Researchers studied CladT therapy in a very small group of 13 individuals with relapsing multiple sclerosis. The team looked at how the treatment changed immune cells in the cerebrospinal fluid, which is the liquid surrounding the brain and spinal cord. They measured these changes at several time points, including five weeks, ten weeks, one year, and two years after the therapy began.
The study found that the cellular composition of immune cells in the fluid was profoundly altered by the treatment. Specifically, the number of switched memory B cells in the fluid decreased, while naive B cells recovered. Additionally, a type of immune cell called CD4 Treg cells appeared early and stayed elevated for a year. Other immune cell types showed moderate decreases in numbers. However, the transcriptional phenotype of these cells did not change.
Safety data were limited because the number of side effects was relatively low, and no serious adverse events were reported in this small group. The main reason to be careful is that the study was conducted at a single site with only 13 participants. This means the results may not apply to everyone, and the mechanisms by which cladribine helps in multiple sclerosis remain unclear. Readers should view these findings as early observations rather than proof of benefit or harm.