patient group was divided into 4 clinically distinct subgroups: 7 with left bundle branch block (group A); 7 with previous myocardial infarction (group B); 24 with positive exercise electrocardiography (group C); and 16 with negative exercise electrocardiography (group D). The plasma endothelin concentration was significantly higher in patients compared with control subjects (3.7 [2.9 to 4.3] vs 2.96 [2.4 to 3.4] pg/mL, respectively, median [interquartile range]; P=0.002). Endothelin concentrations were most significantly elevated in group A and group B (4.5 [3.6 to 5.2] pg/mL; P=0.005 and 4.1 [3.9 to 4.5] pg/mL; P=0.001, respectively). Plasma endothelin concentrations were also significantly elevated in group C (3.7 [2.8 to 4.1] pg/mL; P=0.02) but not in group D (3.0 [2.5 to 3.8] pg/mL; P=0.3).

CONCLUSIONS

Plasma endothelin concentration is elevated in patients with angina pectoris and angiographically normal coronary arteries, particularly those with left bundle branch block or previous myocardial infarction.

Increased camptothecin toxicity induced in mammalian cells expressing Saccharomyces cerevisiae DNA topoisomerase I

The yeast Saccharomyces cerevisiae has been useful in establishing the phenotypic effects of specific mutations on the enzymatic activity and camptothecin sensitivity of yeast and human DNA topoisomerase I. To determine whether these phenotypes were faithfully reiterated in higher eukaryotic cells, wild-type and mutant yeast Top1 proteins were epitope-tagged at the amino terminus and transiently overexpressed in mammalian COS cells. Camptothecin preferentially induced apoptosis in cells expressing wild-type eScTop1p yet did not appreciably increase the cytotoxic response of cells expressing a catalytically inactive (eSctop1Y727F) or a catalytically active, camptothecin-resistant eSctop1vac mutant. Using an epitope-specific antibody, immobilized precipitates of eScTop1p were active in DNA relaxation assays, whereas immunoprecipitates of eScTop1Y727Fp were not. Thus, the enzyme retained catalytic activity while tethered to a support. Interestingly, the mutant eSctop1T722A, which mimics camptothecin-induced cytotoxicity in yeast through stabilization of the covalent enzyme-DNA intermediate, induced apoptosis in COS cells in the absence of camptothecin. This correlated with increased DNA cleavage in immunoprecipitates of eScTop1T722Ap, in the absence of the drug. The observation that the phenotypic consequences of expressing wild-type and mutant yeast enzymes were reiterated in mammalian cells suggests that the mechanisms underlying cellular responses to DNA topoisomerase I-mediated DNA damage are conserved between yeast and mammalian cells.

Serum endothelin levels and pain perception in patients with cardiac syndrome X and in healthy controls

The possible algogenic effects of elevated serum endothelin levels in cardiac syndrome X were investigated in a case-control study that examined somatic pain perception in the forearm during submaximal effort tourniquet and cold immersion tests. Pain threshold to both ischemic and cold stimulation of the forearm was demonstrated to be significantly lower in patients with syndrome X than in matched healthy controls, and a negative correlation between ischemic pain threshold and endothelin levels was demonstrated.

Effect of oral aminophylline in patients with angina and normal coronary arteriograms (cardiac syndrome X)

BACKGROUND

Patients with syndrome X (exertional angina, positive exercise test, normal coronary arteriogram) have an altered perception of cardiac pain. This symptom may arise from increased sensitivity to adenosine. Previous studies suggest that intravenous aminophylline (an adenosine receptor blocker) improves exercise tolerance in patients with this disorder.

OBJECTIVE

To examine the efficacy of oral aminophylline in syndrome X.

METHODS

13 patients (11 women and two men, mean (SD) 54 (6) years) with syndrome X were studied. Patients were randomised in a double blind crossover study to receive either oral aminophylline or placebo for three weeks. All patients underwent symptom limited exercise testing and ambulatory electrocardiography at the end of each three week period.

RESULTS

10 patients completed the study. The time to angina during exercise testing in patients who were given aminophylline was longer than for the placebo group (mean (SD) 632 (202) seconds v 522 (264) seconds, P = 0.004). Peak exercise ST depression did not differ significantly between patients who received aminophylline and those administered placebo (mean (SD) -1.9 (0.7) mm v -1.5 (0.8) mm). Six patients taking aminophylline reported a reduction in the total number of episodes of chest pain during the three weeks, but the frequency and duration of ST segment depression during Holter monitoring was unchanged.

