p65BTK is a novel potential actionable target in KRAS-mutated/EGFR-wild type lung adenocarcinoma

Background: Lung cancer is still the main cause of cancer death worldwide despite the availability of targeted therapies and immune-checkpoint inhibitors combined with chemotherapy. Cancer cell heterogeneity and primary or acquired resistance mechanisms cause the elusive behaviour of this cancer and new biomarkers and active drugs are urgently needed to overcome these limitations. p65BTK, a novel isoform of the Bruton Tyrosine Kinase may represent a new actionable target in non-small cell lung cancer (NSCLC). Methods: p65BTK expression was evaluated by immunohistochemistry in 382 NSCLC patients with complete clinico-pathological records including smoking habit, ALK and EGFR status, and in metastatic lymph nodes of 30 NSCLC patients. NSCLC cell lines mutated for p53 and/or a component of the RAS/MAPK pathway and primary lung cancer-derived cells from Kras/Trp53 null mice were used as a preclinical model. The effects of p65BTK inhibition by BTK Tyrosine Kinase Inhibitors (TKIs) (Ibrutinib, AVL-292, RN486) and first-generation EGFR-TKIs (Gefitinib, Erlotinib) on cell viability were evaluated by MTT. The effects of BTK-TKIs on cell growth and clonogenicity were assessed by crystal violet and colony assays, respectively. Cell toxicity assays were performed to study the effect of the combination of non-toxic concentrations of BTK-TKIs with EGFR-TKIs and standard-of-care (SOC) chemotherapy (Cisplatin, Gemcitabine, Pemetrexed). Results: p65BTK was significantly over-expressed in EGFR-wild type (wt) adenocarcinomas (AdC) from non-smoker patients and its expression was also preserved at the metastatic site. p65BTK was also over-expressed in cell lines mutated for KRAS or for a component of the RAS/MAPK pathway and in tumors from Kras/Trp53 null mice. BTK-TKIs were more effective than EGFR-TKIs in decreasing cancer cell viability and significantly impaired cell proliferation and clonogenicity. Moreover, non-toxic doses of BTK-TKIs re-sensitized drug-resistant NSCLC cell lines to both target- and SOC therapy, independently from EGFR/KRAS status. Conclusions: p65BTK results as an emerging actionable target in non-smoking EGFR-wt AdC, also at advanced stages of disease. Notably, these patients are not eligible for EGFR-TKIs-based therapy due to a lack of EGFR mutation. The combination of BTK-TKIs with EGFR-TKIs is cytotoxic for EGFR-wt/KRAS-mutant/p53-null tumors and BTK-TKIs re-sensitizes drug-resistant NSCLC to SOC chemotherapy. Therefore, our data suggest that adding BTK-TKIs to SOC chemotherapy and EGFR-targeted therapy may open new avenues for clinical trials in currently untreatable NSCLC

Clinical and hematologic parameters address the outcomes of non-small-cell lung cancer patients treated with nivolumab

Aim: This prospective study aimed to envisage the putative prognostic significance of clinical and hematologic parameters in advanced non-small-cell lung cancer patients treated with nivolumab. Materials & methods: Correlations of several parameters with disease control and survival outcomes were provided. Results: A total of 54 patients were included. An ECOG performance status 0-1, the lack of liver and bone metastases and a timeframe from the last systemic treatment ≥4 months correlated with better disease control. The same was observed for baseline low levels of white blood cells and neutrophils, for high levels of NK cells and a neutrophil/lymphocyte ratio <4. The mentioned parameters were also associated with longer overall survival. Conclusion: Nivolumab efficacy in non-small-cell lung cancer patients is influenced by clinicopathological parameters and specific leucocyte subsets

Monitoring cfDNA in Plasma and in Other Liquid Biopsies of Advanced EGFR Mutated NSCLC Patients: A Pilot Study and a Review of the Literature

In order to study alternatives at the tissue biopsy to study EGFR status in NSCLC patients, we evaluated three different liquid biopsy platforms (plasma, urine and exhaled breath condensate, EBC). We also reviewed the literature of the cfDNA biological sources other than plasma and compared our results with it about the sensitivity to EGFR mutation determination. Twenty-two EGFR T790M-mutated NSCLC patients in progression to first-line treatment were enrolled and candidate to osimertinib. Plasma, urine and EBC samples were collected at baseline and every two months until progression. Molecular analysis of cfDNA was performed by ddPCR and compared to tissue results. At progression NGS analysis was performed. The EGFR activating mutation detection reached a sensitivity of 58 and 11% and for the T790M mutation of 45 and 10%, in plasma and urine samples, respectively. Any DNA content was recovered from EBC samples. Considering the plasma monitoring study, the worst survival was associated with positive shedding status; both plasma and urine molecular progression anticipated the radiological worsening. Our results confirmed the role of plasma liquid biopsy in testing EGFR mutational status, but unfortunately, did not evidence any improvement from the combination with alternative sources, as urine and EBC

