Ex vivo organotypic cultures for synergistic therapy prioritization identify patient-specific responses to combined MEK and Src inhibition in colorectal cancer.

Translating preclinical studies to effective treatment protocols and identifying specific therapeutic responses in individuals with cancer is challenging. This may arise due to the complex genetic makeup of tumor cells and the impact of their multifaceted tumor microenvironment on drug response. To find new clinically relevant drug combinations for colorectal cancer (CRC), we prioritized the top five synergistic combinations from a large in vitro screen for ex vivo testing on 29 freshly resected human CRC tumors and found that only the combination of mitogen-activated protein kinase kinase (MEK) and proto-oncogene tyrosine-protein kinase Src (Src) inhibition was effective when tested ex vivo. Pretreatment phosphorylated Src (pSrc) was identified as a predictive biomarker for MEK and Src inhibition only in the absence of KRASG12 mutations. Overall, we demonstrate the potential of using ex vivo platforms to identify drug combinations and discover MEK and Src dual inhibition as an effective drug combination in a predefined subset of individuals with CRC.

Durvalumab after concurrent chemotherapy and high-dose radiotherapy for locally advanced non-small cell lung cancer.

The standard of care for stage III non-small cell lung cancer (NSCLC) is chemoradiotherapy (CRT) followed by durvalumab. Although doses higher than 66 Gy are standard in our center, they were used in only 6.9% of patients in the PACIFIC trial. We report our experience with durvalumab after high-dose radiotherapy. The database of a tertiary hospital for patients with stage III NSCLC who were treated with CRT and adjuvant durvalumab was evaluated. Progression-free survival (PFS), overall survival (OS), and local-regional failure (LRF) were measured from the administration of durvalumab. Thirty-nine patients were included. All were treated with intensity-modulated radiation (mean dose 69.9 Gy); Median follow-up time was 20.4 months (range 1-35.4). At 12 months, PFS was 49%, OS 79%, and LRF 14%. Intrathoracic failure at first progression was demonstrated in 8 (21%) patients. Adverse events requiring corticosteroids occurred in 10(25.6%) patients: pneumonitis - 6 (15.4%), hepatitis - 2 (5.1%), and arthralgia and pericarditis - 1 (2.6%). One patient (2.6%) died of pneumonitis. The occurrence of pneumonitis was significantly associated with lung V5 (55% vs. 42%, p = .04) and V20 (28% vs. 19%, p = .01) and mean lung dose (14.8 Gy vs.11.6 Gy, p = .05). The similar 12-month PFS and OS rates of our cohort and the PACIFIC trial support the use of high-dose radiotherapy in patients with stage III NSCLC. Treatment-related mortality was similar to the PACIFIC results. The intrathoracic failure rate in our cohort was lower than that reported from the PACIFIC trial, suggesting that radiation dose escalation may improve local control.

The Relationship of Diabetes Mellitus to Efficacy of Immune Checkpoint Inhibitors in Patients with Advanced Non-Small Cell Lung Cancer.

INTRODUCTION: Immune checkpoint inhibitors (ICI) are the new standard therapy in patients with metastatic NSCLC (mNSCLC). Metformin, previously associated with improved chemotherapy efficacy in diabetic and nondiabetic cancer patients, was recently associated with increased ICI efficacy. In this study, we aimed to explore the correlations between diabetes mellitus (DM), metformin use, and benefit from ICI in mNSCLC patients. METHODS: All mNSCLC patients treated with ICI in our center between February 2015 and April 2018 were identified. Demographic and clinical data were extracted retrospectively. Cox proportional hazards regression, t tests, and χ2 tests were employed to evaluate associations of progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and disease control rate (DCR), with DM status, metformin use, and HbA1c levels, as appropriate. RESULTS: Of 249 mNSCLC patients treated with ICI, 57 (22.8%) had DM. Thirty-seven (64.9% of all diabetic patients) patients were treated with metformin. A significant negative correlation of DM with PFS and OS was demonstrated (HR 1.5 [1.01-2.06], p = 0.011, and HR 1.5 [1.08-2.08], p = 0.017, respectively). Metformin exposure had no significant correlation with PFS or OS in diabetic mNSCLC patients (HR 1.08 [0.61-1.93], p = 0.79, and HR 1.29 [0.69-2.39], p = 0.42, respectively). There were no differences between groups with respect to ORR and DCR. CONCLUSION: Our data show a potential negative relationship between DM and ICI efficacy in mNSCLC patients. In contrast to reports with chemotherapy, we found no positive relationship between metformin use and ICI therapy in diabetic patients with mNSCLC. Further studies are needed to evaluate the effect of metformin in nondiabetic mNSCLC patients.

Venous thromboembolism incidence and risk assessment in lung cancer patients treated with immune checkpoint inhibitors.

