A new immunotherapy that targets cells infected with Epstein-Barr Virus (EBV) has halted the progression of multiple sclerosis (MS) in a small trial. Perhaps even more incredibly, in some patients, it is possible that symptoms of MS were actually reversed, though this was not fully identified in the most recent presentation of results.
Targeting the virus has become an increasingly promising avenue for helping those with the chronic neurological disease, as significant evidence has linked infection of EBV and the eventual development of MS. The link is extremely strong but EBV may not be the sole culprit, but just one factor in a long cascade of events leading to the disease onset.
If a patient’s MS slowly gets worse over time from the start of disease onset they have something called progressive MS, which affects 10-15 percent of patients. Progressive MS results in symptoms that slowly deteriorate as the immune system targets myelin on the surface of nerve cells, damaging them and preventing effective signal transmission. There are limited treatment options for progressive MS.
Attempting to “transform treatment of Multiple Sclerosis”, Atara Biotherapeutics has developed an allogeneic T-cell therapy called ATA188. The concept is simple – when cells are infected with EBV, they express small proteins called antigens on the cell surface, and the immunotherapy contains immune cells that target and destroy them.
In a trial of 24 patients who received the therapy, 20 saw improvements or stability in their symptoms and no fatal or serious adverse effects were reported. Early brain scans suggest that some damaged nerve cells may have been "repaired" by the therapy in a process called remyelination, which could mean a reversal of damage caused by MS in the nervous system, but this has not yet been confirmed.
While the results are extremely promising, it is an early Phase 1 trial with a small sample size and no placebo or control group, so it is unclear whether the results are significant at this stage. However, it is unlikely that this repair would occur naturally, suggesting the therapy is having a beneficial effect on some level.
The researchers now continue to enroll participants for their randomized Phase 2 clinical trial, which will include a larger sample size of 80 and a placebo dose delivered to another group.