Sana Biotechnology SC451 (hypoimmune stem-cell islets)

Type 1 diabetes destroys the insulin-producing islet cells in the pancreas. Replacing those cells works, but transplanted cells face two attacks: ordinary transplant rejection, and the original autoimmunity that caused the disease. Today's cell therapies hold both off with lifelong immunosuppressive drugs, which carry real side effects. Sana Biotechnology's hypoimmune ("HIP") platform takes a different route: gene-edit the cells so the immune system never flags them as foreign or as a target — a "cloak" instead of the "cage" of encapsulation.¹

How it works. The HIP recipe, developed in the Deuse and Schrepfer lab, inactivates the genes that display the cell's identity to immune T cells (MHC class I and II) and adds extra CD47, a "don't-eat-me" signal that also calms the NK cells that would otherwise notice the missing MHC.² Apply this to insulin-producing islet cells and, in theory, they can be transplanted into anyone without anti-rejection drugs. SC451 is Sana's stem-cell version: islet cells grown from induced pluripotent stem cells (iPSCs) — an essentially unlimited, off-the-shelf supply — then HIP-edited to evade the immune system.³

Clinical evidence. SC451 itself has not yet been tested in people. The human proof-of-concept came from a sister product, UP421: primary islet cells from a deceased donor, gene-edited with CRISPR-Cas12b plus a CD47 transgene, and transplanted into the forearm muscle of one man with long-standing T1D — with no immunosuppression at all.⁴ In the New England Journal of Medicine, the team reported that at 12 weeks there was no detectable immune response against the edited cells, and C-peptide (the fingerprint of the cells' own insulin) was stable and rose appropriately after a meal.⁴ Four adverse events occurred, none serious or attributed to the cells.⁴ Sana later reported the graft was still visible on a 52-week PET-MRI scan, with C-peptide sustained through 14 months — still without immunosuppression.⁵ Crucially, this was a deliberately low-dose safety study, not designed to make the person insulin-independent, so it shows survival and function, not yet a cure.⁵

Durability and safety. The 14-month signal is encouraging but comes from a single participant and a low cell dose.⁵ Whether hypoimmune editing can hold off the returning autoimmune attack for years — and at a dose large enough to free someone from insulin — is the central open question. Permanently switching off MHC also raises theoretical concerns (NK-cell control, response to infections, tumor surveillance) that long-term follow-up must address.¹

Eligibility and availability. Nothing is approved or available; this is research-stage. The UP421 trial enrolled adults aged 30-45 with T1D at a single site in Sweden.⁶ An off-the-shelf, drug-free product like SC451, if it works, could one day reach the broad T1D population rather than only the most severe cases — but that is years away.³

What's coming. Sana said it expected to file an Investigational New Drug (IND) application for SC451 and begin a Phase 1 trial "as early as 2026."⁵ The donor-islet (UP421) trial continues to report longer follow-up.⁶ The decisive next milestones are a therapeutic-dose study showing meaningful glucose control or insulin reduction, and confirmation that the hypoimmune cloak durably resists both rejection and autoimmunity — the result that would turn this from a landmark proof-of-concept into a genuine drug-free cure.¹

References

1. Perrier Q, Lablanche S, Benhamou PY. Cell therapy for type 1 diabetes: tracing historical progress and exploring emerging technologies. Cell Transplantation (2025). https://doi.org/10.1177/09636897251394787 ↩ ↩² ↩³

2. Deuse T, Hu X, Gravina A, et al. Hypoimmunogenic derivatives of induced pluripotent stem cells evade immune rejection in fully immunocompetent allogeneic recipients. Nature Biotechnology (2019). https://doi.org/10.1038/s41587-019-0016-3 ↩

3. Sana Biotechnology. For Patients — SC451 (hypoimmune iPSC-derived islet cell therapy). Sana Biotechnology (2026). https://sana.com/for-patients/ ↩ ↩²

4. Carlsson PO, Hu X, Scholz H, et al. Survival of transplanted allogeneic beta cells with no immunosuppression. New England Journal of Medicine (2025). https://pubmed.ncbi.nlm.nih.gov/40757665/ ↩ ↩² ↩³

5. Sana Biotechnology. Continued positive clinical results through 14 months from type 1 diabetes study of islet cell transplantation without immunosuppression. GlobeNewswire (2026). https://www.globenewswire.com/news-release/2026/03/13/3255502/0/en/Sana-Biotechnology-Announces-Continued-Positive-Clinical-Results-Through-14-Months-from-Type-1-Diabetes-Study-of-Islet-Cell-Transplantation-Without-Immunosuppression.html ↩ ↩² ↩³ ↩⁴

6. Carlsson PO (sponsor). First-in-human safety study of hypoimmune pancreatic islet transplantation in adult subjects with type 1 diabetes (UP421). ClinicalTrials.gov NCT06239636 (2024). https://clinicaltrials.gov/study/NCT06239636 ↩ ↩²