Combination of immunotherapy, radiotherapy and denosumab as the best approach even for NSCLC poor prognosis patients: a case report with strong response, prolonged survival and a review of literature

Non-Small Cell Lung Cancer (NSCLC) with bone metastasis and poor performance status has the worst prognosis even in strong PD-L1 expression patients. Treatment approach includes immuno- or chemo-immunotherapy, Radiotherapy (RT) and Bone-Targeted Therapy (BTT) but there is insufficient data to suggest the best time to use each of them, alone or in combination. Using an integrated and synergistic treatment strategy with immunotherapy, radiotherapy, and Denosumab as BTT is probably the best treatment planning for metastatic NSCLC for both good and poor performance status patients, although more data are needed to confirm this approach. Here we describe an interesting case report on patient with extensive bone involvement from NSCLC and PS >2 treated simultaneously with radiotherapy, immunotherapy and BTT, achieving an excellent clinical benefit, radiological and metabolic complete response, as a sort of Lazarus effect. We analyzed our result comparing with currently published data about radio-immunotherapy or immunotherapy and BTT combination even though there is no published experience about integration of all 3 treatments. Approval studies often do not represent real-world experience (RWE), so we analyzed data from both RWE and clinical trials.

Development of Population-Based Pediatric Computational Phantoms for Radiotherapy Applications

PURPOSE/OBJECTIVE(S)

Age-specific pediatric computational phantoms are used in radiotherapy (RT) for quality assurance and for reconstruction of historical RT doses (within others). Phantoms are typically developed from healthy patients and may not effectively represent those with cancer due to pathology and/or treatment effects. This study evaluated a set of population-based pediatric computational phantoms developed in-house in terms of anatomical plausibility.

MATERIALS/METHODS

Planning CTs and contours from historical craniospinal irradiation (CSI) patients (n = 74, median age 7y, range: 1-17y) were used to generate and evaluate a set of in-house age-specific population-based RT phantoms (RT-P). The RT-P were generated by combining a sub-set of clinical CTs and contours through groupwise deformable image registration, generating average models of CSI sub-populations (n = 74, median age 7y, range: 3-14y). Models were then compared against clinical data and two libraries of phantoms representing healthy populations: the International Commission on Radiological Protection (ICRP) pediatric reference computational phantoms (n = 8, median age 8y, range: 1-15y) and a variety of default 4D extended cardiac torso (XCAT) phantoms (n = 75, median age 9y, range: 1-18y). Variation between organ volumes for the different datasets was assessed through a linear fit of organ volume with age, reporting the slope (∑) of each fit [y-1]. Average difference between the volume datapoints and the linear fit for clinical data (Δ) [%] were also reported. This allowed for comparisons of the RT-P to clinical and reference data in terms of organ volumes across developmental stages.

RESULTS

The table shows 9 of the 19 investigated organs. The ∑ reported for RT-P models were of similar magnitude as the clinical data and other phantoms, effectively modelling changes with age. The greatest and least ∑ were reported from lungs and thyroid respectively, in agreement with expected relative sizes between organs. Larger values for Δ were likely due to differences in organ filling and segmentation strategy between datasets, limitations of RT-P methodology, and/or anatomical differences between healthy and cancer populations.

CONCLUSION

The RT-P models show promise in representing the RT cohort that may benefit from specialized anatomical phantoms. Further work is needed to address the limitations of the current methodology and its applicability to other RT cohorts.

Cardiac involvement in creatine deficiency syndrome

Background

Previous reports have demonstrated electrocardiographic and echocardiographic abnormalities consistent with early-stage cardiomyopathy in patients with creatine transporter (CrT) deficiency, but cardiac involvement has never been accurately characterized.

Purpose

To investigate the cardiac phenotype associated with creatine deficiency in a murine transgenic model and in patients with creatine deficiency syndrome (CDS).

Methods

Wild type and transgenic CrT−/y mice (n=20) were serially evaluated in vivo by electrocardiogram (EKG) and echocardiography for six months, and ex vivo by histological and biochemical analyses. Nine patients with CDS (n=4 with L-arginine:glycine amidinotransferase - AGAT- deficiency, n=5 with CrT deficiency) underwent blood samples, including cardiac biomarkers, EKG, Holter monitoring, echocardiography and cardiac magnetic resonance (CMR).

