Donor islet transplant (Lantidra / donislecel)

Donor islet transplantation puts working insulin-producing cells back into the body. Islets are isolated from the pancreas of one or more deceased organ donors, purified, and infused through a thin catheter into the portal vein of the liver, where they lodge, grow a blood supply, and begin releasing insulin in response to glucose.³ Marketed as Lantidra (donislecel), it is given as a single infusion, with up to three infusions used in the trials to reach a target islet dose.⁴

In June 2023 the FDA approved Lantidra — the first cell therapy of any kind approved for type 1 diabetes, and the first allogeneic (deceased-donor) pancreatic islet product.⁵ Approval rested on two single-arm studies (UIH-001 and UIH-002) in 30 adults with "brittle" T1D and severe hypoglycemia: 21 of 30 went without injected insulin for a year or more, including 10 who stayed insulin-free for over five years; across the program, 25 of 30 achieved insulin independence at some point.¹

Separate evidence: CIT-07 (NCT00434811) was a 48-person multicenter donor-islet study, not one of the Lantidra approval studies. It reported that 87.5% reached an HbA1c under 7.0% and were free of severe hypoglycemia at one year, with hypoglycemia awareness restored.⁶

The hard requirement is immunosuppression. To stop the immune system from rejecting the donor cells — and from re-attacking them as it did the original islets — recipients take ongoing immune-suppressing drugs (such as basiliximab induction, then tacrolimus and sirolimus).⁷ That carries real cost: roughly 87% of recipients had an infection-related adverse event, and the label flags serious risks from both the infusion (liver laceration, bleeding) and chronic immunosuppression (severe infections, malignancy, kidney decline).⁸⁴ About 90% had at least one serious adverse reaction. Two participants died during follow-up: one from sepsis and one from progressive micro-ischemic disease. These were observed study deaths, not a claim that the infused cells alone caused them.¹²

Separately, a small Australian single-centre series (16 recipients of deceased-donor islets, followed a median of about five years — a different cohort from the Lantidra trials) found HbA1c fell by 1.2 percentage points at 12 months with no new cases of proliferative diabetic retinopathy, though a quarter of recipients still had some worsening of eye outcomes; the authors call for systematic eye monitoring around transplant.⁹

Durability and eligibility. Graft function often wanes over years, and some recipients return to insulin, though many keep partial function (detectable C-peptide) that still blunts dangerous lows.³ Because the trade-off — trading insulin for immunosuppression — only makes sense in the most dangerous cases, Lantidra is reserved for adults whose severe hypoglycemia persists despite optimized insulin, pumps, and CGM.⁵³ Islets must be isolated from deceased-donor pancreases, and some recipients need more than one donor infusion, limiting supply.¹ Eligibility and supply statements follow the FDA review and label cited on this page.

What's coming. This therapy is best read as proof-of-concept for replacing the cells — the unsolved problems are an unlimited cell source and protection without lifelong drugs. The leading answer to supply is islets grown from stem cells: in 2025, Vertex's zimislecel (VX-880) reported that 10 of 12 recipients were insulin-independent at one year in an early-phase trial (NCT04786262), removing the donor-scarcity ceiling but still requiring immunosuppression.¹⁰ The remaining frontier — encapsulation and gene-edited "hypoimmune" cells that evade the immune system without drugs — is what would turn this narrow, last-resort procedure into a broadly usable cure.¹⁰ Figures as reported in the cited 2025 New England Journal of Medicine report of the FORWARD trial (NCT04786262); small early-phase sample.