This is a multicenter, 2-part study in adult subjects with progressive forms of MS with an open-label, single-arm sequential dose-escalation period (Part 1) and a double-blind, randomized, placebo-controlled dose-expansion period (Part 2) and OLE, both of which may be initiated at the sponsor’s discretion, based on a review of data from the dose-escalation cohorts. This study will evaluate the safety and efficacy of ATA188 administered by intravenous (IV) infusion. ATA188 will be selected for each subject based on matching at least 2 human leukocyte antigen (HLA) alleles shared between ATA188 and the subject including at least 1 HLA-restricting allele.

The primary objectives of the study are:Both Study Parts: To characterize the safety and tolerability of adoptive transfer of ATA188 (allogeneic latency-2 Epstein-Barr virus-targeted cytotoxic T lymphocytes [allogeneic L2-EBV-CTLs]), as a monotherapy, in subjects with progressive forms of multiple sclerosis (MS) (ie, primary progressive and secondary progressive [PPMS/SPMS])                      

Part 1 (Dose-escalation Period): To determine the recommended Phase 2 dose (RP2D) of ATA188 as monotherapy in subjects with progressive forms of MS                                                                                           

Part 2 (Double-blind, Randomized, Placebo-controlled Period): To evaluate the effect of ATA188 treatment on biological markers of disease activity in cerebral spinal fluid (CSF)

The secondary objectives of the study are:

Part 1 (Dose-escalation Period): To evaluate the change from baseline in Expanded Disability Status Scale (EDSS) score
Part 2 (Double-blind, Randomized, Placebo-controlled Period):  To evaluate the effect of ATA188 treatment on magnetic resonance imaging (MRI) volumetric measures. To evaluate the effect of ATA188 treatment on measures of clinical disability

The exploratory objectives for both study parts are:

  • To characterize the frequency, persistence, and expansion of circulating EBV-specific T cells, and to correlate cellular kinetics with efficacy and safety endpoints
  • To examine subject and disease factors that may predict clinical benefit

The objective of the open-label extension (OLE) is to assess the long-term safety and efficacy of ATA188 insubjects with progressive forms of MS.

Project members