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Sana SC451: hypoimmune stem-cell-derived islets without immunosuppression

A stem-cell-derived islet therapy gene-edited to hide from the immune system, aiming to cure type 1 diabetes with a single off-the-shelf treatment and no immunosuppression. SC451 still has no trial registered (Sana guides to an IND and a Phase 1/2 "as early as" 2026), but is built on a landmark first-in-human study in which gene-edited donor islets survived and made insulin for 14 months — now peer-reviewed in the New England Journal of Medicine — in a patient taking no immunosuppressive drugs. That study used a deliberately low dose and was never designed to reduce insulin needs.

Primary endpoints

  • SC451: endpoints not yet defined (trial not registered); expected to be safety/tolerability and evidence of engraftment and insulin production in a first-in-human Phase 1/2
  • Foundational UP421 study primary endpoint: safety, measured by number of treatment-related adverse events (CTCAE v5.0) over 12 months

Results so far

No SC451 clinical results yet (trial not started; SC451 has never been given to a human). In the foundational UP421 first-in-human study, gene-edited donor islets transplanted into a forearm muscle without any immunosuppression produced stable, glucose-responsive insulin with no immune response at 12 weeks. Continued cell survival, insulin production and immune evasion through 14 months were published in July 2026 as a peer-reviewed letter in the New England Journal of Medicine — fasting and meal-stimulated C-peptide at month 14 were comparable to the first six months and higher than at months 9 and 12, 52-week PET-MRI showed islet cells still present at the transplant site, and there were no serious treatment-related adverse events. Note the deliberate limit of this study: it is a single participant given a low dose, and Sana states it "is not intended to show improvement in glycemia and/or reduction in exogenous insulin administration". This is evidence of durable graft survival without immunosuppression — not of insulin independence.

The full picture

What is being tested and why it matters

SC451 is an experimental cell therapy that aims to cure type 1 diabetes rather than manage it. The idea is to replace the insulin-making islet cells the immune system destroyed — but to do it without the lifelong anti-rejection drugs that have kept islet transplants from being practical for most people.1 Today, transplanting donor islets works, but it requires both a scarce supply of donor pancreases and heavy immunosuppression, whose side effects often outweigh the benefit for all but the most severe cases.2

SC451 attacks both problems at once. The cells are grown from induced pluripotent stem cells (iPSCs), so supply is effectively unlimited, and they are "O-negative" to act as a universal, off-the-shelf product.3 Crucially, they are gene-edited with Sana's "hypoimmune" (HIP) technology so the body's immune system does not see them as foreign — the goal being a single treatment, with no immunosuppression, that restores normal blood sugar without insulin injections.3

Who it's for

SC451 is being developed for people with established type 1 diabetes. As of July 2026 it still has no trial registered — Sana says it expects to file an IND (the FDA application to begin human testing) and start a Phase 1/2 trial "as early as this year".4 We checked ClinicalTrials.gov on 14 July 2026 and found no registered SC451 study; the only Sana-linked type 1 diabetes trial there is the UP421 study below.5 Exact eligibility will be set when the SC451 trial opens. SC451 itself has never been given to a human.

The landmark study it is built on

SC451's credibility rests on a first-in-human study (NCT06239636) run at Uppsala University Hospital in Sweden and published in the New England Journal of Medicine in 2025.6 In that study, an earlier product, UP421 — HIP-edited islets from a donor, edited using CRISPR-Cas12b and lentiviral methods — was transplanted into a forearm muscle of a man with long-standing type 1 diabetes who received no immunosuppressive drugs.6 At 12 weeks he showed no immune response against the cells, and C-peptide (the marker of the body's own insulin production) was stable and rose appropriately after meals.6 Four adverse events occurred, none serious or related to the cells.6

What changed in July 2026: the 14-month follow-up, which Sana had previously announced only by press release,7 is now peer-reviewed — published as a Letter in the New England Journal of Medicine on 10 July 2026.8 At month 14, both fasting and meal-stimulated C-peptide were comparable to the first six months and higher than at months 9 and 12; a PET-MRI scan at 52 weeks showed islet cells still present at the transplant site in the forearm muscle; and no safety issues were identified — all with no immunosuppression at any point.84 That upgrade from company announcement to peer-reviewed publication is the single most important thing to happen to this programme this year.

