A Phase 1/2 interventional study of FT839 in ANCA-Associated Vasculitis (AAV), Idiopathic Inflammatory Myositis (IIM) and Rheumatoid Arthritis (RA), sponsored by Fate Therapeutics. Recruiting at 1 site in United States. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Fate Therapeutics · Phase 1/2, Interventional, and Treatment
The primary objectives of this trial are to evaluate the safety and tolerability and to determine the maximum tolerated dose (MTD) or recommended Phase 2 dose of FT839 with or without rituximab and/or background therapy and/or conditioning therapy.
This is a multicenter, Phase 1/2, open-label trial designed to evaluate the safety, pharmacokinetics (PK), anti-B-cell activity, and clinical activity of FT839 in participants with moderate-to-severe ANCA-associated vasculitis (AAV), idiopathic inflammatory myositis (IIM), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and systemic sclerosis (SSc).
Participants will receive FT839 as monotherapy or in combination with rituximab, with or without conditioning therapy and/or stable background therapy. Participants will be enrolled in 2 stages during the Phase 1 portion of the trial: a dose-escalation stage and a dose-expansion stage. In the dose-escalation stage, safety and tolerability will be assessed to define the MTD (or through the maximum assessed dose [MAD] in the absence of dose-limiting toxicities [DLTs] defining the MTD). The DLT evaluation period will extend from Day 1 through Day 29. Participants will be followed during the post-treatment follow-up period for up to 2 years after the first dose of FT839, followed by long-term-follow-up for safety and survival for up to 15 years after the first dose of FT839.
In the dose-expansion stage, participants will be enrolled into disease-specific cohorts to further evaluate the safety and activity of FT839.
Following completion of the Phase 1 portion, the Phase 2 portion of the trial will further evaluate the efficacy of FT839 within each disease cohort.
157 studies on the registry are indexed under Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; 75 are open to participants now.
This study's planned enrollment of 446 is above the median of 34 across 116 interventional studies indexed under Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis.
Browse Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis studies →Fate Therapeutics is the lead sponsor of 25 studies on the registry; 5 are open to participants now.
Of its 11 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
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.
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.
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.
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.
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.
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.
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.
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.
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
FT839, allogeneic T cells targeting CD19 and CD38
Biological: FT839
Single Intravenous (IV) infusion of FT839 administered on Day 1 and Day 4
Phase 1: Incidence of Dose-limiting Toxicity, Adverse Events, and Serious Adverse Events
Incidence and severity of dose-limiting Toxicity (DLT)s, adverse event (AE)s, and serious adverse event (SAE)s
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Change from baseline in Birmingham Vasculitis Activity Score
Birmingham Vasculitis Activity Score (BVAS) will be measured to evaluate the efficacy of FT839 in AAV. The BVAS score ranges from 0 to 63, with lower scores indicating better outcomes.
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Change from baseline in Manual muscle testing-8
Manual muscle testing-8 (MMT-8) will be measured to evaluate the efficacy of FT839 in IIM. The MMT-8 score ranges from 0 to 150, with higher scores indicating better outcomes.
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Change from baseline in Disease Activity Score using 28 joint counts and C-reactive protein (a composite measure)
Disease Activity Score using 28 joint counts and C-reactive protein (DAS28-CRP) will be measured to evaluate the efficacy of FT839 in RA. The validated composite measure DAS28-CRP score ranges from 0.0 to 9.4, with lower scores indicating better outcomes.
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Change from baseline in SLE Disease Activity Index 2000
SLE Disease Activity Index 2000 (SLEDAI-2K) score will be measured to evaluate the efficacy of FT839 in SLE. The SLEDAI-2K score ranges from 0 to 105, with lower scores indicating better outcomes.
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Change from baseline in Modified Rodnan skin score
Modified Rodnan skin (mRSS) score will be measured to evaluate the efficacy of FT839 in SSc. The mRSS score ranges from 0 to 51, with lower scores indicating better outcomes.
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 1: Maximum concentration and area under the curve of FT839 in peripheral blood
Pharmacokinetics (PK) of FT839 in peripheral blood including but not limited to maximum concentration (Cmax) and area under the curve (AUC) will be estimated based on observed plasma concentration-time data.
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Incidence of AEs and SAEs
Incidence and severity of AEs and SAEs
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: Cmax of FT839 in peripheral blood
PK of FT839 in peripheral blood including but not limited to Cmax will be estimated based on observed plasma concentration-time data
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Phase 2: AUC of FT839 in peripheral blood
PK of FT839 in peripheral blood including AUC will be estimated based on observed plasma concentration-time data
Time frame: From enrollment to the end of the post-treatment follow-up at 2 years
Plan to share: No
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