Closing Panel : Organizers’ Summary

1. International Stem Cell Banking Initiative (ISCBI) Closing Panel: Organizers’ Summary PSC 2019, June 30th 2019, Los Angeles, CA. Chairs: Glyn Stacey (ISCBI) and Stephen Lin (CIRM) Participants: Ngaire Elwood (ISCT), Lucilia Mouriès (HESI CT-TRACS), Yoji Sato (NIHS; HESI CT-TRACS), Stephen Sullivan (GAiT)

2. Closing Panel Ngaire Elwood Glyn Stacey LuciliaMouriès Director Director, BMDI Cord Blood Bank Scientific Program Manager ISCBI Stephen Lin Stephen Sullivan Yoji Sato Senior Science Officer International Liaison Officer Head of Division, Cell-Based Therapeutic Products PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

3. Spectrum of activities to make a PSC therapy product Primary Donor Material iPSC generation Final Differentiated Product Autologous • No donor eligibility determination • Limited material testing • Traceability of reagents & materials • Regulatory approval • Master Cell Bank • Testing • Reprogramming/Gene Modification/Editing • Materials • Manufacturing process • Regulatory approval • Product stability • Safety Testing • Efficacy Testing • Storage • Final formulation Allogeneic • Donor Recruitment and Appropriate Donor Selection • Donor consent determination • Screening and testing required within 7 days of harvest PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

4. Panel 2: Pluripotent Stem Cells as Manufacturing Cell Substrates - Challenges Encountered and Forecast • Understanding and reducing process variation: need to understand genetic drift of material. Define CQAs at all stages of development form beginning to end • Demonstrating comparability: comparability tests change depending on chronic vs acute condition • Biggest challenge for pluripotent stem cell derived therapies: understand how they work (not just paracrine effect) PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

5. Panel 3: International Standardization Data sharing • Clinical: hPSCreg database now developing, welcome input Challenges with EU/GDPR regulations new developments in other countries. • Consents: ISSCR standards, still issues with institutional variation • Standardization with high content analytics: Understand biology in early development. Linking data from different systems is a challenge. May need new kinds of reference materials. Standards will improve regulatory acceptance. PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

6. Panel 4: Defining Quality Parameters as manufacturing intermediates • Deriving quality of starting material: donor eligibility guidelines WiCell assays – 298 page document for all tests • Multiple clones, how to pick the best one. Narrow down, physically separate. • Risks/benefits initiating manufacture in GMP from start to finish vs transitioning a research grade intermediate into GMP. Cost more to switch to GMP from research than to start with research • Potency for PSCs as an intermediate: Look at end product. Cardiomyocyte vs neuron. Test your final product. Break up process and isolate tests PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

7. Panel 5: Roadmap for comparability • Donor material: Keep as much as possible to test. Emphasize on donor eligibility. • Testing: Take risk-based approach. Try to share information. Learn from failures. Develop robust protocols. PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

8. Panel 6 - tumorigenicity • Diversity of testing methods; no consensus on best practices. • Better characterization of testing methods are critical for the translation of iPSC-derived products. • Identifying ideal positive control cells for predictivity of clinical safety is a challenge. PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

9. HESI Cell Therapy-TRAcking, Circulation and Safety (CT-TRACS) Committee lmouries@hesiglobal.org www.hesiglobal.org

10. Panel 7 – Automated and closed manufacture Enabling technology development • Key aspects of automation: Expansion Want mature process before addressing this • Variable that predicts risk for automation development: Need to separate lines. PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

11. Panel 8 – Financial and logistics challenges • Logistics costs/challenges: TPP, quality by design They are high, but good therapeutic will justify costs. Difficult to hire and keep manufacturing experts • Not thinking about IP strategies PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

