Enrollment Begins for Phase 1b Clinical Trial of T-cell Immunotherapy for Progressive Multiple Sclerosis 

The first participant has been enrolled in a phase 1b study of the allogeneic EBV T-cell immunotherapy (ATA188; Atara Biotherapeutics, South San Francisco, CA), for individuals with progressive forms of multiple sclerosis (MS).

Participants in clinical sites across the US and Australia will be randomly assigned to receive T-cell immunotherapy or matching placebo at the cohort 3 dose selected from the phase 1a portion of the study. The primary end point will be evaluated at 12 months, after which, all participants will be switched to active treatment and followed for an additional 12 months. All participants will have the opportunity to enter into a 3-year open-label extension after the first 2 years of treatment.

Progression into the randomized, placebo-controlled study of ATA188 is supported by data from the phase 1a study. These data demonstrated that T-cell immunotherapy was safe and well-tolerated across all 4 dose cohorts. Importantly, there was a higher proportion of participants with sustained disability improvements as dose was increased, and sustained disability improvements seen at 6 months were maintained at 12 months in all 3 cohorts that have reached the 12-month time point in the study.

The phase 1b study (NCT03283826) is a double-blind randomized placebo-controlled study evaluating the efficacy and safety of the T-cell immunotherapy. In addition to measuring change in disability measures compared with baseline, the phase 1b study will also include multiple measures of participants’ function as well as various biomarkers. Types of data to be collected includes standard disability measures (EDSS, timed 25-foot walk test, 9-hole peg test); cognition and outpatient ambulatory activity; patient-reported fatigue; visual acuity; biomarkers in blood and cerebrospinal fluid (CSF); and MRI imaging.

“We are thrilled at the investigator and patient interest in our randomized placebo-controlled phase 1b study assessing the efficacy and safety of ATA188,” said AJ Joshi, MD, senior vice president and chief medical officer of Atara Biotherapeutics. “The initiation of this study, including first-patient-enrolled, is an important step in further assessing the potential of ATA188 in progressive MS, a complex disease of high unmet medical need where disability continues to progress despite approved treatment options. Based on the promising results of safety and sustained disability improvements seen to date in the Phase 1a study, we look forward to continuing enrollment in this randomized placebo-controlled study with the goal of developing a transformative therapy for patients that could halt or reverse the progression of this severe disease.”