Atara to Extend Phase 1 Trial of Potential Immunotherapy for All MS Forms to US Patients

Atara Biotherapeutics has received a green light to enroll U.S. patients into a Phase 1 trial of ATA188 for progressive or relapsing-remitting multiple sclerosis (MS).

The study was initially launched in Australia, but with the U.S. Food and Drug Administration (FDA) having cleared the company’s application, the trial will now include study sites across the U.S.

Atara also intends to start recruiting also patients in Europe.

“We are pleased with FDA’s decision to allow off-the-shelf ATA188 to proceed into clinical development in patients with MS in the U.S.,” Chris Haqq, the company’s executive vice president of Research and Development and chief scientific officer, said in a press release.

ATA188 is a T-cell immunotherapy that targets immune B-cells and plasma cells in the brain and spinal cord that have been infected with the Epstein-Barr virus (EBV). A considerable body of research links EBV infection with the autoimmune processes in MS.

The therapy being investigated is an off-the-shelf version because researchers use donated T-cells to make a general treatment. Atara has also explored a so-called autologous version, called ATA190. This treatment is made from a patient’s own immune cells, which are gathered and modified to target the EBV-infected cells.

The treatment was originally developed by scientists at Brisbane-based biomedical institute QIMR Berghofer in Australia.

“We believe that an off-the-shelf T-cell immunotherapy such as ATA188 may allow for a more consistent reactivity against target EBV antigens, which may be correlated with clinical improvements based on data from a previous autologous ATA190 Phase 1 study in patients with progressive MS,” Haqq said.

In the Phase 1 trial (NCT03283826) of ATA188, patients with progressive forms (primary and secondary relapsing) or relapsing-remitting MS receive two cycles of treatment, with each cycle consisting of three infusions given approximately seven days apart.

The first cycle is followed by a 20-day observation period with weekly follow-up visits. After the second cycle, patients continue being monitored for about a year.

As a Phase 1 study, the trial is mainly focusing on the treatment’s safety. Another objective is to determine a dose with which to continue Phase 2 testing. Researchers will also look for potential signs of effectiveness by measuring disability levels, relapse rates, and brain or spinal cord lesions.

The company plans to enroll 60 patients across the U.S., Australia, and Europe — half of whom will be patients with progressive MS. Enrollment information and eligibility criteria is available by clicking on the study’s identification number.

The study will run until 2020, but researchers expect to start analyzing data earlier.

“We look forward to the first results from the ATA188 Phase 1 study in patients with progressive MS in the first half of 2019,” Haqq concluded.