Stem-cell-derived islet clusters (Seraxis SR-02)
Seraxis
Seraxis SR-02 is allogeneic pancreatic endocrine cell clusters grown from a proprietary stem-cell line and implanted into the omentum (the fatty apron in the abdomen), where they aim to form a functional mini-pancreas. Its first-in-human Phase 1/2 trial (SUGR) is registered with a November 2026 start and is not yet recruiting; it requires immunosuppression. A gene-edited, immunosuppression-free successor (SR-03) is company-stated but has no registered trial.
The scorecard
No human data yet — the Phase 1/2 trial is registered but does not start until November 2026, so insulin independence in people with T1D is unproven and scored on potential only. The trial's efficacy measure is stimulated C-peptide (a marker of the graft making insulin), not insulin independence.[2]
Durability rests on preclinical and manufacturing data; the omentum site is intended to support stable engraftment, but no human durability has been demonstrated.[1]
The trial registry states plainly that immunosuppression to prevent rejection is required in this first-in-human study; the immunosuppression-free advance is deferred to the separate gene-edited SR-03 program, which has no registered trial.[2]
Cells are surgically implanted onto the omentum (a laparoscopic abdominal procedure) rather than infused, making it more invasive than a portal-vein infusion, though the site is accessible.[1]
Nothing is available yet, and the registered trial is narrow — adults 18–65, diagnosed with T1D before age 40, insulin-dependent for at least five years, with recurrent severe hypoglycemia. Only nine people are planned. An unlimited stem-cell source could broaden eligibility later if efficacy is shown.[2]
Earliest-stage of the cell-replacement candidates here: FDA IND allowed (Oct 2024), and the Phase 1/2 dose-escalation study (SUGR) is registered for a November 2026 start with 9 planned participants but is not yet recruiting. No clinical readouts.[2]
The full picture
Seraxis is pursuing a manufactured, off-the-shelf islet replacement for type 1 diabetes. Its lead candidate, SR-02, is made of allogeneic pancreatic endocrine cell clusters grown at clinical scale from a proprietary stem-cell line that the company reprogrammed from healthy donor pancreas tissue. The aim is an essentially unlimited supply of insulin-producing cells, sidestepping the scarcity of deceased-donor pancreases that limits conventional islet transplants.
What distinguishes SR-02 from liver-infusion approaches is the implantation site. Rather than delivering cells into the hepatic portal vein, Seraxis places the clusters onto the omentum — the fatty, blood-vessel-rich apron of tissue in the abdomen — where they are intended to engraft and organize into a functioning endocrine pancreas outside the native organ. This site is surgically accessible and potentially supportive of long-term graft survival.
SR-02 is at an early stage. The U.S. FDA allowed its investigational new drug application in late 2024, and the resulting first-in-human study — a Phase 1/2 dose-escalation trial called SUGR (NCT07581197) — is now registered on ClinicalTrials.gov. It is not yet recruiting: the listed start date is November 2026, with primary completion in November 2028 and study completion in November 2029. It plans to enrol just nine adults aged 18 to 65 who were diagnosed with type 1 diabetes before age 40, have depended on insulin for at least five years, and have recurrent severe hypoglycemia. The main things being measured are safety over the first year and the change in C-peptide (a marker that the transplanted cells are making insulin) after a mixed-meal test — not insulin independence. In short, no human results exist yet, and the earliest meaningful data are still years out.
SR-02 also still relies on immunosuppression: the trial registry states directly that anti-rejection drugs will be required in this first-in-human study. Seraxis says it is separately developing a gene-edited successor, SR-03, engineered so that immunosuppression would not be needed. That remains a company-stated plan — no SR-03 trial is registered, and no start date is confirmed.
Coming soon
ETA · Phase 1/2 dose-escalation trial (SUGR, NCT07581197) registered with a Nov 2026 start and not yet recruiting; primary completion Nov 2028 and study completion Nov 2029, so first human data are years away. Immunosuppression is required in this first-in-human study
- →First-in-human Phase 1/2 dose-escalation trial (SUGR) of SR-02 begins — 9 adults with severe type 1 diabetes · Nov 2026
- →Gene-edited successor SR-03, engineered so anti-rejection drugs are not needed — company-stated, but no trial is registered and no start date is confirmed · Timing unconfirmed
Sources
- [1]Seraxis Announces FDA IND Allowance for Clinical Study of SR-02 Replacement Islets for Type 1 Diabetes · manufacturer · 2024-10-01
- [2]A Phase 1/2 Dose Escalation Study to Evaluate the Safety and Efficacy of SR-02 Pancreatic Endocrine Cell Clusters Implanted in the Omentum of Adults With Type 1 Diabetes (SUGR; NCT07581197) · registry · 2026-07-14 — Not yet recruiting; enrolment 9; start Nov 2026; primary completion Nov 2028; study completion Nov 2029. States that immunosuppression is required in this first-in-human study.
- [3]Breakthrough T1D — Cell therapies in clinical trials for type 1 diabetes (Seraxis SR-02 / SR-03 overview) · news