Recombinant interleukin-2 at ultra-low doses studied for regulatory T-cell (Treg) expansion in autoimmune disease and immune aging. Distinct from high-dose IL-2 cancer immunotherapy — entirely different mechanism and safety profile at ultra-low doses.
85 minutes half-life; ultra-low dose regimens: 3 days on/2 weeks off in trials
SKUs
1
Evidence
Moderate Evidence
Low-dose Interleukin-2 (IL-2) refers to the use of interleukin-2, an immune signaling protein, at doses far lower than those used in cancer immunotherapy. At low doses, IL-2 selectively expands regulatory T cells (Tregs), which help prevent the immune system from attacking the body's own tissues. This approach has been studied for autoimmune diseases and inflammatory conditions.
Autoimmune Disease Research
Low-dose IL-2 has been studied in conditions including type 1 diabetes, lupus, rheumatoid arthritis, and graft-versus-host disease. Multiple phase 1 and 2 trials have shown it selectively expands Tregs without causing the toxic effects seen at the high doses used in cancer treatment.
Treg Biology Research
Low-dose IL-2 has become an important tool for studying regulatory T cell biology in humans. Research has characterized how Treg populations respond to different dosing regimens and how expansion of Tregs correlates with clinical outcomes in inflammatory diseases.
NASH and Metabolic Inflammation
Some research has examined low-dose IL-2 for metabolic inflammatory conditions including non-alcoholic steatohepatitis, based on the role of Tregs in limiting hepatic inflammation.
Selectively expands regulatory T cells at low doses without major toxicity.
Multiple phase 2 trials show signals of benefit in autoimmune conditions including lupus and type 1 diabetes.
The SELECT trial (for type 1 diabetes) and TRANSREG trial (for multiple autoimmune conditions) are notable examples of phase 2 research.
IL-2 receptor signaling is well-characterized — the Treg-selective effect at low doses is mechanistically explained.
Low-dose IL-2 has not been approved for autoimmune uses, and phase 3 trial data are still emerging. The dosing window for Treg-selective expansion is narrow — doses that are too high begin to expand other immune cell types including potentially harmful effector T cells. Administration is by injection, typically multiple times per week. Long-term safety beyond trial periods is not yet fully characterized.
The immune system includes both attack cells (effector T cells that fight infections and can cause inflammation) and peacekeeping cells (regulatory T cells, or Tregs, that calm the immune response and prevent it from attacking normal tissue). IL-2 is a signaling molecule that both types of T cells respond to, but they respond at different concentrations. At very low doses, Tregs are much more sensitive and expand preferentially. At higher doses, other immune cells also respond, which is what causes the severe side effects seen when IL-2 is used at high doses for cancer. By giving IL-2 at very low doses, researchers can selectively amplify the peacekeeping arm of the immune system, potentially damping down autoimmune activity without shutting down normal immune defense.
At low doses, IL-2 is generally well-tolerated compared to the high-dose cancer therapy regimen. Common side effects include injection site reactions and mild flu-like symptoms. The narrow therapeutic window between Treg-selective and broader immune stimulation means dosing precision is important. Long-term effects of chronic low-dose IL-2 are still being studied. It is not FDA-approved for autoimmune indications.
Moderate Evidence
This compound has been studied in Phase 1 or Phase 2 human trials. Evidence is encouraging but more large-scale trials are needed.
Published Research Ranges
0.33–3 million IU/day (ultra-low vs 600,000 IU/kg for cancer) in Treg expansion trials; subcutaneous
Research Context Only: These are ranges reported in published scientific studies for educational reference. They are not dosing recommendations. This is not medical advice. Always consult a qualified healthcare professional.
Sources listed here are from the platform research library. All links open the original publication. No citations are generated by AI.
Low-Dose IL-2 Selectively Expands Regulatory T Cells in Autoimmune Disease
Long-Term Follow-up of a Phase III Study of ch14.18 (Dinutuximab) + Cytokine Immunotherapy in Children with High-Risk Neuroblastoma: COG Study ANBL0032
ALT-803, an IL-15 superagonist, in combination with nivolumab in patients with metastatic non-small cell lung cancer: a non-randomised, open-label, phase 1b trial
Metronomic cyclophosphamide regimen selectively depletes CD4+CD25+ regulatory T cells and restores T and NK effector functions in end stage cancer patients
The use of anti-inflammatory drugs in the treatment of people with severe coronavirus disease 2019 (COVID-19): The Perspectives of clinical immunologists from China
Research Education Only: This profile is for educational purposes only. All information is sourced from published scientific literature. This is not medical advice. Not for human consumption. Consult qualified medical professionals for any health decisions.
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