From the beginning to resistance: study of plasma monitoring and resistance mechanisms in a cohort of patients treated with osimertinib for advanced T790M-positive NSCLC

INTRODUCTION: Analysis of circulating tumor DNA (ctDNA) for the identification of T790M mutation in advanced EGFR-mutated NSCLC patients can replace tissue re-biopsy for resistance characterization and, being non-invasive, may be applied for disease monitoring. We analysed ctDNA during osimertinib treatment to correlate mutational levels with clinical outcome and to predict pattern of resistance. MATERIALS AND METHODS: Forty patients with advanced NSCLC receiving osimertinib for T790M + disease after previous EGFR-TKI were enrolled in a pilot study to collect plasma at baseline and every 12 weeks until progression. Molecular analysis of ctDNA was performed by ddPCR and Therascreen®. When feasible at progression, tissue re-biopsy and NGS analysis were performed. RESULTS: Thirty-eight patients had baseline plasma samples suitable for molecular analysis. Patients with low levels of the EGFR activating mutation in ctDNA [&lt; 2200 copies/mL or allele frequency (AF) &lt; 6.1%] showed better progression-free survival (17.8 or 17.8 months vs. 4.3 or 2.7, p = 0.022 or p = 0.018, respectively) and overall survival (23.6 or 23.6 vs. 7.7 or 7.3, p = 0.016 or p = 0.013, respectively) than patients with high levels (≥ 2200 copies/mL or AF ≥ 6.1%). Patients with detectable EGFR mutations in plasma (shedders) presented worse outcome than negative subjects (non-shedders). Low levels of T790M, higher T790M/activating mutation ratio and complete clearance after 2 months were associated with a trend towards better outcome. Tissue re-biopsy at resistance showed 3 patients with EGFR C797S, 1 with MET amplification, 1 with MYC amplification, 1 with PTEN loss, 3 with SCLC transformation. CONCLUSIONS: The mutational analysis performed on plasma plays a significant role in prognostic stratification, especially for the EGFR activating mutation, since patients with absence or low levels of mutations presented a better outcome to osimertinib. At progression, tissue re-biopsy remains a crucial issue for the identification of resistance mechanisms

p65BTK is a novel potential actionable target in KRAS-mutated/EGFR-wild type lung adenocarcinoma

BACKGROUND: Lung cancer is still the main cause of cancer death worldwide despite the availability of targeted therapies and immune-checkpoint inhibitors combined with chemotherapy. Cancer cell heterogeneity and primary or acquired resistance mechanisms cause the elusive behaviour of this cancer and new biomarkers and active drugs are urgently needed to overcome these limitations. p65BTK, a novel isoform of the Bruton Tyrosine Kinase may represent a new actionable target in non-small cell lung cancer (NSCLC). METHODS: p65BTK expression was evaluated by immunohistochemistry in 382 NSCLC patients with complete clinico-pathological records including smoking habit, ALK and EGFR status, and in metastatic lymph nodes of 30 NSCLC patients. NSCLC cell lines mutated for p53 and/or a component of the RAS/MAPK pathway and primary lung cancer-derived cells from Kras/Trp53 null mice were used as a preclinical model. The effects of p65BTK inhibition by BTK Tyrosine Kinase Inhibitors (TKIs) (Ibrutinib, AVL-292, RN486) and first-generation EGFR-TKIs (Gefitinib, Erlotinib) on cell viability were evaluated by MTT. The effects of BTK-TKIs on cell growth and clonogenicity were assessed by crystal violet and colony assays, respectively. Cell toxicity assays were performed to study the effect of the combination of non-toxic concentrations of BTK-TKIs with EGFR-TKIs and standard-of-care (SOC) chemotherapy (Cisplatin, Gemcitabine, Pemetrexed). RESULTS: p65BTK was significantly over-expressed in EGFR-wild type (wt) adenocarcinomas (AdC) from non-smoker patients and its expression was also preserved at the metastatic site. p65BTK was also over-expressed in cell lines mutated for KRAS or for a component of the RAS/MAPK pathway and in tumors from Kras/Trp53 null mice. BTK-TKIs were more effective than EGFR-TKIs in decreasing cancer cell viability and significantly impaired cell proliferation and clonogenicity. Moreover, non-toxic doses of BTK-TKIs re-sensitized drug-resistant NSCLC cell lines to both target- and SOC therapy, independently from EGFR/KRAS status. CONCLUSIONS: p65BTK results as an emerging actionable target in non-smoking EGFR-wt AdC, also at advanced stages of disease. Notably, these patients are not eligible for EGFR-TKIs-based therapy due to a lack of EGFR mutation. The combination of BTK-TKIs with EGFR-TKIs is cytotoxic for EGFR-wt/KRAS-mutant/p53-null tumors and BTK-TKIs re-sensitizes drug-resistant NSCLC to SOC chemotherapy. Therefore, our data suggest that adding BTK-TKIs to SOC chemotherapy and EGFR-targeted therapy may open new avenues for clinical trials in currently untreatable NSCLC