Results

Compared to wild type, CRT−/y mice showed a prolongation of QT interval (p=0.008) (Fig. 1), as well as significant reduction in cardiac ATP production from mitochondria (p<0.001) (Fig. 2). No differences were detected in the left ventricular systolic function, in terms of ejection fraction and global longitudinal strain, along the whole follow-up. Similarly, 3 patients with CrT deficiency also showed a prolonged QTc interval (median QTc 515 ms), while other 2 had a borderline QTc at Holter monitoring, while no tachyarrhythmias could be observed. No subject had abnormal systolic and diastolic function. At CMR, an increase of native T1 value was reported in the 4 subjects (median 1076 ms) with AGAT deficiency, 1 with an increase of extracellular volume matching with the detection of late gadolinium enhancement. Finally, subjects with AGAT deficiency showed an increase level of plasma norepinephrine. Familiar carriers (3 for AGAT and 1 for CrT) showed no notable cardiac functional alterations, except for QTc prolongation in 2 subjects.

Conclusion

Prolonged QT interval is observed in the murine model and in subjects with CrT deficiency. Biohumoral signs of neurohormonal activation and an initial replacement fibrosis – the latter suggested by the increase of native T1 – are identified in subjects with AGAT deficiency, but their clinical significance remains to be determined.

Funding Acknowledgement

Type of funding sources: None.

Cetuximab Rechallenge Plus Avelumab in Pretreated Patients With RAS Wild-type Metastatic Colorectal Cancer: The Phase 2 Single-Arm Clinical CAVE Trial

Importance

Rechallenge therapy with anti-epidermal growth factor receptor (EGFR) drugs has been suggested in patients with chemo-refractory RAS wild-type (WT) metastatic colorectal cancer (mCRC) after initial response to anti-EGFR-based first-line treatment. The association of treatment with cetuximab plus avelumab with overall survival (OS) may be worthy of investigation in this setting.

Objective

To assess the efficacy and safety of cetuximab rechallenge therapy plus avelumab.

Design, Setting, and Participants

This single-arm, multicenter phase 2 trial enrolled patients from August 2018 to February 2020. Eligible patients with RAS WT mCRC had a complete or partial response to first-line chemotherapy plus anti-EGFR drugs, developed acquired resistance, and failed second-line therapy. Baseline circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF, and EGFR-S492R mutation analysis was done.

Interventions

Patients received avelumab (10 mg/kg every 2 weeks) and cetuximab (400 mg/m2 and, subsequently, 250 mg/m2 weekly) until disease progression or unacceptable toxic effects.

Main Outcomes and Measures

The primary end point was OS. Secondary end points were progression-free survival (PFS), overall response rate (ORR), and safety.

Results

Seventy-seven patients were enrolled (42 men, 35 women; median age, 63 years); 71 had microsatellite stable tumors (MSS), 3 microsatellite instability-high tumors (MSI-H), 3 unknown. The study met the primary end point, with median OS (mOS) of 11.6 months (95% CI, 8.4-14.8 months). Median PFS (mPFS) was 3.6 months (95% CI, 3.2-4.1 months). Common grade-3 adverse events were cutaneous eruption, 11 (14%), and diarrhea, 3 (4%). For 67 of 77 (87%) patients, baseline analysis of plasma circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF, and EGFR-S492R variations was feasible. Forty-eight patients had WT disease, whereas 19 had mutations. Patients with RAS/BRAF WT ctDNA had mOS of 17.3 months (95% CI, 12.5-22.0 months) compared with 10.4 months (95% CI, 7.2-13.6 months) in patients with mutated ctDNA (hazard ratio [HR], 0.49; 95% CI, 0.27-0.90; P = .02). The mPFS was 4.1 months (95% CI, 2.9-5.2 months) in RAS/BRAF WT patients compared with 3.0 months (95% CI, 2.6-3.5 months) in patients with mutated ctDNA (HR, 0.42; 95% CI, 0.23-0.75; P = .004).

Conclusions and Relevance

The findings of this single-arm phase 2 trial suggest that cetuximab plus avelumab is an active, well tolerated rechallenge therapy in RAS WT mCRC. Plasma ctDNA analysis before treatment may allow selection of patients who could benefit.

Trial Registration

ClinicalTrials.gov Identifier: NCT04561336.

Immunotherapy in colorectal cancer: is the long-awaited revolution finally happening?

Immunotherapy has recently become a major treatment modality for several types of solid tumours, achieving remarkable and long-lasting remissions. In metastatic colorectal cancer patients (mCRC), immune checkpoint inhibitors (ICIs) were found to be effective as treatment for deficient mismatch repair (dMMR)/ microsatellite instability high (MSI-H) tumours and received regulatory approval for this indication. However, mCRC is a complex disease and dMMR/MSI-H tumours represent a minority of the cases; therefore, new strategies are needed to extend the benefits of immunotherapy to a larger population of patients. This review explores the immunological differences between dMMR/MSI-H and proficient mismatch repair (pMMR)/ microsatellite instability low (MSI-L) tumours, focuses on new proposed biomarkers to predict response to immunotherapy and illustrates results reported from the main clinical trials with immunotherapeutic agents in CRC, addressing the most promising approaches being currently developed.

