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A Study to Evaluate the Safety and Preliminary Efficacy of ATA3219 in Participants With Systemic Lupus Erythematosus

Phase 1
Withdrawn
Conditions
Lupus Nephritis
Systemic Lupus Erythematosus
Interventions
Registration Number
NCT06429800
Lead Sponsor
Atara Biotherapeutics
Brief Summary

The purpose of the study is to evaluate the safety and preliminary efficacy of ATA3219 (following lymphodepletion) for treatment of participants with lupus nephritis (LN).

Detailed Description

This is a Phase 1, multi-centered, open-labeled, dose escalation study to evaluate the safety and preliminary efficacy of ATA3219 (as monotherapy) in participants with LN. Up to 3 dose levels (DLs) will be explored in the dose escalation portion of the study and if needed a lower dose may be explored. Prior to undergoing any screening procedure, prospective participants must undergo the ATA3219 inventory check assessments to ensure availability of an appropriate partially human leukocyte antigen (HLA)-matched ATA3219 lot. Before administration of ATA3219, participants will receive conditioning chemotherapy. For all enrolled participants, hospitalization during and following ATA3219 dosing is mandatory. Participants will receive a single dose intravenous (IV) infusion of ATA3219 (monotherapy) on Day 1. Participants will remain inpatient for a minimum of 1 week post ATA3219 dosing, where they will be frequently monitored. Lupus nephritis activity will be assessed by the investigator on Day 28 (+ 5 days) following each dose of ATA3219. During dose escalation, up to 3 dose levels of ATA3219 are planned to be evaluated sequentially and a lower dose may be added. At least 3 and up to 6 dose-limiting toxicity (DLT)-evaluable participants, those who complete the 28-day DLT observation period, will be assessed at each dose level. Within each dose level, treatment will be staggered to allow appropriate safety monitoring by an independent Data Safety Monitoring Committee (DSMC).

Participants who do not receive ATA3219 for any cause may be replaced. Participants who experience an adverse event (AE) prior to completion of the 28-day DLT observation period will not be replaced. If a participant is treated with ATA3219 and discontinues for any reason other than a DLT prior to completing the 28-day DLT observation period, an additional participant may be enrolled at the dose level to ensure that the recommended phase 2 dose (RP2D) can be determined. In rare situations, retreatment of participants with inadequate renal response may be considered.

After treatment is completed or discontinued, participants will be followed for safety and renal response for up to 24 months from the last dose of ATA3219. A separate long-term follow-up study will be conducted to follow participants for up to a total of 15 years after their last dose of ATA3219.

Recruitment & Eligibility

Status
WITHDRAWN
Sex
All
Target Recruitment
26
Inclusion Criteria
  1. Diagnosed with SLE according to the 2019 European League Against Rheumatism/American College of Rheumatology classification for SLE or the Systemic Lupus International Collaborating Clinics Classification criteria [Petri 2012].

  2. Meets one or more of the following immunologic criteria during screening:

    1. Anti double stranded DNA above laboratory reference range, except enzyme linked immunosorbent assay (2 × above laboratory reference range), OR
    2. Presence of anti-Smith antibody, OR
    3. Low complement as demonstrated by low complement component 3, low complement component 4, or low complement CH50.
  3. History of International Society of Nephrology/Renal Pathology Society (ISN/RPS) Class III or IV with or without Class V glomerulonephritis on renal biopsy either within 6 months prior to screening or as performed during screening. Biopsy should demonstrate evidence of active nephritis.

  4. Proteinuria level between ≥ 1.0 to 6.0 g/day via urine protein creatinine ratio during screening.

  5. Has refractory LN defined as having received 1 or more standard therapies for LN (which must have included mycophenolate mofetil, mycophenolic acid, or cyclophosphamide), and:

    1. Has worsening LN (per criteria listed in [Gordon 2009]) while on treatment, OR
    2. Has not achieved a complete renal response (CRR) after 2 or more lines of therapy, OR
    3. Has not achieved a CRR after first-line therapy after a minimum of 12 months.
  6. Is using a stable, optimized dose of a renin angiotensin system inhibitor for at least 4 weeks prior to enrollment, unless deemed inappropriate by the investigator.

  7. Participants must have been previously vaccinated for pneumococcus within 5 years prior to screening (and no later than 4 weeks prior to enrollment) or be willing to receive prophylaxis against infections with encapsulated bacteria via vaccination in accordance with local standards of practice and/or guidelines.

  8. Is current per national or local health authority or institutional guidelines for immunocompromised individuals on the following vaccinations, unless refused or medically contraindicated: varicella zoster (Shingrix), pneumococcal, influenza, and Corona virus disease 2019 (COVID-19).

