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Phase 1TerminatedNCT05565248

VCTX211: CRISPR gene-edited hypoimmune stem-cell islets

A first-in-human trial of CRISPR-edited, stem-cell-derived insulin-making cells engineered to hide from the immune system, so they could be implanted without anti-rejection drugs. The second-generation successor to VCTX210, it was terminated early after dosing only 5 people, with no efficacy results posted; its value is as a proof-of-concept step for "hypoimmune" gene editing.

Primary endpoints

  • Incidence of adverse events related to VCTX211, the implant procedure, and study interventions (safety/tolerability)
  • Change from baseline in C-peptide, a marker of the implanted cells producing insulin

Results so far

None reported. No results were posted to ClinicalTrials.gov, and no peer-reviewed efficacy data (such as C-peptide, time-in-range, or insulin-use changes) have been published. The study was terminated, with the registry citing follow-up of participants in a separate long-term study (VCTX-201).

The full picture

What was being tested and why it matters

VCTX211 tested a bold idea: instead of giving someone donor islet cells and then suppressing their immune system for life, you edit the cells themselves so the immune system leaves them alone.1 The product combined lab-grown, stem-cell-derived pancreatic cells (called PEC211) — engineered with CRISPR/Cas9 to evade immune attack and survive better — placed inside a small, removable, perforated implant device.2 If it worked, people with type 1 diabetes might one day get insulin-making cells without the toxic anti-rejection drugs that make islet transplants impractical for most.1

It was the second-generation successor to VCTX210, the first-ever gene-edited cell replacement therapy dosed in a person (February 2022).3 VCTX210's cells were edited to knock out a gene called B2M (which normally flags cells to the immune system) and add PD-L1 (a "don't attack me" signal).4 VCTX211 added further edits aimed at dodging both T-cells and natural killer cells and resisting cellular stress.2

Who it was for and how it was designed

The trial enrolled adults aged 18-65 with type 1 diabetes for at least 5 years, on a stable regimen.5 It was an open-label, single-group Phase 1 study (no randomization, no placebo) — a first-in-human safety test — run at two Canadian sites, the University of Alberta and the University of British Columbia.5 The main goals were safety (tracking side effects) and a first look at whether the implanted cells made insulin, measured by C-peptide.5

What happened

The study was terminated, having enrolled just 5 participants — far short of its planned size.5 The registry lists the reason as participants being followed in a separate study (VCTX-201).5 No efficacy results were posted, and none have been published in peer-reviewed form.5 In the background, sponsor Vertex Pharmaceuticals ended its cell-protection collaboration tied to this program in January 2024, leaving CRISPR Therapeutics to carry it forward.6

What it means and what's next

Despite ending early without data, VCTX211 matters as a real-world proof-of-concept for "hypoimmune" editing — the strategy of making transplanted cells invisible to the immune system, which underpins much of the next wave of T1D cure research.7 The unanswered question it leaves is the central one for the whole field: can edited cells survive and keep working long-term without immunosuppression?7

References

  1. CRISPR Therapeutics & ViaCyte. First Patient Dosed in Phase 1 Trial of Novel Gene-Edited Cell Replacement Therapy for T1D. Press release (2022). https://crisprtx.com/about-us/press-releases-and-presentations/crispr-therapeutics-and-viacyte-inc-announce-first-patient-dosed-in-phase-1-clinical-trial-of-novel-gene-edited-cell-replacement-therapy-for-treatment-of-type-1-diabetes-t1d ↩ ↩2

  2. CRISPR Medicine News. Clinical Trial: Type 1 Diabetes (NCT05565248). CRISPR Medicine (2023). https://crisprmedicinenews.com/clinical-trial/type-1-diabetes-t1d-nct05565248/ ↩ ↩2

  3. GEN. Sweet Spot: CRISPR Therapeutics, ViaCyte Dose First Patient with Cell Therapy for Type 1 Diabetes. Genetic Engineering & Biotechnology News (2022). https://www.genengnews.com/gen-edge/sweet-spot-crispr-therapeutics-viacyte-dose-first-patient-with-cell-therapy-for-type-1-diabetes/ ↩

  4. Sintov E, et al. Whole-genome CRISPR screening identifies genetic manipulations to reduce immune rejection of stem cell-derived islets. Stem Cell Reports (2022). https://pmc.ncbi.nlm.nih.gov/articles/PMC9481918/ ↩

  5. U.S. National Library of Medicine. VCTX211 in Subjects With T1D (NCT05565248). ClinicalTrials.gov (2025). https://clinicaltrials.gov/study/NCT05565248 ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  6. JDCA. Vertex T1D Trial Paused After 2 Unrelated Patient Deaths; CRISPR Collab Ends Next Day. Juvenile Diabetes Cure Alliance (2024). https://www.thejdca.org/publications/report-library/archived-reports/2024-reports/vertex-t1d-trial-paused-after-2-unrelated-patient-deaths-crispr-collab-ends-next-day.html ↩

  7. 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