BACKGROUND: There are scarce data on venous thromboembolism (VTE) rates among non-small cell lung cancer (NSCLC) patients treated with immune-checkpoint inhibitors (ICI). The Khorana Score (KS), used to guide thromboprophylaxis in cancer patients, was validated in patients receiving chemotherapy. OBJECTIVE: To assess VTE rates and KS performance among NSCLC patients treated with ICI or chemotherapy. METHODS: We performed a retrospective cohort study of NSCLC patients starting either ICI or platinum-based chemotherapy. The 6-month cumulative incidence of VTE in the ICI and chemotherapy cohorts and hazard ratios (HR) with 95% confidence intervals (CI) were calculated, using death as a competing risk. Subgroup analysis of low (0-1) and high (≥2) KS risk groups was performed. RESULTS: The study included 345 NSCLC patients receiving single agent ICI (n = 176) or chemotherapy (n = 169). The 6-month cumulative incidence of VTE was 7.1% in the chemotherapy cohort and 4.5% in the ICI cohort (HR for chemotherapy = 1.6, 95% CI 0.66-3.9). Among chemotherapy treated patients, the high-risk KS group had a trend toward a higher VTE incidence, compared with patients with a low-risk KS (HR 3.04, 95% CI 0.82-11.22). Among ICI-treated patients, the high-risk KS group had a trend toward a lower VTE incidence compared with the low-risk group (HR 0.17, 95% CI 0.02-1.36). CONCLUSIONS: VTE rates were higher among NSCLC patients treated with platinum-based chemotherapy than those treated with ICI alone, though the precision of the relative estimate is low. The KS did not identify high-risk ICI-treated patients, suggesting that an ICI-specific risk model is warranted.

ERBB2 Pathway in Biliary Tract Carcinoma: Clinical Implications of a Targetable Pathway.

BACKGROUND/AIMS: Current chemotherapy regimens for cholangiocarcinoma (CCA) yield poor outcomes, with a median overall survival of <12 months. Recent data on the genomic landscape of CCAs have created opportunities for targeted therapy. Yet, data regarding its efficacy are scarce. We aimed to describe the genomic landscape of a CCA patient cohort using next-generation sequencing (NGS), focusing on the ERBB/EFGR pathway and assessing response to anti-HER2 agents. METHODS: Tissue samples of intrahepatic CCA (IHCC) and extrahepatic CCA (EHCC) underwent NGS for somatic aberrations. The clinical outcomes for patients treated with anti-HER2 agents were evaluated. RESULTS: A total of 1,863 CCA cases (1,615 IHCCs and 248 EHCCs) underwent NGS, and they revealed a high prevalence of ERBB alterations (IHCC, 4.2%; EHCC, 9.7%). Among these, 23.8% of the IHCCs and 53.6% of the EHCCs had a point mutation in ERBB2, and 66.6% of the IHCCs and 41.2% of the EHCCs had ERBB copy number amplification. Three EHCC patients were diagnosed at our institute with ERBB/EGFR aberrations; 2 patients were treated with neratinib and 1 patient with a chemotherapy-trastuzumab combination. All 3 achieved disease stabilization and a clinical benefit. One patient underwent a liquid biopsy before and after 3 months of treatment, demonstrating disappearance of the ERBB2 clone and emergence of a Myc-mutated clone after treatment. CONCLUSIONS: The genomic landscape of CCAs may harbor targetable alterations, especially in the ERBB/EGFR pathway. These alterations may have clinical significance in everyday practice.

Lower tumor volume is associated with increased benefit from immune checkpoint inhibitors in patients with advanced non-small-cell lung cancer.

AIM: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment for advanced non-small-cell lung cancer (NSCLC), yet many patients do not benefit from Programmed cell death protein 1 (PD-1) axis inhibitors, emphasizing the need for additional markers for better patient selection. Our aim was to evaluate the association between tumor volume and response to ICI. METHODS: This retrospective ethically-approved study included all consecutive patients with advanced NSCLC who were evaluated with a fluorodeoxyglucose-positron emission tomography scan, prior to the first administration of a single-agent ICI between 1/2016 and 6/2017. Tumor burden was calculated based on total body metabolic tumor volume and sum of all measurable lesions (SOML). RESULTS: Median SOML was 88 mm, and was inversely and significantly associated with progression-free survival (PFS) (hazard ratio [HR] 2, CI 1.28-3.37, P = .003) and overall survival (OS) (HR 2.36, CI 1.13-4.94, P = .02). SOML≤80 mm had a significantly longer PFS compared to patients with a SOML≥80 mm (median PFS 9.7 vs 3.7 months, respectively, HR for progression 2.26, CI 1.1-4.5, P = .02). Patients with a SOML≤80 also had longer median OS compared to patients with SOML≥80 (median OS 12 vs 9.8 months, respectively, HR for death 3.1, CI 1.2-8, P = .018). CONCLUSIONS: Low tumor burden was associated with higher response rates (RR), and better PFS and OS in advanced NSCLC patients treated with ICI. These results may improve the selection of patients for treatment with single-agent ICI, as opposed to the combination with chemotherapy, which might be more appropriate for patients with high tumor burden. Prospective analysis is warranted.