How I treat anal squamous cell carcinoma

Squamous cell carcinoma of the anus (SCCA) is a rising health issue, strongly related to other relevant medical conditions such as (HIV) and human papillomavirus (HPV) infection. Correct assessment of patients with SCCA requires a multidisciplinary evaluation and adequate follow-up. Accurate local and systemic staging, as well as risk evaluation, are essential to optimal treatment planning. Early stage tumours can be definitively treated with a combination of chemotherapy and radiotherapy, while salvage surgery is usually reserved for patients who develop local recurrence. Distant recurrence and de novo metastatic disease are associated with poorer prognosis and require palliative systemic chemotherapy, with different single agent and combination options available. Finally, recent discoveries on the carcinogenesis of SCCA have allowed the development of innovative treatment options, the most promising being immune checkpoint inhibitors. The limited systemic treatments for SCCA and low incidence of the disease, together with insufficient data from clinical research could explain the poor outcomes of these patients, which should therefore be managed in high volume centres and enrolled in clinical trials whenever possible. This article summarises the main strategies for treating patients with SCCA.

Final results from the CAVE (cetuximab rechallenge plus avelumab) mCRC phase II trial: Skin toxicity as a predictor of clinical activity

3578

Background: Promising antitumor activity of so called rechallenge treatment with anti-epidermal growth factor receptor (EGFR) drugs in patients with RAS wild type (RAS WT) metastatic colorectal cancer (mCRC) has been recently reported. Beside the absence of resistance mutations at plasma circulating tumor DNA (ctDNA) analysis, no biomarkers of response to anti-EGFR rechallenge strategy have been identified. Methods: We conducted the single arm phase II CAVE mCRC trial to evaluate the combination of cetuximab as rechallenge plus avelumab treatment in 77 RAS WT mCRC patients, with complete (CR) or partial response (PR) to first line chemotherapy plus anti-EGFR drugs, who developed acquired resistance and received a subsequent line of therapy. A post-hoc baseline analysis of circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF and EGFR-S492R mutations was performed for 67/77 (87%) patients. The correlation of skin toxicity (ST) and other clinical variables with OS, PFS and response rate (RR) was assessed. Results: Cetuximab plus avelumab provided in the intention to treat population (ITT) median overall survival (mOS) of 11.6 months [95% Confidence Interval (CI), 8.4-14.8] and median PFS (mPFS) of 3.6 months (95% CI, 3.2-4.1) with a manageable toxicity profile. Thirty-three (42.9%) patients experienced grade 2-3 ST with mOS of 17.8 months (CI 95% 14.9-20.7), whereas 44 (57.1%) patients with grade 0-1 ST exhibited mOS of 8.2 months (CI 95% 5.6-11), (HR 0.51, CI 95% 0.29-0.89, P = 0.019). mPFS was 4.6 months (CI 95% 3.5-5.8) in patients with grade 2-3 ST, compared to 3.4 months (CI 95% 2.8-4.1) in patients with grade 0-1 ST (HR 0.49, CI 95% 0.3-0.8, P = 0.004). Grade 2-3 ST and baseline RAS/BRAF/EGFR WT ctDNA were the only variables with statistically significant effect on OS both at univariate and multivariate analyses. ST, number of metastatic sites ≤2, surgery of primary tumor and RAS/BRAF/EGFR WT ctDNA were associated with an improvement in PFS only at univariate analysis. In the 33 patients with grade 2-3 ST, 1 (3%) CR, 2 (6.1%) PR and 24 (72.7%) stable disease (SD) were observed, with disease control rate (DCR) of 81.8%. In the 44 patients with grade 0-1 ST 0 CR, 3 (6.8%) PR, 20 (45.5%) SD, with 52.3% DCR were reported. Conclusions: Cetuximab plus avelumab is effective and well tolerated as rechallenge treatment in mCRC. ST is a clinical biomarker for the identification of RAS/BRAF mCRC patients that could benefit from anti-EGFR rechallenge. Clinical trial information: NCT04561336.

Central and obstructive apneas prevalence in heart failure with reduced, mid-range and preserved ejection fraction

Background

Central apneas (CA) and obstructive apneas (OA) are highly prevalent in heart failure (HF) both with reduced and preserved systolic function. However, a comprehensive evaluation of apnea prevalence across HF according to ejection fraction (i.e HF with patients with reduced, mid-range and preserved ejection fraction- HFrEf, HFmrEF and HFpEF, respectively) throughout the 24 hours has never been done before.

