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Objectives: Realization of the high-standard projects.
Description: The realization of the designed projects will accelerate the transfer of fundamental knowledge into applied research and advance our understanding about “watch and wait”. Excellent and competitive research requires high quality ideas/solutions and access to unique competencies/technologies. The ESRs will acquire this vision through the realization of their projects. CAST has strategically setup ways to promote interactions and collaborations between its members. The lead partner will guarantee that cross-fertilization occurs by overseeing the consortium-wide exchanges. Furthermore, the lead partner also promotes together with a dedicated ESR adherence to the European Charter for Researchers and Responsible Research and Innovation (RRI).
Task 2.1: Ensuring the implementation of the 15 ESRs projects, which are summarized in 8 groups:
WP2.1: Objectives linked to the individual projects of ESRs 2, 3, 14 and 15:
- To develop a flexible endoscope that could be used for diagnostic procedures, with a focus on those with rectal cancer, based upon characterising the changes in endogenous tissue properties and the local concentration of fluorescent contrast agents;
- To demonstrate preclinically that state-of-the-art endoscopy together with targeted specific fluorescence may be used for surveillance of inaccessible tumours.
Task 2.1.1: Imaging system design. A dedicated endoscope will be designed and fabricated with a custom endoscopic light source to create an imaging platform. Our goal will be to design a camera system that can image and analyse multimodal structural and functional tissue data in real time.
Task 2.1.2: Process, analysis and in vivo visualization. This imaging platform will be used to develop novel processing, analysis and visualization methods to maximize the information content. This will follow four stages of requirements:
- the methods should be modular so that new updates can be easily added,
- for translation into clinical practice and flexible in design,
- intuitive visualization and
- correctness of the processing results.
Task 2.1.3: Validation in vivo. For validating our approach, we propose to work with two animal models, the first model (mice) to validate the potential to provide good sensitivity and specificity and the second model (pigs) to validate the ergonomics and workflow of the novel instrument in combination. Four NIRF targeted probes will be used to validate the endoscope:
- EMI-137 (c-Met),
- EMI-200 (neutrophil activation),
- SGM-101 (CEA) d) cRGD-ZW800 (neovasculature). SGM-101 has already been shown to be safe and can influence clinical decision-making during surgical procedures of patients with colorectal cancer (Boogerd LSF et al, Lancet Gastroenterol Hepatol, 2018).
WP2.2: Objectives linked to the individual projects of ESRs 2 and 7: To co-register nuclear tracers with NIRF on a PLGA nanoparticle platform where we will:
- demonstrate hybrid PET-CT and fluorescence imaging in order to derive complementary information of molecular events from two different imaging modalities and
- show tumour targeting of PLGA nanoparticles.
Task 2.2.1: PLGA platform for dual modality PET-CT and fluorescence imaging. NIRF has the potential to address limitations in using a radionuclide by providing better spatial resolution and allowing for real-time optical detection within the surrounding anatomy (37). Even though the signal from fluorescent probes is limited by depth of penetration into tissue, the addition of fluorescence provides both imaging entities to be visibly co-localised. We aim to use PLGA nanoparticles, derivatised with DTPA or DOTA, so that nuclear tracers, 18FDG and 68Ga, may be captured onto the PLGA. A NIRF dye with 700-800nm excitation / emission, such as indocyanine green (ICG), will be encapsulated within the PLGA.
Task 2.2.2: Besides the presence of the dual modality imaging contrast agents, the PLGA nanoparticles will also be made to be targeted towards the selected tumour. Conjugation of a cRGD peptide, SGM-101 and EMI-137 antibodies will be compared. These will be validated in mouse models but the most promising will then be sent to STRAS for testing in the pig model.
WP2.3: Objectives linked to the individual projects of ESRs 12 and 13: The current standard of using tissue biopsies leads to inadequate diagnostic procedures. They are invasive, cannot be used repeatedly and are not sufficient in providing better understanding of metastatic risk, disease progression or treatment effectiveness. In contrast, liquid biopsies reveal metastasis in action, providing live information about the patient’s disease status. Our objective is to develop technologies that can lead to more rapid, sensitive and specific assays that could detect cells/biomarkers in patients with metastatic disease.
