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Sana Biotechnology SC451 (hypoimmune stem-cell islets)

Sana Biotechnology

A cure without anti-rejection drugs — unproven.

Insulin-producing islet cells gene-edited to be "invisible" to the immune system so they survive without anti-rejection drugs. Sana's hypoimmune (HIP) platform showed proof-of-concept in a person with type 1 diabetes using edited donor islets (UP421); SC451 is the earlier-stage, stem-cell-derived version aiming for an off-the-shelf, drug-free treatment.

Years awayEarly evidencestem-cellisletgene-editinghypoimmuneimmune-evasionipsccell-therapycombinationdonor

The scorecard

Efficacy40

This criterion asks whether the approach restores regulated insulin production — and SC451 has restored it in nobody. The edited donor islets of the UP421 study did secrete glucose-responsive C-peptide, but at a dose deliberately set too low to treat anyone, so no one came off insulin. That is proof the mechanism works, not proof it can cure.[1]

Durability45

A peer-reviewed NEJM Letter (July 2026) reports C-peptide holding at month 14, with the graft still visible on 52-week PET-MRI and no immunosuppression — the longest drug-free record for hypoimmune islets anywhere. But it is one person, at a sub-therapeutic dose, with a different product from the one scored here: a small graft may escape an immune attack that a curative-sized one would not.[1]

Safety58

First-in-human UP421 had only four non-serious, unrelated adverse events, and the peer-reviewed 14-month follow-up identified no safety issues; but permanent MHC-I/II disruption raises theoretical NK-cell, infection and tumor-surveillance risks needing long-term follow-up.[1]

Immunosuppression-free75

The strongest drug-free evidence anywhere in this pillar: edited donor islets survived 14 months in a man with long-standing T1D on no immunosuppression at all. Knocking out MHC-I/II removes the target for both attacks — transplant rejection and the original autoimmunity — so this is real evidence against both, not a dodge. But it is n=1, at a deliberately sub-therapeutic dose, and SC451 itself has never been in a human: the mechanism is shown, the cure is not.[1]

Eligibility breadth60

If durable, an off-the-shelf iPSC product needing no immunosuppression could reach the broad T1D population — not just severe cases — but no trial has yet enrolled for SC451.

Maturity35

Strong preclinical data and a single human proof-of-concept with primary islets; SC451 (iPSC-derived) was still pre-IND in July 2026, with a Phase 1/2 trial only expected to start "as early as" that year.[2]

Immunosuppression-free is scored here, as it is for cell replacement and encapsulation — freeing a therapy from lifelong anti-rejection drugs is the central barrier this whole pillar is trying to clear, so an approach that achieves it must be able to earn credit for it. It is scored on evidence, not intent: a platform designed to avoid immunosuppression but never yet tested at a therapeutic dose scores on what it has shown. Approaches that transplant nothing (in-vivo gene therapy, reprogramming) need no anti-rejection drugs by construction, but they still face the original autoimmune attack — that unresolved risk belongs in this score, not hidden by it.

The full picture

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

In July 2026 the Uppsala team published the 14-month follow-up as a peer-reviewed Letter in the New England Journal of Medicine — a short research letter rather than a full paper, but a step up from the company press releases that carried this result before.5 It reports that fasting and meal-stimulated (MMTT) C-peptide at month 14 were comparable to the first six months and higher than at months 9 and 12; that a 52-week PET-MRI scan still showed islet cells at the transplant site in the forearm muscle; and that no safety issues were identified — all with no immunosuppression at any point.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.6

Durability and safety. The 14-month signal is the longest drug-free record for hypoimmune islets so far, and it is now peer-reviewed — but it still comes from a single participant at a cell dose chosen to be too low to treat.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.7 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 says it expects to file an Investigational New Drug (IND) application for SC451 and begin a Phase 1/2 trial "as early as this year" — note that as of mid-July 2026 that IND had still not been filed, and no SC451 trial was registered.8 In April 2026 Sana announced a collaboration with the Mayo Clinic, which includes an equity investment in Sana, to provide clinical, surgical and trial-design support for SC451.9 The donor-islet (UP421) study continues to report longer follow-up.7 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. Carlsson PO, Hu X, Scholz H, et al. Long-term survival of hypoimmune allogeneic islets without immunosuppression (Letter). New England Journal of Medicine (10 July 2026). PMID 42430558. https://doi.org/10.1056/NEJMc2604408 ↩ ↩2 ↩3

  6. 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 ↩

  7. 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

  8. 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. GlobeNewswire (13 July 2026). https://www.globenewswire.com/news-release/2026/07/13/3326134/0/en/Sana-Biotechnology-Announces-Follow-On-Publication-in-The-New-England-Journal-of-Medicine-NEJM-Highlighting-Groundbreaking-Long-Term-Data-and-Durability-of-Hypoimmune-Modified-Isle.html ↩

  9. Sana Biotechnology and Mayo Clinic announce strategic collaboration focused on improving care in type 1 diabetes and accelerating development of SC451. GlobeNewswire (13 April 2026). https://www.globenewswire.com/news-release/2026/04/13/3272888/0/en/Sana-Biotechnology-and-Mayo-Clinic-Announce-Strategic-Collaboration-Focused-on-Improving-Care-in-Type-1-Diabetes-and-Accelerating-Development-of-SC451.html ↩

Coming soon

ETA · SC451 IND not yet filed as of July 2026; Sana guides to an IND filing plus a Phase 1/2 trial start "as early as 2026" (SC451 is still untested in humans)

  • →File Investigational New Drug (IND) application for SC451 · as early as 2026
  • →Begin first Phase 1/2 trial of SC451 (iPSC-derived hypoimmune islets) · as early as 2026
  • →Follow-up beyond 14 months from the donor-islet (UP421) study

Sources

  1. [1]Long-Term Survival of Hypoimmune Allogeneic Islets without Immunosuppression (Letter) · peer-reviewed · 2026-07-10 — Carlsson PO, Hu X, Scholz H, et al. N Engl J Med 2026. PMID 42430558. A Letter to the Editor, not a full paper — 14-month follow-up of the single UP421 recipient.
  2. [2]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 · manufacturer · 2026-07-13 — Company release announcing the NEJM Letter; also states Sana expects to file an IND and start a Phase 1/2 trial of SC451 "as early as this year".
  3. [3]Sana Biotechnology and Mayo Clinic Announce Strategic Collaboration Focused on Improving Care in Type 1 Diabetes and Accelerating Development of SC451 · manufacturer · 2026-04-13
  4. [4]Survival of Transplanted Allogeneic Beta Cells with No Immunosuppression · peer-reviewed · 2025-08-04 — Carlsson PO, et al. N Engl J Med 2025. The original first-in-human UP421 report (12-week data).
  5. [5]First-in-Human Safety Study of Hypoimmune Pancreatic Islet Transplantation in Adult Subjects With Type 1 Diabetes (UP421) · registry · 2024-02-01 — NCT06239636. Uppsala University Hospital; adults aged 30-45; planned enrolment 2.