Materials and methods

700 HF patients were prospectively enrolled and then divided according to left ventricular EF (408 HFrEF, 117 HFmrEF, 175 HFpEF). All patients underwent a thorough evaluation including: 2D echocardiography; 24-h Holter-ECG monitoring; cardiopulmonary exercise testing; neuro-hormonal assessment and 24-h cardiorespiratory monitoring.

Results

In the whole population, prevalence of normal breathing (NB), CA and OA at daytime was 40%, 51%, and 9%, respectively, while at nighttime 15%, 55%, and 30%, respectively.

When stratified according to left ventricular EF, CA prevalence decreased from HFrEF to HFmrEF and HFpEF: (daytime CA: 57% vs. 43% vs. 42%, respectively, p=0.001; nighttime CA: 66% vs. 48% vs. 34%, respectively, p<0.0001), while OA prevalence increased (daytime OA: 5% vs. 8% vs. 18%, respectively, p<0.0001; nighttime OA: 20 vs. 29 vs. 53%, respectively, p<0.0001).

When assessing moderte-severe apneas, defined with an apnea/hypopnea index >15 events/hour, prevalence of CA was again higher in HFrEF than HFmrEF and HFpEF both at daytime (daytime moderate-severe CA: 28% vs. 19% and 23%, respectively, p<0.05) and at nighttime (nighttime moderate-severe CA: 50% vs. 39% and 28%, respectively, p<0.05). Conversely, moderate-severe OA decreased from HFrEF to HFmrEF to HFpEF both at daytime (daytime moderate-severe OA: 1% vs. 3% and 8%, respectively, p<0.05) and nighttime (noghttime moderate-severe OA: 10% vs. 11% and 30%, respectively, p<0.05).

Conclusions

Daytime and nighttime apneas, both central and obstructive in nature, are highly prevalent in HF regardless of EF. Across the whole spectrum of HF, CA prevalence increases and OA decreases as left ventricular systolic dysfunction progresses, both during daytime and nighttime.

Funding Acknowledgement

Type of funding source: None

Central apneas and Ticagrelor related dyspnea in patients with acute coronary syndrome

Background

Patients treated with ticagrelor often develop dyspnea of unknown origin. We aim to explore the contribution of central apneas to ticagrelor-related dyspnea in patients with acute coronary syndrome (ACS).

Methods

We consecutively enrolled patients with ACS, preserved left ventricular ejection fraction and no history of obstructive sleep apnea, treated either with ticagrelor 90 mg bid (n=30) or prasugrel 10 mg od (n=24). One week after ACS onset, all patients underwent, beyond thorough cardiovascular and respiratory assessment, 24-hour cardiorespiratory monitoring and assessment of chemosensitivity to hypercapnia.

Results

Patients treated with ticagrelor reported more frequently dyspnea than patients treated with prasugrel (43% versus 4%, p=0.001), despite no difference in demographic, clinical, echocardiographic and pulmonary data. Patients with dyspnea induced by ticagrelor showed higher apnea-hypopnea and central apnea index both at daytime and at nighttime compared to patients treated with ticagrelor but without dyspnea and patients treated with prasugrel (daytime AHI: 26 [7–34] vs 6 [4–14] and 6 [0–11] events/hour; nighttime AHI: 65 [17–72] vs 22 [8–37] and vs 11 [4–23] events/hour; daytime CAI: 5 [1–15] vs 1 [0–6] and 0 [0–1) events/hour; nighttime CAI 34 [2–55] vs 3 [0–9] and 0 [0–1], all p<0.05). Likewise, they also presented with higher hypercapnic ventilatory response (2.4 [1.9–2.7] vs 1.3 [1.1–1.9] and 0.9 [0.5–2.1] L/min/mmHg, all p<0.05).

Conclusions

Central apneas should be considered a likely mechanism of dyspnea in ACS patients treated with ticagrelor. A drug-related sensitization of the chemoreflex may be the cause of ventilatory instability in this setting.

Funding Acknowledgement

Type of funding source: None

Sacubitril/valsartan improves ventilation stability in patients with chronic heart failure

Background

Sacubitril/valsartan (SV) ameliorates symptoms and prognosis in patients with heart failure and reduced ejection fraction (HFrEF), but the reasons for such effects are unclear. The impact of SV on ventilation has never been investigated. In HFrEF, apneas are highly prevalent both at daytime and nighttime and are associated with increased mortality.