Task 2.3.1: Current approaches to capturing CTCs by specific marker molecules and enumerating them are still complex. We will therefore utilise wide field and fluorescent microscopy to identify rare cell types based upon semi-automation, which means more cell types besides CTCs for a more comprehensive analysis will be undertaken. To prevent damage and loss of cells during the process, we use just two steps towards the identification. Pattern recognition algorithms will be used to identify also different cell types in a wide field of view under microscopy.
Task2.3.2: To select RNA-based aptamers able to specifically recognise rectal cancer-derived exosomes, a differential SELEX strategy will be adopted. Exosomes purified from epithelial primary cells obtained from different subtypes of rectal cancer patients will be used for positive selection. The best ligands will be identified by binding assay (using RT-qPCR and confocal microscopy) on exosomes. A novel aptamer-based sandwich assay will be designed, by using the best aptamer ligands as biological recognition element that captures the target and a reporter element to convert the target binding into a detectable signal. Cutting-edge machine learning and data visualization algorithms (such as t-SNE) will be integrated into novel data analysis strategies to analyse the selection process.
WP2.4: Objectives linked to the individual projects of ESRs 1 and 9: Patients with localized rectal cancer are currently treated with surgery and in more advanced rectal cancers this may sometimes be combined with RT. However, the increased use of endoscopy, new methods of imaging and neoadjuvant therapy has meant more emphasis on active surveillance for those who achieve a cCR. This allows organ preservation which has less detrimental effect on bowel function. The objective of WP4 is therefore to explore the best RT treatment options for rectal cancer, combining the best in state-of-the-art technologies with an optimal watch and wait strategy.
Task 2.4.1: Optimising CRT. With high dose radiation therapy, cCR rates exceeding 70% could be achieved, but long-term toxicity is still unknown. Recent studies have shown that induction treatment consisting of 5x5 Gy followed by consolidation chemotherapy does not compromise local control and has the potential to minimize radiation toxicity by decreasing the total dose of radiotherapy applied. Our aim is to therefore demonstrate the hypothesis that 5x5 Gy followed by consolidation chemotherapy could lead to equal (or higher) cCR rates and lower radiation toxicity. We will investigate a) oncological as well as b) functional outcomes.
Task2.4.2: If regrowth does occur, we will look at implementing local radiotherapy in two formats:
- brachytherapy may be used by placing a radiation source close to the tumour for a predetermined length of time and
- Papillon (contact) therapy, which are groundbreaking treatments for rectal cancer.
WP2.5: Objectives linked to the individual projects of ESRs 2 and 11: Intra-tumour or local site injection of immunotherapeutic agents may be more effective than a systemic injection since the associated layer which is the tumour microenvironment would also be targeted directly. Local delivery also means less systemic toxicity while focusing the immune response on the malignancy and the affected draining lymph nodes. Our objective is to show that local immunotherapeutic agents may be applied clinically combined with conventional therapies in the format of combination immunotherapy encapsulated in a PLGA vehicle.
Task 2.5.1: Nanoparticle carriers such as PLGA and SLNP have the capacity to carry multiple immunotherapeutic agents and sustainably release them at the site of the tumour. We will therefore test out the hypothesis in preclinical studies using SLNP (not yet approved for clinical use) or PLGA (FDA-approved) plus two clinically approved immune agents, an anti-CTLA-4and a PD-1-blocking antibody, which are to be encapsulated. Furthermore, we will add on two more modifications in the form of:
- targeting of the PLGA towards CD40, DEC-205 or CD11c molecules found on DCs and
- the addition of a CD40 agonist to target the tumour microenvironment and induce rapid stromal rearrangement.
Task 2.5.2: We will use FDA-approved PLGA to encapsulate the two antibodies. By injecting locally at the tumour site, those lymphocytes that have already infiltrated the tumour are targeted and also we penetrate through the tumour microenvironment and the stroma.
WP2.6: Objectives linked to the individual projects of ESRs 4, 5 and 6: Despite the increasing interest in organ-preservation strategies, especially from the patient community, there are still many unanswered questions regarding long-term functional and oncological outcomes, long-term toxicity of radiotherapy, optimal radiation dose and fields. Our research objective will be to set up a knowledge centre of current surveillance protocols, updated on a regular basis and able to be given out to personnel in all centres.
Task 2.6.1: In order to ensure high quality patient care, it is essential that a multidisciplinary approach is taken to select patients carefully for study participation. We aim to implement standardized procedures for response and follow-up assessments to be performed multidisciplinary by radiologists, surgeons and gastroenterologists.
