globenewswire news
Promising Early Safety Data as Quell Therapeutics Advances QEL-005 – a Novel Engineered nTreg Therapy – to Second Dose Cohort in CHILL Phase 1/2 Trial in Difficult-to-Treat Rheumatoid Arthritis and Systemic Sclerosis
- Safe completion of the first dose cohort in which QEL-005 was well tolerated, with no dose-limiting toxicities (DLTs), no treatment-related adverse events of special interest (AESIs) and no serious adverse events (SAEs)
- These early observations support the potential of QEL-005 to meet its target product profile as a transformational outpatient therapy for complex autoimmunity
- Initial clinical data from CHILL, including six-month durability, are expected in H1 2027
London, UK – 21 October, 2026 – Quell Therapeutics announced today that QEL-005, its CD19 B-cell activated Phenotype-Locked™ engineered nTreg therapy, has advanced to the second planned dose cohort in the CHILL Phase 1/2 clinical study. The decision follows completion of the first dose cohort in which QEL-005 was well tolerated, with no dose-limiting toxicities (DLTs), no treatment-related adverse events of special interest (AESIs) and no serious adverse events (SAEs).
In the first dose cohort, no acute toxicities were observed, including infusion reactions, cytokine release syndrome, local immune effector cell-associated toxicity syndrome, or immune effector cell-associated neurotoxicity syndrome, and no elevations in cytokines were observed. All participants were fit for discharge on the next morning following infusion. These early observations support the potential of QEL-005 to meet its target product profile as a transformational outpatient therapy for complex autoimmunity.
Professor Chris Buckley, Chief Investigator of the CHILL study, said: “Complex autoimmunity is driven by multiple pathogenic cell types. CHILL represents a unique opportunity to investigate the ability of nTregs to regulate - or ‘chill’ - that complex immune network, with the aim of achieving disease reset with benign safety. Completion of the first dose cohort provides an encouraging early indication of the potential safety of this therapeutic modality.”
CHILL is a Phase 1/2 study evaluating QEL-005, Quell’s engineered nTreg therapy for complex autoimmune diseases, including difficult-to-treat rheumatoid arthritis (D2TRA) and systemic sclerosis (SSc), using a lymphodepletion-free regimen. The first participant was dosed in the UK at Leeds Teaching Hospitals NHS Trust, followed by two participants at Oxford University Hospitals NHS Foundation Trust. Successful completion of this initial cohort marks an important milestone for the program.
The CHILL study is enrolling at seven sites in the UK, with a further four sites across Germany and Spain. Rapid study start-up has been a defining feature of CHILL, supported by outstanding engagement from physicians and patients. Initial clinical data from CHILL are expected in H1 2027.
Luke Devey, Chief Medical Officer at Quell Therapeutics, said: “We are encouraged by the early safety profile of QEL-005 and look forward to seeing clinical efficacy data, underpinned by deep translational insights, as the study progresses, with initial six-month data expected in H1 2027. We would like to thank the patients who have entrusted us with their care.”
Professor Francesco Del Galdo, Principal Investigator at Leeds Teaching Hospitals NHS Trust, said: “We were thrilled to dose the first CHILL patient in the world. The team worked together admirably, and it was rewarding to see the patient able to return home the day after dosing. This potentially transformational treatment is an important step forward for patients, and I am proud to contribute to this work.”
About QEL-005 and CHILL
QEL-005 is a novel therapeutic product candidate built on Quell’s proprietary Phenotype Locked™ engineered natural regulatory T cell (nTreg) platform. Regulatory T cells (Tregs) are specialized immune cells that keep the immune system in balance, calming excessive responses and helping prevent tissue damage. Natural Tregs (nTregs), also called thymic Tregs, develop in the thymus, where they acquire a stable identity and hard-wired to keep this protective role. QEL-005 is designed to be selectively activated and exert immune suppression within inflamed tissues and surrounding lymphoid structures, providing broad control of disease activity. Through an nTreg-optimized B-cell activated CAR, QEL-005 nTregs regulate immune responses through bystander suppression, modulating pro-inflammatory T cells, B cells, macrophages and stroma.
Results from preclinical studies, presented at the American College of Rheumatology annual meeting (ACR Convergence 2025) in October 2025, demonstrated the immunomodulatory activity of QEL-005 across multiple immune cell lineages involved in complex autoimmune inflammation, including B cells, T cells and inflammatory macrophages.
QEL-005’s broad mechanism of action leverages bystander suppression of multiple pathogenic immune cell types. This differentiated approach is designed to deliver durable transformational efficacy with a benign safety profile. QEL-005 remains an investigational product in development.
QEL-005, is currently being evaluated in the ongoing Phase 1/2 CHILL (Controlling Hyperactive Immunity with Long-lasting Lymphocytes) study in difficult-to-treat rheumatoid arthritis and systemic sclerosis. Initial clinical data are expected in H1 2027. QEL-005 mechanism of action provides the opportunity to address multiple complex autoimmune conditions (a pipeline-in-a-product) where B-cells are present at the site of the pathology.
About Quell Therapeutics
Quell Therapeutics is the world leader in developing engineered natural regulatory T cell (nTreg) therapies, for complex autoimmune conditions.
The Company is leveraging its proprietary FOXP3 Phenotype Lock™ technology and manufacturing capability to design and develop a pipeline of engineered nTreg cell therapies with potential for transformational efficacy, durability and benign safety.
Quell’s lead clinical asset, QEL-005, is a pipeline-in-a-product for complex autoimmune diseases and is currently being evaluated in the ongoing Phase 1/2 CHILL study in difficult-to-treat rheumatoid arthritis and systemic sclerosis. Initial clinical data are expected in H1 2027. www.chillstudy.life
Quell’s pipeline also includes two further clinic-ready engineered nTreg candidates:
- QEL-003, a Th17 cell activated nTreg as a pipeline-in-a-product for multiple indications, starting with inflammatory bowel diseases
- QEL-002, a Beta cell activated nTreg for treatment of recent onset type 1 diabetes.
Contacts
Quell Therapeutics
Media