Purpose

We hypothesize that treatment with SV could favourably stabilize ventilation by reducing the severity of central apneas in patients with HFrEF.

Methods

51 patients with HFrEF (mean age 67±9 years, mean left ventricular ejection fraction, LVEF 27±7%) and apneas defined by an apnea-hypopnea index, AHI≥5 (median 16, interquartile range 8–28) events/hour, eligible to treatment with SV and previously on optimal medical therapy for HFrEF, were enrolled. An extensive evaluation including cardiac ultrasound and a 24-hour cardiorespiratory monitoring was performed.

Results

After six months of treatment with SV, left ventricle systolic and diastolic function, mitral regurgitation (MR), left atrial volume (LAVI) and systolic pulmonary artery pressure (sPAP) were improved. Severity of apneas was reduced by 50%, 65% and 36% throughout the 24-hour, at daytime and nighttime, respectively.

Conclusion

Besides its known efficacy on cardiac remodeling, SV positively decreases the apneic burden in patients with HFrEF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics unrestricted grant

P215 Effects of ARNI therapy on left atrial and ventricular longitudinal deformation and functional capacity in HFrEF patients

Background

valsartan and sacubitril combination (angiotensin receptor-neprilysin inhibitor, ARNI) was superior, in randomized trials, to lone ACE inhibitors in terms of reduction of cardiovascular mortality rate and hospitalization for acute heart (HF) in patients with HF with reduced ejection fraction (HFrEF). Purpose: the main goal of our study was to assess the effects of ARNI on left atrial (LA) and left (LV) and right ventricular (RV) function, evaluated by standard and speckle tracking echocardiography (STE), and on patients’ functional capacity by cardiopulmonary exercise testing (CPET), in patients with HFrEF. Methods: we prospectively enrolled 16 patients with a LV EF ≤35% and >18 years old, in two different centers with high expertise in HF management. Exclusion criteria included: symptomatic hypotension, stage IV renal failure (eGFR < 30 ml/min/1.73 m2), ACE-inhibitor (ACEi) intolerance or previous angioedema, poor acoustic window, refuse to participate to the study. At enrollment (T0), all patients were in therapy with ACEi or sartans (ARBs) and underwent physical examination, ECG, blood test (including NT-proBNP), standard echo, STE and CPET. We shifted therapy from ACEi/ARBs according to HF guidelines and we repeated all tests after 6 months. Results: population had an average age of 63 ± 9 years, 94% was males. Etiology was ischemic in one third of the subjects. At 6 months follow up, NT-proBNP was significantly lower (512.2 ± 518.5 vs 431.2 ± 330.1 ng/l, p 0,001) together with reduced LV filling pressure evaluated by E/A ratio and E/e’ ratio (11.2 ± 8.6 vs 8.8 ± 4.8, p 0.01). LV EF improved from 31.7 ± 3.4% to 36.2 ± 7.2% (p 0.01) and LV dimensions decreased. LV global longitudinal strain (GLS) did not change significantly while free wall RV GLS increased from – 20.4 ± 6.3% to – 24.6 ± 9%, p 0.001, as peak atrial longitudinal strain (PALS) did (16.1 ± 2.6% vs 27.6 ± 4.1%, p 0.001). Between CPET indexes, only VE/VCO2 slope improved but only with borderline statistical significance (32.7 ± 5.3 vs 29.7 ± 6.8, p 0.05, Fig. 1). Conclusions: this preliminary study evaluated for the first time the effects of ARNI on echocardiographic and CPET parameters at the same time. Our results could explain the favorable clinical benefits of ARNI therapy in HFrEF: improved biventricular function, lower LV filling pressure and a more efficient ventilatory response during effort.

Abstract P215 Figure. Fig.1

Clinical Practice Use of Liquid Biopsy to Identify RAS/BRAF Mutations in Patients with Metastatic Colorectal Cancer (mCRC): A Single Institution Experience

Tumor heterogeneity represents a possible cause of error in detecting predictive genetic alterations on tumor tissue and can be overcome by testing alterations in circulating tumor DNA (ctDNA) using liquid biopsy. We assessed 72 consecutive patients with a diagnosis of metastatic colorectal cancer (mCRC) using Idylla™ Biocartis, a fully automated platform that evaluates the most frequent mutations of KRAS, NRAS and BRAF genes. We correlated the results of liquid biopsy and standard tissue-based next generation sequencing (NGS) analyses to patient clinical features. The overall agreement was 81.94%. Concordance was 85.71% and 96.15% in treatment-naïve patients and in the patient subgroup with liver metastases, respectively. In liver metastases positive, treatment-naïve patients, sensitivity, specificity and positive predictive value (PPV) were 92.31%, 100% and 100%, respectively. Circulating mutational fraction (CMF) was significantly higher in patients with liver metastases and high carcinoembryonic antigen (CEA) levels. In a subgroup of patients pre-treated with anti-Epidermal Growth Factor Receptor (EGFR) agents, emerging KRAS mutations were evidenced in 33% of cases. Testing RAS/BRAF mutations on plasma using the Idylla™ Biocartis platform is feasible and reliable in mCRC patients in clinical practice.