Design

This was a tiny first-in-human safety study — about 2 participants, "Early Phase 1," with safety over 12 months as the main endpoint.5 It was a proof of concept, not a randomized efficacy trial. The same hypoimmune approach previously achieved insulin independence in a diabetic monkey without immunosuppression.9

Two limits worth being blunt about. First, this is one person. Second, the dose was deliberately small: Sana states plainly that the study "examines a low dose of HIP-modified primary islets" and "is not intended to show improvement in glycemia and/or reduction in exogenous insulin administration".4 So the result is durable graft survival and function without immunosuppression — it is not a demonstration of insulin independence, and the participant did not come off insulin.

What it means and what's next

The takeaway: gene-edited islets can hide from the immune system and keep working for over a year in a person, drug-free — the central bet of a universal cure — and that finding has now cleared peer review.68 The open questions are unchanged: moving from scarce donor cells (UP421) to scalable stem-cell-derived cells (SC451), from a low proof-of-concept dose to a therapeutic one, and from one patient to many. Watch for SC451's IND filing and the start of its Phase 1/2 trial, which Sana guides to "as early as this year".4

References

  1. Ziegler A-G, Cengiz E, Kay TWH. The future of type 1 diabetes therapy. Lancet (2025). https://doi.org/10.1016/S0140-6736%2825%2901438-2 ↩

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

  3. Sana Biotechnology. Reports Fourth Quarter and Full Year 2025 Financial Results and Business Updates. GlobeNewswire (2026). https://www.globenewswire.com/news-release/2026/03/03/3248908/0/en/Sana-Biotechnology-Reports-Fourth-Quarter-and-Full-Year-2025-Financial-Results-and-Business-Updates.html ↩ ↩2

  4. Sana Biotechnology. Announces Follow-On Publication in the New England Journal of Medicine Highlighting Long-Term Data and Durability of Hypoimmune-Modified Islet Cell Transplantation Without Immunosuppression in Type 1 Diabetes (13 July 2026). https://www.biospace.com/press-releases/sana-biotechnology-announces-follow-on-publication-in-the-new-england-journal-of-medicine-nejm-highlighting-groundbreaking-long-term-data-and-durability-of-hypoimmune-modified-islet-cell-transplantation-without-immunosuppression-in-type-1-diabetes ↩ ↩2 ↩3 ↩4

  5. ClinicalTrials.gov. First-in-human Safety Study of Hypoimmune Pancreatic Islet Transplantation in Adult Subjects With Type 1 Diabetes (NCT06239636). https://clinicaltrials.gov/study/NCT06239636 ↩ ↩2

  6. Carlsson P-O, Hu X, Scholz H, et al. Survival of Transplanted Allogeneic Beta Cells with No Immunosuppression. N Engl J Med (2025);393:887-894. https://doi.org/10.1056/NEJMoa2503822 ↩ ↩2 ↩3 ↩4 ↩5

  7. Sana Biotechnology. Announces 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 ↩

  8. Carlsson P-O, Hu X, Scholz H, et al. Long-Term Survival of Hypoimmune Allogeneic Islets without Immunosuppression. N Engl J Med (2026), Letter, published 10 July 2026. https://doi.org/10.1056/NEJMc2604408 ↩ ↩2 ↩3

  9. Hu X, White K, Young C, et al. Hypoimmune islets achieve insulin independence after allogeneic transplantation in a fully immunocompetent non-human primate. Cell Stem Cell (2024);31:334-340. https://doi.org/10.1016/j.stem.2024.02.001 ↩