Exclusion Criteria
  1. Severe kidney disease as assessed locally, defined as history of ISN/RPS Class VI or isolated Class V glomerulonephritis (without co existent/predominant Class III or IV glomerulonephritis) on renal biopsy.
  2. Has a concurrent systemic autoimmune disease that may confound study assessments other than SLE, LN, or cutaneous lupus erythematosus.
  3. Has any unstable or progressive manifestation of SLE that is likely to warrant an intensification of lupus-directed therapy
  4. Has a history of confirmed or suspected drug-induced lupus.
  5. Has a history of catastrophic antiphospholipid syndrome, or any history of prior thrombosis due to antiphospholipid syndrome resulting in hospitalization due to myocardial infarction, pulmonary embolism, or stroke.
  6. Has a history of bleeding disorder requiring hospitalization or systemic therapeutic intervention within the previous 3 months, or for participants without a prior kidney biopsy meeting eligibility criterion within the past 6 months who will require a biopsy during screening, any contraindication to kidney biopsy.
  7. Severe B cell immunodeficiency as evidenced by clinically significant refractory/recurrent infection.
  8. Any prior cellular therapies, obinutuzumab, anti-cluster of differentiation 19 (CD19) antibody, or B-cell targeting bispecific antibody, unless B-cells have recovered to baseline as assessed by the investigator. Investigational therapies or initiation of new SLE-directed therapies within 4 weeks.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Cohort LN: ATA3219 Dose Level -1ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level -1 (if required) on Day 1 of a 28-day dose limiting toxicity (DLT) observation period.
Cohort LN: ATA3219 Dose Level 1ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level 1 on Day 1 of a 28-day DLT observation period.
Cohort LN: ATA3219 Dose Level 2ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level 2 on Day 1 of a 28-day DLT observation period.
Cohort LN: ATA3219 Dose Level 3ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level 3 on Day 1 of a 28-day DLT observation period.
Cohort ERL: ATA3219 Dose Level -1ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level -1 (if required) on Day 1 of a 28-day DLT observation period.
Cohort ERL: ATA3219 Dose Level 1ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level 1 on Day 1 of a 28-day DLT observation period.
Cohort ERL: ATA3219 Dose Level 2ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level 2 on Day 1 of a 28-day DLT observation period.
Cohort ERL: ATA3219 Dose Level 3ATA3219Participants will receive a single IV infusion of ATA3219 Dose Level 3 on Day 1 of a 28-day DLT observation period.
Primary Outcome Measures
NameTimeMethod
Number of Participants With treatment-emergent adverse events, including adverse events of special interestFrom administration of pretreatments (LD or methylprednisolone) through 90 days after administration of study drug
Number of Participants With Dose-limiting ToxicitiesDay 1 through Day 28 of first dose of study drug
Maximum Tolerated doseDay 1 through Day 28 of first dose of study drug
Recommended Phase 2 dose of ATA3219Day 1 through Day 28 of first dose of study drug
Secondary Outcome Measures
NameTimeMethod
Change From Baseline in British Isles Lupus Assessment Group (BILAG) IndexBaseline (Day 28) through 24 months after the last dose on a defined schedule
Change From Baseline in SLE Responder Index (SRI)-4Baseline (Day 28) through 24 months after the last dose on a defined schedule
Maximum Observed Plasma Concentration (Cmax) of ATA3219Pre-dose on Day 1 through 24 months after the last dose on a defined schedule
Time to Reach Cmax (Tmax) of ATA3219Pre-dose on Day 1 through 24 months after the last dose on a defined schedule
Partial Area Under the Curve (pAUC) of ATA3219Pre-dose on Day 1 through 24 months after the last dose on a defined schedule
Last Observed Plasma Concentration (Clast) of ATA3219Pre-dose on Day 1 through 24 months after the last dose on a defined schedule
Time of Clast of ATA3219Pre-dose on Day 1 through 24 months after the last dose on a defined schedule
Terminal Half-life (t1/2) of ATA3219Pre-dose on Day 1 through 24 months after the last dose on a defined schedule
Change From Baseline in the Modified Version of the Safety of Estrogens in Lupus Erythematosus National Assessment version of the Systemic Lupus Nephritis Disease Activity (Hybrid SELENA-SLEDAI) IndexBaseline (Day 28) through 24 months after the last dose on a defined schedule
Complete Renal ResponseWeeks 24 and 52
Partial Renal ResponseWeeks 24 and 52
Renal Objective Response RateWeeks 24 and 52
Change From Baseline in Urine protein-to-Creatinine RatioBaseline (Day -5) through 24 months after the last dose on a defined schedule
Change From Baseline in Estimated Glomerular Filtration RateBaseline (Day -5) through 24 months after the last dose on a defined schedule
Duration of Urine Protein-to-Creatinine ratio ≤ 0.5Baseline (Day -5) through 24 months after the last dose on a defined schedule
Change From Baseline in Lupus Low Disease Activity State (LLDAS)Baseline (Day 28) through 24 months after the last dose on a defined schedule
Change From Baseline in Definition of Remission in Systemic Lupus Nephritis (DORIS)Baseline (Day 28) through 24 months after the last dose on a defined schedule
Change From Baseline in BILAG-based Composite Lupus Assessment (BICLA) ResponseBaseline (Day 28) through 24 months after the last dose on a defined schedule
Change From Baseline in Antibodies to Double Stranded Deoxyribonucleic AcidBaseline (Day -5) through 24 months after the last dose on a defined schedule
Change From Baseline in Complement Component 3 (C3) and Complement Component 4 (C4) LevelsBaseline (Day -5) through 24 months after the last dose on a defined schedule
Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) Activity ScoreBaseline (Day 28) through 24 months after the last dose on a defined schedule
Number of Swollen and/or Tender JointsBaseline (Day 28) through 24 months after the last dose on a defined schedule

Trial Locations

Locations (1)

Atara Biotherapeutics

🇺🇸

Thousand Oaks, California, United States

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