CONCLUSION

Oral aminophylline has a favourable effect on exercise induced chest pain threshold in patients with syndrome X. The disparate effects on symptoms and ST segment changes are intriguing and further study is warranted.

Angiotensin-converting enzyme insertion/deletion polymorphism in angina pectoris with normal coronary arteriograms

We investigated the relation between angiotensin-converting enzyme gene insertion/deletion polymorphism and syndrome X (angina with normal coronary arteriogram). The results of our study suggest that this polymorphism does not play a major role in the pathogenesis of microvascular angina.

Concentration of circulating plasma endothelin in patients with angina and normal coronary angiograms

BACKGROUND

Some patients with angina pectoris and normal coronary arteriograms have reduced coronary flow reserve and abnormal endothelium dependent vasodilator responses. Endothelin-1 (ET-1), a potent vasoconstrictor, is an important modulator of microvascular function and may also have algogenic properties.

METHOD

Plasma ET-1 was measured in peripheral venous blood in 40 patients (30 women) (mean (SD) age 56 (8) years) with angina and normal coronary arteriograms and 21 normal controls (17 women) (mean (SD) age 53 (7) years). Patients with systemic hypertension, left ventricular hypertrophy, or coronary spasm were excluded. Plasma ET-1 was measured using radioimmunoassay.

RESULTS

Thirty five patients had > or = 1 mm ST segment depression during exercise. Left bundle branch block was present in four patients at rest and in one during exercise. Mean (SD) (range) concentration of ET-1 (pg/ml) was higher in patients than in controls (3.84 (1.25) (1.97-7.42) v 2.88 (0.71) (1.57-4.48) P < 0.0001). In patients with "high" (> control mean (one SD)) ET-1 concentrations (n = 23), the time to onset of chest pain during exercise was significantly shorter (6.21 (3.9) v 9.03 (3.9) min; p = 0.01) than in patients with "low" ET-1 concentrations. Of the five patients with left bundle branch block, four had plasma ET-1 concentration > 4.0 pg/ml.

CONCLUSION

Plasma endothelin is raised in patients with angina and normal coronary arteriograms and is consistent with the demonstration of endothelial dysfunction in such patients. The association between "high" plasma ET-1 and an earlier onset of chest pain during exercise suggests that endothelin may also have a role in the genesis of chest pain in patients with normal coronary arteries.

A study of building structural features associated with high indoor air concentrations of organochlorine termiticides

As part of a two-year study of post-treatment residential exposure to the termiticide, aldrin, the building structural features of ten houses with crawl-space-type floors were assessed by an independent inspector. Building attributes recorded on a checklist included the age of the dwelling, room characteristics, floor details and the nature of subfloor ventilation. At the end of each inspection, the inspector, who was blinded to data on airborne aldrin concentrations, provided a rating of expected indoor air contamination. Several of the building attributes, including the age of the house, the area of exterior subfloor vents, as well as the inspector's rating, were significantly correlated with airborne aldrin values. No single building variable, however, was highly correlated with every measure of aldrin concentration over a 12-month period. The observed data are consistent with poor subfloor ventilation and a 'leaky' floor being important contributors to indoor air pollution. It is recommended that pest control companies advise householders about any obvious floor and ventilation deficiencies before soil treatment work is undertaken. Pesticide exposure (by analogy with geological radon exposure) may be reduced by sealing gaps in floors and/or by improving subfloor ventilation.

Serum tobramycin levels in low- and very low-birthweight infants

This study was designed to evaluate the serum concentration of tobramycin sulfate following a 2.5-mg/kg intravenous infusion in 43 premature infants on days 1, 3, and 5 of age (therapy). Twenty premature infants weighing 1500 gm or less at birth and 23 others whose birthweights ranged from 1501 to 2500 gm made up the study population. Serum tobramycin levels were measured by an enzymatic immunoassay (EMIT) at one, four to six, and 12 hours after injection. Peak serum levels increased from day 1 (means, 5.2 +/- 2.2 mcg/ml) to day 3 (means, 6.1 +/- 2.6 mg/ml) and then remained unchanged at day 5 (means, 6.1 +/- 2.4 mg/ml). Approximately 40% of the study population presented trough levels above 2 mcg/ml on day 1 and over 70% on days 3 and 5. No evidence of renal toxicity or auditory dysfunction was observed. In light of the high trough levels observed during the first week of life in premature infants, it may be judicious to monitor serum tobramycin concentration and to decrease the dosage or to prolong the dose interval in order to maintain trough concentrations below 2 mcg/ml.