BTK inhibitors synergise with 5-FU to treat drug-resistant TP53-null colon cancers

Colorectal cancer (CRC) is the fourth cause of death from cancer worldwide mainly due to the high incidence of drug-resistance. During a screen for new actionable targets in drug-resistant tumours we recently identified p65BTK - a novel oncogenic isoform of Bruton's tyrosine kinase. Studying three different cohorts of patients here we show that p65BTK expression correlates with histotype and cancer progression. Using drug-resistant TP53-null colon cancer cells as a model we demonstrated that p65BTK silencing or chemical inhibition overcame the 5-fluorouracil resistance of CRC cell lines and patient-derived organoids and significantly reduced the growth of xenografted tumours. Mechanistically, we show that blocking p65BTK in drug-resistant cells abolished a 5-FU-elicited TGFB1 protective response and triggered E2F-dependent apoptosis. Taken together, our data demonstrated that targeting p65BTK restores the apoptotic response to chemotherapy of drug-resistant CRCs and gives a proof-of-concept for suggesting the use of BTK inhibitors in combination with 5-FU as a novel therapeutic approach in CRC patients. (c) 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd

Systematic vitamin D supplementation is associated with improved outcomes and reduced thyroid adverse events in patients with cancer treated with immune checkpoint inhibitors: results from the prospective PROVIDENCE study

Background: Hypovitaminosis D can have a negative prognostic impact in patients with cancer. Vitamin D has a demonstrated role in T-cell-mediated immune activation. We hypothesized that systematic vitamin D repletion could impact clinical outcomes in patients with cancer receiving immune-checkpoint inhibitors (ICIs). Methods: We planned a prospective observational study (PROVIDENCE) to assess serum vitamin D levels in patients with advanced cancer receiving ICIs (cohort 1 at treatment initiation, cohort 2 during treatment) and the impact of systematic repletion on survival and toxicity outcomes. In an exploratory analysis, we compared the clinical outcomes of cohort 1 with a control cohort of patients followed at the participating centers who did not receive systematic vitamin D repletion. Results: Overall, 164 patients were prospectively recruited in the PROVIDENCE study. In cohort 1, consisting of 101 patients with 94.1% hypovitaminosis (≤ 30&nbsp;ng/ml) at baseline, adequate repletion with cholecalciferol was obtained in 70.1% at the three months re-assessment. Cohort 2 consisted of 63 patients assessed for vitamin D at a median time of 3.7&nbsp;months since immunotherapy initiation, with no patients having adequate levels (&gt; 30&nbsp;ng/ml). Even in cohort 2, systematic supplementation led to adequate levels in 77.8% of patients at the three months re-assessment. Compared to a retrospective control group of 238 patients without systematic vitamin D repletion, PROVIDENCE cohort 1 showed longer overall survival (OS, p = 0.013), time to treatment failure (TTF, p = 0.017), and higher disease control rate (DCR, p = 0.016). The Inverse Probability of Treatment Weighing (IPTW) fitted multivariable Cox regression confirmed the significantly decreased risk of death (HR 0.55, 95%CI: 0.34-0.90) and treatment discontinuation (HR 0.61, 95%CI: 0.40-0.91) for patients from PROVIDENCE cohort 1 in comparison to the control cohort. In the context of longer treatment exposure, the cumulative incidence of any grade immune-related adverse events (irAEs) was higher in the PROVIDENCE cohort 1 compared to the control cohort. Nevertheless, patients from cohort 1 experienced a significantly decreased risk of all grade thyroid irAEs than the control cohort (OR 0.16, 95%CI: 0.03-0.85). Conclusion: The PROVIDENCE study suggests the potential positive impact of early systematic vitamin D supplementation on outcomes of patients with advanced cancer receiving ICIs and support adequate repletion as a possible prophylaxis for thyroid irAEs