Clinical Study of BCT301 Cell Injection Therapy for Refractory Autoimmune Diseases

A Study of BCT301 (Anti-CD19 Chemically Induced Pluripotent Stem Cell (CiPSC)-Derived CAR-iT Cells) Therapy for Refractory Autoimmune Diseases

This study primarily involves the use of BCT301, an anti-CD19 Chemically induced pluripotent stem cell (CiPSC)-derived CAR-iT cells, for the treatment of patients with refractory autoimmune diseases, aiming to evaluate its safety, tolerability, and dose-limiting toxicities(DLT), and to determine the recommended therapeutic dose for further investigation. Additionally, the study assesses the efficacy of BCT301 cell injection in refractory autoimmune diseases, as well as the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics in study participants.

Study Overview

• Status: Not yet recruiting
• Conditions: Antiphospholipid Syndrome; ANCA Associated Vasculitis; Sjogren Syndrome; Inflammatory Myositis; Systemic Sclerosis (SSc); System Lupus Erythematosus
• Intervention / Treatment: Biological: BCT301

Detailed Description

Autoimmune diseases are a class of disorders caused by abnormal immune responses against the body's own tissues or organs. Although significant therapeutic advances have been made, such as the use of biologics (e.g., rituximab), most available drugs can only alleviate symptoms or slow disease progression, rather than achieve a complete cure.BCT301 cell injection is a CD19-targeted CAR-iT (chemically induced T-cell) therapy derived from human chemically induced pluripotent stem cells (CiPSCs) through chemical reprogramming technology. Starting from healthy donor cells, human CiPSCs are generated via small molecule-based reprogramming, followed by induced hematopoietic differentiation, iT-cell differentiation and expansion, and finally CAR lentiviral transduction to produce the off-the-shelf, CD19-targeted CAR-iT cell product (BCT301 cell injection). This approach holds promise as a potentially effective treatment strategy.

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Early Phase 1

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

General Inclusion Criteria

1. Voluntarily sign the informed consent form.
2. Male or female, aged 18-80 years (inclusive), with a body weight ≥40 kg.
3. Female participants of childbearing potential and male participants with female partners of childbearing potential must use medically approved contraceptive methods or practice abstinence during the treatment period and for at least 6 months after the end of the treatment. Female participants of childbearing potential must have a negative serum human chorionic gonadotropin (HCG) test within 7 days prior to enrollment and must not be breastfeeding.

4. Participants currently receiving one or more of the following treatments at stable doses: glucocorticoids, antimalarials, immunosuppressants:

   1. If the participant is receiving glucocorticoid therapy, the following conditions must be met: the maximum dose at screening and during the screening period is 30 mg/day of prednisone (or equivalent). The dose must have been stable for ≥7 days prior to screening, and adjustments during the screening period must not exceed 5 mg/day of prednisone (or equivalent);
   2. If the participant is receiving antimalarials and/or conventional immunosuppressants: the treatment must have been initiated ≥12 weeks prior to screening. The dose must have been stable for ≥8 weeks prior to screening and remain stable during the screening period;
   3. If biological agents (belimumab, telitacicept, rituximab, etc.) were used prior to the screening period, a washout period of at least 5 half-lives must be completed before screening.
5. Peripheral blood B cells must show positive CD19 expression as detected by flow cytometry.

Disease-Specific Inclusion Criteria

1. Systemic Lupus Erythematosus (SLE)

1. Meet the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria for SLE.
2. Have moderate to severe disease activity at screening, with a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2000) score >6.
3. Have inadequate response to conventional therapy or experience disease relapse after remission. Conventional therapy includes glucocorticoids (at full or pulse doses), two or more immunosuppressants, or biologic agents for at least 6 months, including cyclophosphamide, mycophenolate mofetil, cyclosporine, tacrolimus, azathioprine, leflunomide, methotrexate, belimumab, telitacicept, and rituximab.
4. Have positive serological autoantibody tests: positive antinuclear antibodies (ANAs) and/or anti-ds-DNA antibodies and/or anti-Sm antibodies.