P3525Buspirone effect on chemoreflex and central apneas in heart failure

Background

Increased chemosensitivity to carbon dioxide (CO2) is an important trigger of central apneas in heart failure (HF), contributing to HF progression and mortality. We hypothesized that buspirone, a 5HT1A receptor agonist that inhibits serotonergic chemoreceptor neuron firing in animals, can decrease CO2 chemosensitivity, thus preventing CA in patients with HF.

Methods

Sixteen patients with systolic HF (age 71.3±5.8 years, left ventricular ejection fraction 29.8±7.8%) and moderate-severe central apneas (nighttime apnea/hypopnea index AHI≥15 events/hour) underwent a double-blind, placebo-controlled, cross over, randomized study of oral buspirone administration (45 mg/day for 1 week).

Results

Buspirone reduced CO2 chemosensitivity compared to placebo (1.2 IR [1.1–1.5] vs. 2.0 [1.6–2.2] L/min/mmHg, p=0.008). Furthermore, buspirone improved: the AHI at nighttime (16.5 [8.5–24.7] vs. 27.5 [23.0–37.3] events/hour, p=0.002), and daytime (8.0 [2.3–11.5] vs. 11.5 [6.3–18.8] events/hour, p=0.006); the central apnea index at nighttime (4.0 [1.0–19.0] vs. 12.5 [8.3–27.3] events/hour, p=0.01) and daytime (1.0 [0.0–3.0] vs. 4.0 [1.3–6.0] events/hour, p=0.009); and the oxygen desaturation index at nighttime (4.7 [1.0–11.0] vs. 20.0 [8.7–26.5] events/hour, p=0.004) and daytime (0.2 [0.1–0.7] vs. 1.2 [0.3–4.8] events/hour, p=0.005). Buspirone showed a good safety profile and had no effect on neurohormones, arrhythmias, exercise capacity and mood/daytime sleepiness.

Conclusion

Buspirone reduces CO2 chemosensitivity and inhibits central apneas both during the day and the night in patients with systolic HF.

Abstract 2627: Inhibition of TGFβ in colorectal cancer cells is associated with a compensatory activation of AXL and p38 MAPK signaling pathways

According to the consensus molecular subtypes (CMS), almost 23% of human colorectal cancer (CRC) are classified in the CMS4 group, characterized by a mesenchymal signature and the activation of transforming growth factor β (TGF-β) signaling. AXL is a tyrosine kinase receptor involved in epithelial to mesenchymal transition, angiogenesis and immune modulation in CRC. We have previously demonstrated that AXL gene is amplified in approximately 5% of human CRC, and that AXL inhibition causes a significant blockade of CRC cell proliferation and migration. Here we have evaluated the role of TGF-β signaling and the potential interaction between TGF-β and AXL in human CRC cell lines. We assessed the expression and activation of TGF-β and AXL in a panel of six human CRC cell lines by western blot (WB) and real time PCR. We tested the sensitivity of HCT116 and LOVO cells to treatment with galunisertib ( LY21209761), a selective TGF-β R1 inhibitor, by MTT, cell invasion, wound healing and soft-agar colony forming assays. Further, intracellular CRC cell signaling was evaluated following galunisertib treatment by WB. TGF-β receptors 1 and 2 were expressed in all human CRC cell lines (HCT116, SW480, LOVO, LIM 1215, SW48 and CaCo2), whereas AXL expression was restricted to HCT116, SW480, LOVO cells. Treatment with galunisertib had little or no effect on cancer cell growth, whereas it partially reduced TGF-β induced cell migration, invasion and colony formation in HCT116 and LOVO cells (that co-expressed both TGF-β receptors and AXL). Interestingly, TGF-β inhibition resulted in a concomitant significant activation of AXL and p38 MAPK in both cell lines, that could represent a cancer cell adaptive mechanism of resistance to galunisertib treatment. These results suggest a potential functional cross talk between TGF-β, AXL and p38 MAPK signals in human CRC cells. In this respect, further experiments are ongoing to better understand this interaction with the aim of identifying potential novel anti-AXL and anti-TGF-β therapeutic strategies.

