Community Research and Development Information Service - CORDIS

FP7

BIOIMAGE-NMD Report Summary

Project ID: 602485
Funded under: FP7-HEALTH
Country: United Kingdom

Periodic Report Summary 2 - BIOIMAGE-NMD (BIOIMAGE-Neuromuscular Diseases)

Project Context and Objectives:
BIOIMAGE-NMD will develop and apply imaging technology to monitor response to novel therapies in neuromuscular diseases (NMD) and will use Duchenne muscular dystrophy (DMD) as an exemplar disease. DMD is well characterised genetically and clinically, but to date a disease modifying treatment is not available. One promising development for future treatment of NMD is RNA modulation through antisense oligonucleotides (AON). In DMD, AON are used for exon skipping and this is a genuine example of personalised medicine, where patients are treated according to their specific gene mutation. To enable treatment trials in patient groups with rare diseases such as the NMD it is essential to have sensitive and early biomarkers for therapeutic effect and imaging techniques form an important part of the clinical assessment armoury. Quantitative Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopic Imaging (MRSI) are used to assess structural and metabolic muscle pathology in NMD but their effectiveness in monitoring therapy is yet to be shown.
The BIOIMAGE-NMD project will establish and apply a simultaneous MRI/MRSI protocol in multi-centre clinical trials of AON therapy in DMD with the aim of establishing a clinical proof of principle that these imaging measures are effective biomarkers of therapeutic response. To enhance the imaging protocol, novel Diffusion Tensor MRI (DTI) methods will be developed and optimised to assess muscle microstructure and applied in these trials. The project will also develop methods for radiolabelling of AON and demonstrate the use of pre-clinical Positron Emission Tomography (PET)/MRI to assess the tissue targeting, bio-distribution and pharmacokinetics of AON in vivo. BIOIMAGE-NMD will deliver PET/MRI and MRI/MRSI technologies for both drug development and clinical evaluation roles which will significantly contribute to bringing personalized therapeutic interventions in rare and common diseases to the market.

Project Results:
WP1 Diffusion MRI (DWI) methods have been developed to assess muscle pathology and used in a comprehensive study of excised muscle from wildtype and mdx mice. Significant difference were found in DWI measures in dystrophic muscle, but only when using radically different scanning parameters to those routinely clinically used in other body areas. Computer simulations, powered by the experimental data show that quantitative estimation of muscle fibre radii from DWI scans is challenging. However, the DWI scans contain important contrast reflecting changes in muscle microstructure which is not exploited in conventional approaches. We have advanced DWI analysis methods by applying Shannon Entropy to characterise changes in diffusion signal behaviour.
WP2 tests the sensitivity and reproducibility of muscle DWI in vivo. Using diffusion scanning and computer modelling we finalised an imaging protocol which provides a robust dataset sensitive to muscle structural changes. Differences in MRI methods between different preclinical MRI scanner manufacturers have been overcome allowing multi-site scanning. We have studied neuromuscular disease models including mdx, mdx-xist and wild type mice and with exercise intervention to increase muscle damage in mdx animals. Apparent diffusion coefficient (ADC) is higher in dystrophic muscle at long diffusion times despite muscle fibre radii being reduced. Intra-site ADC variance was <8% (CV) at both sites supporting the translation of diffusion measurements into the clinical domain for evaluation in clinical trials.
WP3 aims to improve existing MRI methods (T2 mapping and Dixon imaging), test conventional DWI methods in human muscle and translate our DWI methods to patient study. Methods to shorten the scan protocol have been developed allowing T2 and fat fraction to be extracted from a single acquisition. Efficient fat suppression schemes have been developed achieving high quality data in patients with extensive muscle fat. The methods have been transferred to clinical scanners across the consortium and normative and repeatability data collected across the sites. The first ever DWI study in neuromuscular disease patients (Becker muscular dystrophy) has been completed.
WP4 acquired MRI data in DMD patients to evaluate proof of principle for the use of imaging as a biomarker in clinical trials. A total of 75 patients were enrolled across 13 sites; Natural history scans were collected in 23 subjects (60 scans) while 52 patients were scanned during interventional clinical trials of exon skipping treatment (160 scans). Data is now undergoing analysis.
WP5 will determine the value of the new imaging methods for clinical trials. Formally WP5 has been delayed awaiting completion of the BMD diffusion study which is under final analysis. Initial data review suggests there is novel information in these scans. A consensus decision will be made, but we note that no clinical trials will be running during the remaining BIOIMAGE-NMD period in which the methods could be tested.
WP6 is developing and applying state of the art data handling and analysis tools to the clinical scans. A web-based interface is being developed to facilitate secure, anonymised transfer of scans from clinical sites to a central analysis server. Software has been developed for supervised muscle group segmentation, validated in healthy subjects and is in test on clinical data. Scan processing was performed for all patients in the clinical trial and natural history study. In the final phase of the programme imaging data will be evaluated alongside clinical measures.
WP7 developed synthetic protocols to prepare (19F)-labelled oligonucleotides using a 4-[19F]SFB pathway and we have shown that the label does not alter AON exon skipping bioactivity.
WP8 The automated preparation of the 4-[18F]SFB and its subsequent conjugation to the AON bearing an amine linking group has been achieved using the Eckert & Zeigler Modular Lab platform. Purification using HPLC was successful however the activity/volume ratio was not always suitable for pre-clinical use. In an attempt to address this the starting levels of 18F activity were increased (4 GBq to > 10GBq) which improved the situation.
WP9 During the M19 – M36 reporting period, dissemination has focused predominantly on publications from the consortium partners, attending conferences and the BIOIMAGE-NMD involvement in the organisation and hosting of an international conference entitled “'Making outcomes work' - Stakeholder Workshop on outcome measure development and implementation for DMD”. The coordinator from Newcastle University, along with many representatives from the BIOIMAGE-NMD consortium partners including WP leads from WP1, WP2, WP3, WP5 and WP6 attended.
WP10 UNEW has continued to work closely with all project partners and has led on negotiations for a number of complex issues during the reporting period including the termination of a project partner, SCITO, from the BIOIMAGE-NMD consortium and the subsequent amendments to the Description of Work as well as the drafting and signing of a Data Sharing Agreement.

