The FDA has started a review of Roche’s multiple sclerosis pill fenebrutinib, according to the report. The filing represents a notable regulatory step for a BTK inhibitor program positioned in multiple forms for MS, where the agency’s prior posture had not included an application in the same way. While the review begins, safety questions remain a key overhang for the program. The decision underscores how MS oral small molecules continue to face heightened scrutiny around benefit-risk profiles as developers expand into additional patient subgroups and dosing regimens. For biotech, the update highlights the continuing role of FDA risk assessment in determining how quickly next-gen immunology drugs move from trials into registrational pathways.