A Phase 1/2 interventional study of QEL-005 in Diffuse Cutaneous Systemic Sclerosis, Rheumatoid Arthritis (RA) and Systemic Sclerosis (SSc), sponsored by Quell Therapeutics Limited. Recruiting at 10 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-19.
Sponsored by Quell Therapeutics Limited · Phase 1/2, Interventional, and Treatment
This study is a Phase 1/2, open-label clinical trial to test an experimental treatment called QEL-005 in adults with two autoimmune conditions: diffuse cutaneous systemic sclerosis (dcSSc) and difficult-to-treat rheumatoid arthritis (D2TRA). The main goals are to find out whether QEL-005 is safe, how well people tolerate it, and whether it may help reduce disease activity or improve symptoms.
QEL-005 is made from a participant's own white blood cells (autologous cells). These cells are collected and then changed in a laboratory using genetic methods to create specialized immune cells called CAR-T regulatory cells that target a protein on B cells called CD19. These modified cells are then given back to the participant by intravenous (IV) infusion.
To take part, eligible participants will first have a procedure called leukapheresis, where some of their white blood cells are removed from the blood. The study team will use these cells to manufacture QEL005. After QEL005 is ready, participants will receive an IV infusion of their modified cells, stay in hospital overnight for monitoring, and will then be followed closely in the clinic.
Throughout the trial, participants will have regular safety checks, which may include blood tests, imaging scans, questionnaires about symptoms and daily functioning, and biopsies taken from involved tissues, to help understand how QEL005 is working in the body. Detailed follow up will be for 1 year after QEL-005 infusion, and there is long-term follow up for a total of 15 years, which is standard for cell therapies. The information from this Phase 1/2 study will help determine an appropriate dose and dosing schedule of QEL005 for future studies.
This is a single-arm, open label, multicentre, Phase 1/2, first in human study of QEL005 in adult participants with diffuse cutaneous systemic sclerosis (dcSSc) or difficult to treat rheumatoid arthritis (D2TRA). QEL005 is an autologous chimeric antigen receptor regulatory T-cell (CAR-Treg) therapy directed against the CD19 marker found on B cells.
The primary objective of this study is to evaluate the safety and tolerability of single IV infusions of QEL005 across different dose levels in participants with dcSSc or D2TRA. Secondary and exploratory objectives include assessment of preliminary clinical efficacy (for example, changes in disease activity scores, skin involvement, or joint symptoms, as appropriate for each disease) and evaluation of biological activity (including effects on B cell populations, immune biomarkers, and other laboratory measures).
The study uses a dose escalation phase then a dose expansion phase. In the dose escalation phase, sequential cohorts of participants receive increasing doses of QEL005 under close safety monitoring. Safety assessments include recording of adverse events, vital signs and laboratory abnormalities.
QEL005 is manufactured from autologous leukapheresis material obtained at baseline. Participants undergo leukapheresis for collection of peripheral blood mononuclear cells, which are then genetically modified ex vivo to express a CD19directed CAR-T regulatory cell.
Over the course of the trial, participants will attend scheduled visits for clinical evaluations, laboratory tests, imaging studies, and patient reported outcome questionnaires, as well as tissue biopsies, to characterize the safety profile and to explore pharmacodynamic and immunologic effects of QEL005. There are detailed assessments over the first year following QEL-005 infusion, and then additional long-term follow up for 15 years, standard for cell therapy trials. Data from this Phase 1/2 trial will inform the recommended dose, regimen, and patient population for subsequent studies of QEL005 in autoimmune diseases.
310 studies on the registry are indexed under Scleroderma, Diffuse; 76 are open to participants now.
This study's planned enrollment of 16 is below the median of 38 across 227 interventional studies indexed under Scleroderma, Diffuse.
Browse Scleroderma, Diffuse studies →Quell Therapeutics Limited is the lead sponsor of 3 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Specific inclusion criteria for participants with difficult to treat rheumatoid Arthritis (D2TRA) only:
Specific inclusion criteria for participants with diffuse cutaneous systemic sclerosis (dcSSc) only:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dose escalation will involve 3 distinct dose level ranges. Each dose level will enrol at least 3 participants
Drug: QEL-005
The dose selected for dose expansion will be based on safety and any relevant additional data emerging from the Dose Escalation phase
Drug: QEL-005
QEL-005 is an autologous cell therapy that is composed of engineered regulatory T cells transduced with a lentiviral vector containing a CAR directed against the B cell marker CD19. Treatment will be given via an IV infusion.
D2TRA & SSc: Incidence of Protocol-Defined Dose Limiting Toxicities (DLTs) to Assess Safety and Tolerability (Dose Escalation Phase Only)
Assessment of safety and tolerability of QEL-005 during the Dose Escalation Phase, as measured by the incidence of protocol-defined dose limiting toxicities (DLTs).
