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Beta Bionics iLet — bihormonal (insulin + dasiglucagon)

Beta Bionics (glucagon: Zealand Pharma)

The investigational dual-hormone iLet, descended from the Boston University/MGH bionic pancreas, pairing autonomous insulin dosing with dasiglucagon as a hypo-defending second hormone. Only the insulin-only iLet is FDA-cleared; this bihormonal configuration remains a research lineage that regulated sensor glucose to ~139 mg/dL with minimal input in early home-use studies.

Years awayEarly evidencedual-hormoneglucagonfully-closed-loop

The scorecard

Hypo protection82

In the home-use trial the bihormonal config cut time below 54 mg/dL to a median 0.2% vs 0.6% insulin-only, with autonomous microdose dasiglucagon defending lows.

Time in range76

Achieved 79% time in 70-180 mg/dL and mean glucose 139 mg/dL with body-weight-only setup and no carb counting, beating the insulin-only arm (72%, 149 mg/dL).

Automation level80

Fully autonomous adaptive dosing initialized only with body mass; no carb counting, though meals were still announced qualitatively in the iLet workflow.

Maturity18

Only a 10-person, 7-day feasibility study exists for the dasiglucagon configuration; the bihormonal iLet is not FDA-cleared, and its successor — using a different glucagon formulation — is back at the Phase 2a feasibility stage, still far from a registration trial.

Low burden45

Two chambers and a second consumable, but a single prefilled dasiglucagon cartridge lasted the full 7 days with no occlusions or site reactions; mild nausea was the main side effect.

Access & cost5

Not available anywhere: investigational only, with no regulatory clearance or commercial supply of the bihormonal configuration.

As with AID systems, glycemic criteria reflect the levels achieved in real-world or trial Type 1 use rather than the improvement over baseline, and Type 2 diabetes data is not used to score a Type 1 system.

The full picture

The bihormonal iLet is the dual-hormone version of Beta Bionics' bionic pancreas, descended from the Boston University and Massachusetts General Hospital "bionic pancreas" research program.1 It delivers two hormones: insulin to bring glucose down, and glucagon — the body's natural counter-hormone — in tiny automated microdoses to push glucose back up before a low becomes dangerous. That second hormone is what lets a closed loop run more aggressively without trading tight control for hypoglycemia.2 In this configuration the glucagon is dasiglucagon, a 29-amino-acid glucagon analog engineered by Zealand Pharma with seven substitutions so it stays stable as a ready-to-use liquid at neutral pH — solving the old problem that natural glucagon clumps and degrades within hours in water and must be reconstituted fresh.3

The defining evidence is a 2021 home-use study, the first human test of the bihormonal iLet and the first multi-day use of dasiglucagon. Ten adults with type 1 diabetes used each configuration for 7 days with no diet or exercise restrictions, the device initialized only with body weight.4 In the bihormonal arm, mean sensor glucose was 139 mg/dL with 79% time in range (70-180 mg/dL), versus 149 mg/dL and 72% on insulin alone. Median time below 54 mg/dL — the dangerous-low threshold — fell to just 0.2% (from 0.6%).4 This echoed earlier bionic-pancreas trials: a 2014 outpatient study reached a mean of 138 mg/dL,1 and a 2016 home-use trial (using reconstituted human glucagon) lowered mean glucose to ~140 mg/dL with less hypoglycemia and no carb counting.2

Device burden is the honest trade-off. A two-hormone pump means a second reservoir and a second consumable, but the 2021 study was encouraging on practicality: a single prefilled dasiglucagon cartridge lasted the entire 7 days (average dose 0.35 mg/day), with no occlusions or infusion-site reactions. The main side effect was mild nausea (0.47 on a 0-10 scale), with one episode of vomiting.4 The chief complication was insulin leakage at the cartridge connector — a hardware issue the team redesigned for future devices.4

Maturity and access — read this carefully. Only the insulin-only iLet is FDA-cleared (May 2023, for people 6 and older with type 1 diabetes, paired with a compatible CGM) and commercially sold.5 The bihormonal configuration is not approved or available anywhere — it remains investigational, evaluated only in small feasibility studies. Beta Bionics holds FDA Breakthrough Device Designation across its insulin-only, glucagon-only, and bihormonal configurations.3 We classify this record as research and historical lineage, not a shipping product.

