The 3Rs aim of this project is to replace animals in preclinical testing of anti-cancer medicines. Our scientific aim is to develop a scalable patient-specific organoid/microtissue (organoids are spheroid structures that act as miniature tissues) platform and to apply this model following validation to identify new treatments for blood cancers. We will work with our commercial partner Alcyomics Ltd and academic collaborators, throughout the project lifespan to ensure we meet requirements for optimal uptake of our platform by industry and academia. Improved strategies to reduce side effects and avoid treatment failure are urgently needed in leukaemia treatment. Cancer drug development has the highest “drug attrition” rates, meaning that very few newly developed medicines are successful in clinical trials despite being deemed suitable in preceding preclinical studies. Hence we need preclinical models with improved clinical translatability. Cell line models do not retain cancer cell biological properties characteristic of the patient. Patient derived leukaemia cells from clinical samples are ideal; however, these cells fail to grow outside the patient’s body possibly due to lack of surrounding BM (bone marrow) cells. Hence the mouse BM is commonly used as an external “home” for culturing patient derived leukaemia cells. Leukaemia research by our group at Newcastle requires 3600 animal procedures every year. These animal experiments are classified as “moderate severity”; meaning they cause significant pain, suffering and distress and clearly detectable disruptions to the animal’s normal state.
We developed synthetic BM cells from human stem cells which supported the growth of patient-leukaemia cells whilst retaining chief cancer cell properties so they behaved similarly to how they would have behaved in the patient’s body. Local metrics confirmed that using this pilot approach we replaced mice in 67 drug tests last year. Given minimum of 40 animals are needed per drug test we replaced 2680 animals (out of 3600) which constituted a minimum 73% local animal replacement. Besides requiring detailed validation to ensure these proof-of-concept metrics are reproducible key limitations of our existing preliminary approach are that our model applies to only a select range of leukaemia samples and furthermore incorporates labour-intensive techniques lacking scalability which hinders its uptake by the wider scientific community. To overcome these obstacles in this project we propose to use our synthetic human BM cells to develop an automated 3D BM-organoid approach to culture and study patient derived leukaemia cells. Through pilot experiments we have shown that preliminary 3D BM microtissues provide superior support to leukaemia cell proliferation than preceding 2D approaches and hence we anticipate that the proposed new 3D approach will allow us to grow additional leukaemia samples consequently replacing even larger number of animals. Furthermore, following validation steps proposed in this project we will generate standardised protocols to facilitate wider endorsement of our synthetic BM-organoids through existing and new collaborations. Developing an automation-based approach will allow us to test new medicines at a larger scale and generation of standardised protocols will ensure that we overcome current barriers to the uptake of our platform.
Home Office returns and annual expenditure reports from major UK cancer research funders indicate that 9,000 animal procedures are used in leukaemia research annually. Following wider endorsement during this project lifespan, our local 73% reduction in animal numbers replicated nationally would mean a minimum target reduction of 6500 animal experiments per year in leukaemia research. Furthermore, our platform will provide proof-of-concept preclinical models for application to other solid tumours to replace even larger number of animals in cancer research.