Study Drugs
Everyone who joins this clinical trial will be split into two groups randomly and receive either the investigational drug (fenebrutinib) or the comparator drug.
About the Investigational Drug

The immune system is a complete network of cells that work together to protect the body from harmful substances.
B cells are one component of this network. They produce antibodies to help the body fight harmful substances, but in some autoimmune conditions, such as multiple sclerosis, B cells can overreact and cause harm.
The investigational drug, fenebrutinib, is designed to work by suppressing B cells.
Fenebrutinib has been studied in more than 1,200 people to date across several inflammatory diseases
About the Comparator Drug
The comparator drug is a currently-available, approved treatment for RMS. It is administered as a once-daily pill.