2. Systemic Sclerosis (SSc)

1. Meet the 2013 EULAR/ACR classification criteria for SSc.

2. Fulfill either (a) or (b) below:

   1. Inadequate response to conventional therapy or disease relapse after remission. Conventional therapy includes glucocorticoids (at full or pulse doses), two or more immunosuppressants, or biologic agents for at least 6 months, including cyclophosphamide, mycophenolate mofetil, cyclosporine, tacrolimus, azathioprine, leflunomide, methotrexate, belimumab, telitacicept, and rituximab.
   2. Disease progression: skin progression with a modified Rodnan Skin Score (mRSS) ≥10; and/or interstitial lung disease evidenced by ground-glass opacities on high-resolution computed tomography (HRCT); a decline in forced vital capacity (FVC) ≥10%, or a decline in FVC ≥5% accompanied by a decline in diffusing capacity for carbon monoxide (DLCO) ≥15%.
3. Have positive SSc-related autoantibodies. 3. Antiphospholipid Syndrome (APS)

1) Meet the 2006 Sydney criteria for primary antiphospholipid syndrome. 2) Have medium to high titers of antiphospholipid antibodies (lupus anticoagulant [LA], anti-β2-glycoprotein 1 [β2GP1] IgG/IgM, or anti-cardiolipin [aCL] IgG/IgM); 3) Fulfill either (a) or (b) below:

1. Receiving standard treatment with warfarin or alternative vitamin K antagonists (maintaining target international normalized ratio [INR]), or standard therapeutic doses of low molecular weight heparin (LMWH), and/or glucocorticoids and immunosuppressants/biologics (e.g., cyclophosphamide, cyclosporine, tacrolimus, rituximab, etc.).
2. Meet all four criteria for catastrophic APS:

i) Involvement of three or more organs, systems, and/or tissues; ii) Development of manifestations within one week; iii) Histopathological confirmation of small vessel occlusion in at least one organ or tissue; iv) Positive antiphospholipid antibodies (aPL).

4. Inflammatory Myopathy (IM)

1. Meet the 2017 EULAR/ACR classification criteria for inflammatory myopathy (including dermatomyositis, polymyositis, anti-synthetase syndrome, and immune-mediated necrotizing myopathy).
2. Have positive myositis-specific autoantibodies.
3. For participants with muscle involvement: a Manual Muscle Test-8 (MMT-8) score <142, and at least two of the following five core abnormalities: Physician Global Assessment ≥2, Patient Global Assessment ≥2, or extramuscular disease activity score ≥2; Health Assessment Questionnaire (HAQ) total score ≥0.25; muscle enzyme levels ≥1.5 times the upper limit of normal; or MMT-8 ≥142 but with active interstitial lung disease (ground-glass opacities on HRCT).

5. Sjögren's Syndrome (SS)

1. Meet the 2016 ACR/EULAR classification criteria for Sjögren's syndrome.
2. Have a EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score ≥5.
3. Have positive anti-SSA/Ro antibodies.
4. Have inadequate response to conventional therapy or disease relapse after remission. Conventional therapy includes glucocorticoids (at full or pulse doses), two or more immunosuppressants, or biologic agents for at least 6 months, including cyclophosphamide, mycophenolate mofetil, cyclosporine, tacrolimus, azathioprine, leflunomide, methotrexate, belimumab, telitacicept, and rituximab.

6. Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis (AAV)

1. Meet the 2022 ACR/EULAR classification criteria for ANCA-associated vasculitis (AAV), including microscopic polyangiitis, granulomatosis with polyangiitis, and eosinophilic granulomatosis with polyangiitis.
2. Have a history of or currently positive ANCA.
3. Have a Birmingham Vasculitis Activity Score (BVAS) ≥15 (total score 63).
4. Have inadequate response to conventional therapy or disease relapse after remission. Conventional therapy includes glucocorticoids (at full or pulse doses), two or more immunosuppressants, or biologic agents for at least 6 months, including cyclophosphamide, mycophenolate mofetil, cyclosporine, tacrolimus, azathioprine, leflunomide, methotrexate, belimumab, telitacicept, and rituximab.

Exclusion Criteria:

Study participants who meet any of the following criteria will be excluded from the study:

1. Any medical condition that, in the opinion of the investigator, would contraindicate participation in the study, such as a life-threatening illness.

2. Decreased organ function reserve not attributable to the primary disease:

   a) Neutrophil count <1×10⁹/L; lymphocyte count <0.3×10⁹/L; hemoglobin <70 g/L; platelet count <50×10⁹/L; b) Alanine aminotransferase (ALT) >3 × upper limit of normal (ULN); aspartate aminotransferase (AST) >3 × ULN; total bilirubin >2 × ULN; c) Creatinine clearance <40 mL/min; estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m²; or serum creatinine >2.5 mg/dL; d) Left ventricular ejection fraction (LVEF) <45% as measured by echocardiography; e) Oxygen saturation <92% on room air.

