Type 1 disease modification: preserve, replace, protect
Separate immune modulation, beta-cell replacement, cell protection, and clinically meaningful insulin independence.
By The Diabetes Guide editorial project · Updated 30 Sept 2026
On this page
Scientists are working on three tasks for Type 1: save the cells that are left, replace the ones that are lost, and protect the new ones.
Step 1: Preserve
Immune-changing medicines may slow the loss of insulin-making in some people.
For example: Putting a fence around the last apple trees so they are not chopped down.
Step 2: Replace
Donor or lab-grown islet cells can make insulin again, for some people, at the moment with medicines that dampen the immune system.
For example: Planting new trees in the orchard.
Step 3: Protect
New cells can still be attacked or rejected, so protection is the hardest part.
For example: Even new trees need a fence, or the same problem returns.
Remember: Solving one task does not solve the other two.
The full story
Want more? Below is the detailed version with the real science words. It is fine to skip it.
Three distinct research tasks
Preserve remaining beta-cell function through immune modulation. Replace lost capacity with donor or manufactured cells. Protect those cells from rejection and autoimmune injury. Achieving one task does not automatically solve the others.
Type 1 research: solve several problems together
Preserve. Immune modulation can preserve function or delay progression in selected people.
Read every step in a list
- Preserve. Immune modulation can preserve function or delay progression in selected people.
- Replace. Donor or stem-cell-derived islets can supply insulin-producing cells.
- Protect. Immune rejection and recurrent autoimmunity require durable solutions.
- Scale safely. Long-term safety, reliable manufacturing, cost and access remain essential.
What human studies establish
The 2026 pediatric Stage 3 teplizumab indication targets decline of insulin production. Zimislecel offers early evidence of functional replacement under immunosuppression. Edited donor islets offer a small, short-term proof of immune protection. Their populations, endpoints and evidence strength differ substantially. 123
What would count as durable progress?
Longer follow-up, independent replication, clinically important benefit, acceptable harms and scalable access matter more than a headline. Read the 2026 evidence review for dates and limitations.
Trace the evidence
Sources and further reading
1.FDA accelerated approval: teplizumab in selected recently diagnosed pediatric Stage 3 T1D (opens in a new tab)
US Food and Drug Administration · 2026 · Regulatory
Who was studied, limits and source check
Population: Children aged 8–17 recently diagnosed with Stage 3 T1D
Sample: PROTECT: 328 participants
Limitations: June 12 accelerated approval based on C-peptide preservation, a surrogate. Confirmatory clinical benefit and label conditions matter.
Source checked 2026-09-30. See the original publication for full methods.
2.Stem Cell–Derived, Fully Differentiated Islets for Type 1 Diabetes (opens in a new tab)
Reichman et al.; New England Journal of Medicine · 2025 · Early human study
Who was studied, limits and source check
Population: Selected adults with T1D, severe hypoglycemia and impaired awareness
Sample: 14 with ≥12-month follow-up; 12 at full dose
Limitations: Small, uncontrolled interim analysis; required immunosuppression; serious adverse events and deaths occurred. Not a routine cure.
Source checked 2026-09-30. See the original publication for full methods.
3.Survival of Transplanted Allogeneic Beta Cells with No Immunosuppression (opens in a new tab)
Carlsson et al.; New England Journal of Medicine · 2025 · Early human study
Who was studied, limits and source check
Population: One adult with long-standing T1D
Sample: 1 participant; 12-week reported follow-up
Limitations: Single participant, low cell dose and short follow-up. Does not demonstrate generalizable insulin independence.
Source checked 2026-09-30. See the original publication for full methods.
Source checking is an editorial literature check, not independent medical review. This page is for learning. It cannot diagnose you or make a treatment plan. Evidence labels describe the cited claims, not the whole topic.
What does “Preliminary” mean?
Early results. They need to be repeated. Like a first test drive of a new car.
Keep reading
The body
The one-page mental model
Diabetes means there is too much sugar in the blood for too long, because the body does not have enough insulin or cannot use it well.
Type 1
Type 1 diabetes: the complete journey
Type 1 diabetes is usually an autoimmune condition. The body’s defence system harms the beta cells, so less and less insulin is made.
Type 2
Type 2 diabetes: how the system changes
Type 2 diabetes happens when the body’s need for insulin grows and the pancreas cannot keep up, so sugar slowly rises.