Treatment beyond progression with immune checkpoint inhibitors in non-small-cell lung cancer.

Aim: The treatment paradigm of advanced non-small-cell lung cancer has recently changed with the introduction of immune checkpoint inhibitors (ICIs). It is common practice to continue treatment beyond progression (TBP) in selected cases. The aim of this study was to evaluate real life practice and outcomes related to TBP. Materials & methods: We retrospectively evaluated advanced non-small-cell lung cancer patients treated with ICI therapy and identified patients who were treated beyond progression. Results: Of 207 patients included in this analysis, 22% patients received TBP. A total of 36% achieved a clinical benefit. A total of 27% patients had a progression-free interval over 6 months after receiving TBP. Conclusion: A subset of patients who were treated beyond progression with ICI achieved a clinically meaningful response with durable disease control.

MUC1-ARF-A Novel MUC1 Protein That Resides in the Nucleus and Is Expressed by Alternate Reading Frame Translation of MUC1 mRNA.

Translation of mRNA in alternate reading frames (ARF) is a naturally occurring process heretofore underappreciated as a generator of protein diversity. The MUC1 gene encodes MUC1-TM, a signal-transducing trans-membrane protein highly expressed in human malignancies. Here we show that an AUG codon downstream to the MUC1-TM initiation codon initiates an alternate reading frame thereby generating a novel protein, MUC1-ARF. MUC1-ARF, like its MUC1-TM 'parent' protein, contains a tandem repeat (VNTR) domain. However, the amino acid sequence of the MUC1-ARF tandem repeat as well as N- and C- sequences flanking it differ entirely from those of MUC1-TM. In vitro protein synthesis assays and extensive immunohistochemical as well as western blot analyses with MUC1-ARF specific monoclonal antibodies confirmed MUC1-ARF expression. Rather than being expressed at the cell membrane like MUC1-TM, immunostaining showed that MUC1-ARF protein localizes mainly in the nucleus: Immunohistochemical analyses of MUC1-expressing tissues demonstrated MUC1-ARF expression in the nuclei of secretory luminal epithelial cells. MUC1-ARF expression varies in different malignancies. While the malignant epithelial cells of pancreatic cancer show limited expression, in breast cancer tissue MUC1-ARF demonstrates strong nuclear expression. Proinflammatory cytokines upregulate expression of MUC1-ARF protein and co-immunoprecipitation analyses demonstrate association of MUC1-ARF with SH3 domain-containing proteins. Mass spectrometry performed on proteins coprecipitating with MUC1-ARF demonstrated Glucose-6-phosphate 1-dehydrogenase (G6PD) and Dynamin 2 (DNM2). These studies not only reveal that the MUC1 gene generates a previously unidentified MUC1-ARF protein, they also show that just like its 'parent' MUC1-TM protein, MUC1-ARF is apparently linked to signaling and malignancy, yet a definitive link to these processes and the roles it plays awaits a precise identification of its molecular functions. Comprising at least 524 amino acids, MUC1-ARF is, furthermore, the longest ARF protein heretofore described.

Antibody targeting of cell-bound MUC1 SEA domain kills tumor cells.

The cell-surface glycoprotein MUC1 is a particularly appealing target for antibody targeting, being selectively overexpressed in many types of cancers and a high proportion of cancer stem-like cells. However the occurrence of MUC1 cleavage, which leads to the release of the extracellular α subunit into the circulation where it can sequester many anti-MUC1 antibodies, renders the target problematic to some degree. To address this issue, we generated a set of unique MUC1 monoclonal antibodies that target a region termed the SEA domain that remains tethered to the cell surface after MUC1 cleavage. In breast cancer cell populations, these antibodies bound the cancer cells with high picomolar affinity. Starting with a partially humanized antibody, DMB5F3, we created a recombinant chimeric antibody that bound a panel of MUC1+ cancer cells with higher affinities relative to cetuximab (anti-EGFR1) or tratuzumab (anti-erbB2) control antibodies. DMB5F3 internalization from the cell surface occurred in an efficient temperature-dependent manner. Linkage to toxin rendered these DMB5F3 antibodies to be cytotoxic against MUC1+ cancer cells at low picomolar concentrations. Our findings show that high-affinity antibodies to cell-bound MUC1 SEA domain exert specific cytotoxicity against cancer cells, and they point to the SEA domain as a potential immunogen to generate MUC1 vaccines.