Citation Format: Davide Ciardiello, Pietro Paolo Vitiello, Nunzia Matrone, Valentina Belli, Claudia Cardone, Luca Poliero, Carola Borrelli, Gianluca Arrichiello, Giulia Martini, Vincenza Ciaramella, Giusi Barra, Floriana Morgillo, Teresa Troiani, Davide Melisi, Fortunato Ciardiello, Erika Martinelli. Inhibition of TGFβ in colorectal cancer cells is associated with a compensatory activation of AXL and p38 MAPK signaling pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2627.

Abstract 295: Synergism between oxaliplatin or irinotecan with the PARP inhibitor niraparib in a preclinical model of KRAS/BRAF mutated colorectal cancer is associated with MSI status

DNA damage response (DDR) is crucial in a variety of tumors and several new drugs that interfere with this mechanism are already available or in advanced clinical testing. RAS-MAPK pathway activation, induced by either RAS or BRAF mutation, is a frequent feature of colorectal cancers (CRCs) and is strongly associated to mitotic stress and dependency upon DDR. Among the drugs used for CRC, oxaliplatin and irinotecan are known to induce DNA damage in form of single or double strand breaks (SSB/DSBs) and thus require active DDR systems in cancer cells to be tolerated. The poly-ADP-Ribose Polymerase (PARP) inhibitor Niraparib (MK-4827) is an FDA-approved orally bioavailable drug with strong PARP1-trapping activity, a feature ofted associated with synergism in combination with platinum salts, while synergism with other DNA damaging agents is independent of the PARP1-trapping activity. We tested the activity of niraparib used in combination with oxaliplatin or irinotecan (in the form of its active metabolite SN38) in a panel of 8 KRAS or BRAF mutated CRC cell lines (LOVO, HCT15, SW1116, LS1034, SW948, WiDr, SW480, HCT116) with different microsatellite and CIMP status. Combination index (CI) analysis was performed in order to evaluate the synergism between niraparib and the chemotherapeutics. Cell cycle distribution and apoptosis assays were performed in order to further characterize the effects of the combinations.

The combination between niraparib and oxaliplatin resulted synergistic in 6 out of 8 cell lines, with strong synergism (CI < 0,5) in 2 cell lines, while the combination between niraparib and irinotecan (SN38) resulted synergistic in 7 out of 8 cell lines, with strong synergism in 5 cell lines and very strong synergism (CI < 0,1) in 3 cell lines. Interestingly, the only non-synergistic cell line to the combination with irinotecan is also non-synergistic to the combination with oxaliplatin; on the other hand, the cell lines that exhibit strong synergism to the combination with irinotecan do not present strong synergism to the combination with oxaliplatin and vice versa. Moreover, all the microsatellite instable (MSI) cell lines tested resulted synergistic for the two combinations. Finally, the synergistic combinations showed an increased induction of apoptosis and cell cycle arrest compared to non-synergistic combinations.

Taken together, these data investigate the combination between the PARP inhibitor niraparib and the antiproliferative agents oxaliplatin and irinotecan in KRAS/BRAF mutated CRC cell lines, showing how MSI status predicts good synergism with the drug combinations, while MSS status is not a good predictor of synergism. Further studies are needed to identify better predictive biomarker beyond MSI status, in order to optimize the use of these combinations for future development.

Citation Format: Pietro Paolo Vitiello, Davide Ciardiello, Claudia Cardone, Giulia Martini, Valentina Belli, Nunzia Matrone, Luca Poliero, Carola Borrelli, Pasquale Vitale, Nicoletta Zanaletti, Teresa Troiani, Davide Melisi, Fortunato Ciardiello, Erika Martinelli. Synergism between oxaliplatin or irinotecan with the PARP inhibitor niraparib in a preclinical model of KRAS/BRAF mutated colorectal cancer is associated with MSI status [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 295.

Phase II study of avelumab in combination with cetuximab in pre-treated RAS wild-type metastatic colorectal cancer patients: CAVE (cetuximab-avelumab) Colon