Potential Impact:
There remains an urgent need for biomarkers for therapeutic trials in rare diseases such as the neuromuscular diseases being addressed in BIOIMAGE-NMD, where the small numbers of patients prevents traditional large-scale clinical trial procedures. Instead trials require sensitive biomarkers appropriate for small-scale studies. BIOIMAGE-NMD is addressing these issues by developing (i) imaging biomarkers based on current technologies applicable to immediate clinical trials, (ii) next generation imaging biomarkers, & (iii) radioisotope labelling pathways to enable rapid drug bio-distribution studies in animals models which we believe will translate into important imaging methods for first in man evaluation of new drugs. BIOIMAGE-NMD has already made a number of significant advances over the previous state of the art for muscle imaging:
Optimised diffusion imaging studies have revealed significant differences between normal and pathologic muscle using only very small groups of animals. Comparing the variance in the data in animal models against the magnitude of disease and ageing related differences suggest that trial group sizes of less than 10 subjects are sufficient to detect pathological differences, making them ideal for use in rare disease populations. We have solved the problem of confounding signal from fatty muscle infiltration which is a major methodological hurdle in the translational pathway to clinical application. Our methods have been applied in cross-sectional human studies (patient and controls) and subject compliance is good. Final analysis is expected to show that there is novel information in the diffusion scans which informs on the state of muscle pathology and processes (fibre permeability) which directly influence drug delivery for AONs. These new diffusion imaging methods complement existing imaging methodology to provide non-invasive, quantitative assessments of muscle pathology. In turn this will help eliminate the need for muscle biopsies in a patient population where muscle function is already compromised.
AON compounds are an important group of potential therapeutic agents. The ability to rapidly assess AON bio-distribution in vivo is important as a translational tool to ensure the drug reaches target in early human trials, with the ultimate goal of producing highly effective treatments and improving patient outcome and for the development of next-generation compounds. AON radiolabelling is a critical step in providing such a tool. We have achieved the first fluorinated-labelling of AON compounds, demonstrated the preferred synthetic route and shown that our AON bioactivity is unaffected by the presence of the label. We have subsequently converted the synthetic process to 18-F labelling to create a radiotracer for positron emission tomography (PET) scanning. While the focus of BIOIMAGE-NMD has been the application of AONs in neuromuscular disease, the therapeutic use extends more widely to diseases such as neurodegenerative conditions and our technology is poised to make significant contributions to the wider field of AON development.
During the lifetime of the BIOIMAGE-NMD, imaging technologies have seen a significant advance with the genesis of combined PET-MRI scanners which allow the simultaneous measurement of radiotracers by PET with the multitude of MR methods. This technology has been rapidly accepted within Europe as a valuable research tool with a large number of scanners now installed. The novel imaging methods we have developed during BIOIMAGE-NMD have a natural home in the new PET-MR scanners where their use will allow a more complete evaluation of patients in a single and shorted examination. This is particularly important in paediatric patient populations such as the DMD group we are studying.

List of Websites:
www.bioimage-nmd.eu

Contact

Helen Gallon, (Grants & Contracts Manager)
Tel.: +44 0 1912824513
E-mail

Subjects

Life Sciences
Record Number: 193540 / Last updated on: 2017-01-18