Experimental Arthritis Therapy Advances in Trial
The study moves to a new dosing phase for patients with rheumatoid arthritis, with initial safety markers met.
Updated on Oct. 21, 2026 in Arthritis
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Quell Therapeutics has advanced its experimental QEL-005 therapy into the second dose cohort of the CHILL clinical trial for rheumatoid arthritis and systemic sclerosis. Early results show no serious adverse events or dose-limiting toxicities in the first group of participants, with initial data expected in early 2027.
Why it matters
The study explores a new approach to managing complex autoimmune conditions by using regulatory T cells to address multiple pathogenic immune cell types at once. This trial is significant for patients as it tests a lymphodepletion-free regimen, potentially offering a different pathway for disease control.
The ongoing Phase 1/2 CHILL trial is currently enrolling participants at 11 sites across the UK, Germany, and Spain to evaluate the safety of QEL-005. While the first dose cohort reported no treatment-related adverse events, the study's overall efficacy is still under investigation.
The players
Quell Therapeutics
A biotechnology company focused on developing engineered T-regulatory cell therapies for autoimmune diseases.
Leeds Teaching Hospitals NHS Trust
A major UK hospital network that served as the initial site for dosing in the CHILL study.
Oxford University Hospitals NHS Foundation Trust
A prominent UK clinical research center participating in the patient dosing phase of the CHILL trial.
The details
QEL-005 uses nTregs, a type of regulatory T cell, designed to modulate the immune system through bystander suppression. By targeting T cells, B cells, macrophages, and stroma, the treatment aims to dampen the systemic immune response that drives complex autoimmunity. Notably, the study protocol avoids lymphodepletion, a procedure that clears immune cells before treatment, which is commonly required in other cell therapies.
Timeline
October 2025: Preclinical results were presented at ACR Convergence 2025.
October 21, 2026: Quell Therapeutics announced the move to the second dose cohort.
H1 2027: Initial clinical and six-month durability data are expected.
Health Landscape
The CHILL clinical trial represents a shift toward more targeted immune-regulatory therapies for complex autoimmune diseases like rheumatoid arthritis. This approach contrasts with traditional treatments that often suppress the entire immune system rather than specifically recalibrating the underlying immune network.
For patients with rheumatoid arthritis or systemic sclerosis, this trial highlights an emerging area of cell-based research that does not require lymphodepletion. While the treatment is not yet available for clinical use, patients interested in how such therapies work should discuss the latest clinical trial advancements with their rheumatologist.
The takeaway
This trial tests a novel way to manage immune-driven diseases by using engineered regulatory cells instead of broad immune suppression. Patients should track clinical progress for updates and consult their physician regarding ongoing research opportunities for chronic autoimmune conditions.
Further reading
For more information on current treatment trends, visit our Arthritis section.
More information
To review enrollment criteria or study details, visit the CHILL study information portal.
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Would you feel comfortable participating in a clinical trial for an engineered cell-based therapy?