TPS731

Background: The immune system plays a crucial role in modulating response to monoclonal antibodies therapy in cancer. Novel immunecheckpoint inhibitors have demonstrated potent efficacy alone and in combinations with cytotoxic agents in several cancers. In this regard, avelumab in combination with cetuximab might be a relevant rechallenge strategy in RAS wild-type (WT) metastatic colorectal cancer (mCRC) patients treated in first-line with chemotherapy (CT) in combination with anti-EGFR drugs and who achieved a complete or partial response. Methods: CAVE Colon is a single arm, multi-center phase II study designed to evaluate the efficacy of avelumab and cetuximab in pre-treated RAS WT mCRC patients. Eligible patients: pathologically confirmed RAS WT mCRC treated with a first-line CT in combination with an anti-EGFR agent with a major response achieved (complete or partial), who have progressed to a second line therapy, and received no prior immunotherapy. Primary endpoint is overall survival, secondary endpoint are overall response rate according to RECIST 1.1, progression free survival and safety profile. The current study seeks to demonstrate a median OS of 11 months (alternative hypothesis) by the experimental combination for comparison with historical median OS 8.0 (null hypothesis) with standard third line treatments, which correspond to an improvement of OS at six months from 40% to 57%. It was estimated that it would be needed to enroll 66 patients to achieve a 80% power with a one-sided 5% level test. The accrual period will be 18 months and the total duration of the study will be 36 months. Considering a potential drop-out of approximately 15% of patients, a total of 75 patients will be recruited. Seven patients have been enrolled and started treatment to date (September 15, 2018) with avelumab 10 mg/kg q14 as a one-hour i.v. infusion and cetuximab at 400 mg/m2 over two-hour and subsequently 250 mg/m2 q 14 as one-hour i.v. infusion until disease progression or unacceptable toxicity. EudraCT number: 2017-004392-32. This study is partially supported by Merck KgA, Darmstadt, Germany. Results: N/A. Conclusions: N/A. Clinical trial information: EudraCT number: 2017-004392-32.

Composite membranes modified with recognition-able nanobeads as potential adsorbers for purification of biological fluids

Therapeutic approaches in the clinical field require advanced properties for delivery or recognition of clinical species. The molecular imprinting method allows selective cavities to be inserted into a polymeric material built ""around"" a stamp molecule (template) through polymerization or phase inversion. This study focuses on the application of both methods in the realization of polymeric membranes with selective recognition and adsorption properties. Imprinted polymethacrylic acid (PMAA) particles, exhibiting specific binding sites for cholesterol molecule (template), were realized via precipitation polymerization in the shape of nanobeads and loaded in the bulk or on the surface of methylmethacrylate-acrylic acid P(MMA-co-AA) membranes obtained by the non-solvent induced phase separation (NIPS) technique. In this way, specific cavities were introduced into the membrane network to enhance and specialize uptake performances of the porous membranes taking advantage of the particle characteristics. Rebinding performances towards cholesterol in a physiological environment were tested showing very interesting results: the adsorption of cholesterol molecules from physiological solution was increased by using composite membrane-nanobead systems instead of control membranes (a quantitative increase of 14 mg of cholesterol per g of polymer matrix in respect of blank membrane was detected). The results obtained showed an improved performance of composite membranes, but also an unmodified behavior of loaded nanobeads (with respect to free ones) concerning the recognition capability in aqueous medium, which is the most difficult obstacle to overcome in molecular imprinting. The absolute rebinding capacity and the imprinting efficiency of membranes were in the range (and in some case higher) of other efficient systems, but the real improvement was that molecularly imprinted embranes showed an excellent recognition capacity in physiological medium instead of organic solvents.

Cryotherapy in the prevention of oral mucositis in patients receiving low-dose methotrexate following myeloablative allogeneic stem cell transplantation: a prospective randomized study of the Gruppo Italiano Trapianto di Midollo Osseo nurses group

Severe oral mucositis is a major cause of morbidity following allogeneic hematopoietic stem cell transplantation (AHSCT). Cryotherapy, that is, the application of ice chips on the mucosa of the oral cavity during the administration of antineoplastic agents, may reduce the incidence and severity of chemotherapy-related oral mucositis. In this multicenter randomized study, we addressed whether cryotherapy during MTX administration is effective in the prevention of severe oral mucositis in patients undergoing myeloablative AHSCT. One hundred and thirty patients undergoing myeloablative AHSCT and MTX-containing GVHD prophylaxis were enrolled and randomized to receive or not receive cryotherapy during MTX administration. The incidence of severe (grade 3-4) oral mucositis, the primary end point of the study, was comparable in patients receiving or not cryotherapy. Moreover, no difference was observed in the incidence of oral mucositis grade 2-4 and the duration of oral mucositis grade 3-4 or 2-4, or in the kinetics of mucositis over time. In univariate and multivariate analysis, severe oral mucositis correlated with TBI in the conditioning regimen and lack of folinic acid rescue following MTX administration. Thus, cryotherapy during MTX administration does not reduce severe oral mucositis in patients undergoing myeloablative allogeneic HSCT. Future studies will assess cryotherapy before allogeneic HSCT.