Time frame: up to 28 days post-infusion
D2TRA & SSc: Incidence and grade of treatment-emergent adverse events (TEAEs), adverse events (AEs) and adverse events of special interest (AESIs)
Assessment of safety and tolerability of D2TRA \& SSc through the collection and evaluation of the incidence and severity grades of all TEAEs, AEs, and AESIs using the Common Terminology Criteria for Adverse Events (CTCAE)
Time frame: From time of signing the informed consent form (ICF) through to week 52
D2TRA & SSc: Incidence of clinically significant abnormalities in safety laboratory parameters, electrocardiogram (ECG) findings, and vital signs
Evaluation of safety through the assessment of clinically significant abnormalities in safety laboratory parameters, ECG findings, and vital signs.
Time frame: Up to week 52
D2TRA: Change from baseline in American College of Rheumatology (ACR) response criteria
Assessment of absolute values and change from baseline using a validated functional assessment tool that incorporates patient-reported measures of physical function and clinician-reported evaluations of disease activity, joint involvement, and pain
Time frame: Week 4,8,12,24,38 and 52
D2TRA: Change from baseline in a disease activity score-28 C-reactive protein (DAS28-CRP)
Assessment of absolute values and change from baseline using a validated composite clinical disease activity score that incorporates clinician-reported joint assessments, patient-reported disease activity, and laboratory or physiological indicators of inflammation
Time frame: Week 4,8,12,38 and 52
D2TRA: Change from baseline in Health Assessment Questionnaire Disability Index
Assessment of absolute values and change from baseline in a standardised patient reported quality of life questionnaire evaluating overall disease impact
Time frame: Week 4,8,12,24,38 and 52
D2TRA: Change from baseline in Ultrasound Outcome Measure in Rheumatology (OMERACT) score
Changes in standardised imaging score assessing synovitis and synovial vascularity in predefined joint.
Time frame: Week 12 and 52
D2TRA: Clinical response status
Proportion of participants achieving predefined levels of disease activity improvements and functional improvements
Time frame: Week 12 and 52
D2TRA & SSc: Use of additional background disease modifying therapy
Need for escalation of background disease modifying therapy above permitted baseline medication
Time frame: Week 12 and 52
D2TRA: Cumulative steroid exposure
Total systemic steroid dose received over specified intervals
Time frame: Baseline to week 12 and baseline to week 52
D2TRA: Ability to reduce glucocorticoid dose
Proportion of participants able to reduce systemic glucocorticoid use below a predefined daily threshold
Time frame: Up to week 52
D2TRA & SSc: Change from baseline in autoantibodies
Evaluation of change in blood levels of disease related autoantibodies
Time frame: Baseline to week 52
D2TRA & SSc: Presence of replication competent viral vector
Assessment of detectable replication competent viral vector in blood
Time frame: Week 52
SSc: Change From Baseline in a Modified Rodnan Skin Score (mRSS)
Assessment of absolute values and change from baseline in a validated, standardised skin involvement assessment score evaluating the extent and severity of cutaneous involvement in systemic sclerosis.
Time frame: Week 12,24,38 and 52
SSc: Change from baseline in Digital ulcers
Number of digital ulcers
Time frame: Week 12, 24, 38 and 52
SSc: Change From Baseline in a Standardised Lung Function Assessment Score
Assessment of absolute values and change from baseline using a validated, standardized lung function assessment score that evaluates pulmonary functional capacity
Time frame: Week 12, 24, 38 and 52
SSc: Change From Baseline in a Standardised High Resolution Computed Tomography (HRCT) Based Pulmonary Fibrosis Assessment Score
Assessment of absolute values and change from baseline in a validated, standardised HRCT based scoring system of interstitial lung disease, quantifying the extent and severity of pulmonary fibrosis.
Time frame: Week 24 and 52
SSc: Change From Baseline in a Standardised Positron Emission Tomography (PET) Based Pulmonary Fibrosis Assessment Score
Assessment of absolute values and change from baseline in a validated, standardised PET based assessment of fibroblast activation and fibrosis activity in predefined lung regions.
Time frame: Week 24 and 52
SSc: Change from baseline in Health Assessment Questionnaire Disability Index
Assessment of absolute values and change from baseline in a standardised patient reported quality of life questionnaire evaluating overall disease impact
Time frame: Week 12, 24, 38 and 52
SSc: Change From Baseline in the EUropean Scleroderma Trials And Research group (EUSTAR) Activity Index
Assessment of absolute values and change from baseline in a validated composite clinical disease activity assessment score used to evaluate systemic sclerosis disease activity.
Time frame: Week 12, 24, 38 and 52
SSc: Change From Baseline in the Sclerderma Clinical Trial Consortium (SCTC) Disease Damage Index
Assessment of absolute values and change from baseline in a validated disease damage assessment score used to evaluate longer-term organ involvement.
Time frame: Week 12, 24, 38 and 52
Change from Baseline in the European Alliance of Associations for Rheumatology Systemic Sclerosis Impact of Disease (EULAR ScleroID)
Assessment of absolute values and change from baseline in a validated patient-reported outcome questionnaire designed to measure the overall impact of systemic sclerosis on patients' daily function and quality of life.
Time frame: Week 12, 24, 38 and 52
Plan to share: No
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