Task 2.6.2: Clinical training imaging strategies. The radiographers/MR technicians, radiologists, surgeons and gastroenterologists that will perform image acquisition, image evaluation and endoscopic evaluation will receive extensive training from experts from the primary investigating centre. The training is mandatory and will need to be completed before patient inclusion may be initiated. Additionally, an e-learning procedure will be developed containing imaging teaching files from 25 watch and wait cases from the IWWD.
Task 2.6.3: Clinical training in fluorescence imaging. New imaging techniques such as fluorescence-endoscopy and per-operative fluorescence imaging (for both laparoscopic and open surgery) are easily learnt and do not always require presence of technical experts. However, interpretation of fluorescence imaging and the use of camera systems should be taught in an expert centre. An intensive 3-day training program for clinicians from new watch and wait centres will therefore be developed.
WP2.7: Objectives linked to the individual projects of ESRs 1, 8, 10 and 13: The objective of this study will be to provide a new standard-of-care paradigm for watch and wait. This will include shared decision making with patients and multiple techniques to achieve more accurate prediction of response to nCRT.
Task 2.7.1: Prediction of response to nCRT. Current treatment plans are based on cTNM staging at diagnosis, mostly a combination of endoscopy, MRI and CT. However, we aim to employ multiple techniques to achieve prediction of response, such as NGS on tissue biopsies, liquid biopsies and biomarker analysis.
Task 2.7.2: Identification of cCR. The accuracy to predict a complete response based on currently available imaging modalities (MRI, CT-scan and PET/CT) is variable, and seems to be far higher when assessed by clinical experts on watch and wait regimens. Our aim is to create universal imaging criteria, based upon novel tumour-targeted imaging strategies using PET-CT and fluorescence endoscopy, by which patients with a complete clinical response could be identified with high accuracy.
Task 2.7.3: Shared decision making. One of the most important aspects of personalized treatment in rectal cancer patients is including the patient’s preferences in the decision-making process. It is our duty to accurately inform each patient about the benefits and risks of treatment options. To achieve this, it is our aim to develop a pre-treatment nomogram predicting the risks and benefits based on baseline characteristics.
WP2.8: Objectives linked to the individual projects of ESRs 2, 6, 8 and 10: Once patients are selected for a watch and wait strategy, it is essential that the oncological risks are minimal by improving the diagnostics to detect cancer regrowth or distant metastasis. By improving the follow-up protocols, we emphasize that more patients can be included for watch and wait strategies. Our objective will be to set up a plan for specific population groups to be more inclusive for the majority of rectal cancer patients in our watch and wait strategies.
Task 2.8.1: Elderly/patients unfit for surgery. For patients in whom TME is not feasible because of extensive comorbidity or frailty, palliative standard CRT may be too physically intensive without even the benefit of any positive outcome. Therefore, following on from the validation studies in WP4, we will follow up to explore the effectiveness of applying localised high dose RT (brachytherapy/ Papillon contact therapy) to these patients and monitor the output in the form of improvement in the quality of life and prevention of any bleeding or obstruction.
Task 2.8.2: Patients with local regrowth. For implementation of watch and wait strategies it is essential to minimize the risks of cancer regrowth. Our aim will therefore to implement fluorescent endoscopy combined with a tumour-targeted probe as described in the preclinical phase of work in WPs 2.1, 2.2 and 2.5 to distinguish between polypus tissues, fibrosis or cancer regrowth.
Task2.8.3: Patients with nCR. Most currently available research on watch and wait strategies focuses on patients with a cCR. However, the biological behaviour and clinical implications of a nCR after CRT is still unknown. We will therefore pool data from patients with a nCR from the IWWD so that information on the long-term outcomes and risks of regrowth may be collated.
Task 2.8.4: Early stage rectal cancer. For early stage (T1) rectal cancer with “high risk” features, the current golden standard is TME surgery. However, to select patients whom are eligible for organ preserving treatment after local excision, it is essential to assess the completeness of the resection with high certainty. Tumour-targeted fluorescence endoscopy will therefore be employed to make this assessment.
/EU_Projects/CAST.nsf/xsp/.ibmmodres/domino/OpenAttachment/EU_Projects/CAST.nsf/77606748F4059475C12584000035B1E6/Content_E/
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