“A Study of LY3541860 in Adult Participants With Relapsing Multiple Sclerosis”

Prior treatment

• Have had a diagnosis of: • primary progressive multiple sclerosis (MS) according to the 2017 revision of McDonald diagnostic criteria (Thompson et al. 2018), or • nonactive secondary progressive MS ( Klineova and Lublin 2018). • Meet criteria for neuromyelitis optica spectrum disorder (Wingerchuk and Lucchinetti 2022). • Have a history of clinically significant central nervous system (CNS) disease. • Have had a confirmed relapse with systemic corticosteroid administration <30 days prior to randomization. • Have more than 20 active GdE brain lesions on screening MRI scan. • Have received any of these medications or treatments. • Have a current or recent acute, active infection. • Have current serious or unstable illnesses. Have any other clinically important abnormality at screening or baseline.

• Participants must meet criteria for relapsing forms of multiple sclerosis, including relapsing-remitting multiple sclerosis based on the 2017 revision of the McDonald diagnostic criteria (Thompson et al. 2018) with a relapsing course (RMS) activity according to Klineova and Lublin 2018. • Participants must have 1 of these: • at least 1 documented relapse within the previous year • at least 2 documented relapses within the previous 2 years, or • at least 1 active GdE brain lesion on an MRI scan in the past 180 days prior to screening. • Have an Expanded Disability Status Scale (EDSS) score of less than or equal to (≤) 5.5 at screening and randomization.