12. Panel 9 – Immune rejection/engraftment failure Pre-recorded interviews for this panel: Jeanne Loring (Aspen Tx) discusses autologous cell therapy development and how while it might not be as scalable as allogenic approaches, it will probably be the best approach to identify proof of concept, David Turner (SNBTS) discusses the current state of transplantation immunology and how even the clinical immunologists do not know everything, Marc Peschanski(INSERM) discusses their upcoming iPSC clinical trial for AMD and the considerable amount of work required to get regulatory approval. • Immune rejection remains a formidable barrier to stem cell transplantation. Stem cell biology has assisted the interrogation of immune rejection after tissue transplantation but immunology can assist with making stem cell derivatives less likely to be rejected after transplantation. • Immunosuppressive agents, especially when chronically administered, have serious side effects. Impeded immune function can lead to a greater cancer risk (through lowered onco-vigilance) and also a greater risk of opportunistic infection (opportunistic microbes are not normally a problem but can be a significant clinical complication during reduced immune function). Strategies to reduce the clinical reliance on such non-specific agents should be welcomed. Many publications over the last year dealing with genetic modifying cells so that they are less likely to trigger an immune response. The so called ‘universal donor’ strategy submits that through such editing, an engineered cell could potential be introduced into any patient without immune rejection. At a shallow level of interrogation at least, such an approach seems elegant, quick and the most prudent. However, once considered in detail, it may not be the magic bullet it appears to be. For example, Universal Cells LLC introduced HLA-E component to stop natural killer (NK) response but this does not stop all NK cells. Chad Cowan sticking on HLA-G expressed instead. Different NK cells have different inhibitory antigens. Might need combination of these approaches and also there is immune rejection not mediated through NK cells. Immune response dependent on many variables (e.g. Cell/Site/Exposure/Response related variables). Immune system not fully characterized. Development of humanized model for predicting immune response hindered by fetal tissue ban in USA. Off-target modifications, unforeseen consequences of on-target modifications (e.g. capacities to differentiate and/or scale – will these be affected) – if you are engineering the cell, it should be checked that deleterious to the process of therapeutic development itself. Additionally, engineering a cell that cannot be detected by the immune system, means if there is a problem (i.e. tumor formation) you know longer have the default system for dealing with such undesirable cells. This would necessitate the introduction of an inducible cell suicide system which comes with further complications. Taking away immune system capacity to respond for safety purposes may mean you are actually not making your process any safer overall. Universal donor approach is not a magic bullet yet and may not ever be. Immune systems not fully characterized. In many cases we do not have good models to anticipate immune response. Different models will be useful in different cases. Also CAS-9 introduction itself can cause immune response, but this would be a problem is CAS-6 persists in your stem cells (genetic integration). Either transient expression or mRNA introduction should be all that is required for engineering proposes so the other challenges will probably be more clinically significant. • Engraftment encapsulation, choosing immune-privileged sites (brain, eye) and immune matching (haplobanking) are other approaches. Karolinska Institute is adopting a combinatorial strategy: haplobanking approach/ cell engineering/ transplantation into an immune-privileged site. • The more novel technology used, the more safety testing and paperwork will be required to gain regulatory approval. • Immune system not fully characterized and our capacity to absolutely predict immunomodulatory element is not perfect. In many cases we do not have good models to anticipate immune response. Different models will be useful in different cases. No magic bullet for bypassing the immune system. Each approach has advantages/disadvantages. Approaches may not be mutually exclusive and may be used in a combinatorial therapy. PSC Manufacturing Expert Panels 2019 - June 30th 2019, Los Angeles, CA.

13. www.isct-na2019.com

14. Save the Date! ISCT Returns to the City of Lights in 2020

15. Health & Environmental Sciences Institute (HESI) 740 15th St NW, Suite 600| Washington, DC 20005 www.hesiglobal.org SAVE THE DATE! Follow-up PSC meeting: 9/27/2019 HESI Offices, Washington DC Let’s keep moving forward! CT-TRACS CONTACT: Lucilia Mouriès, PhD Scientific Program Manager lmouries@hesiglobal.org Follow us: www.hesiglobal.org @HESI_Global (#CT_TRACS)

16. PSC 2019 Mtg, June 30th 2019, Los Angeles, CA. By building holistic understanding of complete translation process there will be less waste and confusion and will accelerate therapies to the clinic International Stem Cell Banking Initiative (ISCBI)