3. History of alcohol or substance abuse within the past 24 weeks.
4. History of malignancy other than B-cell lymphoma.
5. Presence of infections including human immunodeficiency virus (HIV), hypogammaglobulinemia, T-cell deficiency, syphilis, chronic hepatitis B or C, or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
6. Known active tuberculosis (TB) infection or active bacterial infection.
7. History of myocardial infarction, coronary angioplasty or stenting, unstable angina, clinically significant arrhythmia, or other clinically significant cardiac disease within 6 months prior to screening.
8. Symptomatic deep vein thrombosis or pulmonary embolism within 6 months prior to screening, except in cases of antiphospholipid syndrome (APS).
9. History of severe allergic reaction to any component of cellular therapy or other immunotherapeutic agents.
10. Prior organ transplant requiring ongoing immunosuppressive therapy.
11. Concurrent participation in another clinical trial that may interfere with disease assessment or study treatment.
12. Prior treatment with CD19- and/or BCMA-targeted therapy or any CAR-T cell product; except in cases where prior therapy is deemed to have clearly failed (e.g., no response, short duration of response, or disease progression) as assessed by the investigator, the current disease state warrants the study treatment, and there is no clear evidence that toxicity from prior therapy would compromise the safety of the current study.
13. Severe psychiatric disorder or significant cognitive impairment.
14. Pregnancy, lactation, or planned pregnancy.
15. Any other condition that, in the judgment of the investigator, would make the participant unsuitable for enrollment in this clinical trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BCT301	Biological: BCT301; BCT301, an anti-CD19 Chemically induced pluripotent stem cell (CiPSC)-derived CAR-iT cells.Participants will receive a single infusion of BCT301 cell injection at escalating dose levels.Prior to infusion, patients undergo a lymphodepleting conditioning regimen with fludarabine and cyclophosphamide given intravenously for three consecutive days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dose-limiting toxicities of BCT301	Adverse events occurring within 28 days post-infusion that were possibly, probably, or definitely related to BCT301 cell injection (per NCI-CTCAE v5.0).	28 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Efficacy of refractory systemic lupus erythematosus（SLE）- The change of SLEDAI-2K	The primary efficacy endpoint will be the change from baseline in the SLEDAI-2K score. The SLEDAI-2K is a validated index for assessing SLE disease activity, with scores ranging from 0 to 105. A higher score indicates worse disease activity.	90, 180, 360 days
Efficacy of refractory SLE-The change of PGA	The Physician Global Assessment (PGA) will be used to evaluate overall SLE disease activity. The PGA is a clinician's determination of disease activity based on history and physical exam, independent of laboratory results. It is scored on a scale from 0 to 3, where a higher score indicates worse disease activity.	90, 180, 360 days
Efficacy of refractory SLE-The change of SF36	The SF-36 health survey will be employed as a patient-reported outcome to assess health-related quality of life. This 36-item questionnaire generates scores from 0 to 100 across eight health domains and two summary components (Physical and Mental). A lower score indicates a worse health state	90, 180, 360 days
Efficacy of refractory SLE-The change of antibodies	Changes in autoantibody titers (e.g., anti-dsDNA) will be assessed as a serological outcome. A higher autoantibody titer reflects more severe underlying immunologic activity	90, 180, 360 days
Efficacy of refractory systemic sclerosis (SSc)-The change of mRSS	The modified Rodnan Skin Score (mRSS) will be the primary endpoint to assess skin disease activity. The mRSS evaluates skin thickness in 17 body areas, with each scored from 0 (normal) to 3 (severe thickening). The total score ranges from 0 to 51, where a higher score indicates worse skin involvement and a poorer prognosis.	90, 180, 360 days
Efficacy of refractory SSc-The change of CRISS	The Combined Response Index for Systemic Sclerosis (CRISS) will be used as the primary composite endpoint. This index calculates a probability of improvement (score from 0.0 to 1.0) by integrating changes in skin thickness (mRSS), physician and patient global assessments, functional ability (HAQ-DI), and the absence of new organ damage. A higher score indicates a better treatment response, while a score of 0 indicates treatment failure.	90, 180, 360 days
Efficacy of refractory SSc-The change of antibodies	Changes in autoantibody titers (e.g., anti-SCL70) will be assessed as a serological outcome. A higher autoantibody titer reflects more severe underlying immunologic activity.	90, 180, 360 days
Efficacy of refractory Antiphospholipid Syndrome (APS)-new onset thrombotic event	The primary efficacy endpoint is the time to first new objectively confirmed arterial or venous thrombotic event. The occurrence of a new thrombotic event is considered a treatment failure, as it directly demonstrates the failure of the therapy.	90, 180, 360 days
