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Phase 1/2Active, not recruitingNCT03513939

Sernova Cell Pouch: implantable islet-transplant scaffold

A prevascularized, pocket-sized scaffold implanted under the skin to house transplanted donor islet cells. In an early Phase 1/2 trial, the first patients achieved sustained insulin independence — one for over four years — with living, insulin-producing islets recovered from the pouch more than five years after transplant.

Primary endpoints

  • Safety: number and severity of adverse events judged probably or highly probably related to the Cell Pouch, through 365 days after islet transplant
  • Endocrine (islet) tissue survival within the Cell Pouch
  • Reduction in severe hypoglycemic events
  • Reduction in HbA1c

Results so far

Early, investigator-reported results are encouraging but come from a small, non-randomized, single-arm study. In the first cohort (6 patients, 8-channel pouch), all 6 achieved sustained insulin independence, with the first patient remaining insulin-free for more than 4 years and HbA1c in the non-diabetic range (≤6.5%). Functioning, well-vascularized islets producing insulin, glucagon and somatostatin were recovered from the pouch more than 5 years after transplant, with no harmful scarring. Across both cohorts combined (12 patients), an interim update reported 8 of 12 insulin-independent, 9 of 12 with HbA1c <7.0%, and 7 of 12 with restored C-peptide (≥0.3 ng/mL). No final, peer-reviewed efficacy results have been published yet. The confirmatory Cohort C — which will substitute Eledon's investigational anti-CD40L antibody tegoprubart (AT-1501) for tacrolimus — is now expected to start in H2 2026 and is explicitly contingent on Sernova securing additional funding.

The full picture

What is being tested, and why it matters

Replacing the insulin-making islet cells that type 1 diabetes destroys is one of the most direct routes to a functional cure. The standard way to do this — infusing donor islets into a vein in the liver — works for some people, but the liver is a harsh home: many cells die soon after infusion, the graft can't be biopsied or removed, and the procedure carries bleeding risk.1 The Sernova Cell Pouch takes a different approach: a small, retrievable scaffold is implanted just under the skin of the abdomen and left in place for a few weeks so the body grows a network of blood vessels into it. Only then are the donor islets loaded into the now "prevascularized" pouch, giving the transplanted cells an oxygen-rich place to survive.2 The concept was first shown to reverse diabetes in mice, where islets placed in the pouch restored normal blood sugar while islets placed under the skin without the device failed to engraft.3

Who it is for

The trial enrolls adults (18–65) who have had type 1 diabetes for at least 5 years and — critically — have lost the ability to feel their blood sugar dropping (hypoglycemia unawareness) and have suffered dangerous low-sugar episodes.4 These are people for whom insulin alone is no longer keeping them safe. Participants must have no insulin production of their own left and no previous islet or pancreas transplant.4

How the study is designed

This is a Phase 1/2 study: prospective, single-arm, non-randomized, with no placebo and no blinding.4 It is run at the University of Chicago, sponsored by Sernova Biotherapeutics, with an estimated 17 participants across sequential cohorts.4 The main goal is safety — tracking adverse events related to the pouch through one year after transplant — with islet survival, fewer severe lows, and lower HbA1c as further measures.4 Recipients still take immunosuppressive drugs to stop rejection.4

Key results so far

In the first cohort of 6 patients (using an 8-channel pouch), the sponsor reported that all 6 achieved sustained insulin independence, the first patient for more than 4 years, with HbA1c in the non-diabetic range (≤6.5%).5 When one pouch was removed and examined more than 5 years after transplant, it contained abundant, well-vascularized, functioning islets making insulin, glucagon and somatostatin, with no harmful scarring.5 A larger second cohort (Cohort B) received an optimized 10-channel pouch with 56% more islet capacity than the 8-channel version.56 A May 2025 interim update across both cohorts (12 patients) reported 8 of 12 insulin-independent, 9 of 12 with HbA1c below 7.0%, and 7 of 12 with restored C-peptide (≥0.3 ng/mL) — figures Sernova reconfirmed in its June 2026 quarterly filing.76

What it means and what's next

These early signals suggest a subcutaneous, retrievable pouch can keep transplanted islets alive and functioning for years — addressing the durability and access problems of the liver site.15 But the numbers come from a small, non-randomized study run by the device's maker, results are interim, and final peer-reviewed efficacy data are not yet published, so they should be read with caution.7

