In a significant achievement, InnoSer has successfully validated tumorigenicity assay as part of the HEAL project, a major initiative aimed at accelerating the development of an allogeneic iPSC-based heart therapy. This milestone lays out the groundwork for safe and effective stem cell-based therapies targeting heart disease through advanced human induced pluripotent stem cell (iPSC) technologies. 

The HEAL project, entitled “HLA-homozygous iPSC-cardiomyocytE Aggregate manufacturing technologies for allogenic cell therapy to the heart” focuses on overcoming scientific, regulatory, and safety challenges to bring innovative iPSC-derived therapies closer to the first-in-man (FIM) clinical trials. With its success, HEAL aims to develop HLA-homozygous iPSC-cardiomyocyte aggregates (CMAs), offering a scalable alternative to autologous cell therapies for treating heart disease in broader patient populations.  

The HEAL project consortium is made up of world leading expertise of academic, clinical and industrial partners in the field of iPSC technology, bioprocessing, genomic engineering, preclinical drug development and safety, immunology and clinical translation. The HEAL project is funded by the European Union Research & Innovation action, coordinated by the Medical School Hannover (MHH).  

InnoSer’s key role in the HEAL project is to validate an in vivo tumorigenicity and biodistribution assay to explore the safety of cell therapy, since iPSC-derived cellular products are not subject to conventional pharmacokinetic safety testing. The assay was set-up in line with current regulatory requirements as laid out by the European Medicines Agency (EMA).  

Advancing allogeneic stem cell heart therapy with HEAL 

Heart failure is one of the leading causes of morbidity and mortality worldwide, and while traditional treatments can help manage symptoms, they often fall short of fully restoring the damaged heart’s function. The HEAL project envisions a breakthrough in heart failure treatment, using iPSC-derived cardiomyocyte aggregates (CMAs) to regenerate the damaged heart tissue.  

A major advantage of HEAL’s approach is that HLA-homozygous iPSC-derived CMAs can be administered to diverse patient populations, reducing the need for personalized, autologous treatments, which are often costly and time-consuming. However, before any such therapy can enter human trials, strict safety protocols need to be met, including rigorous preclinical tumorigenicity and safety testing. 

Tumorigenicity assay for novel cell therapy products 

The development of cell therapy products from human iPSCs holds great promise for treating complex diseases like heart failure. However, these advanced therapies bring unique challenges. One key concern is that pluripotent stem cells inherently carry the risk of tumorigenicity, even if small amounts of undifferentiated cells remain in the product. Because these therapies are not suitable for conventional pharmacokinetic safety testing, it is crucial to develop sensitive and reliable assays to assess both iPSCs biodistribution in vivo and to detect possible tumor formation.  

InnoSer, as a key consortium partner in the HEAL project, has achieved a significant milestone in this project by validating an in vivo tumorigenicity assay.  

The tumorigenicity assay was set-up using immunodeficient (NSG) mouse models which were injected with positive controls (HeLa cells), iPSCs as cell-product specific positive controls together with fully differentiated CMAs, and CMAs spiked with iPSCs as well as a sham negative control (PBS). HeLa cells were used as a positive control to validate the assay’s ability to detect tumors. Undifferentiated iPSCs served as product-specific positive controls, representing the highest tumorigenicity risk. Fully differentiated CMAs acted as negative controls, ensuring they were non-proliferative. CMAs together with iPSCs at different concentrations allowed the determination of sensitivity of the assay in detecting tumor formation. The results demonstrated that the assay could reliably detect tumor formation even when only 0.1% of contaminating iPSCs were present. PBS vehicle control confirmed the absence of spontaneous tumor formation.  

A human specific qPCR gene (Alu repeats) together with a human specific histopathology marker (Ku80) were validated to track the biodistribution of human cells across different organs at both DNA and protein levels, ensuring no unintended migration or accumulation in off-target tissues.  

This accomplishment represents a critical step toward ensuring the safety and clinical readiness of the iPSC-CMA product.  

Conclusions: what this means for the future of iPSC-based heart failure therapies 

The HEAL project is paving the way for safe and effective iPSC-based heart failure therapies. By achieving a validated tumorigenicity assay, the project has cleared a significant hurdle toward clinical application. As researchers continue to refine these therapies, preclinical safety studies like this will play a pivotal role in addressing potential risks, ensuring compliance with the latest set of guidelines laid out by the regulatory agencies.  

The next steps will involve continued development of CMA iPSC –based therapy with full safety and efficacy studies, bringing the vision of regenerative heart treatment closer to those who need it the most – patients.   

For more information and updates, visit the HEAL project website: https://www.heal-horizon.com/  

For more information about InnoSer’s capabilities in carrying out preclinical tumorigenicity testing studies, please reach out to our team here: https://www.innoserlaboratories.com/contact/