Efficacy of refractory APS-The change of antibodies	Reduction in titers of antiphospholipid antibodies (aCL, anti-β2GPI, and LA) will be assessed as a key biomarker of response. A decrease in these antibody levels is interpreted as evidence of a positive immunologic treatment effect.	90, 180, 360 days
Efficacy of refractory APS-The change of platelet	In patients with baseline thrombocytopenia, an increase in platelet count is considered a positive indicator of treatment efficacy, signifying control of the underlying autoimmune and consumptive processes in APS.	90, 180, 360 days
Efficacy of refractory APS- The change of fibrinogen	In patients with baseline hypofibrinogenemia, an increase in fibrinogen level is considered a positive indicator of treatment efficacy	90、180、360 days
Efficacy of refractory inflammatory myositis (IM)-The change of TIS	Total Improvement ScoreThe Total Improvement Score (TIS) will be the primary endpoint to define treatment response. The TIS is a composite score (range 0-15) quantifying improvement from baseline across six core domains: muscle strength, physical function, physician and patient global assessments, muscle enzymes, and extramuscular activity. A TIS of ≥ 20 is defined as a clinically meaningful treatment response, with a higher score indicating a greater magnitude of improvement.	90, 180, 360 days
Efficacy of refractory IM-The change of CK	Serum Creatine Kinase (CK) level will be assessed as a key biomarker of muscle inflammation. A reduction in CK from baseline, is a defined indicator of positive biochemical treatment response.	90, 180, 360 days
Efficacy of refractory IM-The change of antibodies	Reduction in titers of antibodies (e.g. anti-MDA5) will be assessed as a key biomarker of response. A decrease in these antibody levels is interpreted as evidence of a positive immunologic treatment effect.	90, 180, 360 days
Efficacy of refractory Sjögren's Disease（SjD）-The change of ESSDAI	The EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) will be the primary endpoint to assess systemic disease activity. The ESSDAI scores 12 organ domains, with a total range from 0 (no activity) to 123 (maximal activity). A reduction in the ESSDAI score of ≥3 points from baseline defines a clinically meaningful treatment response, indicating effective suppression of systemic disease.	90, 180, 360 days
Efficacy of refractory SjD- Achieving STAR response or not	The Sjögren's Tool for Assessing Response (STAR) will be used as a key patient-reported outcome. The STAR quantifies symptom burden on a scale from 0 (none) to 10 (worst imaginable). A decrease from baseline of ≥1 point in the STAR score defines a clinically meaningful treatment response, indicating a significant reduction in the patient's experience of core symptoms like dryness, fatigue, and pain.	90, 180, 360 days
Efficacy of refractory SjD-The change of antibodies	Changes in autoantibody titers (e.g., anti-SSA) will be assessed as a serological outcome. A reduction in titer is considered a favorable immunologic response to therapy.	90, 180, 360 days
Efficacy of refractory SjD-The change of immune globulin	Changes in immune globulin will be assessed as a serological outcome. A reduction in titer is considered a favorable immunologic response to therapy.	90, 180, 360 days
Efficacy of refractory ANCA associated vasculitis (AAV)-The change of BVAS	The Birmingham Vasculitis Activity Score (BVAS) will be the primary endpoint to assess disease activity. The BVAS quantifies new or worsening vasculitis symptoms across nine organ systems. The total score ranges from 0 (no activity) to over 50, where a higher score indicates worse disease. A reduction in BVAS, particularly to 0, defines treatment response.	90, 180, 360 days
Efficacy of refractory AAV-The change of antibody	Serial quantitative ANCA titers (anti-PR3 and anti-MPO) will be assessed as a serological biomarker of response. A significant decrease in ANCA titer is considered a favorable indicator of treatment efficacy.	90, 180, 360 days
pharmacokinetic (PK)	time to peak (Tmax)	0-28 days
pharmacokinetic (PK)	peak concentration (Cmax)	0-28 days
pharmacokinetic (PK)	area under the concentration-time curve	0-28 days
pharmacokinetic (PK)	area under the concentration-time curve	0-90 days
pharmacodynamic (PD)	The count of B cells in peripheral blood post-infusion.	0-28 days

Collaborators and Investigators

• Sponsor: Peking University Third Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): December 11, 2025
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: November 17, 2025
• First Submitted That Met QC Criteria: December 9, 2025
• First Posted (Actual): December 24, 2025

Study Record Updates

• Last Update Posted (Actual): December 24, 2025
• Last Update Submitted That Met QC Criteria: December 9, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Mouth Diseases; Stomatognathic Diseases; Vascular Diseases; Cardiovascular Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Eye Diseases; Skin Diseases; Skin Diseases, Vascular; Arthritis, Rheumatoid; Xerostomia; Salivary Gland Diseases; Dry Eye Syndromes; Lacrimal Apparatus Diseases; Vasculitis; Systemic Vasculitis; Skin and Connective Tissue Diseases; Lupus Erythematosus, Systemic; Sjogren's Syndrome; Scleroderma, Systemic; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antiphospholipid Syndrome
• Other Study ID Numbers: BCT301

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is no plan to share IPD.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No