The trial itself is no longer recruiting: NCT03513939 is listed as active but closed to enrolment, with 17 participants and a completion date of October 2026.4 A confirmatory Cohort C was originally planned for late 2025 but has slipped — Sernova now expects it to begin in H2 2026 and states it is contingent on securing additional funding.6 Cohort C will also swap tacrolimus — a standard anti-rejection drug that is itself toxic to islets and raises blood sugar — for tegoprubart (AT-1501), an investigational anti-CD40L antibody licensed from Eledon Pharmaceuticals under a July 2025 collaboration.68 To be clear about what that swap is and is not: anti-CD40L is itself chronic systemic immunosuppression, so Cohort C would be a calcineurin-inhibitor-free regimen, not an immunosuppression-free one. Participants would still take anti-rejection drugs indefinitely. The pouch is a scaffold, not a shield — it houses the cells and makes them retrievable; it does not hide them from the immune system. Read the timeline with caution: in the same June 2026 filing, Sernova disclosed that material uncertainty exists which may cast significant doubt on its ability to continue as a going concern (accumulated deficit of $171.7M and a working-capital deficit of $9.4M as at 30 April 2026).6 That is a standard disclosure for a clinical-stage company, not a bankruptcy announcement — but it does mean the schedule depends on money the company does not yet have. Longer term, Sernova still aims to pair the pouch with lab-grown (iPSC-derived) islets developed with Evotec — which, if successful, would remove the dependence on scarce donor pancreases.6

References

  1. Pepper AR, Pawlick R, Gala-Lopez B, et al. Diabetes Is Reversed in a Murine Model by Marginal Mass Syngeneic Islet Transplantation Using a Subcutaneous Cell Pouch Device. Transplantation (2015), via PubMed. https://doi.org/10.1097/TP.0000000000000864 ↩ ↩2

  2. Sernova Biotherapeutics Inc. A Safety, Tolerability and Efficacy Study of Sernova's Cell Pouch for Clinical Islet Transplantation (intervention description). ClinicalTrials.gov, NCT03513939. https://clinicaltrials.gov/study/NCT03513939 ↩

  3. Pepper AR, Pawlick R, Gala-Lopez B, et al. Diabetes Is Reversed in a Murine Model by Marginal Mass Syngeneic Islet Transplantation Using a Subcutaneous Cell Pouch Device. Transplantation (2015), via PubMed. https://doi.org/10.1097/TP.0000000000000864 ↩

  4. Sernova Biotherapeutics Inc. A Safety, Tolerability and Efficacy Study of Sernova's Cell Pouch for Clinical Islet Transplantation (phase, design, eligibility, outcomes, status). ClinicalTrials.gov, NCT03513939 (last updated Feb 2026). https://clinicaltrials.gov/study/NCT03513939 ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7

  5. Sernova Corp. Sernova Announces New Positive Data from Phase I/II Trial Regarding Islet Survival and Function. Sernova press release (Sep 12, 2024). https://sernova.com/press_releases/sernova-announces-new-positive-data-from-phase-i-ii-trial-regarding-islet-survival-and-function/ ↩ ↩2 ↩3 ↩4

  6. Sernova Biotherapeutics Inc. Management's Discussion and Analysis for the three and six months ended April 30, 2026 (Cohort C timing and funding contingency; 56% greater islet capacity; interim efficacy figures; going-concern disclosure). Sernova (dated June 11, 2026). https://sernova.com/wp-content/uploads/2026/06/Q2_2026_MDA_Final.pdf ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  7. Sernova Biotherapeutics. Sernova Biotherapeutics Provides Positive Interim Data from Ongoing Phase 1/2 Clinical Trial of Cell Pouch Bio-hybrid Organ in Patients Living with Type 1 Diabetes. Sernova press release (May 14, 2025). https://sernova.com/press_releases/sernova-biotherapeutics-provides-positive-interim-data-from-ongoing-phase-1-2-clinical-trial-of-cell-pouch-bio-hybrid-organ-in-patients-living-with-type-1-diabetes/ ↩ ↩2

  8. Sernova Biotherapeutics. Sernova Biotherapeutics Announces Collaboration with Eledon Pharmaceuticals to Advance a Potential Functional Cure for Type 1 Diabetes. Sernova press release (July 9, 2025). https://sernova.com/press_releases/sernova-biotherapeutics-announces-collaboration-with-eledon-pharmaceuticals-to-advance-a-potential-functional-cure-for-type-1-diabetes/ ↩