CHILL Trial Launch: Quell’s QEL‑005 CAR‑Treg Enters Phase 1/2

Quell Therapeutics said in a company press release that it has initiated the Phase 1/2 CHILL basket clinical study evaluating its autologous CAR‑Treg candidate QEL‑005 in rheumatoid arthritis and systemic sclerosis, following UK Medicines and Healthcare products Regulatory Agency (MHRA) approval of the company’s Clinical Trial Application (CTA). The announcement outlines the study’s scope, the company’s description of QEL‑005, and supporting preclinical and clinical observations it cites as context.

Quell describes CHILL as a multinational clinical study recruiting up to 16 adult participants across the UK, Germany, and Spain, with patient enrolment underway at leading clinical centres across the UK. The release also states that early clinical findings are expected during Q1 2027. These location, recruitment, and timing elements are presented as the core logistics and anticipated reporting window for this early‑phase program.

QEL‑005 is characterized in the release as a novel product candidate built on the Phenotype Locked™ CAR‑Treg platform and engineered around a Treg‑optimized CD19‑directed chimeric antigen receptor. Quell states that the CAR‑Tregs are activated in the presence of B cells and are designed to be selectively activated and exert immune suppression within inflamed tissues and surrounding lymphoid structures. The company presents these design features as rationale for evaluating the therapy in inflammatory disease settings, without asserting clinical outcomes.

As context for initiating CHILL, the release points to two categories of prior observations. First, Quell notes that preclinical results presented at ACR Convergence 2025 (October 2025) demonstrated immunomodulatory activity of QEL‑005 across multiple immune cell lineages involved in autoimmune inflammation. Second, the announcement cites findings from the company’s LIBERATE Phase 1/2 trial in liver transplantation as demonstrating clinical safety, persistence, and functional stability of its Phenotype Locked™ CAR‑Treg cells for over one year, along with evidence of trafficking and engraftment within target tissues. These observations are presented as background supporting the decision to move QEL‑005 into the CHILL clinical study.

CHILL is described as a Phase 1/2 multinational “basket” clinical study planning to recruit up to 16 adult participants in the UK, Germany, and Spain. Overall, the press release provides an overview of regulatory status, trial footprint, and how the company is positioning QEL‑005 and its cited supporting data, while leaving several operational and assessment details unstated.

Key Takeaways:

• Quell Therapeutics reports UK MHRA CTA approval and initiation of its Phase 1/2 CHILL basket study evaluating autologous CAR‑Treg QEL‑005 in refractory rheumatoid arthritis and systemic sclerosis.
• The release describes a multinational footprint (UK, Germany, Spain), a planned enrollment size of up to 16 adults with enrollment underway in the UK, and an expectation for early clinical findings in Q1 2027.
• QEL‑005 is described as a Phenotype Locked™ CAR‑Treg built around a Treg‑optimized CD19‑directed CAR, and the company cites preclinical ACR Convergence 2025 immunomodulatory findings and LIBERATE liver transplant observations (including safety and >1‑year persistence/functional stability with tissue trafficking/engraftment) as contextual support.