What's coming. The original path to market was the Zealand dasiglucagon program.3 In May 2024, however, Beta Bionics signed an exclusive worldwide agreement with Xeris Biopharma to supply a pump-compatible glucagon using Xeris's XeriSol stable-glucagon technology for the bihormonal iLet — and by 2025 had completed pump-compatibility milestones with Xeris and reported a glucagon pharmacokinetic study in Canada.6 The dasiglucagon iLet is therefore best understood as the foundational research that proved a two-hormone closed loop works; the live commercial path now runs through the Xeris glucagon formulation.6

That path has restarted in the clinic. Beta Bionics reported completing a first-in-human Phase 2a feasibility trial in New Zealand in the fourth quarter of 2025 — the first human test of the full system together: the glucagon asset, the pump and the dosing algorithms.7 It then initiated a second Phase 2a feasibility trial in New Zealand in the first quarter of 2026.8 These are early feasibility studies, not registration trials: the company says it expects to progress afterwards to a Phase 2b, which it describes as a pivotal-trial-enabling, more robust feasibility trial.7 One honest caveat — neither announcement names the glucagon it is using, referring only to "the glucagon asset", so the Xeris formulation is the reasonable read from the 2024 supply agreement rather than something the 2026 releases state outright.8

References

  1. Russell SJ, El-Khatib FH, Sinha M, et al. Outpatient glycemic control with a bionic pancreas in type 1 diabetes. N Engl J Med (2014). https://doi.org/10.1056/NEJMoa1314474 ↩ ↩2

  2. El-Khatib FH, Balliro C, Hillard MA, et al. Home use of a bihormonal bionic pancreas versus insulin pump therapy in adults with type 1 diabetes: a multicentre randomised crossover trial. Lancet (2016). https://doi.org/10.1016/S0140-6736%2816%2932567-3 ↩ ↩2

  3. Zealand Pharma / Beta Bionics. Beta Bionics receives FDA Breakthrough Device Designation for the iLet Bionic Pancreas System (describes dasiglucagon as a stable, ready-to-use aqueous glucagon analog for the bihormonal iLet). GlobeNewswire (2019). https://www.globenewswire.com/news-release/2019/12/10/1958323/0/en/Zealand-Pharma-partner-Beta-Bionics-receives-FDA-Breakthrough-Device-Designation-for-the-iLet-Bionic-Pancreas-System.html ↩ ↩2 ↩3

  4. Castellanos LE, Balliro CA, Sherwood JS, et al. Performance of the insulin-only iLet bionic pancreas and the bihormonal iLet using dasiglucagon in adults with type 1 diabetes in a home-use setting. Diabetes Care (2021); NCT03840278. https://doi.org/10.2337/dc20-1086 ↩ ↩2 ↩3 ↩4

  5. U.S. Food and Drug Administration. FDA clears new insulin pump and algorithm-based software to support enhanced automatic insulin delivery (iLet ACE Pump and iLet Dosing Decision Software, insulin-only, ages 6+, May 2023). FDA (2023). https://www.fda.gov/news-events/press-announcements/fda-clears-new-insulin-pump-and-algorithm-based-software-support-enhanced-automatic-insulin-delivery ↩

  6. Beta Bionics. Fourth Quarter and Full Year 2024 Financial Results (completion and delivery by Xeris of a pump-compatible XeriSol glucagon formulation for the bihormonal pump; bihormonal pipeline advancement). GlobeNewswire (2025). https://www.globenewswire.com/news-release/2025/03/25/3049143/0/en/Beta-Bionics-Announces-Fourth-Quarter-and-Full-Year-2024-Financial-Results-and-Introduces-Annual-Guidance-for-Full-Year-2025.html ↩ ↩2

  7. Beta Bionics. Fourth Quarter and Full Year 2025 Financial Results and Annual Guidance for Full Year 2026 (completed first-in-human Phase 2a bihormonal feasibility trial in New Zealand covering the glucagon asset, pump and dosing algorithms; additional Phase 2a expected in H1 2026; Phase 2b anticipated to be pivotal-trial-enabling). GlobeNewswire (17 February 2026). https://www.globenewswire.com/news-release/2026/02/17/3239730/0/en/Beta-Bionics-Announces-Fourth-Quarter-and-Full-Year-2025-Financial-Results-and-Introduces-Annual-Guidance-for-Full-Year-2026.html ↩ ↩2

  8. Beta Bionics. First Quarter 2026 Financial Results and Raised Full Year 2026 Guidance (initiated a Phase 2a bihormonal feasibility trial in New Zealand in Q1 2026, including the glucagon asset, pump and dosing algorithms). GlobeNewswire (21 April 2026). https://www.globenewswire.com/news-release/2026/04/21/3278400/0/en/Beta-Bionics-Announces-First-Quarter-2026-Financial-Results-and-Raises-Full-Year-2026-Guidance.html ↩ ↩2

Coming soon

ETA · Research / investigational lineage — the dasiglucagon configuration was tested only in a 10-person, 7-day feasibility study; the bihormonal iLet is not FDA-cleared, and its successor (using a different glucagon formulation) is back in early Phase 2a feasibility trials

  • →Beta Bionics signed exclusive worldwide agreement with Xeris Biopharma to supply pump-compatible XeriSol glucagon for the bihormonal iLet, and completed pump-compatibility milestones · agreement May 2024; milestones by 2025
  • →Beta Bionics completed the first-in-human Phase 2a bihormonal feasibility trial in New Zealand — the first human test of the full system including its glucagon asset, pump and dosing algorithms · Q4 2025
  • →Beta Bionics initiated an additional Phase 2a bihormonal feasibility trial in New Zealand; a Phase 2b, which the company describes as pivotal-trial-enabling and a more robust feasibility trial, is expected to follow · Q1 2026