Phase 1/2 Study to Evaluate the Safety and Efficacy of ATA188 in Subjects With Progressive Multiple Sclerosis

• Status: Recruiting
• Trial end date: 2026-02-01
• Target enrollment: 0
• Participant gender: All

Summary

The purpose of this study is to evaluate the safety and tolerability of ATA188 as a monotherapy in Parts 1 and 2, to determine the recommended Part 2 dose (RP2D) of ATA188 as monotherapy in Part 1, and to evaluate the effect of ATA188 treatment on clinical disability, as assessed by sustained Expanded Disability Status Scale (EDSS) improvement at 12 months in Part 2 in participants with progressive forms of multiple sclerosis (MS) (primary progressive multiple sclerosis [PPMS] and secondary progressive multiple sclerosis [SPMS]).

• Phase: Phase 1/Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Atara Biotherapeutics

Criteria

Inclusion Criteria:

• For Part 2: 18 to < 61 years of age

• For Part 2: Current diagnosis of a progressive form of MS as defined by the 2017 Revised McDonald criteria

• For Part 2: EDSS scores of 3.0 to 6.5

• Positive EBV serology

• For Part 1 (recruitment completed): 18 to < 66 years of age

• For Part 1 (recruitment completed): History of progressive forms of MS as defined by the 2010 Revised McDonald criteria for the diagnosis of MS

• For Part 1 (recruitment completed): EDSS scores of 3.0 to 7.0

Exclusion Criteria:

• Clinical relapse as follows: For Part 2: Documented clinical and/or radiological relapse for 2 years prior to screening, including gadolinium (Gd)-enhancing lesion(s) on any brain MRI scans available during this period (A participant will also be considered ineligible if any clinical and/or radiological relapse is reported between screening and the first dose of study drug.); For Part 1 (recruitment completed): Active clinical relapse between providing informed consent and the first dose of study drug

• Concurrent serious uncontrolled or unresolved medical condition

• Positive serology and/or nucleic acid testing (NAT) for human immunodeficiency virus (HIV), active hepatitis B virus (HBV) infection or carrier status for HBV, active hepatitis C virus (HCV) infection

• For Part 1: Positive serology for syphilis or human T cell lymphotrophic virus I/II

• Clinically significant abnormalities of full blood count, renal function, or hepatic function

• Any contraindication to MRI and/or Gd, eg., any object that is reactive to strong static magnetic, pulsed-gradient fields including any metallic fragments or foreign body (eg, aneurysm clip[s], pacemakers, electronic implants, shunts)

• Prior therapy with corticosteroids (within 2 weeks before Cycle 1 Day 1)

• Prior therapy (30 days) B-cell depleting agent (eg, anti-CD20 agents such as ocrelizumab); participant must be progressing despite therapy to be eligible

• Prior therapy (6 half-lives or 30 days, whichever is longer) with glatiramer acetate, interferon (IFN) β, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activators (eg, dimethyl fumarate ), methotrexate, azathioprine, cyclosporine, fingolimod, natalizumab, teriflunomide, mitoxantrone, cyclophosphamide, any other immunosuppressant or cytotoxic therapy (other than steroids), antithymocyte globulin or similar anti-T cell antibody therapy, or any other investigational product for Parts 1 and 2, and cladribine for Part 1 and IV immunoglobin, plasmapheresis, Bruton's tyrosine kinase inhibitors, all sphingosine 1-phosphate receptor modulators for Part 2

• Any previous treatment with alemtuzumab, stem cell transplant, or EBV T-cell therapy for both parts and cladribine for Part 2

• Unwilling to use protocol specified contraceptive methods

• Women who are breastfeeding

• Pregnancy